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Kīlauea

Photo of this volcano
  • Country
  • Primary Volcano Type
  • Last Known Eruption
  •  
  • 19.421°N
  • 155.287°W

  • 1222 m
    4009 ft

  • 332010
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number
Most Recent Weekly Report: 31 January-6 February 2024 Citation IconCite this Report

HVO reported that seismicity at Kilauea increased on 27 January and during 27-30 January the locations of the earthquakes became more widespread. Inflation at the summit was ongoing and remained at a high level. Sulfur dioxide gas emission rates were low. Seismicity intensified in the late hours of 30 January, just before midnight. By 0300 on 31 January, the network had recorded 25-30 earthquakes. The earthquakes were located at depths of 1.5-3 km in clusters that had migrated between the area just S of Halema`uma`u Crater and the region SW of the outer caldera boundary. The rate of inflation increased at around 0400. The seismic and deformation data suggested that magma was rising towards the surface, and as a result HVO raised the Volcano Alert Level to Watch (the second highest level on a four-level scale) and the Aviation Color Code to Orange (the second highest level on a four-color scale) at 0441. They noted that the patterns of earthquake activity and ground deformation were concentrated S of the caldera, so new eruptive activity could occur in or near Halema`uma`u Crater or the region S of the caldera.

Seismicity continued to intensify. During 0300-1755 on 31 January, over 500 earthquakes had been located, making a total of more 1,400 earthquakes recorded since 0900 on 27 January. The earthquakes occurred at a rate of 25-40 per hour. The events were located along the Koa’e fault system, SW of the summit. The magnitudes ranged from less than 1 to as high as 3.4; several of the earthquakes were large enough to be felt by HVO staff in the field and neighboring communities. The larger earthquakes triggered rockfalls in Halema`uma`u. About 20 microradians of inflation were detected by deformation instruments.

Seismicity decreased by the morning of 1 February, with 25-30 earthquakes per hour, and throughout the day the rate dropped further to 15-20 earthquakes per hour. The events continued to be located at depths of 1-4 km with epicenters in the vicinity of Pu’ukoa’e, 8-11 km SW of the caldera. Seismic and deformation data suggested that magma continued to move along the fault system. Models suggested that as much as 30 million cubic meters of magma had accumulated in the region SW of the caldera. Instruments detected almost 40 microradians of inflation by the morning on 1 February, but by 2 February the deformation data indicated deflation. Earthquake and ground deformation rates decreased significantly during 2-3 February, suggesting that the intrusion of magma had slowed or stopped and that the likelihood of an eruption had decreased. At 0810 on 3 February the Volcano Alert Level was lowered to Advisory, and the Aviation Color Code was lowered to Yellow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


Most Recent Bulletin Report: August 2022 (BGVN 47:08) Citation IconCite this Report

Lava effusions persisted in the lava lake at Halema’uma’u during January-June 2022

Kīlauea is the southeastern-most volcano in Hawaii and overlaps the E flank of the Mauna Loa shield volcano. Its East Rift Zone (ERZ) has been intermittently active for at least 2,000 years. An extended eruption period began in January 1983 and was characterized by open lava lakes and lava flows from the summit caldera and the East Rift Zone. During May 2018 lava migrated into the Lower East Rift Zone (LERZ) and opened 24 fissures along a 6-km-long NE-trending fracture zone that produced lava flows traveling in multiple directions. Lava fountaining was reported in these fissures and the lava lake in Halema’uma’u crater drained (BGVN 43:10).

The current eruption period started during September 2021 and has included seismicity, new fissures on the Halema’uma’u crater that generated lava flows, lava fountaining, and an active lava lake (BGVN 47:01). Similar activity with intermittent pauses continued during this reporting period of January through June 2022 using daily reports, volcanic activity notices, and abundant photo, map, and video data from the US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO).

Summary of activity during January-June 2022. Activity at Kīlauea consisted of intermittent lava effusions from the western vent in the Halema’uma’u crater and ooze-outs along margins of the crusted over eastern side of the lake (figure 509). The lake had risen about 70 m since lava was first detected on 29 September 2021 and measurements from a helicopter overflight on 30 December 2021 indicated that the total erupted volume of lava since September was approximately 40 million cubic meters. Activity remained confined to the crater. Summit tiltmeters and nearby seismometers detected inflation and deflation events and volcanic tremors that rose and declined in frequency, reflective of pauses in the eruption. Sulfur dioxide emissions were frequently measured, reaching as much as 4,500 t/d on 1 February.

Figure (see Caption) Figure 509. Reference map of the summit eruption at Kīlauea on 7 January 2022. One eruptive vent (orange color) is intermittently active in the Halema’uma’u crater along the western edge of the lava lake, which frequently effuses lava that moves into the active portion of the lake (red color). During eruptive pauses, the only active lava is within a pond just N of the vent (purple color). The eruption statistics listed at the bottom of the map were updated on 30 December 2021. Courtesy of USGS, HVO.

Activity during January 2022. The lava lake at the Halema’uma’u crater remained active during January, showing several large overflows onto older ones and strong crater incandescence. Lava was visible at the western vent of the crater at 1445 on 31 December and remained confined to the crater. Seismicity in the summit region remained below background levels, and the sulfur dioxide emission rate was approximately 5,000 tons/day (t/d), based on measurements from 28 December. Pause events occurred throughout much of the reporting period and were characterized by lower effusion rates, deflation events, and lower volcanic tremor events. HVO issued a notice on 2 January at 0914 stating that the eruption was entering a pause, meaning that lava effusions continued, but at a much lower rate. Summit tiltmeters tracked rapid deflation during the early morning of 2 January. In addition, volcanic tremor associated with the eruption and recorded by nearby seismometers, also rapidly decreased. The lava lake began to cool at the same time. A large breakout along the northern margin of the crusted-over lava lake was observed during the morning; no effusions were reported from the western vent.

At approximately 0400 on 5 January the summit eruption at Halema’uma’u crater resumed, beginning with volcanic tremors detected at 0340 and then lava erupting from the western vent. On 6 January the sulfur dioxide emission rate was 3,300 t/d. Following another short pause, lava effused from the western vent at 1840 on 11 January, and lava ooze-outs were observed along the margins of the crusted over eastern side of the lake. The lava lake rose approximately 13 m, which was then followed by decreases in the summit tilt, tremor, and lake level. The total volume of lava erupted measured on 14 January was 45 million cubic meters. On 16 January HVO reported that lava had stopped erupting from the western vent and the level of the lake surface had dropped about 10 m. Occasional minor activity was reported at the vent on the N side of the spatter cone, as well as small lava ooze-outs along the margins of the crusted over eastern side of the lake.

After another multi-day pause, lava returned to the western vent at 1045 on 18 January and by 1630 the lava lake level had increased by about 12 m (figure 510). There were also several ooze-outs along the SE and NW margins of the lake. The active lava lake was confined to a small pond north of the western vent overnight during 20 January. Just after 0400 on the morning of 21 January the rate of effusion had increased, and the lava lake remained confined to the western half of the crater. Two overflow events were reported during the night of 21 January, with lava flowing NW, SW, and SE out of the lava lake. In addition, several ooze-out events occurred along the NW, N, SE, and S margins of the lake. By this time, the lava lake level had increased about 83 m since the beginning of the eruption period in late September 2021. Again, activity was confined to a small pond N of the western vent and several long-lived ooze-outs occurred along the margins of the E and NW side of the crater. Lava effusions into the pond were intermittent, with several hours in between short-lived periods of lava input. On 19 January the rate of sulfur dioxide emissions was 2,100 t/d and another measurement taken on 24 January showed that the rate had decreased to 58 t/d.

Figure (see Caption) Figure 510. Comparison of two images of the active lava lake at Kīlauea on 18 January 2022 at 1230 (top) and 1345 (bottom). The two photos compare the active portion of the lava lake shortly after the eruption restarted when the lake level was lower (top) to when it had refilled with lava (bottom). The white arrows point to approximately the same spot on both images, the level of which is different by about one meter. Courtesy of K. Mulliken, USGS.

During the morning of 25 January at 0552 a lava flow from the top of the western vent was observed that traveled W and N along the crater margin. The lava lake began to rise around 0630 and by 0820, it had risen 11 m. Overflows from the lava lake and the small pond N of the western vent, the largest of which were on the W and S margins, continued until the afternoon. A small lava flow was noted along the N margin of the larger inactive lava lake surface during the early morning of 27 January, and a small spatter zone that was active in the E section of the crater had produced a small and steep cone. Field crews working in the caldera on 27 January noted loud gas-jetting from the new cone that had developed earlier that morning. The sulfur dioxide emission rate was measured at 2,800 t/d on 25 January, during which time lava was being erupted from the western vent.

HVO reported that on at 0800 on 29 January there was no active lava visible in the Halema’uma’u crater, which indicated a pause in activity. The lava lake depth had very gradually decreased less than one meter. Some overturning during the afternoon was observed in the eastern part of the crater, which briefly exposed surficial lava, and circulating lava was occasionally visible in the small pond N of the western vent. Then, just before 2130 on 30 January, a lava overflow in the western vent occurred, moving NW. The small pond also began to quickly fill with lava, which flowed into the lava lake and occupied the W part of the crater by 2200. The lake began to rise and was overflowing by midnight. Lava flows travel to the S and then E along the margin of the crater. Lava also began to ooze out along the N margin of the larger inactive lava lake surface just after 0500 on 31 January.

Activity during February 2022. Lava continued to intermittently erupt from the western vent in the Halema’uma’u crater during February, with overflows feeding a lava flow to the SE along the S margin of the crater until 1100 on 31 January. Multiple ooze-outs occurred intermittently along the N, E, and S margins of the crater, some of which remained weakly active, with substantial portions of the inactive E lava lake being resurfaced by these flows. A small pond to the N of the western vent also fed the active part of the lava lake via a small lava flow (figure 511). The level of the lava lake continued to fluctuate, depending on the lava supply and summit inflation or deflation. The small spatter cone near the E end of the crater was less than 6 m tall and was erupting lava fountains up to approximately 10 m high for several hours during the night of 1 February and into early the next morning. These fountains fed a short lava flow that was contained near the E margin of the crater. The sulfur dioxide emission rate was approximately 4,500 t/d measured on 1 February and during an eruptive pause they were around 330 t/d on 8 February. A particularly vigorous ooze-out was observed at the far E side of the crater during 4-5 February. Heavy rain at the summit occurred between 1320 and 1800 on 13 February, which triggered spattering in the lava lake. As a result, there were brief decreases in the level of the lake during 1330 and 1557; the lake level returned to its pre-spatter measurement within an hour of each spattering episode. The sulfur dioxide emission rate was 2,800 t/d measured on 14 February.

Figure (see Caption) Figure 511. Photo of the small 20-m-wide pond to the N of the western vent in Kīlauea’s Halema’uma’u crater taken at 0930 on 1 February 2022. A small lava flow is shown feeding the active part of the lava lake. Photo was taken from the western rim of the crater. Courtesy of D. Downs, USGS.

Short-lived overflows of the active western lava lake to the W started around 1000 on 20 February, and were followed by lava flows coming from the western vent and flowing to the S and W an hour later, at 1100. Minor ooze-outs also continued intermittently along the crater floor margins. Lava continued to erupt from the western vent and move to the S, W, and into the western lava lake through the rest of the month. The sulfur dioxide emission rate was 2,500 t/d on 25 February. The Halema’uma’u crater floor had risen about 96 m since the eruption began in September 2021.

Activity during March 2022. Activity continued to fluctuate at the summit crater during March. Throughout February, the main western cone had broken down and by 4 March, lava effused from multiple vents, including the tallest cone (19 m high). The eruption was paused at 0130 on 1 March, meaning that the effusions from the western vent into the lava lake had diminished, though short-lived minor flows continued to be observed. These flows moved S, W, and into the western part of the lake, although they had stopped by the morning. Little to no ooze-outs along the crater margins were also reported. At 0100 on 2 March the eruption resumed, consisting of increased tremor that began 30 minutes earlier and continuous flows from the western vent moved to the S, W, and into the western lava lake (figure 512). During 4-5 March several ooze-outs were reported along the E and N margins of the crater floor. Spatter was also observed from the western vents on 4 March (figure 513). The total measured volume of the effusions since the start of the eruption was 53.6 million cubic meters on 4 March. During the early morning of 9 March, a small lava flow breakout began on the SE margin of the crater floor, but was already crusting over by 0900. The sulfur dioxide emission rate was approximately 2,200 t/d on 8 March and 1,900 t/d on 10 March. A sustained breakout from the NE edge of the crater began at around 1700 on 10 March and lasted until about 0630 the next day. On 11 March, HVO reported that lava was supplied from an embayment just N of the tallest cone in the western part of the crater, which had since grown to 27 m high (figure 514). Another small breakout occurred on the NW side of the crater floor from about 1700 on 12 March to 0500 the next day. Minor and slow crustal overturning occurred on the NW side of the crater floor during 13-14 March and began on the SE side of the crater floor edge, lasting for several hours.

Figure (see Caption) Figure 512. A helicopter overflight on 2 March 2022 allowed for aerial visual and thermal imagery to be taken of the Halema’uma’u crater at Kīlauea’s summit crater. The active part of the lava lake is confined to the western part of the crater. The scale of the thermal map ranges from blue to red, with blue colors indicative of cooler temperatures and red colors indicative of warmer temperatures. Courtesy of USGS, HVO.
Figure (see Caption) Figure 513. Photo of spatter erupting from the western vents in the Halema’uma’u crater at Kīlauea, near where the main cone used to be. On 4 March the tallest of these vents, at 19 m high, was seen characterized by spattering activity. Courtesy of L. Gallant, USGS.
Figure (see Caption) Figure 514. Telephoto view looking east of the active lava lake in the Halema’uma’u crater at Kīlauea on 11 March 2022. The broken down remains of the main western vent cone is visible in the lower right (through the volcanic gas plume). Lava supplies the lake through a small embayment and spillway (bottom center) just N of the western vent area. Some lava spills over a narrow divide into a second smaller lake to the SE (upper right). Courtesy of N. Deligne, USGS.

At around 0700 on 16 March a lava flow that originated from the N part of the western vent area started to advance NW onto the crater floor and remained active for several hours into the early afternoon. At least one ooze-out occurred on the E crater floor. A lava flow advanced onto the NW crater floor from during noon to midnight on 18 March and 2100 to 0700 during 19-20 March. Measurements taken on 17 March showed that the total volume of lava erupted since the eruption began was 57.7 million cubic meters and the lava lake level had risen 89 m. HVO reported a notable ooze-out along the N margin of the crater floor at 0345 on 21 March and continued into the next day. Some ooze-outs were also observed along the N and S crater margins during 23-24 March. The sulfur dioxide emission rate measured on 23 March as approximately 1,400 t/d, which increased to 3,100 t/d on 29 March. Numerous and sustained ooze-outs along the margins of the crater floor continued but showed decreasing activity; by 29 March the volume of the lava effused measured 64 million cubic meters. During 30-31 March a hornito forming on the E side of the lake had a few periods of spattering throughout the day (figure 515).

Figure (see Caption) Figure 515. Telephoto view looking north of the active lava lake in the Halema’uma’u crater at Kīlauea on 30 March 2022. Minor spattering is shown on the eastern margin (left) of the lava lake while circulation in the lake primarily moves from west to east (left to right). Sometimes lava can spatter up when it encounters the active lake margin, as shown in this image (right). Courtesy of N. Deligne, USGS.

Activity during April 2022. Intermittent activity continued during April with numerous and sustained ooze-outs along the NW, NE, and E half of the crater floor, occasional crustal overturning on the NW margin, and lava effusions from the western vent into the lava lake. On 6 April ooze-outs were observed along the NW margin of the crater floor, as well as the E half. The active part of the lava lake showed continuous surface activity and had risen about 1 m. The sulfur dioxide emission rate was 3,400 t/d on 5 April and 3,200 t/d on 6 April. The crater floor had risen about 99 m since the beginning of the eruption, and approximately 66 million cubic meters of lava had been erupted. Overnight on 8 April a small breakout from the active western part of the lava lake was observed, in addition to a small ooze-out along the E lake margin. Small ooze-outs were also detected during 9-10 April along the NW, E, and SE lake margins. Shortly after 2315 on 10 April a surface flow emerged from the S side of the western vent. The flow traveled S on the crater floor and covered the SW and W lake margin and remained active through 14 April. The sulfur dioxide emission rate measured 1,300 t/d on 8 April. Sporadic lava breakouts also occurred along the E, NE, S, and N lake margins. By 17 April lava flowed from the breakouts along the margins of the crater: N to the NE, and a smaller one to the S. During the morning of 27 April and into the next day, HVO reported increased roiling and spattering in the SE portion of the lake, particularly to the E. Sporadic breakouts also continued along the crater margins, particularly to the E. On 27 April the sulfur dioxide emission rate increased to 4,300 t/d, but dropped to 1,800 t/d by the next day.

Activity during May 2022. Lava continued to effuse into the lava lake and onto the crater floor during May; the active part of the lake showed continuous surface activity. The level of the lake fluctuated as a result of inflation, sporadic to continuous breakouts along the margins of the crater, and lava effusions. A particularly vigorous and expansive ooze-out began along the NW margin after 0200 on 5 May, accompanying relatively sluggish lava ooze-outs along the NE and S margins of the crater floor. Around 0700 on 7 May a new lava flow effused from the western vent onto the crater floor, but had stalled an hour later. The sulfur dioxide emission rate was 2,600 t/d on 4 May and 2,800 t/d on 12 May. Overflight measurements taken on 10 May indicated that the crater floor had risen about 106 m and 77 million cubic meters of lava had been effused since the September 2021. On 18 May HVO reported that the lake was draining into a small pond while spatter occurred along the margins of the crater (figure 516). This activity was also accompanied by loud whooshing and roiling noises, sometimes audible from the Keanakako‘i public overlook. On 31 May the sulfur dioxide emissions rate was 3,900 t/d.

Figure (see Caption) Figure 516. Photo of the active lava lake in the Halema’uma’u crater at Kīlauea during the morning of 18 May 2022. The active lake is shown draining into a small pond to the right while spattering along the margins occurred (top center). Courtesy of L. Gallant, USGS.

Activity during June 2022. During June, lava effusions persisted from the Halema’uma’u western vent into the active lava lake, in addition to frequent ooze-outs along the E, NE, NW, W, S, and N crater floor margins and some spattering activity at the margins. Minor fluctuations in the lava lake level were also recorded throughout the month due to consistent surface activity. The sulfur dioxide emission rate was approximately 2,500 t/d on 2 June and 1,350 t/d on 10 June. On 10 June an overflow from the western vent produced a lava flow that moved onto the W side of the crater floor. Overflight measurements made on 17 June indicated that the crater floor had risen about 120 m and that 93 million cubic meters of lava had been effused since the start of the eruption (figure 517). On 24 June there was a small zone of weak ooze-outs effusing from the crater floor (figure 518). The sulfur dioxide emission rates were measured again on 23 and 29 June that were 3,000 t/d and 1,200 t/d, respectively.

Figure (see Caption) Figure 517. Reference map of the summit eruption at Kīlauea on 17 June 2022. One eruptive vent (orange color) was active in the Halema’uma’u crater along the western edge of the lava lake, which frequently effused lava that moved into the active portion of the lake (red color). An adjacent pond (purple color) fed lava to a larger lake (light red), though at times the lava level declined and circulation decreased. Lava was visible from three public visitor overlooks in Hawai‘i Volcanoes National Park: Keanakako‘i Overlook and Kupina‘i Pali (Waldron Ledge) can see the eruptive vent and lava lake, while Kīlauea Overlook occasionally saw lava ooze-outs in the southeast part of the crater. The eruption statistics listed at the bottom of the map were updated on 21 June 2022. Courtesy of USGS, HVO.
Figure (see Caption) Figure 518. Photo looking just north of the main lava lake in Halema’uma’u crater at Kīlauea showing a small zone of weak ooze-outs effusing from the crater floor on 24 June 2022. Courtesy of M. Patrick, USGS.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: http://hvo.wr.usgs.gov/).

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31 January-6 February 2024 Citation IconCite this Report

HVO reported that seismicity at Kilauea increased on 27 January and during 27-30 January the locations of the earthquakes became more widespread. Inflation at the summit was ongoing and remained at a high level. Sulfur dioxide gas emission rates were low. Seismicity intensified in the late hours of 30 January, just before midnight. By 0300 on 31 January, the network had recorded 25-30 earthquakes. The earthquakes were located at depths of 1.5-3 km in clusters that had migrated between the area just S of Halema`uma`u Crater and the region SW of the outer caldera boundary. The rate of inflation increased at around 0400. The seismic and deformation data suggested that magma was rising towards the surface, and as a result HVO raised the Volcano Alert Level to Watch (the second highest level on a four-level scale) and the Aviation Color Code to Orange (the second highest level on a four-color scale) at 0441. They noted that the patterns of earthquake activity and ground deformation were concentrated S of the caldera, so new eruptive activity could occur in or near Halema`uma`u Crater or the region S of the caldera.

Seismicity continued to intensify. During 0300-1755 on 31 January, over 500 earthquakes had been located, making a total of more 1,400 earthquakes recorded since 0900 on 27 January. The earthquakes occurred at a rate of 25-40 per hour. The events were located along the Koa’e fault system, SW of the summit. The magnitudes ranged from less than 1 to as high as 3.4; several of the earthquakes were large enough to be felt by HVO staff in the field and neighboring communities. The larger earthquakes triggered rockfalls in Halema`uma`u. About 20 microradians of inflation were detected by deformation instruments.

Seismicity decreased by the morning of 1 February, with 25-30 earthquakes per hour, and throughout the day the rate dropped further to 15-20 earthquakes per hour. The events continued to be located at depths of 1-4 km with epicenters in the vicinity of Pu’ukoa’e, 8-11 km SW of the caldera. Seismic and deformation data suggested that magma continued to move along the fault system. Models suggested that as much as 30 million cubic meters of magma had accumulated in the region SW of the caldera. Instruments detected almost 40 microradians of inflation by the morning on 1 February, but by 2 February the deformation data indicated deflation. Earthquake and ground deformation rates decreased significantly during 2-3 February, suggesting that the intrusion of magma had slowed or stopped and that the likelihood of an eruption had decreased. At 0810 on 3 February the Volcano Alert Level was lowered to Advisory, and the Aviation Color Code was lowered to Yellow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 September-19 September 2023 Citation IconCite this Report

HVO reported that the eruption located at the W side of the down-dropped block within Kilauea’s Halema`uma`u Crater had ceased after activity declined over a few days. During 12-14 September multiple active vents, that were roughly E-W-trending and spanned a distance of about 750 m, produced lava fountains that rose as high as 10 m. Ramparts built by spatter were almost 20 m tall on the S sides (downwind side) of the vents. Lava from the vents flowed onto the N and W parts of the crater floor on 12 September, onto the N and E parts on 13 September, and only onto the W part by 14 September; the distances of the active flows progressively decreased. The area N of the active vents had become perched and was 3 m higher than the surrounding surface. Sulfur dioxide emissions averaged 20,000 tonnes per day (t/d) on the afternoon of 13 September, down significantly from 190,000 t/d measured just after the onset of the eruption. Effusion rates had decreased but remained at high levels.

Vigorous spattering and lava fountains that rose 10-15 m were visible at the westernmost large spatter cone during 14-15 September. Minor spattering at the next cone to the E did not rise above its rim. Lava continued to flow from the vents and travel N and W, confined to the W part of the down-dropped block and the NE parts of Halema`uma`u. A laser rangefinder pointed at the W portion of the crater continued to record uplift from the magmatic intrusion beneath the caldera since the onset of the eruption; the total local uplift was 6 m by 13 September, 9 m by 14 September, and 10 m by 15 September. Field crews observed that eruptive activity had greatly diminished or ceased at several of the vents by the morning of 15 September. Lava was no longer flowing onto the crater floor but active lava was ponded in an area N of the vents. Intermittent spattering was visible overnight at the large, westernmost cone but beginning at around 0700 on 16 September webcam images recorded minor to no fountaining. By 1115 spattering ceased and by noon the ponded lava had stagnated. Tremor levels indicting fluid movement decreased during 15-16 September and retuned to pre-eruption levels by 1700 on 16 September. Sulfur dioxide emission rates had also decreased and were 800 t/d by 16 September, only slightly above the 100-200 t/d typical of non-eruptive periods. At 0902 on 17 September HVO lowered the Volcano Alert Level to Advisory (the second level on a four-level scale) and the Aviation Color Code was lowered to Yellow (the second color on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 September-12 September 2023 Citation IconCite this Report

HVO reported that a new eruption began in Kilauea’s Halema`uma`u Crater on 10 September following a period of increased seismicity. Seismicity increased on 22 August; most of the earthquakes were located at depths of 2-3 km and were all smaller than M2. About 150 occurred during 9-10 September. Tiltmeter and Global Positioning System (GPS) data showed inflation in the S portion of the crater.

At 0252 on 10 September HVO raised the Volcano Alert Level to Watch (the third level on a four-level scale) and the Aviation Color Code to Orange (the third level on a four-color scale) due to increased earthquake activity and changes in ground deformation that indicated magma moving towards the surface. An eruption commenced at about 1515 in the E part of the caldera based on field reports and webcam images. Fissures opened on the crater floor and produced lava fountains and flows. The Volcano Alert Level and Aviation Color Code were raised to Warning and Red, respectively. Gas-and-steam plumes rose from the fissures and drifted downwind. By 1900 the line of fissures was about 1.4 km long and extended into the E wall of the down-dropped block. Multiple active fountains were about 20-25 m high; fountains at the initial eruption onset were an estimated 50 m.

At 0810 on 11 September the Volcano Alert Level was lowered back to Watch and the Aviation Color Code was lowered back to Orange because the style of eruption and fissure location had stabilized, the initial extremely high effusion rates had declined (but remained at high levels), and no infrastructure was threatened. The eruption plume, mainly comprised of sulfur dioxide and particulates, rose as high as 3 km (10,000 ft) a.s.l. and had become less dense. Lava erupted from fissures on the down-dropped block flowed W towards Halema`uma`u, covering much of the surface with active lava as deep as about 2.5 m. During 11-12 September easternmost vents on the down-dropped block and the westernmost vents in Halema`uma`u became inactive; the active vents were E-W-trending and spanned a distance of about 750 m. Channelized lava flows traveled N and W onto the Halema`uma`u Crater floor, burying the E rim of the crater and most of the crater floor; higher older lava flows prevented movement onto the SW part of the floor. Lava fountaining continued, rising as high as 15 m by the morning of 12 September. A laser rangefinder pointed at the W portion of the crater recorded almost 5 m of uplift from the magmatic intrusion beneath the caldera since the onset of the eruption.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 June-4 July 2023 Citation IconCite this Report

On 30 June HVO stated that Kilauea was no longer erupting. Lava supply to the lake ceased on 19 June and sulfur dioxide emissions had decreased to near pre-eruption background levels. Seismicity was also low. The Volcano Alert Level was lowered to Advisory (the second level on a four-level scale) and the Aviation Color Code was lowered to Yellow (the second color on a four-color scale). The report noted that gradual inflation was detected at summit tiltmeters during 19-30 June. Incandescence from previously erupted lava was visible in overnight webcam images during 29-30 June; the lava continued to cool.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 June-20 June 2023 Citation IconCite this Report

HVO reported that the eruption on the floor of Kilauea’s Halema'uma'u Crater continued during 14-20 June. Activity was characterized by effusion primarily from the vent on the SW wall of the crater, circulation within the crater lakes, slow rise of the crater floor, eruptive tremor, and elevated sulfur dioxide levels (4,500-6,300 tonnes per day). Lava flows from vents at the base and top of a cone on the SW wall of Halema'uma'u entered the lava lake in the far SW portion of the crater; intermittent spattering from the cone was visible at night. Other eruptive vents within the SW lava lake (previously dome fountains) had ceased by 13 June. The surface of the SW lava lake slowly rose about 0.5 m per day during 13-15 June. Additionally, lava circulation continued within the central basin. At 0800 on 15 June the top of the SW wall cone collapsed, leading to nearly constant spattering from the top vent and a change in activity from the base vent. The central basin level has been dropping relative to the rising crater floor (due to lava accumulation underneath), allowing several flows from the SW lava lake to cascade into the basin.

By 16 June, renewed activity on the SW wall was producing vigorous fountaining to at least 10 m high with some higher spatters, with lava flowing into the SW lake. This activity continued into 19 June as the crater floor continued to rise, circulation in central basin slowed, and flows from the base of the SW wall cone changed paths. Around 1600 on 19 June activity rapidly declined, shown by a drop in the SW lake surface, decreased seismicity, and a transition to inflationary tilt from the deflationary trend of the previous two days. Seismic activity remained low and on 20 June HVO reported that the eruption had paused.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 June-13 June 2023 Citation IconCite this Report

A new eruption at Kilauea began at 0444 on 7 June with the burst of tall lava fountains from a vent on the central part of the Halema’uma’u Crater floor. The Volcano Alert Level was raised to Warning (the highest level on a four-level scale) and the Aviation Color Code was raised to Red (the highest level on a four-color scale). Soon after, lava fountains were active along multiple fissures on the crater floor, and along one fissure that bisected the SW crater wall. Between 0800-0900 the sulfur dioxide emission rate was about 65,000 tonnes per day. Residents of Pahala, 30 km downwind of the summit, reported minor deposits of fine gritty ash and Pele?s hair. Lava flows inundated the crater floor (about 1.5 square km) and added about 6 m depth of new lava within a few hours. A small spatter cone had formed at the vent on the SW wall by midday, and lava from the cone was flowing into the active lava lake below. Fountain heights had decreased from the onset of the eruption and were 4-9 m high by 1600, with occasional higher bursts. Inflation switched to deflation and summit earthquake activity greatly diminished shortly after the eruption onset.

At 0837 on 8 June HVO lowered the Volcano Alert Level to Watch and the Aviation Color Code to Orange because the initial high effusion rates had declined, and no infrastructure was threatened. The lava lake had dropped by about 2 m likely due to gas loss by the morning of 8 June. The drop left a wall of cooled lava around the margins of the crater floor. Multiple lava fountains were active in the central E part of the lake and fountains rose as high as 10 m. The spatter cone continued to build over the SW wall vent; lava flows from the vent fed the SW part of the lava lake. The preliminary average effusion rate for the first 24 hours of the eruption was about 150 cubic meters per second, though the estimate did not account for vesiculated lava and variations in crater floor topography. The effusion rate during the very earliest phases of the eruption appeared to be significantly higher than the previous three summit eruptions based upon the rapid coverage of the entire crater floor.

During 8-9 June multiple lava fountains remained active and rose up to 10 m high. The SW wall vent continued to effuse lava into the crater lake which had increased in depth by about 1.5 m. Active lava and vents covered much of the W half of the crater floor, arranged in a broad horseshoe shape around a central uplifted area. This feature in the basin of the 2021-22 lava lake was described as the "western lava lake" from prior eruptions and had reactivated along with a smaller circular pool just SE of the lake. An active lava lake centered within the uplifted area was fed by a vent in its NE corner. A much smaller area of lava was active in the E portion of the crater floor. The sulfur dioxide emission rate was about 11,000 tonnes per day on 9 June and about 8,900 tonnes per day on 10 June.

During 10-12 June multiple lava fountains remained active and were up to 9 m high, and the SW wall vent continued to effuse lava into the crater lake. The active features in the E portion of the lake had stagnated during 10-11 June. Sulfur dioxide emissions averaged 7,400 tonnes per day on 11 June. The W part of the lake rose about 1 m during 11-12 June, likely due to the construction of a levee around the pond. Gas plumes rose to 2.4-3 km (8,000-10,000 ft) a.s.l. and were trapped under a weather inversion layer. Activity decreased during 12-13 June and only a few small lava fountains were active. The western lake and the smaller lava pond in the central portion of the crater floor remained active, along with the vent on the SW wall.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 May-6 June 2023 Citation IconCite this Report

HVO reported that earthquake activity and changes in the patterns of ground deformation beneath Kilauea’s summit began to be detected during the evening of 6 June. The data indicated magma movement towards the surface, prompting HVO to raise the Volcano Alert Level to Watch (the second highest level on a four-level scale) and the Aviation Color Code to Orange (the second highest level on a four-color scale).

At about 0444 on 7 June incandescence in Halema’uma’u Crater was visible in webcam images indicting that a new eruption had begun. The Volcano Alert Level was raised to Warning and the Aviation Color Code was raised to Red. Lava flowed from fissures that had opened on the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 March-21 March 2023 Citation IconCite this Report

On 21 March HVO reported that Kilauea was no longer erupting. The lava lake in Halema’uma’u Crater was no longer being supplied as of 7 March based on lava lake levels and crater floor observations. Sulfur dioxide emissions had decreased to near pre-eruption background levels. The Volcano Alert Level was lowered to Advisory (the second lowest level on a four-level scale) and the Aviation Color Code was lowered to Yellow (the second lowest color on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 March-7 March 2023 Citation IconCite this Report

HVO reported that the eruption on the floor of Kilauea’s Halema’uma’u Crater continued during 1-6 March but at a decreased rate. The western lake in the basin of the 2021-2022 lava lake remained weakly active; a few lava flows were visible on 1 March. A small amount of lava circulated within the lake and there were intermittent crustal overturns, but the lake was mostly crusted over and the active area got substantially smaller through the week; by 5 March the lake was completely crusted over. Minor lava ooze outs were visible on 6 March, and the eruption had paused by 7 March. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 February-28 February 2023 Citation IconCite this Report

HVO reported that the eruption on the floor of Kilauea’s Halema’uma’u Crater continued during 22-28 February but at a decreased rate. The E and central vents were not erupting. The western lake in the basin of the 2021-2022 lava lake remained active but with weak lava flows. A small amount of lava is circulating within the lake with intermittent crustal overturns; the lake is mostly crusted over. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 February-21 February 2023 Citation IconCite this Report

HVO reported that the eruption on the floor of Kilauea’s Halema’uma’u Crater continued during 15-21 February but at a decreased rate during the last half of the week. Lava erupted from three locations during 15-17 February. The lava lake in E half of the crater was active, had a small lava fountain, and remained at about 10 hectares in size; the smaller western lake in the basin of the 2021-2022 lava lake was also active. The smaller lava pond in the central portion of the crater floor had a small lava fountain, produced nearly continuous overflows, and channeled lava to the E lake. Activity in the E and central lakes diminished in the late afternoon on 17 February, and by 18 February both had stopped erupting. The western lake was active but at a greatly reduced level and lava only minimally circulated; the lake was mostly crusted over and about 10 m lower by 19 February. The lake produced small lava flows and intermittent crustal overturns during 19-20 February. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 February-14 February 2023 Citation IconCite this Report

HVO reported that lava continued to erupt from three locations on Kilauea’s Halema’uma’u Crater floor during 7-14 February. The lava lake in E half of the crater was active and remained at about 10 hectares in size. A small 3-6 m high lava fountain in the S part of the E lake was active during the first few days but had diminished during 10-11 February and remained at lower levels during the rest of the week. The smaller western lake in the basin of the 2021–2022 lava lake as well as the smaller lava pond in the central portion of the crater floor remained active and overflowed frequently each day. Activity in the southern small lava pond had decreased. During 12-14 February a small lava fountain was visible in the smaller central lava pond and was active along with the fountain in the S part of the E lake. Lava continued to overflow the pond and possibly connected to the larger E lava lake. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 February-7 February 2023 Citation IconCite this Report

HVO reported that lava continued to erupt on Kilauea’s Halema’uma’u Crater floor during 1-7 February. Activity was concentrated in the E half of the crater in a large, perched lava lake with well-defined levees, covering about 10 hectares. A smaller lake to the W was active in the basin of the 2021-2022 lava lake. Part of the E lake began to crust over on 1 February, forming a crusted isthmus through the center of the lake and two smaller areas of lava on the N and S sides. The lava fountain was located on the S side. Lava in each of the two smaller areas independently circulated in opposite directions from each other. At around 2315 lava fountaining ceased but resumed about 45 minutes later, rising 1-2 m. During 0100-0400 on 2 February lava from the S side flooded across the whole E lake, covering the isthmus, and returning the E lake to the size it was (10 hectares). The W Lake, and two smaller lava ponds in the central and S portions of the crater floor, remained relatively stable, though one of the ponds overflowed. Two small floating islands in the E lake sank during 2-3 February.

During 2-7 February the E lake, the W lake, and the two small lava ponds remained active and stable. The lava fountain continued to be active, though during 4-5 February bursts of activity caused the fountain to double in height. A second small lava fountain was temporarily active near the first fountain during 0300-0700 on 5 February. Starting at around 2100 on 5 February through 0900 on 6 February a large breakout occurred on the N portion of the crater floor covering an area equal to or slightly larger than the E lava lake. A smaller breakout S of the E lake occurred around 0000 on 6 February. The large breakout continued to be active on 6 February but was only weakly active by 7 February. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 January-31 January 2023 Citation IconCite this Report

HVO reported that lava continued to erupt in the E portion of Kilauea’s Halema’uma’u Crater floor during 24-31 January. Activity was concentrated in the E half of the crater in a large, perched lava lake with well-defined levees, covering about 10 hectares. A smaller lake to the W was active in the basin of the 2021-2022 lava lake. One dominant lava fountain, 6-7 m high, was active in the E lake. Small daily overflows occurred along the margins of the E lake. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 January-24 January 2023 Citation IconCite this Report

HVO reported that lava continued to erupt in the E portion of Kilauea’s Halema’uma’u Crater floor during 17-24 January. Activity was concentrated in a large, perched lava lake, covering about 10 hectares in the E half of the crater by 17 January, and in a smaller lake to the W, in the basin of the 2021-2022 lava lake. One dominant lava fountain, 6-7 m high, was active in the E lake. Small daily overflows occurred along the margins of the E lake. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 January-17 January 2023 Citation IconCite this Report

HVO reported that lava continued to erupt from vents on the central E portion of Kilauea’s Halema’uma’u Crater floor during 10-17 January. Activity was concentrated in a large lava lake, covering about 12 hectares in the E half of the crater on 10 January. One dominant lava fountain, 6-7 m high, was active within this area. Lava flows built up the margins of the lake, causing the lake to be perched; small overflows along the margins were visible during 13-16 January. A smaller area of lava was active within the basin in the W half of the crater that had been the focus of activity during 2021-2022. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 January-10 January 2023 Citation IconCite this Report

Small earthquake swarms were recorded at Kilauea on 30 December 2022 and 2 January 2023, with heightened seismicity in between those dates. Increased seismicity and changes in the pattern of deformation began to be recorded during the morning of 5 January. At around 1500 both the rate of deformation and seismicity dramatically increased indicating magma moving towards the surface; at 1520 HVO raised the Volcano Alert Level to Watch (the second highest level on a four-level scale) and the Aviation Color Code to Orange (the second highest color on a four-color scale).

Incandescence seen in webcam images at 1634 on 5 January indicated that an eruption began in Halema’uma’u Crater, prompting HVO to raise the Volcano Alert Level to Warning (the highest level on a four-level scale) and the Aviation Color Code to Red (the highest color on a four-color scale). Vents opened in the E central portion of the crater floor and produced multiple lava fountains and flows. Fountain bursts ejected lava as high as 50 m during the initial phase of activity, though in general fountaining was consistently 10 m high. By 1930 lava had covered most of the crater floor (an area of about 120 hectares) to a depth of 10 m. A higher-elevation island that formed during the initial phase of the December 2020 eruption remained exposed (and appeared darker in images) along with a ring of older lava around the lava lake that was active prior to December 2022. Overnight during 5-6 January the lava fountains became less vigorous, rising to 5 m, and lava effusion slowed. By 0815 on 6 January HVO lowered the Volcano Alert Level to Watch and the Aviation Color Code to Orange because the initial high effusion rates were declining and there was no threat of significant volcanic ash outside of the closed area within?Hawai’i Volcanoes National Park. The sulfur dioxide emission rate was about 12,500 tonnes per day. Lava continued to erupt from the vents during 6-8 January, though the footprint of the active area had shrunk, which has been common during the early stages of recent eruptions within Halema’uma’u. By 9 January only one dominant fountain was visible that continued to be active at least through 10 January.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 December-13 December 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 6-8 December and entered the lava lake, though the eruption rate had diminished, and the floor of the crater had deflated. The eruption ceased on 9 December. During 10-12 December the lake crusted over, no incandescence was visible, and sulfur dioxide emissions had decreased to near pre-eruption background levels. On 13 December HVO lowered the Volcano Alert Level to Advisory (the second lowest level on a four-level scale) and the Aviation Color Code to Yellow (the second lowest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 November-6 December 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 30 November-6 December entering the lava lake and flowing onto the crater floor. The active part of the lake remained at a steady level most of the week, fluctuating only a few meters during 4-6 December. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 November-29 November 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 23-29 November entering the lava lake and flowing onto the crater floor. The active part of the lake remained at a steady level all week. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 November-22 November 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 16-22 November entering the lava lake and flowing onto the crater floor. The active part of the lake remained at a steady level all week. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 November-15 November 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 9-15 November, entering the lava lake and flowing onto the crater floor. On 9 November the sulfur dioxide emission rate was 600 tonnes per day (t/d). The active part of the lake remained at a steady level all week. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 November-8 November 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 2-8 November entering the lava lake and flowing onto the crater floor. The active part of the lake remained at a steady level all week. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 October-1 November 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 25 October-1 November entering the lava lake and flowing onto the crater floor. The active part of the lake remained at a steady level all week. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 October-25 October 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 19-25 October entering the lava lake and flowing onto the crater floor. The active part of the lake remained at a steady level all week. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 October-18 October 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 11-18 October entering the lava lake and flowing onto the crater floor. Part of the lake’s surface was continuously active. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 October-11 October 2022 Citation IconCite this Report

HVO reported that by 5 October about 111 million cubic meters of lava had been erupted from the vent in the lower W wall of Kilauea’s Halema`uma`u Crater since the current eruption began on 29 September 2021, raising the crater floor by 143 m. Lava continued to enter the lake during 5-11 October. The active part of the lake stayed at a relatively steady level through the week, varying only slightly. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 September-4 October 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 27 September-4 October, entering the lava lake. The active part of the lake stayed at a relatively steady level through the week, varying only slightly. Sulfur dioxide emissions were approximately 970 and 1,800 tonnes per day on 28 and 30 September, respectively. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 September-27 September 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 20-27 September, entering the lava lake and flowing onto the crater floor. The continuously active part of the lake dropped 10 m, regained 3 m during 19-22 September, and then was unchanged the rest of the week. Breakouts of lava occurred at the W and N margins of the lake during most of the week. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 September-20 September 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 13-20 September, entering the lava lake and flowing onto the crater floor. Part of the lake’s surface was continuously active. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 September-13 September 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 6-13 September, entering the lava lake and flowing onto the crater floor. Part of the lake’s surface was continuously active. By 12 September about 111 million cubic meters of lava had been erupted from the vent since the current eruption began on 29 September 2021, raising the crater floor by 143 m. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 August-6 September 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 30 August-6 September, entering the lava lake and flowing onto the crater floor. Part of the lake’s surface was continuously active. The lake level mostly remained within the bounding levees, though breakouts were visible along the W and NW margins. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 August-30 August 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 24-30 August, entering the lava lake and flowing onto the crater floor. Part of the lake was continuously active. The lake level mostly remained within the bounding levees, though daily breakouts were visible along the margins. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 August-23 August 2022 Citation IconCite this Report

HVO stated that by 16 August about 104 million cubic meters of lava had been erupted from a vent in the lower W wall of at Kilauea’s Halema`uma`u Crater since the current eruption began on 29 September 2021, raising the crater floor by 137 m. Lava continued to effuse from the vent during 17-22 August, entering the lava lake and flowing onto the crater floor. Part of the lake was continuously active. The lake level mostly remained within the bounding levees, though daily breakouts were visible along the margins. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 August-16 August 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 9-16 August, entering the lava lake and flowing onto the crater floor. Part of the lake was continuously active. The lake level mostly remained within the bounding levees, though daily breakouts were visible along the margins. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 August-9 August 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 2-9 August, entering the lava lake and flowing onto the crater floor. The lake level remained within the bounding levees. Daily minor ooze-outs were visible along the margins of the crater floor. Intense incandescence from the W vent was visible during 5-9 August. Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 July-2 August 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 26 July-2 August, entering the lava lake and flowing onto the crater floor. Minor ooze-outs along the margins of the crater floor were visible during 1-2 August. The lake level remained at the bounding levees. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 July-26 July 2022 Citation IconCite this Report

HVO stated that by 19 July about 98 million cubic meters of lava had been erupted from a vent in the lower W wall of at Kilauea’s Halema`uma`u Crater since the current eruption began on 29 September 2021, raising the crater floor by 133 m. Lava continued to effuse from the vent during 19-26 July, entering the lava lake and flowing onto the crater floor. The lake level remained at the bounding levees, though lava oozed from the lake margins on most days. The sulfur dioxide emission rate was approximately 1,300 tons/day on 21 July. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 July-19 July 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 12-19 July, entering the lava lake and flowing onto the crater floor. The lake level was relatively low, though by 16 July it had risen to the bounding levees along the margins. Incandescence from the W vent complex was visible during 16-19 July. Lava oozed from the lake margins during the early morning of 19 July. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 July-12 July 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 6-12 July, entering the lava lake and flowing onto the crater floor. The lake level was variable, and occasional lava breakouts occurred along the margins. Low-level spattering from the W vent was visible on most days, with material ejected no more than 10 m above the vent. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 June-5 July 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 29 June-5 July, entering the lava lake and flowing onto the crater floor. The lake level was variable, and lava breakouts occurred along the N margin on most days. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 June-28 June 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 22-28 June, entering the lava lake and flowing onto the crater floor. The lake remained active all week, and nearly continuous breakouts occurred along the margins. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 June-21 June 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 14-22 June, entering the lava lake and flowing onto the crater floor. The surface of the lava lake was continuously active all week, and nearly continuous breakouts occurred along the margins. The lake level was variable in response to cycles of inflation and deflation. By 17 June the total volume of erupted lava was an estimated 93 million cubic meters, and the lake which had risen a total of 120 m since 29 September 2021.The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 June-14 June 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 8-14 June, entering the lava lake and flowing onto the crater floor. The surface of the lava lake was continuously active all week, and the lake level was relatively stable. Nearly-continuous breakouts of lava occurred along the margins of the lake. The sulfur dioxide emission rate was approximately 1,900 and 1,350 tonnes per day on 8 and 10 June, respectively. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 June-7 June 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 31 May-7 June, entering the lava lake and flowing onto the crater floor. The surface of the lava lake was continuously active all week, and the lake level was relatively stable, dropping and then rising 6 m. Nearly-continuous breakouts of lava occurred along the margins of the lake. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 May-31 May 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 24-31 May, entering the lava lake and flowing onto the crater floor. The surface of the lava lake was continuously active all week, though the height of the lake was high and relatively stable. Nearly-continuous breakouts of lava occurred along the NW and W margins of the lake. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 May-24 May 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 17-24 May, entering the active lava lake and flowing onto the crater floor. The surface of the lava lake was active all week, though the height of the lake was high and relatively stable. Breakouts of lava occurred along the E, N, NW, and W margins of the lake. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 May-17 May 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 10-17 May, entering the active lava lake and flowing onto the crater floor. By 10 May the total volume of erupted lava was an estimated 77 million cubic meters, and the lake which had risen a total of 106 m since 29 September 2021. The surface of the lava lake was active all week, though the height of the lake was high and relatively stable. Breakouts of lava occurred along the NE and NW margins of the lake during 10-11 May, and more notably from the E margins the rest of the week. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 May-10 May 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 3-10 May, entering the active lava lake and flowing onto the crater floor. The surface of the lava lake was active all week, though the height of the lake was relatively stable. Daily breakouts occurred along the NE, NW, and S margins of the lake. A short-lived lava flow effused from the W vent and onto the crater floor at around 0700 on 7 May. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 April-3 May 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 26 April-3 May, entering the active lava lake and flowing onto the crater floor. Roiling and spattering in the SE part of the lake was visible during 26-27 April. The surface of the lava lake was active all week, and the height of the lake fluctuated; the lake occasionally overflowed the rim, sending lava onto the crater floor. Daily breakouts occurred along the margins of the crater rim. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 April-26 April 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 19-26 April, entering an active lava lake and flowing onto the crater floor. The surface of the lava lake was active all week, and the height of the lake fluctuated; the lake occasionally overflowed the rim, sending lava onto the crater floor. Daily breakouts occurred along the N, NE, E, and S parts of the crater. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 April-19 April 2022 Citation IconCite this Report

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 12-19 April, entering an active lava lake and flowing onto the crater floor. The surface of the lava lake was active all week, and the height of the lake fluctuated. Flows occasionally overtopped perched levees. At 2315 on 10 April a flow emerged from the S side on the vent that covered areas along the southwest and western margins, and was active through 14 April. Breakouts along the N, NE, and S parts of the crater were visible during 14-19 April. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 April-12 April 2022 Citation IconCite this Report

HVO reported that lava effusion from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater continued at variable rates during 5-12 April. Lava from a vent flowed into the active W part of the lava lake, which comprised about 2.3 percent of the total crater floor’s surface, and onto the crater floor. The surface of the lava lake was active all week, and the height of the lake fluctuated. Numerous ooze outs of lava were visible along the lake’s NW, NE, E, and SE margins; a more substantial ooze-out at the N margin was active during 6-7 April. A small outbreak at the W vent was visible overnight during 8-9 April. Just after 2300 on 10 April a flow emerged from the S side on the vent that covered areas along the southwest and western margins through 12 April. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 March-5 April 2022 Citation IconCite this Report

HVO reported that lava effusion from vents in the lower W wall of Kilauea’s Halema`uma`u Crater continued at variable rates during 30 March through 5 April. Lava from a vent flowed into the active W part of the lava lake and onto the crater floor. Numerous and sustained ooze outs of lava along the lake’s margins; effusion along interior surface fractures persisted during the week but showed decreasing activity. On 31 March a hornito that was forming on the E side of the lake exhibited spattering throughout the day. HVO noted that by 29 March about 64 million cubic meters of lava had been erupted since the current eruption began, raising the crater floor by 96 m (315 ft). The sulfur dioxide emission rate was approximately 3,100 tons/day, based on measurements made on 31 March. During 2-5 April continued ooze outs were occurring along the E half of the crater floor and NW margin, but at a decreased rate, and crustal overturning occurred occasionally on the NW margin. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 March-29 March 2022 Citation IconCite this Report

HVO reported that lava effusion from vents in the lower W wall of Kilauea’s Halema`uma`u Crater continued at variable rates during 22-29 March. Lava from a vent flowed into the active W part of the lava lake and onto the crater floor. Numerous and sustained ooze outs of lava along the lake’s margins and interior seams persisted during the week. HVO noted that by 17 March about 58 million cubic meters of lava had been erupted since the current eruption began. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 March-22 March 2022 Citation IconCite this Report

HVO reported that lava effusion from vents in the lower W wall of Kilauea’s Halema`uma`u Crater continued at variable rates during 15-22 March; effusion briefly paused during 0145-0445 on 18 March. Lava flowed in the active W part of the lava lake causing circulation in the lake that was visible on most days. At around 0700 on 16 March a lava flow originating from the embayment just N of the western vent area traveled NW onto the crater floor; this flow periodically advanced through the week. Ooze outs of lava along the lake’s margins were visible on a few of the days; a notable one began along the N margin at 0345 on 21 March and persisted through the next day. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 March-15 March 2022 Citation IconCite this Report

HVO reported that lava effusion from vents in the lower W wall of Kilauea’s Halema`uma`u Crater continued at variable rates during 8-15 March. Throughout February the main cone had broken down and by 4 March lava was effusing from multiple vents, including the tallest cone (19 m high); by 11 March lava was supplied from an embayment just N of the cone which had grown to 27 m high. Lava continued to feed the western active lava lake. Lava breakouts along the SE, NE, and NW lake margins were visible on a few of the days. Minor and slow crustal overturning occurred on the NW and SE parts of the lake’s margins during 13-14 March. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 March-8 March 2022 Citation IconCite this Report

HVO reported that lava effusion at the vent of the main cone in the lower W wall of Kilauea’s Halema`uma`u Crater continued at variable rates during 2-8 March. After a brief pause effusion from the W vent resumed at about 0100 on 2 March and continued through 7 March. Lava from the vent traveled S and W, into the western active lava lake. Lava occasionally oozed out from the margins of the lake during 3-6 March, particularly along the E and N margins. A pause in effusion began in the evening of 7 March. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 February-1 March 2022 Citation IconCite this Report

HVO reported that lava effusion at the vent of the main cone in the lower W wall of Kilauea’s Halema`uma`u Crater continued at variable rates during 22 February-1 March. Effusion from the vent sometimes paused, including from the early afternoon on 23 February to 2115 on 27 February, from 1500 on 26 February to 1000 on 27 February, and again beginning at 0130 on 1 March. When the vent was active lava flowed S and W, into the W part of the lava lake. Lava occasionally oozed out from the margins of the lake. The lake level fluctuated through the week, likely reflecting the lava supply along with periods of inflation and deflation. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 February-22 February 2022 Citation IconCite this Report

HVO reported that lava effusion at the vent of the main cone in the lower W wall of Kilauea’s Halema`uma`u Crater continued at variable rates during 16-22 February. Effusion from the vent was very low or had paused from around 0000 on 16 February until about 0230 on 17 February. After another drop, the effusion rate was relatively stable at least through 22 February. The lake level fluctuated through the week, likely reflecting the lava supply along with periods of inflation and deflation. Short-lived lava ooze-outs were visible along the W margins of the lava lake and small flows from the W vent traveled S and W during 20-22 February. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 February-15 February 2022 Citation IconCite this Report

HVO reported that lava effusion at the vent of the main cone in the lower W wall of Kilauea’s Halema`uma`u Crater continued at variable rates during 9-15 February. Effusion had paused, but restarted at 0120 on 9 February when lava again began entering the lava lake. The lake level fluctuated through the week, likely reflecting variable lava supply along with periods of inflation and deflation. Effusion from the W vent paused during around 0900-1100 on 11 February. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 February-8 February 2022 Citation IconCite this Report

HVO reported that lava effusion at the vent of the main cone in the lower W wall of Kilauea’s Halema`uma`u Crater continued during 2-8 February. The lake level fluctuated, likely reflecting variable lava supply along with periods of inflation and deflation. A small spatter cone, less than 6 m tall, located near the E end of the crater produced lava fountains that were 10 m tall in the evening of 1 February. The fountains fed a short flow confined to the E margin of the crater. Effusion from the W vent paused during around 0900-1730 on 2 February. During the rest of the week the effusion rate fluctuated; the lake continued to circulate, although less when the effusion rate was lower. Multiple ooze-outs of lava along the N, E, and S margins of the crater were visible. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 January-1 February 2022 Citation IconCite this Report

HVO reported that lava effusion at the vent of the main cone in the lower W wall of Kilauea’s Halema`uma`u Crater continued intermittently during 26 January-1 February. The lake level fluctuated, reflecting variable lava supply to the lake and periods of inflation and deflation. Lava effused from the vent during 26-28 January, and the W part of the lake was active along with a small pond N of the W vent cone. A few small flows oozed out from the N margin of the lake and an area of spattering in the E part of the crater built a new, small, steep-sided cone. Field crews working near the crater on 27 January heard loud gas-jetting sounds from the new cone.

Active lava was no longer visible in the crater by 0800 on 29 January. During 29-30 January the lake was mostly crusted over, though foundering of the crust in the E part of the lake exposed lava and circulating lava was occasionally visible in the small pond N of the main cone. Lava again began flowing from the main cone just before 2130 on 30 January. Lava quickly filled the ponded area just to the N and flowed into the lake. The lake began to rise and overflowed the S margins by midnight, and the N margins by 0500 on 31 January. Lava flows from the S part of the lake fed flows that traveled SE along the walls of the crater until 1100. Multiple ooze outs from the N margin continued through 1 February. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 January-25 January 2022 Citation IconCite this Report

HVO reported that lava effusion resumed at the vent in the lower W wall of Kilauea’s Halema`uma`u Crater at around 1045 on 18 January. By 1630 the level of the lava lake had risen 12 m, slightly surpassing the high recorded on 12 January, but then slightly dropped within 30 minutes. The W part of the lake was active. The sulfur dioxide emission rate was about 2,100 tonnes per day the next day. During 19-20 January lava oozed out along the SE and NW margins of the lake, though by the afternoon of the 20th the active portion of the lake was small and located N of the cone. Just after 0400 on 21 January the effusion rate increased and the W half of the lake was again active. Notable overflows of lava later that evening sent flows NW, SW, and SE. The lake level dropped 9 m during the morning of 22 January, and again only a small portion of the lake was active. Lava oozed out from the E and NW lake margins. Lava input into the small lake became intermittent starting at around 1500 on 23 January, though lava oozed out along the NW and S margins. The effusion rate increased at 0552 on 25 January and lava flowed W and N along the crater margins. By 0820 the lava lake had risen 11 m. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 January-18 January 2022 Citation IconCite this Report

HVO reported that lava effusion resumed at the vent in the lower W wall of Kilauea’s Halema`uma`u Crater at around 1840 on 11 January. The level of the lava lake had increased 13 m by about 0300 on 12 January, slightly surpassing the level prior to the pause that began on 10 January; the lake has risen a total of 70 m since the beginning of the eruption. During 12-14 January the lake was active and lava oozed out along the crusted-over E margins. A surge in lava effusion at the vent was recorded at 0545 on 15 January, coincident with a peak in summit inflation. Effusion had paused by the afternoon, though minor activity at the vent on the N side of the spatter cone, minor overturns of the lake, and small oozes of lava at the lake’s margins persisted. The lake level dropped 10 m by the morning of 16 January. Small overturns of the crusted lake were visible during 16-17 January. By 18 January the lake was completely crusted over and a small wispy plume rose from the vent. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 January-11 January 2022 Citation IconCite this Report

HVO reported that lava effusion resumed at the vent in the lower W wall of Kilauea’s Halema`uma`u Crater at around 0400 on 5 January, ending a 3-day pause. The sulfur dioxide emission rate was about 3,300 tonnes per day on 6 January. Lava effused from the vent on most days during 6-11 January, though effusion paused and the lake crusted over for most of the day on 7 January. Several overflows onto older crust were observed after effusion resumed at around 2130 on 7 January through 8 January. The W surface of the lava lake was active during 9-10 January, though there were some more pauses in lava effusion from the W vent during 10-11 January. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 December-4 January 2022 Citation IconCite this Report

HVO reported that lava effusion intermittently continued from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 29 December 2021 to 4 January 2022. Effusion at the vent paused on the evening of 29 December and the lake mostly crusted over, though lava oozed over the edge of the lake margins in several areas, suggesting a continuing supply of molten lava below the crust. Parts of the crusted lake overturned during 2000-2300. Occasional minor activity at the vent was visible during the morning of 30 December, and lava again began effusing form the vent at 1445. Several large lava overflows of the lake occurred in the evening and bright glow was visible in the evening sky from Volcano to lower Puna. Lava effusion was low during 1-2 January and by 0200 on 2 January the lake once again began to crust over. A large breakout along the N margin of the lake was active. Effusion ceased during 2-4 January; the lake was mostly crusted over except a few overturns N of the vent were noted. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 December-28 December 2021 Citation IconCite this Report

HVO reported that lava effusion intermittently continued at a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 21-28 December. Effusion paused for a period during 21-22, and sulfur dioxide emissions were 130 tonnes per day during the pause. Strong volcanic tremor began to be recorded at 1930 on 22 December and by 2000 lava again effused from the vent into the rejuvenated a portion of the lake. The lake overflowed and fed substantial lava flows that traveled SE over older crusted parts of the lake all day on 23 December until around midnight. Lava oozed out along the E margins of the lake during 24-25 December, including onto the lowermost down-dropped block from the 2018 caldera collapse, indicating a continuing supply of lava beneath the lake’s crust. The sulfur dioxide emission rate was about 5,300 tonnes per day on 24 December, much higher than during the pause. The surface of the lava lake had begun crusting over on 25 December and by 26 December lava had again ceased erupting from the vent. An area of the lake, 50 m in diameter, to the N of the vent remained molten on 27 December. The sulfur dioxide emission rate was 125 tonnes per day during the pause. Lava again erupted from the vent later that day, beginning at 1930. The lake was incandescent around the vent and lava overflowed the margins, feeding substantial lava flows to the N and S. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 December-21 December 2021 Citation IconCite this Report

HVO reported that lava effusion continued at a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 14-20 December. The sulfur dioxide emission rate was about 1,400 tonnes per day on 16 December. By 19 December the lake had risen a total of 69 m since the beginning of the eruption. A series of partial overturns of the lake was visible on 20 December, though by the next morning there was no lava effusion from the vent and the lake had crusted over. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 December-14 December 2021 Citation IconCite this Report

HVO reported that lava effusion continued at a vent in the lower W wall of Kilauea’s Halema`uma`u Crater on most days during 8-14 December. The vent contained ponded and sometimes spattering lava that fed the lake through the E part of the W wall cone. The size of the active part of the lake varied, and lava periodically oozed from the cooler, outer margins of the lake onto the lowest of the exposed down-dropped caldera floor blocks. The sulfur dioxide emission rate was about 3,500 tonnes per day on 9 December. The eruption paused on 11 December then resumed at 2100 on 13 December. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 December-7 December 2021 Citation IconCite this Report

HVO reported that lava effusion continued at a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 1-2 December. The rate of effusion sharply decreased, along with volcanic tremor levels, during 1600-1800 on 3 December. A small part of the vent cone collapsed at around 1700. No surface activity was observed on 5 December and most of the next day though weather conditions hindered visual confirmation; a few small hotspots around the vent were visible in thermal camera images. Lava was visible in the vent at about 1730 on 6 December and within 30 minutes was flowing into the lake. By 0300 on 7 December lava had covered the prior extent of the lava lake. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 November-30 November 2021 Citation IconCite this Report

HVO reported that the summit eruption at Kilauea continued at a vent in the lower W wall of Halema`uma`u Crater during 24-30 November. The vent contained ponded and sometimes spattering lava that fed the lake through the E part of the W wall cone. The size of the active part of the lake varied, and lava periodically oozed from the cooler, outer margins of the lake onto the lowest of the exposed down-dropped caldera floor blocks. Earthquake activity remained below background levels and volcanic tremor was elevated. The sulfur dioxide emission rate had averaged 3,000 tonnes per day in recent weeks; on 23 November the rate was higher at 6,400 tonnes per day and on 29 November it was below the average at 1,200 tonnes per day. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 November-23 November 2021 Citation IconCite this Report

HVO reported that the summit eruption at Kilauea continued at a vent in the lower W wall of Halema`uma`u Crater. By 16 November the total volume of erupted lava was an estimated 30 million cubic meters, and the lake which had risen a total of 60 m since 29 September. During 17-23 November earthquake activity remained below background levels but volcanic tremor was elevated. Spattering and ponded lava within the vent were visible; lava entered the lake through the E part of the W wall cone, feeding an active area of the lake. Lava periodically oozed from the cooler, outer margins of the lake onto the lowest of the exposed down-dropped caldera floor blocks. The sulfur dioxide emission rate remained above background levels, and was 3,000-3,800 tonnes per day on 18 and 23 November. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 November-16 November 2021 Citation IconCite this Report

HVO reported that the summit eruption at Kilauea continued at a vent in the lower W wall of Halema`uma`u Crater. By 9 November the total volume of erupted lava was an estimated 27 million cubic meters. The sulfur dioxide emission rate was 2,600 tonnes per day on 9 November. Spatter and ponded lava in the vent were visible during 9-16 November; lava entered the lake through a short channel in the E part of the W wall cone, feeding the lake which had risen 60 m since 29 September. The active area of the lava lake had increased during the week. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 November-9 November 2021 Citation IconCite this Report

HVO reported that the summit eruption at Kilauea continued during 2-9 November at a vent in the lower W wall of Halema`uma`u Crater. Lava entered the lake through a short channel in the E part of the W wall cone, feeding the lake which had risen 56 m since 29 September; the channel was covered with a cooled crust by 3 November. Lava began to flow over the E edge of the lava lake, which is perched above the crater floor, by 4 November. The sulfur dioxide emission rate was 1,700-2,900 tonnes per day during 3-5 November and 250 tonnes per day during 7-8 November. Low roiling and bursts of spatter from the small perched pond in the W vent cone were observed; activity at the vent had decreased by 8 November, along with the area of active lava at the surface of the main lava lake, then returned to higher levels by 9 November. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 October-2 November 2021 Citation IconCite this Report

HVO reported that the summit eruption at Kilauea continued during 26 October-2 November at a vent in the lower W wall of Halema`uma`u Crater. Lava entered the lake through a breach in the E part of the W wall cone, feeding the lake which had risen 52 m since 29 September. The lava lake was not level; the W end was 8 m higher than the stagnant E part on 27 October. The sulfur dioxide emission rate was high at 3,600 tonnes per day on 28 October. Lava fountains rose less than 10 m from the W vent, though by 29 October low roiling and spatter bursts were also observed. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 October-26 October 2021 Citation IconCite this Report

HVO reported that the summit eruption at Kilauea continued during 19-26 October at a vent in the lower W wall of Halema`uma`u Crater. Lava entered the lake through a 10-m-wide breach in the E part of the W wall cone, feeding the lake which had risen 49 m since 29 September. Consistent lava fountains from the W vent rose 5-18 m with occasional bursts up to 23 m, based on field crew observations. The sulfur dioxide emission rate was high at 2,600-3,200 tonnes per day during 21-22 and 24-25 October. The lava lake was not level with the deepest parts surrounding the W vent; the W end was 8 m higher than the stagnant E part by 24 October. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 October-19 October 2021 Citation IconCite this Report

HVO reported that the summit eruption at Kilauea continued in Halema`uma`u Crater during 12-19 October. A 10-m-wide, horseshoe-shaped spatter rampart had formed around the W vent and was open to the E where lava was feeding the lake. For about 10 hours on 12 October a new vent N of the W vent produced 10-15-m-high lava fountains. Lava fountains from the W vent rose as high as 20 m and fed the lava lake which was 46 m deep by 18 October. The lava lake was not level with the deepest parts measured around the W vent; the W end was 4-5 m higher than the N and S parts of the lake and 12 m higher than the E end. Cooled and crusted parts of the lake’s surface overturned, or “foundered,” in all parts of the lake except the E part. The sulfur dioxide emission rate was high at 1,600-6,800 tonnes per day during 12-14 and 16-17 October. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 October-12 October 2021 Citation IconCite this Report

HVO reported that the summit eruption at Kilauea continued in Halema`uma`u Crater during 6-12 October. At the beginning of the eruption, on 29 September, lava erupted from vents along the floor and from the W wall of the crater, though by 8 October only the W vent was active. Sulfur dioxide emissions remained high and were 5,300 tonnes per day on 8 October. A 10-m-wide, horseshoe-shaped spatter rampart had formed around the W vent and was open to the E where lava was feeding the lake. Lava fountains from the W vent were generally 12-15 m high but decreased to 4 m during 10-11 October. The total erupted volume was an estimated 15.9 million cubic meters on 8 October and the lake was as deep as 40 m on 12 October. The lava lake was not level; the W end was 2-3 m higher than the N and S parts of the lake and 5 m higher than the E end. Cooled and crusted parts of the lake’s surface overturned, or “foundered,” in all parts of the lake, though by 11 October foundering was not observed in the E. HVO noted that the central island (or raft) of cooler material from the 2020 eruption remained above the surface as the lava lake rose, and other smaller rafts had reemerged in the E and N parts of the lake. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 September-5 October 2021 Citation IconCite this Report

Seismicity abruptly increased below Kilauea’s summit at about 1400 on 29 September. Around 30 minutes later the earthquakes became more intense, frequent, and shallower, and deformation patterns rapidly changed. The data suggested an upward movement of magma that prompted HVO to raise the Aviation Color Code to Orange and the Volcano Alert Level to Watch at 1509. A new eruption was identified at 1521 when incandescence from Halema`uma`u Crater became visible in webcam views; HVO raised the Aviation Color Code to Red and the Volcano Alert Level to Warning. Fissures opened along the bottom of Halema`uma`u Crater floor and produced lava fountains and flows. A photo taken at 1615 showed a large plume comprised of steam, carbon dioxide, and sulfur dioxide rising from the fissures. Measurements just after the eruption started showed sulfur dioxide emissions of around 85,000 tonnes/day. At about 1640 another fissure with several vents opened on the inner W wall of the crater and produced low lava fountains and flows that descended to the crater floor. The vent expanded by 1709. Lava from both fissures pooled on the solidified lava lake surface and quickly began to overturn and create a lava lake. Tephra was deposited in areas SW of the crater and collected by HVO scientists for analysis.

The tallest lava fountain was near the S end of the lava lake and rose 20-25 m during the night of 29-30 September. During a helicopter overflight around 0730 on 30 September scientists determined that the lake was about 980 m E-W and 710 m N-S, covering an estimated 52 hectares. The W wall vent was visible, and several fountains were rising from the fissure in the central part of the lake. Sulfur dioxide emission rates remained high, estimated at around 20,000 tonnes/day. Overnight during 30 September-1 October fountains rose as high as 15 m at the dominant vent in the W wall. Less vigorous fountaining persisted at other vents, though fewer were active. The lake had risen 24 m by the morning of 1 October, adding 4 m in the past day. Cooled and crusted parts of the lake’s surface overturned, or “foundered.” Sulfur dioxide emission rates remained high, estimated at around 12,900 tonnes per day.

The lake had risen another 2 m by the morning of 2 October; fountains were 7 m tall at the main W wall vent and 1-2 m at the southern vents. Fountains occasionally rose as high as 50-60 m in bursts. Pumice, Pele?s hair, and fragments of volcanic glass were deposited downwind. The sulfur dioxide emission rate on 3 October was again high at 14,750 tonnes/day. The W vent was again the most vigorous during 3-4 October with sustained lava fountains to 10-15 m with occasional bursts up to 20 m. The lake rose 3 m, past the base of the W vent where a 12-m-high spatter cone had formed, and continued to founder in spots. Lava fountains rose 5-10 m from the vents in the S and central portions of the lake, including along a fissure 35-42 m long, with occasional larger bursts. The lake was not level and generally higher near the location of the vents; the W end was 1-2 m higher than the E, and S end was about 1 m higher than the N. By 4 October ledges about 20 m wide separated the N and E parts of the active lava lake from the crater wall and were lower than the lake surface; the N, E, and S margins of the lake were perched about 3 m above the surrounding ledge. The sulfur dioxide emission rate remained elevated but had decreased to 7,000-9,000 tonnes/day. HVO lowered the Aviation Color Code to Orange and the Volcano Alert Level to Watch at 1652. On 5 October lava fountaining from the W vent was unchanged while fountains from the other vents rose 1-5 m. The lake rose 1 more meter.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 September-7 September 2021 Citation IconCite this Report

HVO reported that ground deformation beneath the S part of Kilauea’s summit ceased on 30 August and the earthquake rate decreased during 30-31 August. The data suggested that a magma intrusion had slowed or stopped. Earthquake rates and ground deformation remained near pre-intrusion levels through 7 September. The Volcano Alert Level and Aviation Color Code remained at Advisory and Yellow, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 August-31 August 2021 Citation IconCite this Report

HVO reported that a seismic swarm and ground deformation continued beneath the S part of Kilauea’s summit during 24-25 August. The rate of earthquakes per hour peaked at 28 during 1900-2000 on 24 August and then decreased to 5-12 through 25 August. Most of the earthquakes were between magnitudes 1 and 2, occurring at depths of 1-2 km. By 26 August seismicity and ground deformation levels had decreased, suggesting magma was no longer moving; HVO lowered the Volcano Alert Level and Aviation Color Code to Advisory and Yellow, respectively. Later that day, ground deformation began again in the S part of the caldera at around 1800 and was followed by an increase in seismicity after 2030. Earthquakes in the swarm were located at depths of 1-3 km. The strongest earthquake was a M 2.8, though the majority were less than M 1. The rate of events per hour was 16, with a peak of 24 just after midnight on 27 August, and then declined to about six. Seismicity remained low through 30 August with 7-8 events per hour, all under M 2 and at depths of 1-4 km. Deformation continued to be detected at variable rates. Although the deformation and seismicity suggested renewed magma movement, the data did not indicate an upward movement of magma.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 August-24 August 2021 Citation IconCite this Report

HVO reported that a swarm of earthquakes beneath the S part of Kilauea that began at 1630 on 23 August continued into the early morning of 24 August. The earthquake swarm increased in intensity at 0130 and was accompanied by an increase in the rate of ground deformation to the W of the swarm, as recorded by the Sandhill tiltmeter. This possibly indicated that there was magma movement 1-2 km beneath the S part of the caldera. Over 140 earthquakes were recorded during 24 August, the largest of which was an Mw 3.3; a majority of them were less than Mw 1. Small earthquakes continued at a rate of at least 10 earthquakes per hour through 24 August. As a result, the Aviation Color Code and the Volcano Alert Level were raised to Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 May-1 June 2021 Citation IconCite this Report

On 27 May HVO reported that Kilauea was no longer erupting; the Aviation Color Code and the Volcano Alert Level were lowered to Yellow and Advisory, respectively. A decreasing rate of lava entering the lake caused the area of the active lava lake to shrink to two small ponds by 11 May. Lava had stopped flowing into the lake sometimes during 11-13 May, and it was completely crusted over by 20 May. Weak inflation and an increase in shallow volcano tectonic earthquakes at the summit that began on 11 May also suggested that magma was staying at depth.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 May-25 May 2021 Citation IconCite this Report

HVO reported that lava at Kilauea's Halema`uma`u Crater lava lake circulated in a 20-m-diameter area on 19 May but was stagnant and crusted over on other days through 25 May. A few minor oozes of lava between the W vent and main island were occasionally visible. The depth of the lava lake was 229 m and had remained unchanged since 11 May. Sulfur dioxide emissions were 100-150 tons per day during 19-23 May, close to the less than 50 tonnes per day measured during the non-eruptive period from late 2018 to late 2020. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 May-18 May 2021 Citation IconCite this Report

HVO reported that the W vent on the inner NW wall of Kilauea's Halema`uma`u Crater continued to supply the 229-m-deep lava lake at a low rate through a submerged inlet during 12-18 May. Lava circulated in two small pools in the W part. The solidified portion comprised 99 percent of the total area, based on thermal measurements acquired on 13 May. The sulfur dioxide emission rate was 115-225 tons per day during 12-14 May, continuing a downward trend that began in mid-April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 May-11 May 2021 Citation IconCite this Report

HVO reported that the W vent on the inner NW wall of Kilauea's Halema`uma`u Crater continued to supply the lava lake at a low rate during 5-11 May through a submerged inlet. The depth of the lake was 229 m by 11 May. Lava continued to circulate in the W part, though the active area continued to shrink. The E half of the lake remained solidified and comprised about 93 percent of the total area, based on thermal measurements acquired on 16 April. The sulfur dioxide emission rate was 200-300 tons per day during 5-7 May, and 150 tons per day on 10 May, continuing a downward trend that began in mid-April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 April-4 May 2021 Citation IconCite this Report

HVO reported that the W vent on the inner NW wall of Kilauea's Halema`uma`u Crater continued to supply the lava lake during 28 April-4 May through a submerged inlet. The depth of the lake was about 227 m and lava continued to circulate in the W part, though the active area continued to shrink. The E half of the lake remained solidified and comprised about 93 percent of the total area, based on thermal measurements acquired on 16 April. The sulfur dioxide emission rate was 250 and 475 tons/day on 30 April and 2 May, respectively, continuing a downward trend that began in mid-April; the recent rates suggested that the effusion rate had also decreased. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 April-27 April 2021 Citation IconCite this Report

HVO reported that the W vent on the inner NW wall of Kilauea's Halema`uma`u Crater continued to supply the lava lake during 21-27 April. Lava flowed at a low rate from the main vent into the lake through crusted-over channels and submerged inlets. The depth of the lake was about 226-227 m and lava continued to circulate in the W part, though the active area continued to shrink; the E half of the lake remained solidified. Lava sometimes overflowed the margins of the lake. The sulfur dioxide emission rate was 350, 550, 300, and 350 tons/day on 21, 22, 23, and 24 April, respectively. The rates were the lowest measured during the eruption, though elevated above the levels recorded in the months before the start of the eruption (20 December 2020). The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 April-20 April 2021 Citation IconCite this Report

HVO reported that the W vent on the inner NW wall of Kilauea's Halema`uma`u Crater continued to supply the lava lake during 14-20 April. Lava flowed at a low rate from the main vent into the lake through crusted-over channels and submerged inlets. The depth of the lake was about 226-227 m and lava continued to circulate in the W part, though the active area continued to shrink; the E half of the lake remained solidified. Lava sometimes overflowed the margins of the lake. The sulfur dioxide emission rate was 950 tons/day on 14 April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 April-13 April 2021 Citation IconCite this Report

HVO reported that the W vent on the inner NW wall of Kilauea's Halema`uma`u Crater continued to supply the lava lake during 7-13 April. Lava flowed at a low rate from the main vent into the lake through crusted-over channels and submerged inlets. The depth of the lake was about 225-226 m and lava continued to circulate in the W part, though the active area continued to shrink; the E half of the lake remained solidified. Lava sometimes overflowed the margins of the lake. The sulfur dioxide emission rate was 1,000 tons/day on 8 April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 March-6 April 2021 Citation IconCite this Report

HVO reported that the W vent on the inner NW wall of Kilauea's Halema`uma`u Crater continued to supply the lava lake during 31 March-6 April. Lava flowed at a low rate from the main vent into the lake through crusted-over channels and submerged inlets. The total depth of the lake measured about 225 m and lava continued to circulate in the W part; the E half of the lake remained solidified and expanded toward the W. The sulfur dioxide emission rate was 1,200 tons/day on 1 April. HVO field crews observed weak spattering from two areas at the W vent during 1-2 April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 March-30 March 2021 Citation IconCite this Report

HVO reported that the W vent on the inner NW wall of Kilauea's Halema`uma`u Crater continued to supply the lava lake during 24-30 March. Lava flowed from the main vent into the lake through two crusted-over channels and submerged inlets, the former of which occurred during 24-25 March. The total depth of the lake measured about 224 m and lava continued to circulate in the W part; the E half of the lake remained solidified, expanding toward the W. The sulfur dioxide emission rate was 950 and 650 tons/day on 22 and 26 March, respectively. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 March-23 March 2021 Citation IconCite this Report

HVO reported that two vents on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 17-23 March. Lava flowed from both the main vent and a vent several meters NE into the lake through submerged inlets. Another lava flow emerged from about halfway up the cone structure starting at 0220 on 16 March, but had ended by the next day.

The depth of the western part of the lake rose from about 221 m to 223 m and lava continued to circulate in that part. The E half of the lake remained solidified and lower that the W half, with the crusted E half expanding towards the W. The sulfur dioxide emission rate was 650, 700, and 1,100 tons/day on 17, 18, and 19 March, respectively. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 March-16 March 2021 Citation IconCite this Report

HVO reported that vents on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 10-16 March. Lava flowed from both the main vent and a newer vent several meters NE into the lake through submerged inlets. Another lava flow emerged from about halfway up the cone structure starting at 0220 on 16 March.

The depth of the western part of the lake rose from 221 m to 222 m and lava continued to circulate in that part. The E half of the lake remained solidified and lower that the W half, with the crusted E half expanding towards the W. The sulfur dioxide emission rate was 900 tons/day on 14 March. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 March-9 March 2021 Citation IconCite this Report

HVO reported that a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 2-8 March through a submerged inlet. The sulfur dioxide emission rate was 1,000 tons/day during 2-3 March, and 800 tons/day on 7 March. The depth of the western part of the lake fluctuated around 219-220 m. The E half of the lake remained solidified and lower that the W half, with the crusted E half expanding towards the W. Rangefinder measurements and visual observations indicated that the eastern and western portions of the lake were rising at the same rate, suggesting that lava was accumulating under the crusted eastern portion.

In recent weeks a part of the cone, several meters NE of the main vent, occasionally fed short (less than 100 m) lava flows that entered the lake at the crusted margins. During 5-7 March flows from this vent poured lava into the lake at several shifting inlets, though lava also accumulated on the lake margin within 50 m of the vent. By midday on 7 March the flows had built a perched lava pond on the NW lake margin, but it abruptly collapsed just after 1300. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 February-2 March 2021 Citation IconCite this Report

HVO reported that a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 24 February-2 March. The depth of the western part of the lake deepened from 217 to 219 m. Lava effused from a submerged vent and rapidly developed a thin crust as it flowed E towards the main stagnant island. The crust occasionally overturned at “plate” boundaries, and lava rarely overflowed onto the sloped margins of the lake. The E half of the lake remained solidified; the crusted area expanded towards the W. The sulfur dioxide emission rate was 700-1,100 tons/day during 25-26 February and 1 March.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 February-23 February 2021 Citation IconCite this Report

HVO reported that a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 17-23 February. The depth of the western part of the lake fluctuated between 215 and 218 m and the lake surface actively overturned at “plate” boundaries. The sulfur dioxide emission rate was elevated at 1,000 tons/day on 19 February.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 February-16 February 2021 Citation IconCite this Report

HVO reported that a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 10-16 February. The western part of the lake deepened from 215 m to around 217 m and the lake surface actively overturned at “plate” boundaries. The W end of the lava lake was perched by 3 m above the distal margin of recent overflows. A series of surficial cracks separated the W part of the lake from the stagnant E part. Lava spillovers just N of the inlet of lava sporadically flowed around the NW margin of the perched lake. Gas jetting at two locations above the W vents and two bursts of spatter were observed during 9-10 February. The sulfur dioxide emission rate was 1,600 and 1,100 tons/day on 10 and 12 February, respectively. During 15-16 February a few lava flows were visible along the N and E margins of the E part of the lake.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 February-9 February 2021 Citation IconCite this Report

HVO reported that lava from a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater streamed down the cone into a perched lava lake during 3-9 February. The western half of the lake dropped from 213 m on 3 February to 211 m on 4 February and stayed at that level during 5-6 February; the drop in lake level was likely the result of summit deflation that was detected by tiltmeters. The lake level had risen to 214 m by the morning of 7 February coincident with the onset of summit inflation. A small dome fountain was visible at the entry point of lava into the lake on 8 February. The stagnant E half of the lake, separated by a series of surface cracks, was about 5 m lowed than the W half.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 January-2 February 2021 Citation IconCite this Report

HVO reported that lava from a vent on a cone on the inner NW wall of Kilauea’s Halema`uma`u Crater fed flows that traveled down a channel into a perched lava lake during 27-29 January. The vent was mostly crusted over during 30 January-2 February, though several incandescent areas on cone were visible and lava slowly effused from the base of the cone. The western half of the lake deepened from 209 to 212 m and was elevated ~5 m above the stagnant E half.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 January-26 January 2021 Citation IconCite this Report

HVO reported that low lava fountains from a vent on a cone on the inner NW wall of Kilauea’s Halema`uma`u Crater fed flows that traveled down a channel into a perched lava lake during 20-26 January. The western half of the lake deepened from 202 to 205 m and was perched ~4 m above the solidified lava crust adjacent to the crater wall. The stagnant E half remained slightly lower, perched ~2 m above the adjacent crust. The islands remained stationary in the E part of the lake; the dimensions of the largest island remained unchanged and was 23 m above the lake’s surface at the highest point. The sulfur dioxide emission rate was 2,200 tons/day on 23 January.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 January-19 January 2021 Citation IconCite this Report

HVO reported that low lava fountains from a vent on a cone on the inner NW wall of Kilauea’s Halema`uma`u Crater fed flows that traveled down a channel into a perched lava lake during 13-19 January. The western half of the lake deepened from 198 m to 202 m while the stagnant eastern half remained a few meters lower. The lake was perched 1-2 m above the rim. On 13 January a small portion of the cone collapsed, causing a second vent to open adjacent to the main vent and effuse lava for less than 20 minutes. The islands remained stationary in the E part of the lake; the dimensions of the largest island remained unchanged. The sulfur dioxide emission rate was 4,700 tons/day on 14 January.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 January-12 January 2021 Citation IconCite this Report

HVO reported that lava effusion from vents on a cone on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to feed a growing perched lava lake during 6-12 January. Lava flowed through a crusted channel into the lake during most of the week. A dome fountain of upwelled lava at the partially submerged inlet was 5 m tall early on 6 January. Dome fountaining had weakened early on 7 January, giving way to spattering at the top of the vent and the formation of a second cone. Dome fountaining was possibly visible again on 8 January. The lake was perched at least 1-2 m above its narrow edges, though late on 10 January the stagnant, eastern part of the lake had subsided and was 3-4 m shallower. Overall the lake had deepened just 2 m by 11 January, reaching 196 m, and the lake volume was estimated at more than 27 million cubic meters.

An island of cooler, solidified lava and the 11 smaller islands were relatively stationary in the E part of the lake. The dimensions of the largest island remained unchanged (250 m long and 135 m wide), though on 8 January the W end was 9 m above the lake’s surface and the high point was 23 m above the lake, suggesting that the island was rising. Sulfur dioxide emissions were 2,700 and 2,300 tonnes/day on 7 and 10 January, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 December-5 January 2021 Citation IconCite this Report

HVO reported that lava effusion from a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to feed a growing lava lake during 30 December-5 January. A cone had formed over the remaining active vent, which was one of three that had opened at the beginning of the eruption. Lava sometimes spattered from vents at the top of a cone and flowed down into the lake through a crusted-over channel; during 2-5 January a dome fountain was visible near the lake’s margin, formed by upwelling of lava as in entered the lake at a partially submerged inlet.

The lake deepened from 181 m on 30 December to 191 m by 4 January, and the lake volume was an estimated 26 million cubic meters by 4 January. An island of cooler, solidified lava continued to float around on the lava lake’s surface, and by 4 January the island’s surface was 1-2 m above the surface of the lava lake. Over the week the island was joined by less than a dozen other small islands of cooled and solidified material that also moved around, though they mostly remained in the eastern part of the lake. The lava lake was also becoming perched as overflows of lava onto the narrow edge formed around the lake’s margins continued to build a levee; by 3 January the lake was perched about 1 m above the margin. Sulfur dioxide emissions fluctuated between 3,000 and 6,500 tonnes/day. Seismicity remained elevated but stable.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 December-29 December 2020 Citation IconCite this Report

HVO reported that the eruption from N and W fissure vents on the inner walls of Kilauea’s Halema`uma`u Crater continued to feed a growing lava lake during 23-29 December. Lava erupted from the N and W vents during 23-26 December with lava fountains that were sometimes 10 m high. The lake level rose above the N vent by 0300 on 26 December; later that day, volcanologists noted that the lake was slowly draining at that location. The W vent continued to feed the lake during 27-29 December. An island of cooler, solidified lava (250 m by 135 m in dimension on 28 December) slowly floated around on the lava lake’s surface. The island’s surface was about 6 m above the surface of the lava lake and was covered in tephra, possibly remnants of explosive activity generated when lava first reached the water lake.

The depth of the lava lake increased from 155 m to 169 m during 23-24 December. It continued to rise and was 176 m deep by 1400 on 25 December, though a new, narrow, black rim along the N edge suggested that the lake had briefly been 1-2 m deeper, and then drained back. The lake remained 176-177 m deep through 28 December, but by 29 December had deepened to 180 m. The lake volume was an estimated 22 million cubic meters, and was 770 by 490 m in dimension by 29 December.

Sulfur dioxide emissions decreased over the week, from around 30,000-40,000 tonnes/day on 23 December, to 20,000 tonnes/day on 25 December, 5,000-5,500 tonnes/day during 26-27, and finally dropping to 3,000 tonnes/day during 28-29 December. The emission plume carried Pele’s Hair and Pele’s Tears SW, depositing the tephra in areas downwind, including on HVO monitoring equipment and solar panels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 December-22 December 2020 Citation IconCite this Report

HVO reported that a new eruption at Kilauea began on 20 December, after almost a month of pre-eruptive activity that included a dike intrusion. An earthquake swarm on 30 November centered in the middle of the caldera was recorded followed by periods of increased seismicity in the upper East Rift Zone. Spikes in seismicity began on 2 December; at 1745 earthquakes intensified beneath the S part of the caldera; tiltmeters simultaneously recorded accelerated deformation, resulting in about 8 cm of caldera floor uplift. The data suggested that a small intrusion had a volume equivalent to the amount of lava erupted in just 1-2 hours from Fissure 8 during the 2018 eruption. On 3 December seismcity and deformation decreased to pre-intrusion levels.

On 17 December the number and duration of long-period seismic signals increased. An earthquake swarm and deformation were detected during the evening of 20 December. At about 2136 on 20 December an orange glow was evident in IR monitoring cameras, heralding a new eruption, and prompting HVO to raise the Volcano Alert Level to Warning and the Aviation Color Code to Red. Three fissures successively opened on the inner N, NW, and W walls of Halema`uma`u Crater; lava flows quickly boiled away the water lake, creating a vigorous steam plume, before the lava ponded at the bottom. Minor lava fountaining (25 m high) from the fissures was visible, with the tallest fountains reaching 50 m at the N fissure. Occasional blasts originated from the ponded lava. A M 4.4 earthquake beneath the S flank was recorded at 2236.

A gas plume was seen rising from Halema`uma`u Crater and drifting SW at 0215 on 21 December. Later that morning HVO lowered the Volcano Alert Level to Watch and the Aviation Color Code to Orange. The accumulating lava in the crater rose at a rate of several meters per hour. Sulfur dioxide plumes drifted NW. By the morning of 22 December, the surface of the lava lake was about 134 m above the bottom of the crater, or 487 m below the crater rim, and rising 1 m/hour. An estimated 10 million cubic meters of lava had been erupted so far. Sulfur dioxide emission rates remained high, at around 30,000 tonnes/day. Lava effusion stopped at the NW vent during 0730-0800, and, along with the W vent, was inundated by the lava lake sometime before noon.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 March-26 March 2019 Citation IconCite this Report

HVO reported that during the previous several months monitoring data at Kilauea showed relatively low rates of seismicity, deformation, and gas emissions at the summit and East Rift Zone (ERZ) (including the area of the 2018 eruption). As a result, HVO lowered the Volcano Alert Level to Normal and the Aviation Color Code to Green.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 December-11 December 2018 Citation IconCite this Report

HVO reported that lava at Kilauea’s Fissure 8 cone was last visible on 4 September, signaling the end of the Lower East Rift Zone (LERZ) eruptive phase. Consequently, the end of the LERZ eruption also marks the end of the over-arching, on-going eruption at Kilauea that began at the East Rift Zone (ERZ) in 1983. That determination was made by HVO in part by using the Global Volcanism Program guideline that an eruption should be considered over on the date of the last eruptive activity, and when there has not been renewed activity in the following three months.

HVO noted that geophysical data continued to show magma being supplied to Kilauea, including the refilling of the middle ERZ, and reminded the public that Kilauea remains an active volcano. As of 4 December the Volcano Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 October-9 October 2018 Citation IconCite this Report

On 5 October HVO reported that lava at Kilauea had not been active at the surface for 30 days. Seismicity was low, steady, relatively low rates of deformation across the volcano were recorded, and the summit and East Rift Zone (ERZ) produced only minor gas emissions. These data indicated that near-term resumption of activity at the summit or at the lower ERZ was unlikely; the Volcano Alert Level was lowered to Advisory and the Aviation Color Code was lowered to Yellow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 September-2 October 2018 Citation IconCite this Report

HVO reported no significant incandescence from a collapse pit in the central part of Kilauea’s Fissure 8 cone during 26 September-2 October, though a small amount of fuming was visible during the day. Seismicity and ground deformation remain low at the summit, and small aftershocks from the M 6.9 earthquake in early May were located along faults on the south flank. Sulfur dioxide emissions from the summit and the LERZ were low. On 1 October a rockfall at Pu'u 'O'o produced a small ash plume. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 September-25 September 2018 Citation IconCite this Report

HVO reported no incandescence from a collapse pit in the central part of Kilauea’s Fissure 8 cone during 19-25 September, though a small amount of fuming was visible during the day. Seismicity and ground deformation remain low at the summit, and small aftershocks from the M 6.9 earthquake in early May were located along faults on the south flank. The combined rate of sulfur dioxide emission from the summit and the LERZ (less than 1,000 tonnes/day) were lower than any time since late 2007. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 September-18 September 2018 Citation IconCite this Report

HVO reported minor incandescence from a collapse pit in the central part of Kilauea’s Fissure 8 cone during 12-15 September, and that small amounts of fuming rose from a small spatter cone located towards the back of the Fissure 8 cone during 12-18 September. Seismicity and ground deformation remain low at the summit, and aftershocks from the M 6.9 earthquake in early May were located along faults on the south flank. The combined rate of sulfur dioxide emission from the summit and the LERZ (less than 1,000 tonnes/day) were lower than any time since late 2007. Small collapses at Pu'u 'O'o Crater during 12-14 September generated visible dust plumes. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 September-11 September 2018 Citation IconCite this Report

HVO reported that during 5-11 September weak lava activity at Kilauea’s Fissure 8 was characterized by occasional incandescence; during 9-10 September a small collapse pit formed and exposed hot material underneath. Seismicity and ground deformation remain low at the summit, and aftershocks from the M 6.9 earthquake in early May were located along faults on the south flank. The combined rate of sulfur dioxide emission from the summit and the LERZ (<1,000 tonnes/day) were lower than any time since late 2007. A series of small collapses at Pu'u 'O'o Crater during 8-10 September generated visible brown plumes. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 August-4 September 2018 Citation IconCite this Report

HVO reported a break in visible lava activity at Kilauea’s Fissure 8 during 26-31 August. On 1 September incandescence at Fissure 8 was evident in the afternoon; spattering from a small area produced lava flows that slowly covered the 15 x 65 m crater floor by the evening. Lava continued to fill the Fissure 8 crater on 3 September. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 August-28 August 2018 Citation IconCite this Report

HVO reported that during an overflight on 25 August a small lava pond was visible deep within the vent at Kilauea’s Fissure 8 cone; the pond was no longer visible on 27 August. Lava continued to ooze into the ocean and produce minimal laze plumes, but by 27 August only a small single breakout from the Kapoho Bay lobe was active. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 August-21 August 2018 Citation IconCite this Report

On 17 August HVO lowered the Alert Level for Kilauea to Watch (the Aviation Color Code remained at Orange), noting reduced activity over the previous several days. Specifically, no collapse events had occurred at the summit since 2 August, lava ceased flowing in the channel from the Fissure 8 cone on 6 August, seismicity and ground deformation at the summit were negligible, and the combined rate of sulfur dioxide emission from the summit and the LERZ were lower than any time since late 2007. The small lava pond in Fissure 8 had crusted over by 17 August, with no observed incandescence. Lava continued to ooze into the ocean at a few areas, causing minimal laze plumes. During an overflight on 20 August gas jets ejected spatter from a small incandescent area deep within the Fissure 8 cone.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 August-14 August 2018 Citation IconCite this Report

HVO reported that during 8-14 August activity at Kilauea was characterized by a slowly-circulating lava pond deep within the Fissure 8 vent (though the pond was crusted over by 14 August) and a billowing gas plume, and a few scattered ocean entries. The summit area was quiet except for occasional rockfalls into the crater. Fresh black sand from fragmented lava was transported SW by the ocean current, and accumulated in the Pohoiki harbor, creating a sandbar. The westernmost ocean entry was about 1 km NE of the harbor. Earthquake and deformation data indicated no magma movement or pressurization in the system.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 August-7 August 2018 Citation IconCite this Report

HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and within Halema`uma`u Crater continued during 1-2 August, with lava flowing through the channel and into the ocean producing laze at several points along a broad 2-km-wide flow front at Ahalanui. A few spillovers from the channel set vegetation on fire. By 3 August the lava-flow velocity in the channel was low and on 4 August the output at Fissure 8 had waned. Part of the flow field shifted W about 250 m; the westernmost edge was about 70 m NE of the boat ramp in Isaac Hale Park by 5 August. The lava channel was completely crusted over by 6 August, and a lava lake bubbled in the Fissure 8 cone. The laze plumes at the ocean entry were greatly diminished. During 7-8 August the lava lake in Fissure 8 was 5-10 m below the spillway into the channel. A decreasing number of small active ooze outs near the coast were visible.

A collapse event at the summit was recorded at 1155 on 2 August. Seismicity increased afterwards as has been typical since early on in the LERZ eruption, but then decreased along with the rate of deformation. By 7 August deformation had almost stopped. The quiet conditions at the summit represented a significant change from the pattern of seismicity and deformation detected over the past several months.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 July-31 July 2018 Citation IconCite this Report

HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and within Halema`uma`u Crater continued during 18-24 July. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that continued to spread through Leilani Estates and Lanipuna Gardens subdivisions, and entered the ocean at Ahalanui.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Explosions from collapse events occurred about every other day (38.5 and 53.5 hours in between a few of the events). Sulfur dioxide emissions from the summit were very low.

Fountaining at Fissure 8 continued, producing Pele's hair and other volcanic glass that fell within Leilani Estates. The fountains continued to feed the lava flow that traveled NE, and then SSE, W of Kapoho Crater; lava occasionally overflowed the channel, and on 28 July ignited nearby vegetation. Small plumes of laze (a corrosive steam plume mixed with hydrochloric acid and fine volcanic glass particles) were generated at several points along a broad 2-km-wide flow front at Ahalanui. The westernmost edge was less than 175 m NE of the boat ramp in Isaac Hale Park (by 30 July).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 July-24 July 2018 Citation IconCite this Report

HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and within Halema`uma`u Crater continued during 18-24 July. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline at multiple ocean entries.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Explosions from collapse events occurred almost daily, often followed by a surge in activity at Fissure 8. Sulfur dioxide emissions from the summit were very low.

Fountaining at Fissure 8 continued, producing Pele's hair and other volcanic glass that fell within Leilani Estates. The fountains continued to feed the lava flow that traveled NE, and then SSE, W of Kapoho Crater. Channel overflows on 18 July destroyed structures in the Leilani Subdivision. The channelized ‘a’a flow was incandescent along its entire length as it flowed towards the ocean. It generated plumes of laze (a corrosive steam plume mixed with hydrochloric acid and fine volcanic glass particles) at several points along a broad 6-km-wide flow front, though the main entry area was at Ahalanui, a few hundred meters E of the flow edge which was 175 m NE of Isaac Hale Park (by 24 July). HVO noted that the lava delta was unstable as it has been built out as far as 800 m from the original coastline on unconsolidated lava fragments and sand.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); Big Island Video News


11 July-17 July 2018 Citation IconCite this Report

HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and within Halema`uma`u Crater continued during 11-17 July. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline at multiple ocean entries.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Explosions from collapse events occurred almost daily, producing gas-and-ash-poor plumes. Sulfur dioxide emissions from the summit were very low.

Fountaining at Fissure 8 continued, producing Pele's hair and other volcanic glass that fell within Leilani Estates. The fountains continued to feed the lava flow that traveled NE, and then SSE, W of Kapoho Crater. A few channel overflows occurred. The channelized ‘a’a flow reached the ocean on 12 July, producing a large plume of laze (a corrosive steam plume mixed with hydrochloric acid and fine volcanic glass particles), and covering the Kua O Ka La Charter School and Ahalanui Beach Park. Lava entered the ocean at several points along a broad 6-km-wide flow front, though the main entry area was at Ahalanui (750 m NE of Isaac Hale Park) by 17 July. On 13 July a new island, 6-9 m in diameter, formed a few meters offshore, possibly fed by a submarine tumulus. On 16 July explosions were noted at the main ocean entry, some were strong. Hawaii County Civil Defense Agency noted that an explosion early in the morning ejected tephra that injured 23 people on a nearby tour boat. That same day volcanologists using a radar gun measured an average flow velocity of 29 km/hour of lava exiting Fissure 8.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); Hawaii County Civil Defense Agency


4 July-10 July 2018 Citation IconCite this Report

HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and at Overlook Crater within Halema`uma`u Crater continued during 4-10 July. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline at multiple ocean entries. Fissure 22 produced spattering 50-80 m above its spatter cone and fed short lava flows that traveled NE on 4 July; weak spattering was visible form the cone the rest of the week.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Explosions from collapse events occurred almost daily, producing gas-and-ash-poor plumes.

Fountaining at Fissure 8 continued; lava fountains rarely rose higher than the 55-m-high spatter cone. Pele's hair and other volcanic glass from the fountaining fell within Leilani Estates. The fountains continued to feed the lava flow that traveled NE, and then SE around Kapoho Crater. Occasional overflows sent small flows down the sides of the channel that did not extend beyond areas previously covered in lava in the upper part of the channel; overflows further down traveled beyond the flow-field boundary. Small brush fires were ignited from some of the overflows. A thermal map from 6 July showed that lava was not entering the ocean from the main channel and that the open channel ended about 2 km inland. Lava was flowing into the ocean at the N part of the broad flow front. Observations on 9 July indicated that a blockage had formed upstream of Kapoho Crater, and by 10 July a small lobe was moving around the W side of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 June-3 July 2018 Citation IconCite this Report

HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and at Halema`uma`u Crater continued during 27 June-3 July. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline where the fast-moving flow entered the ocean in the area of the former Kapoho Bay. Fissure 22 produced a few short lava flows during 30 June-3 July.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Steam plumes rose from areas in the crater as well as from circumferential cracks adjacent to the crater. Explosions from collapse events occurred almost daily, producing gas-and-ash-poor plumes that rose less than 1.5 km (5,000 ft) a.s.l. and drifted SW.

Fountaining at Fissure 8 continued; lava fountains rarely rose higher than the 55-m-high spatter cone. Pele's hair and other volcanic glass from the fountaining fell within Leilani Estates. The fountains continued to feed the fast-moving lava flow that traveled NE, and then SE around Kapoho Crater, and into the ocean. Occasional overflows sent small flows down the sides of the channel. Lava entered the ocean on the S side of the flow front mainly through an open channel, but also along a 1-km-long area marked with billowing laze plumes. A thermal map showed that on 29 June the lava channel had crusted over about 0.8 km inland from the ocean entry, with lava moving beneath the crust.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 June-26 June 2018 Citation IconCite this Report

HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and at Halema`uma`u Crater continued during 20-26 June. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline where the fast-moving flow entered the ocean in the area of the former Kapoho Bay. Fissure 16/18 was often incandescent, and lava effusion was visible at Fissure 6 on 21 June. Fissure 22 produced weak lava fountains on 22 June, and weak spattering and small lava flows on 26 June.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Steam plumes rose from areas in the crater as well as from circumferential cracks adjacent to the crater. Explosions from collapse events occurred daily, producing gas-and-ash-poor plumes that rose less than 1.8 km (6,000 ft) a.s.l. and drifted SW. On 24 June HVO noted that since late May these plumes rarely rose higher than 3 km (10,000 ft) a.s.l. where they can cause an aviation hazard; the Aviation Color Code was reduced to Orange.

Fountaining at Fissure 8 continued; lava fountains rose occasionally higher than the 55-m-high spatter cone. Pele's hair and other volcanic glass from the fountaining fell within Leilani Estates. The fountains continued to feed the fast-moving lava flow that traveled NE, and then SE around Kapoho Crater, and into the ocean. Occasional overflows sent small flows down the sides of the channel. The lava-flow front at the ocean was almost 3.2 km wide by 25 June, with lava entering the ocean on the S side of the flow front mainly through an open channel, but also along a 1-km-long area marked with billowing laze plumes.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 June-19 June 2018 Citation IconCite this Report

HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and at Overlook Crater within Halema`uma`u Crater continued during 13-19 June. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline where the fast-moving flow entered the ocean in the area of the former Kapoho Bay. Minor lava activity at Fissures 16/18 was occasionally noted, and spattering was visible at Fissure 6 on 16 June. Hawai‘i County Civil Defense reported that by 17 June a total of 533 homes had been destroyed due to lava flows.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Steam plumes rose from areas in the crater as well as from circumferential cracks adjacent to the crater. Summit explosions occurred daily, producing ash plumes that rose as high as 3 km (10,000 ft) a.s.l. On 18 June residents reported feeling a large earthquake at 0613 and hearing roaring. The event was followed by an ash plume rising to 1.5 km (5,000 ft) a.s.l.

Fountaining at Fissure 8 was stable; lava fountains rose as high 60 m from a 52-m-high spatter cone. Pele's hair and other volcanic glass from the fountaining fell within Leilani Estates. The fountains continued to feed the fast-moving lava flow that traveled NE, and then SE around Kapoho Crater, and into the ocean. Occasional overflows sent small flows down the sides of the channel. Lava entering the ocean built a lava delta that by 16 June was just over 130 hectares in area. A plume of laze rose from the entry points. An area of thermal upwelling in the ocean out from the visible lava-delta front was visible, suggesting lava flowing on the ocean floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 June-12 June 2018 Citation IconCite this Report

HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and at Overlook Crater within Halema`uma`u Crater continued during 7-12 June. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline where the fast-moving flow entered the ocean in the Kapoho Bay area. Minor lava activity at Fissures 16/18 was occasionally noted.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area; the floor had subsided at least 100 m during the previous few weeks, and by 12 June the lowest point was 300 m below the crater rim. Steam plumes rose from areas in the crater as well as from circumferential cracks adjacent to the crater.

Summit explosions occurred almost daily. Explosions at 1607 and 0244 on 6 and 8 June, respectively, each produced an ash plume that rose 3 km (10,000 ft) a.s.l. An explosion was recorded at 0448 on 9 June. Two explosions, the second larger than the first, were recorded at 0046 and 0443 on 11 June. An ash-poor explosion occurred at 0152 on 12 June. A pattern of an increasing number of earthquakes, an explosion, and then a drop-off of seismicity immediately afterwards had emerged during the past few weeks and continued.

A total of 12 rockfalls in Pu'u 'O'o Crater were recorded between 1031 and 1056 on 8 June, following a M 3.2 earthquake at the summit. A red dust plume was visible around 1050 but dissipated quickly.

Fountaining at Fissue 8 was stable, though by 10 June three closely spaced fountains were active within the 35-m-high spatter cone. The heights of the fountains varied, but rose no higher than 70 m. Pele's hair and other volcanic glass from the fountaining fell within Leilani Estates. The fountains continued to feed the fast-moving lava flow that traveled NE, and then SE around Kapoho Crater, and into the ocean. The width of the channel varied from 100-300 m along its length. Periodic overflows sometimes sent small flows down the sides of the channel. Lava entered the ocean at Kapoho Bay, building a lava delta that by 11 June was just over 100 hectares in area. A plume of laze rose from the entry points. An area of strong thermal upwelling in the ocean around 920 m out from the visible lava-delta front was visible beginning on 7 June, suggesting lava flowing on the ocean floor. According to a news report, the Hawaii County Mayor noted that by 8 June lava flows had destroyed over 600 homes.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); USA Today


30 May-5 June 2018 Citation IconCite this Report

HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and at Overlook Crater within Halema`uma`u Crater continued during 30 May-6 June. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and reached the ocean at Kapoho Bay. Fissures 22, 6, and 13 were periodically active on 30 May, and fissures 6/13 spattered on 4 June. Sluggish lava flows were present around Fissure 18.

Inward slumping of the crater rim and walls of Halema`uma`u continued, and earthquake activity beneath the caldera was mostly high, as the summit area adjusted to the withdrawal of magma from Overlook Crater. Passive degassing of SO2 from the summit decreased, but emission rates were high enough to impact air quality downwind. Ash emissions were intermittent and low, though around 1100 on 30 May an ash plume rose to 3.6 km (12,000 ft) a.s.l. A small explosion was detected at 1339 on 1 June. A preliminary M 5.5 earthquake was recorded at 1550 on 3 June, producing an ash plume that rose to 2.4 km (8,000 ft) a.s.l. A small explosion and accompanying M 5.5 earthquake was detected at 0432 on 5 June; an ash plume rose to 1.6 km (5,100 ft) a.s.l.

During the beginning of the reporting period Fissure 8 generated tall lava fountains, rising 80 m, and some secondary fountains that rose 18 m. Pele's hair and other volcanic glass from the high fountaining fell in areas W of the fissure and within Leilani Estates. A small (30 m high) spatter cone formed at the downwind side of the fountain. Volcanic gas emissions from the fissures were very high; trade winds blew vog to the S and W parts of the island.

The lava flow fed by Fissure 8 advanced NE at a rate of 550 m/hour during 29-30 May, but then slowed to 90 m/hour on 31 May. High eruption rates led to the formation of a leveed channel along the W edge of the lava flow; small overflows from the channel occurred along its length. On 2 June lava flowed around the N part of Kapoho Crater and then turned S, entering the Vacationland neighborhood. At 0700 the flow front had entered Kapoho Beach Lots, moving about 75 m/hour. Lava entered Green Lake (70 m x 120 m in dimension, and 60 m deep) at 1000, creating a large steam plume. By 1500 lava had completely filled the lake and boiled off the water. Locals reported that lava (with a flow front 800 m wide) entered the ocean at Kapoho Bay around 2230. By late afternoon on 4 June lava had built a delta extending almost 700 m into the bay.

Overnight during 4-5 June lava fountaining at Fissure 8 was less vigorous, with a maximum height of 55 m. By 0630 on 5 June lava had completely filled Kapoho Bay, creating a new coastline 1.1 km away from the former coastline. To the S lava had overtaken most of the Vacationland subdivision and was entering the tidepools. All but the northern part of Kapoho Beach Lots had been covered.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 May-29 May 2018 Citation IconCite this Report

HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and at Overlook Crater within Halema`uma`u Crater continued during 23-29 May. Lava fountaining and spatter was concentrated in the middle portion of the fissure system, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and also traveled to the ocean.

Earthquakes beneath the summit and ash emissions from Overlook Crater continued as the summit area subsided and adjusted to the withdrawal of magma. Ash emissions were small and frequent, punctuated by larger plumes. The Overlook crater vent continued to widen to the W, and by 25 May the vent area was about 36 hectares. At 1244 on 25 May a M 4 earthquake was located in the summit region. That same day a new pit opened on the N part of Halema`uma`u Crater floor. Three explosions (at 0042, 0144, and 0500) on 26 May generated ash plumes that rose 3-3.3 km (10,000-10,800 ft) a.s.l. A small explosion at 0156 on 29 May sent an ash plume vertically to 4.6 km (15,000 ft) a.s.l. and drifted slightly NW. The explosion was felt by residents in Volcano, and ejected incandescent blocks within Halema`uma`u Crater. On 28 May a M 4.1 earthquake occurred at 1739 along the Koa'e fault zone, S of the caldera.

Lava fountains from Fissure 22 continued to form a channelized lava flow that entered the ocean NE of MacKenzie State Park, causing explosions and generating a plume of hazardous laze (lava haze, a mixture of condensed acidic steam, hydrochloric acid gas, and tiny shards of volcanic glass). On 23 May relatively tall lava fountains at fissures 6 and 13 fed another channelized flow that created a second ocean entry. Observers noted that a perched lava pond/channel was 11 m above ground level, and that methane was seen overnight that burned blue in road cracks. On 24 May lava was entering the ocean at three points between Pohoiki Bay and MacKenzie State Park, though by the next day only two were active.

Overnight during 25-26 May vigorous spatter was observed from a cone on Fissure 8, and multiple booming gas emissions occurred at Fissure 17. By the morning of 26 May an estimated 9.6 square kilometers had been covered by new lava. Fissures 7 and 21 fed a perched lava pond and sent flows NE; the lava-flow fronts became ‘a’a. A perched pond on the W side of Fissure 7 was breached, sending short flows W. Later that day the flows turned S, and by dusk were cascading into Pawaii crater, adjacent to the W margin of the Fissure 6 flow that fed one of the ocean entries. Lava from Fissure 21 flowed onto Puna Geothermal Venture (PGV) property.

During 26-27 May activity at Fissure 7 increased; lava from fountains 45-60 m tall built a large, 30-m-high spatter rampart. Large cracks were observed overnight on Kupono St., near Fissure 9. Three vents active at Fissure 8 spattered and flamed, and doubled in size in one day. On 27 May lava flows from fissures 7 and 8 advanced NE on PGV property; at about 1900 a flow broke out in this area and advanced rapidly to the N and W, through the E portion of Leilani Estates, prompting several residents to evacuate. Three minor ocean entries were again active. Fissure 24 opened in Leilani Estates.

On 28 May the vents that fed the ocean entries stopped erupting, leading to only residual lava in the channel to occasionally enter the ocean. During 28-29 May fountains, lava flows, and spattering from multiple fissures persisted. Pele's hair from vigorous fountaining (60 m high) at Fissure 8 drifted downwind, with some strands falling in Pahoa. According to a news article, the LERZ eruption had destroyed at least 94 structures, including 53 homes, by 29 May. The flows also cut off road access to PGV, which had been evacuated.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); KIII-TV


16 May-22 May 2018 Citation IconCite this Report

On 16 May HVO reported ongoing deflation at Kilauea’s summit, where the lava lake continued to recede in the Overlook Crater; by the afternoon the caldera floor had dropped a total of almost 1 m since the onset of the lake drainage. The drop of the floor stressed faults around the caldera causing earthquakes as strong at M 4.4. HVO and National Park staff reported frequent ground shaking, and damage to roads and buildings. Phreatic explosions had ejected blocks up to 60 cm in diameter that were found in the parking lot a few hundred meters from Halema`uma`u Crater. Ash plume heights varied, but generally rose no higher than 1.2 km and drifted N. Lava continued to erupt from multiple vents at the NE end of the active fissure system at the Lower East Rift Zone (LERZ). Lava from fissure 17 advanced about 90 m. Weak spattering arose from fissure 18, and fissure 20 was again active.

At about 0415 on 17 May an explosive event (or a series of explosions) at Overlook Crater generated an ash plume that, according to the Washington VAAC, rose as high as 9.1 km (30,000 ft) a.s.l. and drifted NE. Ash fell in areas downwind, including in the Volcano Golf Course and Volcano Village. Subsequent gas, steam, and ash emissions rose to 3.7 km (12,000 ft) a.s.l. and drifted SW. Fissure 17 actively spattered, though its lava flow had nearly stalled. Fissures 18, 19, and 20 reactivated, and a new fissure (21) opened between fissures 7 and 3. A 50-100-m-wide depression with cracks formed parallel to the fissures between Highway 130 and Lanipuna Gardens, into which pahoehoe lava flowed from fissures 20 and 21. Fissure 22 opened just downrift of fissure 19.

On 18 May a robust gas-and-steam plume rose from Overlook Crater, punctuated by several minor ash emissions. At 2358 a short-lived explosion generated an ash plume that rose up to 3 km (10,000 ft) a.s.l. and drifted SW. Spattering continued from fissures 15, 17, 18, 20, 21, and 22, with pahoehoe lava flows being erupted from fissures 17, 18, and 20. Large fountains at fissure 17 ejected bits of spatter 100 m high. Lava flows from fissure 18 traveled almost 1 km SE, and a flow from fissure 15 crossed Pohoiki Road. A fast-moving lava flow (275-365 m per hour) emerged from fissure 20 and traveled SE, across Pohoiki Road. Gas emissions remained elevated in areas downwind of the fissure system; air quality was poor from gas emissions as well as smoke from burning vegetation. Earthquake locations had not moved farther downrift in the previous few days.

Small ash emissions from Overlook Crater occurred intermittently on 19 May. The eruption of lava and ground cracking in the area of Leilani Estates subdivision continued. Fissure 17 was weakly active after fountaining earlier in the day. Fissures 16-20 merged into a continuous line of spatter and fountaining; flows from this fissure 20 complex flowed 275 m/hour S. Two of the flows joined less than a 1.6 km from the ocean and continued to flow S between Pohoiki and Opihikao roads.

During 19-20 May there were two explosive eruptions from Overlook Crater, and several smaller ash emissions. Lava flows reached the ocean overnight (late on 19 May) along the SE Puna coast. On 20 May spatter was ejected from fissures 6 and 17, and fissure 20 produced significant lava flows. A ground crack opened under the E lava channel diverting lava into underground voids. Gas emissions tripled as a result of the voluminous eruptions from fissure 20. Photos take in the afternoon showed two ocean entries along approximately 1 km of coastline.

A small explosion at Overlook Crater at 0055 on 21 May produced an ash plume that rose around 2.1 km (7,000 ft) a.s.l. and drifted SW. Several smaller emissions throughout the day ejected abundant ash. Robust steam-and-gas plumes also rose from the crater. Lava fountains from fissure 22 fed a channelized lava flow that entered the ocean N of MacKenzie State Park. Spattering occurred at fissures 6, 17, and 19. Small ash emissions from Overlook Crater continued on 22 May. Lava continued to enter the ocean, though by the afternoon only one entry was active. Most of the LERZ activity shifted to the middle part of the fissure system. The Aviation Color Code remained at Red and the Volcano Alert Level remained at Warning.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 May-15 May 2018 Citation IconCite this Report

On 9 May the intermittent eruption of lava in Leilani Estates in the lower East Rift Zone (ERZ) of Kilauea continued. In the northeast part of the area, fissure 15 extended across Poihiki Road, generating a pahoehoe flow about 20 m (66 ft) long. In the summit caldera, steady lowering of the Overlook Crater lava lake within Halema`uma`u crater raised the potential for steam-driven explosions if the lava column dropped to the groundwater level and allowed water into the conduit. On 10 and 11 May, little new extrusive activity was noted from the ERZ fissures, though there were continued earthquakes, ground deformation, and considerable gas discharge. Tiltmeters recorded ongoing deflation and the Overlook crater lava level continued to drop.

Fissure 16 opened at 0645 on 12 May near the end of Hinalo Road. It produced a lava flow that traveled about 230 m before stalling around 1430. An area that had been actively steaming developed into fissure 17, reported at 1800 just east of fissure 16, and was actively spattering and degassing. At the summit, rockfalls from the steep walls into Overlook crater generated intermittent small steam-and-ash clouds throughout the day.

Lava eruptions continued on 13 May along the lower ERZ. Aerial observations showed that a new outbreak in the early morning about 900 m NE of the end of Hinalo Street and 900 m S of Highway 132 was several hundred yards long and ejected spatter along with a slow-moving lava flow. By late in the day this activity from fissure 17 was dominated by lava fountaining, explosions that sent spatter bombs to 100 m into the air, and several advancing lava flow lobes moving generally NE; as of 1900 one lobe was 2 m thick and advancing roughly parallel to Highway 132. Steady, vigorous plumes of steam and occasionally minor amounts of ash rose from the Overlook vent and drifted downwind to the SW. Later in the day, ash clouds rose up to 650 m (2,000 ft) above the vent. Several strong earthquakes shook the Hawaiian Volcano Observatory and the surrounding area overnight.

Activity on the morning of 14 May in the lower ERZ was dominated by lava fountaining, explosions of spatter more than 30 m (100 ft) into the air, and an advancing flow from fissure 17 at the NE end of the fissure system. As of 0630, the fissure 17 flow had traveled about 1.6 km roughly ESE parallel to the rift zone. Fissure 18 was weakly active. A 19th fissure spotted around 0800 just NE of Pohoiki Road and N of Hinalo Street produced a sluggish lava flow. Volcanic gas emissions remained elevated throughout the area downwind of the vents. Deflationary tilt at the summit continued and seismicity remained elevated.

On the morning of 15 May activity remained concentrated at fissure 17. The lava flow had advanced about 380 m since 1430 on 14 May. At 0645 the flow was nearly 2.5 km long. However, the advance of the flow had slowed significantly since that afternoon. Also in the morning a new fissure (20) located near fissure 18 produced two small pads of lava. Ash emission from the Overlook crater increased compared to previous days. Although varying in intensity, at times the plume contained enough ash to be gray in color. Variable pulses sent the cloud to an estimated 1-1.3 km (3-4,000 ft) above the ground. The ash cloud drifted generally W and SW from the summit and ash fell in the Ka'u Desert. On 15 May the Aviation Color Code was raised from Orange to Red and the Volcano Alert Level remained at Warning.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); Hawaii Emergency Management Agency; Hawaii County Civil Defense Agency


2 May-8 May 2018 Citation IconCite this Report

On 2 May HVO noted that the intrusion of magma into Kilauea’s lower East Rift Zone (ERZ) continued, with deformation and frequent earthquakes (many felt by residents). Small cracks formed on some of the roads in and adjacent to Leilani Estates. Seismicity at Pu'u 'O'o Crater remained elevated after floor collapses which began on 30 April. Short-lived ash plumes periodically rose from the crater. The lava flows on the pali near the Royal Gardens subdivision were sluggish. Deflation at the summit accelerated around midday, accompanied by a drop in the level of the lava lake.

On 3 May the intensity of the ERZ seismicity decreased slightly, and the eastward migration of hypocenters slowed or ceased; deformation continued. The lava level in Overlook crater dropped over 30 m, though spattering in the lake continued. At 1030 ground shaking from a M 5 earthquake S of Pu'u 'O'o caused rockfalls and possibly a collapse in the crater; an ash plume rose from the crater and drifted SW. More ground cracks in the E part of Leilani Estates formed that afternoon; hot white and blue fumes rose from the cracks. Lava spatter and gas bursts began erupting from 150-m-long fissures just after 1700 and ended around 1830. Lava flows spread less than 10 m, and strong sulfur dioxide odors were noted. The lava lake in the Overlook Crater dropped an additional 37 m.

By the morning of 4 May three fissures were active; fissure 2 opened at 0100 and fissure 3 opened around 0600. Spatter was ejected as high as 30 m and lava flows were traveling short distances. Large, loud bubble bursts occurred at fissure 3. Ash plumes from intermittent collapses at Pu'u 'O'o continued to rise above the crater, and the 61 G lava flow was no longer being fed. A M 6.9 earthquake occurred at 1233, centered on the S flank. Fissures 4 and 5 opened at 1039 and 1200, respectively, and by 1600 there were six, each several hundred meters long. The sixth fissure was on the E edge of the subdivision. The Hawaii Emergency Management Agency stated that multiple agencies were assisting with the mandatory evacuation of residents (about 1,700) in the Leilani Estates and Lanipuna Gardens subdivisions. A temporary flight restriction was declared for most of lower Puna. The report noted dangerously high concentrations of sulfur dioxide.

Based on satellite InSAR data, the summit caldera floor subsided about 10 cm during 23 April-5 May. Corresponding to this deflationary trend, the summit lava lake in Overlook crater had dropped to about 128 m below the crater rim since 30 April. Summit seismicity increased during 4-5 May coincident with the M 6.9 earthquake; about 152 events (M 2-3) were recorded. Rockfalls from the inner crater walls produced ash plumes that rose above the Halema'uma'u crater rim on 5 May. New ground cracks on Highway 130 opened on 5 May, and at dawn fissure 7 formed. By mid-afternoon fissure 7 stopped erupting, and the 8th fissure opened at 2044 near fissures 2 and 7. Lava fountains from fissure 8 rose as high as 70 m, and in other areas were as high as 100 m. A lava flow from fissure 7 traveled 260 m NE. The lava lake in Overlook Crater continued to drop.

The eruption from one or two fissures was continuous during 5-7 May, and ‘a’a lava flows from fissure 8 advanced 0.9 km NNE by 1000 on 6 May. HVO warned that poor air quality from sulfur dioxide gas emissions, and smoke plumes from burning asphalt and houses was a health concern. Strong gas emissions rose from the fissures during 6-7 May, though lava effusion was minimal overnight. New cracks crossed Highway 130 west of the eruption site, and some others widened. The level of the summit lava lake continued to drop, and by 7 May was 220 m below the crater rim. Two new fissures emerged on 7 May. The first (fissure 11) opened at about 0930 in a forested area SW of Leilani Estates, and was active for about three hours. The second (fissure 12) opened at about 1220 between fissures 10 and 11. By 1515 both new fissures were active, and the W end of fissure 10 was robustly steaming. According to a news article, lava had covered an area about 36,000 square meters.

Lava effusion at night during 7-8 May was minimal, and by around 0700 on 8 May the ERZ eruption had paused. The fissure system was about 4 km long and continued to strongly emit gas. Ash plumes generated by falling rocks in Overlook crater continued to produced ash plumes. On 8 May the Office of the Mayor stated that 35 structures had been destroyed, and lava covered. HVO maps show the locations and numbers of the fissures.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); Hawaii Emergency Management Agency; Hawaii County Civil Defense Agency


25 April-1 May 2018 Citation IconCite this Report

During 25 April-1 May HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. The lake level was high enough to produce lava flows onto the Halema'uma'u crater floor through 27 April, but afterwards fell to about 15-16 m below the new elevated rim. The lake level rose again, to just below the rim of the Overlook crater vent. Since 21 April about 2/3 of the crater floor had been covered by new lava flows.

Episode 61g lava flows were active above Pulama pali, within 2 km of the active vent. A marked increase in seismicity and ground deformation at Pu'u 'O'o Crater was detected just after 1400 on 30 April, following weeks of uplift and increasing lava levels within the cone. Within a few minutes a webcam on the crater rim recorded the first of two crater floor collapses; the second collapse began at 1520 and lasted about an hour. Thought poor weather conditions inhibited views at times, a webcam recorded what were likely small explosions from the W side of the crater as the floor collapsed. At 1800 seismicity remained elevated, though ground deformation had significantly slowed. A large amount of red ash was produced from the collapses, and deposited around the crater as well as in areas up-rift as far as Mauna Ulu.

Following the collapses of Pu'u 'O'o’s crater floor, seismicity and deformation increased along a large section of the East Rift Zone, in an area 9-16 km down-rift (with seismicity occurring as far E as highway 130), indicating an intrusion of magma. By 0830 on 1 May activity had significantly decreased. During an overflight that day a new, nearly continuous, 1-km-long crack was found on the W (up-rift) side of Pu'u 'O'o. The crack was steaming, and aligned in a segment with small pads of newly-erupted lava and spatter. Thermal images of Pu'u 'O'o Crater suggested that smaller drops of the crater floor likely continued on 1 May.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 April-24 April 2018 Citation IconCite this Report

During 18-24 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. The lake level was high, and by late on 21 April had overflowed the S crater rim. As of midday on 23 April the new flows has covered about 16 ha of the floor, or about 30%. Overflows of the crater rim continued through 24 April, flowing as far as 375 m onto the N, SW, and S parts of the crater floor. HVO noted that the overflows were the first significant ones since May 2015.

Surface lava flows were active above Pulama pali. On 18 April geologists observed the pit crater on the W side of Pu'u 'O'o Crater, noting that overflows had built up the crater rim to several meters above the crater floor and 7 m higher compared to late March.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 April-17 April 2018 Citation IconCite this Report

During 11-17 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. The lake level was high, with spattering visible from HVO and Jaggar Museum; by 16 April the lake level was 10 m below the rim of the Overlook crater. Surface lava flows were active above Pulama pali. On 11 April a moderate swarm of over 200 earthquakes occurred at depths of 7-9 km below the summit. The largest event was a M 2.4. Seismicity returned to background levels at 0230. Three minor ledge collapses were detected on 12 April, one at 1157 and two just after 1830. Surface lava flows were active above Pulama pali; on 13 April most scattered breakouts were within 2.2 km from Pu'u 'O'o Crater, and one was about 5 km away.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 April-10 April 2018 Citation IconCite this Report

During 4-10 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Surface lava flows were active above Pulama pali. Webcams recorded spattering from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. The lava flow from a vent on the SE part of the crater floor continued to expand through 6 April. A rockfall at 1028 on 6 April triggered an explosion in the lava lake, damaging the webcam power system on the crater rim.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 March-3 April 2018 Citation IconCite this Report

During 28 March-3 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Surface lava flows were active above Pulama pali. Webcams recorded spattering from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. The lava flow from a vent on the SE part of the crater floor continued to expand.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 March-27 March 2018 Citation IconCite this Report

During 21-27 March HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Surface lava flows were active above and on Pulama pali. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater, and increased spattering which began on 22 March. Lava flowed out of a vent on the SE part of the crater onto the crater floor on 25 March, and expanded over the next few days.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 March-20 March 2018 Citation IconCite this Report

During 14-20 March HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. Surface lava flows were active above and on Pulama pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 March-13 March 2018 Citation IconCite this Report

During 7-13 March HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. Surface lava flows were active above and on Pulama pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 February-6 March 2018 Citation IconCite this Report

During 28 February-6 March HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. Surface lava flows were active above and on the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 February-27 February 2018 Citation IconCite this Report

During 21-27 February HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. Surface lava flows were active above and on the pali, and on the coastal plain. A small portion of material from the inner veneer of the crater wall collapsed into the lava lake just after 0700 on 23 February.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 February-20 February 2018 Citation IconCite this Report

During 14-20 February HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 February-13 February 2018 Citation IconCite this Report

During 7-13 February HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 January-6 February 2018 Citation IconCite this Report

During 31 January-6 February HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 January-30 January 2018 Citation IconCite this Report

During 24-30 January HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater; spattering was briefly visible from the visitor overlook on 27 and 29 January. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 January-23 January 2018 Citation IconCite this Report

During 17-23 January HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Surface lava flows were active above and on the pali, and on the coastal plain. Early in the morning on 19 January rocks from the inside of Halema’uma’u crater fell into the lava lake producing a short-lived explosion of spatter and wallrock that blanketed an area around the former visitor overlook. Debris fell as far as the Halema?uma?u parking lot.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 January-16 January 2018 Citation IconCite this Report

During 10-16 January HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 January-9 January 2018 Citation IconCite this Report

During 3-9 January HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 December-2 January 2018 Citation IconCite this Report

During 27 December 2017-2 January 2018 HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 December-26 December 2017 Citation IconCite this Report

During 20-26 December HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 December-19 December 2017 Citation IconCite this Report

During 13-19 December HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 December-12 December 2017 Citation IconCite this Report

During 6-12 December HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 November-5 December 2017 Citation IconCite this Report

During 29 November-5 December HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 November-28 November 2017 Citation IconCite this Report

During 22-28 November HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 November-21 November 2017 Citation IconCite this Report

During 15-21 November HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. Surface lava flows were active above and on the pali, and on the coastal plain. On 17 November a field crew visited the Kamokuna ocean entry and observed only very sluggish, pasty flows in a few random spots and minor to no degassing in the usual places.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 November-14 November 2017 Citation IconCite this Report

During 8-14 November HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, ceased entering the ocean at Kamokuna on 8 November but then began reentering the ocean during 12-13 November. Surface lava flows were active above and on the pali, and on the coastal plain, and new breakouts were observed.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 November-7 November 2017 Citation IconCite this Report

During 1-7 November HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 October-31 October 2017 Citation IconCite this Report

During 25-31 October HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above the pali and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 October-24 October 2017 Citation IconCite this Report

During 18-24 October HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above the pali and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 October-17 October 2017 Citation IconCite this Report

During 11-17 October HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface cracks on the delta that had been covered up by new flows had begun to reemerge and become visible. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 October-10 October 2017 Citation IconCite this Report

During 4-10 October HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna although the plume at the entry was weaker. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 September-3 October 2017 Citation IconCite this Report

During 27 September-3 October HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna, although during 1-3 October the plume at the entry waxed and waned. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 September-26 September 2017 Citation IconCite this Report

During 20-26 September HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above and on the pali, and on the coastal plain. During 23-24 September a short-lived breakout above the ocean entry disrupted the ramp and produced a brief "firehose" of lava.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 September-19 September 2017 Citation IconCite this Report

During 13-19 September HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above and on the pali, and on the coastal plain. On 13 September geologists noted that several prominent cracks running parallel to the coastline had widened in the past two weeks, underscoring the potential for bench collapse into the sea.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 September-12 September 2017 Citation IconCite this Report

During 6-12 September HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater, though a deflationary trend the second half of the week caused the lake level to mostly drop. Several rockfalls and collapses of the inner crater wall veneer were noted during 7-10 September; frequent rockfalls were not uncommon during periods of lake level lowering. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above and on the pali, and on the coastal plain. HVO noted that cracks running parallel to the coastline underscored the potential for bench collapse into the sea.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 August-5 September 2017 Citation IconCite this Report

During 30 August-5 September HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above the pali and on the coastal plain. Slumping of seaward portions of the delta continued, and cracks running parallel to the coastline continued to widen. HVO warned of the potential for larger-scale delta collapses.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 August-29 August 2017 Citation IconCite this Report

During 23-29 August HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above the pali and on the coastal plain. Slumping of seaward portions of the delta continued, and cracks running parallel to the coastline continued to widen. HVO warned of the potential for larger-scale delta collapses.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 August-22 August 2017 Citation IconCite this Report

During 16-22 August HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. A breakout 120 m up-slope of the ocean entry began at 0410 on 19 August and lasted about 9.5 hours; it produced a lava fall over the sea cliff W of the ramp and a small ‘a’a flow on the W portion of the delta. At 2135 a large littoral explosion occurred near the front of the delta, producing spatter that was ejected higher than the sea cliff (about 28 m high). Another smaller explosion was observed five minutes later. HVO scientists documented ongoing littoral explosions on 21 August, as well as continued widening of the cracks running parallel to the coastline.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 August-15 August 2017 Citation IconCite this Report

During 9-15 August HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Slumping of seaward portions of the delta continued, and cracks running parallel to the coastline continued to widen. HVO warned of the potential for larger-scale delta collapses.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 August-8 August 2017 Citation IconCite this Report

During 2-8 August HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Slumping of seaward portions of the delta continued, and cracks running parallel to the coastline continued to widen. HVO noted that as recently as 28 July a small slice of the delta fell into the ocean, and warned that there was potential for larger-scale delta collapses.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 July-1 August 2017 Citation IconCite this Report

During 26 July-1 August HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Several large cracks running parallel to the coastline spanned the width of the delta. Surface lava flows were active above the pali and on the coastal plain about 2 km upslope from the gravel emergency route.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 July-25 July 2017 Citation IconCite this Report

During 19-25 July HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Several large cracks running parallel to the coastline spanned the width of the delta. Surface lava flows were active above the pali and on the coastal plain about 2 km upslope from the gravel emergency route.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 July-18 July 2017 Citation IconCite this Report

During 12-18 July HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond (which had many small spattering sites along the margin) in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Several large cracks running parallel to the coastline spanned the width of the delta; several small collapses at the leading edge of the delta were noted on 11 July. Surface lava flows were active above and on the pali, and on the coastal plain within 1 km of the base of the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 July-11 July 2017 Citation IconCite this Report

During 5-11 July HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond (which had many small spattering sites along the margin) in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Several large cracks running parallel to the coastline spanned the width of the delta. Surface lava flows were active above and on the pali, and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 June-4 July 2017 Citation IconCite this Report

During 28 June-4 July HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond (which had many small spattering sites along the margin) in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. A solidified lava ramp extended from the tube exit high on the sea cliff down to the growing delta, whose leading edge was about 100 m from the tube exit on the sea cliff.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 June-27 June 2017 Citation IconCite this Report

During 21-27 June HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond (which had many small spattering sites along the margin) in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Field observations on 31 May revealed that the lava delta had grown to an area of approximately 0.01 square kilometers. A solidified lava ramp extended from the tube exit high on the sea cliff down to the delta, whose leading edge was about 100 m from the tube exit on the sea cliff. Lava flows from the upper portion of the flow field continued to advance downslope, producing surface flows above the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 June-20 June 2017 Citation IconCite this Report

During 14-20 June HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond (which had many small spattering sites along the margin) in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Field observations on 31 May revealed that the lava delta had grown to an area of approximately 0.01 square kilometers. A solidified lava ramp extended from the tube exit high on the sea cliff down to the delta, whose leading edge was about 100 m from the tube exit on the sea cliff. Lava flows from the upper portion of the flow field continued to advance downslope, producing surface flows above and on the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 June-13 June 2017 Citation IconCite this Report

During 7-13 June HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond (which had many small spattering sites along the margin) in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Field observations on 31 May revealed that the lava delta had grown to an area of approximately 0.01 square kilometers. A solidified lava ramp extended from the tube exit high on the sea cliff down to the delta, whose leading edge was about 100 m from the tube exit on the sea cliff.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 May-6 June 2017 Citation IconCite this Report

During 31 May-6 June HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond (which had many small spattering sites along the margin) in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Field observations on 31 May revealed that the lava delta had grown to an area of approximately 0.01 square kilometers. A solidified lava ramp extended from the tube exit high on the sea cliff down to the delta, whose leading edge was about 100 m from the tube exit on the sea cliff.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 May-30 May 2017 Citation IconCite this Report

During 24-30 May HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. A portion of the N Overlook crater wall collapsed into the lake, causing lake agitation and depositing tephra at the Hawaiian Volcano Observatory and Jaggar Museum. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna adding to a growing delta. Narrow cracks on the delta parallel to the coast were noted. Surface lava flows were active above and on the upper slopes of the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 May-23 May 2017 Citation IconCite this Report

During 17-23 May HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater; the lake rose as high as 15 m below the crater rim and was visible from Hawaii Volcanoes National Park's Jaggar overlook. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna adding to a growing delta. Surface lava flows were active above and on the upper slopes of the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 May-16 May 2017 Citation IconCite this Report

HVO reported that the lava delta at Kamokuna (the ocean entry area at Kilauea), which had been growing since late March, collapsed on 3 May. Two large cracks parallel to the coast were visible on 27 April, suggesting instability. Between 0935 and 0940 on 3 May a large steam plume appeared in the middle of the lava delta in the area of large cracks. Weak fountaining or spattering likely occurred initially, because new tephra deposits were visible in the steaming area; that activity ended by 0940. Images acquired over the next 25 minutes showed a progressively weaker steam plume, and a subsiding delta. Photos of the ocean entry taken on 7 May showed multiple streams of lava flowing into the ocean.

During 10-16 May HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above and near the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 May-9 May 2017 Citation IconCite this Report

During 3-9 May HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna adding to the growing delta. Surface lava flows were active above the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 April-2 May 2017 Citation IconCite this Report

During 26 April-2 May HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. A growing lava delta is building where the lava enters the water; a small collapse of the delta on 27 April was indicated by the presence of a large dark plume. Surface lava flows were active above the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 April-25 April 2017 Citation IconCite this Report

During 19-25 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. A growing lava delta is building where the lava enters the water. Surface lava flows were active above the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 April-18 April 2017 Citation IconCite this Report

During 12-18 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. A growing lava delta is building where the lava enters the water. Surface lava flows were active above the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 April-11 April 2017 Citation IconCite this Report

During 5-11 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna from the end of the lava tube, about 20 m above the water. A growing lava delta was an estimated 25 m out from the base of the sea cliff by 10 April. Surface lava flows were active above the pali and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 March-4 April 2017 Citation IconCite this Report

During 29 March-4 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna from the end of the lava tube, about 20 m above the water. National Park Service officials estimated that the lava delta was about 40 m wide and 100 m long. Surface lava flows were active above the pali, and small, short-lived breakouts occurred on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 March-28 March 2017 Citation IconCite this Report

During 22-28 March HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. A small collapse of the S part of the crater wall at 0035 on 23 March was followed by a short time of increased spatter.

Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna from the end of the lava tube, about 20 m above the water; the ocean entry was not consistently visible during the week. Surface lava flows were active above the pali, with most of the activity located 1.9-2.9 km from the 61G vent. During 24-25 March HVO noted that a delta had begun to form at the ocean entry, for the first time since the previous one had collapsed on 31 December 2016.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 March-21 March 2017 Citation IconCite this Report

During 15-21 March HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna; the lava stream was 1-2 m wide on 16 March, and plunged into the ocean from the end of the lava tube, about 20 m above the water. Surface lava flows were active above the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 March-14 March 2017 Citation IconCite this Report

During 8-14 March HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active on the coastal plain, and on and above the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 March-7 March 2017 Citation IconCite this Report

During 1-7 March HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active on the coastal plain, along the E side of 61G, about 500 m upslope of the FEMA emergency road. Other surface flows above the pali appeared during 1-2 March.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 February-28 February 2017 Citation IconCite this Report

During 22-28 February HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. A pit on the W side of the crater contains a small lava pond. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active on the coastal plain, along the E side of 61G, less than 1 km upslope of the FEMA emergency road. Other surface flows streamed down the pali farther inland.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 February-21 February 2017 Citation IconCite this Report

During 15-21 February HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. All surface flows were active within 2.4 km of Pu'u 'O'o. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 February-14 February 2017 Citation IconCite this Report

During 8-14 February HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. All surface flows were active within 2.4 km of Pu'u 'O'o. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. A portion of the sea cliff just W of the ocean entry collapsed on 11 February.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 February-7 February 2017 Citation IconCite this Report

During 1-7 February HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. All surface flows were active within 2.4 km of Pu'u 'O'o.

HVO geologists noted an extensive crack running parallel to the sea cliff about 5-10 m behind the stream of lava entering the ocean at Kamokuna. The crack was 30 cm wide on 28 January and 70 cm wide four days later, on 1 February. In addition, the seaward block bounded by this crack was visibly moving up to 1 cm, and ground shaking could be felt up to several hundred meters away. On 2 February the crack was wider and steaming, and the stream of lava that had been pouring into the ocean from an opening in a lava tube about 20 m above the water was no longer visible (though lava continued to enter the ocean). At about 1255 almost the entire section of the sea cliff that was seaward of the hot crack collapsed. The collapsed block generated a wave that propagated outward from the coast. After the collapse, no lava was visible entering the ocean though a steam plume and spatter from explosions indicated that the entry remained active.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 January-31 January 2017 Citation IconCite this Report

During 25-31 January HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. All surface flows were active within 2.4 km of Pu'u 'O'o.

HVO noted that thermal images showed a high-temperature area about 5-10 m from the edge of the sea cliff, with hot cracks running parallel to the cliff around the entry point, suggesting sea cliff instability. HVO scientists did not observe significant delta development from ground vantage points on 29 January. A stream of lava continued to pour into the ocean from an opening in a lava tube about 20 m above the water.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 January-24 January 2017 Citation IconCite this Report

During 18-24 January HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. All surface flows were active within 2.4 km of Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 January-17 January 2017 Citation IconCite this Report

During 11-17 January HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. Active surface flows near Pu'u 'O'o advanced ESE; one branch was 2.4 km from the vent on 12 January.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 January-10 January 2017 Citation IconCite this Report

During 4-10 January HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lake level rose as high as 9 m below the Halema’uma’u floor. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna. An active branch of 61G remained active E of Pu'u 'O'o and advanced slowly E at a rate of only a few tens of meters per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 December-3 January 2017 Citation IconCite this Report

During 28 December 2017-3 January 2017 HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent, and was visible from the Jaggar Museum overlook on most days. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta. An active branch of 61G remained active E of Pu'u 'O'o and advanced slowly E at a rate of only a few tens of meters per day. On 31 December almost all of the Kamokuna lava delta had collapsed, along with a large section (180 m long and 70 m wide) of the older sea cliff E of the lava delta.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 December-27 December 2016 Citation IconCite this Report

During 21-27 December HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent, and was visible from the Jaggar Museum overlook. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta. An active branch of 61G remained active E of Pu'u 'O'o and advanced slowly E at a rate of only a few tens of meters per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 December-20 December 2016 Citation IconCite this Report

During 14-20 December HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lake level rose as high as 13 m below the Halema’uma’u floor. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta. An active branch of 61G remained active E of Pu'u 'O'o and advanced slowly E at a rate of only a few tens of meters per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 December-13 December 2016 Citation IconCite this Report

During 7-13 December HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lake level rose as high as 9 m below the Halema’uma’u floor. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta. An active branch of 61G remained active E of Pu'u 'O'o and advanced slowly E at a rate of only a few tens of meters per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 November-6 December 2016 Citation IconCite this Report

During 30 November-6 December HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lake level rose as high as 7.5 m below the Halema’uma’u floor. A section of the wall of the Overlook Vent collapsed into the lava lake at 0658 on 2 December ejecting spatter onto the Halema’uma’u Crater rim. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta. Breakouts at the upper part of the lava-tube system sent lava E. Other breakouts occurred at the base of the Pulama pali and on the coastal plain about 1 km inland from ocean.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 November-29 November 2016 Citation IconCite this Report

During 21-29 November HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lake level rose as high as 6.5 m below the Halema’uma’u floor. A section of the wall of the Overlook Vent collapsed into the lava lake on 28 November. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta. Breakouts at the upper part of the lava-tube system began on 21 November, sending lava as far as 500 m S and E. These breakouts, and others inland from the ocean entry, continued to be active through 29 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 November-22 November 2016 Citation IconCite this Report

During 16-22 November HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lake level rose as high as 7.5 m below the Halema’uma’u floor. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 November-15 November 2016 Citation IconCite this Report

During 9-15 November HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lake level rose almost to the rim (Halema’uma’u floor) during 9-10 November. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 November-8 November 2016 Citation IconCite this Report

During 2-8 November HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lava lake fluctuated between 11 and 19 m below the Halema’uma’u floor. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta. Aerial observations on 3 November revealed that the E delta was relatively large with prominent cracks on the surface, suggesting instability.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 October-1 November 2016 Citation IconCite this Report

During 26 October-1 November HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lava lake fluctuated between 13 and 17.5 m below the Halema’uma’u floor. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta. Aerial observations on 27 October revealed prominent surface cracks on the E delta suggesting growing instability; small collapses of the delta occurred earlier in the week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 October-25 October 2016 Citation IconCite this Report

During 19-25 October HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lava lake rose as high as 6 m below the Halema’uma’u floor. A small explosion from the lake on 19 October was triggered by a rockslide, and a slightly larger explosion on 20 October was caused by a collapse of a slice of the crater rim.

Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 October-18 October 2016 Citation IconCite this Report

During 12-18 October HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; on 15 October the lake rose high enough to produce small lobes of lava that flowed E and W on the Halema’uma’u floor. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 October-11 October 2016 Citation IconCite this Report

During 5-11 October HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna; only the E side of the entry was active. Scattered breakouts were active 2 km inland from the coast. National Park Service staff reported that a collapse of the E part of the lava delta occurred sometime between 2-6 October.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 September-4 October 2016 Citation IconCite this Report

During 28 September-4 October HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. The lake level rose as high as 10 m below the Halema'uma'u floor (on 1 October), and was sometimes visible from the Jaggar Museum (NW rim of Kilauea Caldera). Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at multiple locations near Kamokuna. Scattered breakouts were active 2 km inland from the coast.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 September-27 September 2016 Citation IconCite this Report

During 21-27 September HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. The lake level rose as high as 10 m below the Halema?uma?u floor, and was sometimes visible from the Jaggar Museum (NW rim of Kilauea Caldera); lava fountains along the edge of the lake were visible from the museum on 26 September. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at multiple areas near Kamokuna. Scattered breakouts were active 2 km inland from the coast.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 September-20 September 2016 Citation IconCite this Report

During 14-20 September HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. The lake level fluctuated between 11 and 28 m below the Halema?uma?u floor, and was sometimes visible from the Jaggar Museum (NW rim of Kilauea Caldera). A drop in the lake level during 16-17 September caused several collapses of solidified lava that had adhered to the crater walls. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at multiple locations near Kamokuna. Scattered breakouts were active 2 km inland from the coast.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 September-13 September 2016 Citation IconCite this Report

During 7-13 September HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. The lake level fluctuated between 5 and 20 m below the Halema’uma’u floor, and was easily visible from the Jaggar Museum (NW rim of Kilauea Caldera). The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at multiple areas near Kamokuna. A large section of the W part of the delta had collapsed on 5 September, causing a small explosion. Scattered breakouts were active 1.7-2 km inland from the coast.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 August-6 September 2016 Citation IconCite this Report

During 31 August-6 September HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Incandescence was evident in webcam images from several long-established vents on Pu'u 'O'o Crater's floor. A collapse at the W vent increased the size of the vent and a 40-m-diameter lava pond that was 23 m below the vent's rim. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at multiple areas near Kamokuna and spanning about 1 km of coastline and increasing the size of the lava delta at the base of the sea cliff. Scattered breakouts were active on the coastal plain and the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 August-30 August 2016 Citation IconCite this Report

During 24-30 August HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Several incandescent vents on Pu’u ‘O’o Crater’s floor were evident in webcam images. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at multiple areas near Kamokuna and spanning about 1 km of coastline and increasing the size of the lava delta at the base of the sea cliff. Scattered breakouts were active on the coastal plain and the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 August-23 August 2016 Citation IconCite this Report

During 17-23 August HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Several incandescent vents on Pu'u 'O'o Crater's floor were evident in webcam images. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at multiple areas near Kamokuna and spanning about 1 km of coastline. Scattered breakouts were active on the coastal plain and the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 August-16 August 2016 Citation IconCite this Report

During 10-16 August HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Several incandescent vents on Pu’u ‘O’o Crater’s floor were evident in webcam images. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at multiple areas near Kamokuna. Scattered breakouts were active on the coastal plain and the pali. A small delta collapse during the afternoon of 9 August temporarily darkened the ocean-entry plume.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 August-9 August 2016 Citation IconCite this Report

During 3-9 August HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Late on 6 August an explosions triggered by a rockfall into the lake ejected voluminous amounts of hot spatter and rock debris onto the SE rim of Halema’uma’u Crater, covering a broad swath 80 m long and 50 m wide around the formerly-closed public overlook area.

Several incandescent vents on Pu’u ‘O’o Crater’s floor were evident in webcam images. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna in an area that spans 150-240 m wide. A small delta had formed at the entry. An active lobe of lava advanced along the W side of the flow field, crossed the Emergency Access road 500 m W of the main flow, and entered the ocean overnight during 8-9 August.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 July-2 August 2016 Citation IconCite this Report

HVO reported that during 27 July-2 August the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Several incandescent vents on Pu’u ‘O’o Crater’s floor were evident in webcam images. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at the Kamokuna area; the flow at the ocean entry continued to widen and by 30 July was 240 m across. Nighttime webcam views of the flow field showed incandescent areas mostly on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 July-26 July 2016 Citation IconCite this Report

HVO reported that during 20-26 July the lava lake continued to rise and fall, circulate, and spatter in Kilauea's Overlook vent. Several incandescent vents on Pu'u 'O'o Crater's floor were evident in webcam images. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to advance across the coastal plain. The most distal part of the flow had stalled on 18 July but was again active by 22 July. Based on National Park personnel observations, the flow front was about 370 m from the ocean by 24 July. At 0112 on 26 July lava reached the ocean. Nighttime webcam views of the flow field showed incandescent areas from skylights, and advancing lava on the pali and coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 July-19 July 2016 Citation IconCite this Report

HVO reported that during 13-19 July the lava lake continued to rise and fall, circulate, and spatter in Kilauea's Overlook vent. Several incandescent vents on Pu'u 'O'o Crater's floor were evident in webcam images. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to advance across the coastal plain. By midday on 15 July the lava flow was about 870 m from the ocean, advancing only 60 m since 12 July. A satellite image acquired on 17 July showed that the flow front was 820 m from the ocean. By the evening of 18 July the flow tip had stalled but breakouts were active a few hundred meters upslope.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 July-12 July 2016 Citation IconCite this Report

HVO reported that during 6-12 July the lava lake continued to rise and fall, circulate, and spatter in Kilauea's Overlook vent. Several incandescent vents on Pu'u 'O'o Crater's floor were evident in webcam images. Episode 61g, a lava flow originating from a vent on Pu'u 'O'o Crater's E flank, continued to advance across the coastal plain, burning vegetation in the adjacent kipuka at the base of the pali. By 10 July the lava flow was about 1 km from the ocean.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 June-5 July 2016 Citation IconCite this Report

HVO reported that during 29 June-5 July the lava lake continued to rise and fall, circulate, and spatter in Kilauea's Overlook vent. Several incandescent vents on Pu'u 'O'o Crater's floor were evident in webcam images. A lava flow originating from a vent on Pu'u 'O'o Crater's E flank continued to advance and spread SE. Webcams recorded bright incandescence from several skylights along the upper part of the tube system supplying lava to the front part of the flow, and also from the flow field. By 29 June the toe of the lava flow had reached the base of the pali (burning vegetation in the adjacent kipuka), and by 3 July it had advanced 690 m onto the coastal plain, 2.6 km from the ocean.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 June-28 June 2016 Citation IconCite this Report

HVO reported that during 22-28 June the lava lake continued to rise and fall, circulate, and spatter in Kilauea's Overlook vent. Several incandescent vents on Pu'u 'O'o Crater's floor were evident in webcam images. A lava flow originating from a vent on Pu'u 'O'o Crater's E flank continued to advance and spread SE. Webcams recorded bright incandescence from several skylights along the upper part of the tube system supplying lava to the front part of the flow. The advancement rate of the flow front was 100 m/day the previous week and by 24 June the lava flow had entered the N part of the abandoned Royal Gardens subdivision. The advancement rate had increased to 300 m/day during 25-28 June; satellite images acquired on 27 June revealed that the lava flow was 6.3 km long and was progressing down the pali along the W boundary of the subdivision.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 June-21 June 2016 Citation IconCite this Report

HVO reported that during 15-21 June the lava lake continued to rise and fall, circulate, and spatter in Kilauea's Overlook vent. A lava flow originating from a vent on Pu'u 'O'o Crater's E flank continued to advance and spread SE. Webcams recorded bright incandescence from several skylights along the upper part of the tube system supplying lava to the front part of the flow. An active lava pond in Pu'u 'O'o's W pit was confirmed by observers on 16 June.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 June-14 June 2016 Citation IconCite this Report

HVO reported that during 8-14 June the lava lake continued to rise and fall, circulate, and spatter in Kilauea's Overlook vent. A new lava flow that began on 24 May on Pu'u 'O'o Crater's N flank had stalled; a new flow on the E flank had advanced 3.3 km SE along the National Park boundary by 10 June, and was about halfway to the top of Pulama pali. Vents on the crater floor and upper NE flank remained incandescent, and a pit just W of the crater contained a small lava pond. The June 27th NE-trending lava flow appeared to be inactive by 10 June.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 June-7 June 2016 Citation IconCite this Report

HVO reported that during 1-7 June the lava lake continued to rise and fall, circulate, and spatter in Kilauea's Overlook vent. Two new flows from Pu'u 'O'o Crater's N and E flanks, which began on 24 May, continued to be active within 1.3 km of their respective vents. The June 27th NE-trending lava flow continued to be active within 5.4 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 May-31 May 2016 Citation IconCite this Report

HVO reported that around 0650 on 24 May new lava flows broke out from the flanks of Kilauea's Pu'u 'O'o cone. The first flow originated about 250 m from the rim of the cone's NE flank and traveled NW, and the second flow came from an area on the E flank, about 500 m from the cone's rim, and traveled SE. By 0830 the first flow was about 1 km long and the second one was about 700 m long. By the same time on 25 May the first flow had become channelized and a new 950-m-long lobe had descended NW. The other flow was active but had not significantly advanced.

The lava lake continued to circulate and eject spatter in the Overlook vent during 25-31 May; a rockfall into the lake on 26 May and briefly triggered sloshing and agitation of the lake. The June 27th NE-trending lava flow continued to be active within 5 km NE of Pu'u 'O'o Crater. Webcams recorded glow from multiple spatter cones on the Pu'u 'O'o Crater floor. The new lava flows extended about 1.2 km NW and SE by 27 May and continued to be active through 29 May.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 May-24 May 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 18-24 May. The lava lake continued to circulate and eject spatter in the Overlook vent; some rockfall/wall collapse events occurred during 19-20 May. Webcams recorded glow from multiple spatter cones on the Pu'u 'O'o Crater floor and from skylights in the lava tube on the NE flank of the cone. The June 27th NE-trending lava flow continued to be active within 5.8 km NE of Pu'u 'O'o Crater. On 19 May HVO noted that webcams detected about 1 m of uplift of the Pu'u 'O'o Crater floor during the previous few days. During 19-20 May four small rockfalls from the crater wall resulted in disturbance to the lake surface or increased spattering.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 May-17 May 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 11-17 May. The lava lake continued to circulate and eject spatter in the Overlook vent. Webcams recorded glow from multiple spatter cones on the Pu'u 'O'o Crater floor and from skylights in the lava tube on the NE flank of the cone. Vents in the SW and E parts of the crater periodically produced small lava flows within the crater. The June 27th NE-trending lava flow continued to be active within 5.8 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 May-10 May 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 4-10 May. The lava lake continued to circulate and eject spatter in the Overlook vent. Webcams recorded outgassing from multiple spatter cones on the Pu'u 'O'o Crater floor. A small lava flow from a NE vent intermittently flowed onto the crater floor during 4-5 and 7 May. The June 27th NE-trending lava flow continued to be active within 5.8 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 April-3 May 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 27 April-3 May. The lava lake continued to circulate and eject spatter in the Overlook vent. Webcams recorded outgassing from multiple spatter cones on the Pu'u 'O'o Crater floor. A small lava flow from the E vent flowed onto the crater floor during 28 April-1 May. The June 27th NE-trending lava flow continued to be active within 5.7 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 April-26 April 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 20-26 April. The lava lake continued to circulate and eject spatter in the Overlook vent. Webcams recorded outgassing from multiple spatter cones on the Pu'u 'O'o Crater floor. The June 27th NE-trending lava flow continued to be active within 5.7 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 April-19 April 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 13-19 April. The lava lake continued to circulate and eject spatter in the Overlook vent. Webcams recorded outgassing from multiple spatter cones on the Pu'u 'O'o Crater floor. The June 27th lava flow, trending NE, continued to be active within 7.6 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 April-12 April 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 6-12 April. The lava lake continued to circulate and spatter in the Overlook vent. The lava lake dropped during a deflationary event that began on 4 April and, by 7 April, was 52 m below the crater floor, the deepest it has been since 30 December 2015. On 7 April at 0147 a large part of the inner crater wall fell into the lake. The deflationary event lasted for about four days. Webcams recorded outgassing from multiple spatter cones on the Pu'u 'O'o Crater floor. The June 27th NE-trending lava flow continued to be active within 7.6 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 March-5 April 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 30 March-5 April. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded outgassing from multiple spatter cones on the Pu'u 'O'o Crater floor. A very small lava flow briefly erupted onto the crater floor during 31 March-1 April, and on 3 and 4 April. The June 27th NE-trending lava flow continued to be active within 7.6 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 March-29 March 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 23-29 March. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded outgassing from multiple spatter cones on the Pu'u 'O'o Crater floor. A small lava flow broke out from a spatter cone on the NE side of the crater floor on 24 March and again the next evening. The June 27th NE-trending lava flow continued to be active within 7.6 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 March-22 March 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 16-22 March. The lava lake continued to circulate and spatter in the Overlook vent. The June 27th NE-trending lava flow continued to be active within 7 km NE of Pu'u 'O'o Crater. At about 0320 on 22 March a small lava flow was visible on the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 March-15 March 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 9-15 March. The lava lake continued to circulate and spatter in the Overlook vent. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 March-8 March 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 2-8 March. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the northeast rim. At 0200 on 2 March a small cone on the E side of the crater briefly produced spatter, and then at 0815 a vigorous lava flow erupted from a W vent. During 3-4 and 6-7 March minor amounts of lava intermittently flowed from S vents. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater, burning some areas of forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 February-1 March 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 24 February-1 March. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the northeast rim. During 24-25 and 29 February lava from at most two vents flowed onto the crater floor. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater, burning some areas of forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 February-23 February 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 17-23 February. The lava lake continued to circulate and spatter in the Overlook vent. A moderate-size collapse of part of the crater wall into the summit lava lake on 21 February ejected some ash onto the caldera rim. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the northeast rim. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater, burning some areas of forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 February-16 February 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 10-16 February. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the northeast rim. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater, burning some areas of forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 February-9 February 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 3-9 February. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the NE rim. On 8 February a small lava flow erupted from the E vent. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater, burning some areas of forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 January-2 February 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 27 January-2 February. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the northeast rim. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater, burning some areas of forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 January-26 January 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 20-26 January. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the northeast rim. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater, burning some areas of forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 January-19 January 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 13-19 January. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the northeast rim. Several small and brief lava flows erupted onto the crater floor on 14 January. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater, burning some areas of forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 January-12 January 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 6-12 January. The lava lake continued to circulate and spatter in the Overlook vent. At 0351 on 8 January a rockfall triggered a small explosion that ejected lava fragments onto the crater rim. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the northeast rim. A short lava flow erupted onto the crater floor on 6 January. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater, burning some areas of forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 December-5 January 2016 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 30 December-5 January. The lava lake continued to circulate and spatter in the Overlook vent. On 2 January part of the E rim of the Overlook vent collapsed into the lava lake, triggering an explosion that ejected tephra onto the rim of the vent. At 0318 on 4 January another explosion occurred from the collapse of part of the N wall.

Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the northeast rim. During 30 December-1 January a few small lava flows erupted from the vents, and on 4 January a small lava flow erupted from a vent on the NE side of the crater floor. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater, burning some areas of forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 December-29 December 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 23-29 December. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the northeast rim. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 December-22 December 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 16-22 December. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater. Scientists conducting fieldwork on 17 December observed an active lava pond on the E rim of Pu'u 'O'o. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 December-15 December 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 9-15 December. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o. A new incandescent and fuming vent, reported on 10 December, appeared to be from a small collapse into an older, but still hot lava tube. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater, burning some areas of forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 December-8 December 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 2-8 December. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 November-1 December 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 25 November-1 December. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o; lava flowed from two of the vents on 25 November. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 November-24 November 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 18-24 November. The lava lake continued to circulate and spatter in the Overlook vent. A very long-period earthquake detected at 0230 on 24 November corresponded with the collapse of a very large section of the N rim and wall of the summit vent which caused increased lake spattering and turbulence. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o; a lava flow erupted from a vent on the crater floor on 24 November. The June 27th NE-trending lava flow continued to be active within 1.9-6.1 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 November-17 November 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 11-17 November. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o. The June 27th NE-trending lava flow continued to be active within 1.9-6.1 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 November-10 November 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 4-10 November. The lava lake continued to circulate and spatter in the Overlook vent. The June 27th NE-trending lava flow continued to be active within 2.2-6.4 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 October-3 November 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 28 October-3 November. The lava lake continued to circulate and spatter in the Overlook vent. The June 27th NE-trending lava flow continued to be active within 2.2-6.3 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 October-27 October 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 21-27 October. The lava lake continued to circulate and spatter in the Overlook vent; small sections of the inner wall veneer fell into the lake on 22 October causing increased spattering and sloshing. The June 27th NE-trending lava flow continued to be active within 2.2-6.3 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 October-20 October 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 14-20 October. The lava lake continued to circulate and spatter in the Overlook vent; small rockfalls into the lake during 14-15 October caused brief spattering and lake-surface agitation. The June 27th NE-trending lava flow continued to be active within 2.2-6.3 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 October-13 October 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 7-13 October. The lava lake continued to circulate and spatter in the Overlook vent. The June 27th NE-trending lava flow continued to be active within 3-7 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 September-6 October 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 30 September-6 October. The lava lake continued to circulate and spatter in the Overlook vent. The June 27th NE-trending lava flow continued to be active within 3-7 km NE of Pu'u 'O'o Crater. A small lava pond, not visible with the webcams, remained active in a pit on the W side of the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 September-29 September 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 23-29 September. The lava lake continued to circulate and spatter in the Overlook vent. The June 27th NE-trending lava flow continued to be active within 4-8 km NE of Pu'u 'O'o Crater. A small lava pond, not visible with the webcams, remained active in a pit on the W side of the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 September-22 September 2015 Citation IconCite this Report

HVO reported that seismicity and deformation at Kilauea was at normal levels during 16-22 September. The lava lake rose and fell, circulated, and occasionally spattered in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o. The June 27th NE-trending lava flow continued to be active within 4-8 km NE of Pu'u 'O'o Crater; smoke plumes from burning vegetation marked the most distal flows.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 September-15 September 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 9-15 September. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o. The June 27th NE-trending lava flow continued to be active within 4-8 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 September-8 September 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 2-8 September. The lava lake continued to circulate and spatter in the Overlook vent. The June 27th NE-trending lava flow continued to be active within 4-8 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 August-1 September 2015 Citation IconCite this Report

HVO reported that seismicity at Kilauea remained at background levels during 26 August-1 September. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o. On 27 August lava erupted from a vent on the NE side of the crater floor and slowly spread out; the flow was active until about midnight. A large breakout also occurred on the NE flank from a lava tube supplying distant flows; lava traveled 580 m before stopping. On 29 August a very small and short-lived flow emerged from a vent on the SE portion of the crater floor. The June 27th NE-trending lava flow continued to be active in three areas with surface flows within 4-8 km NE of Pu'u 'O'o Crater; smoke plumes from burning vegetation marked the most distal flows.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 August-25 August 2015 Citation IconCite this Report

HVO reported that seismicity at Kilauea remained at background levels during 19-25 August. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o. The June 27th NE-trending lava flow continued to be active in three areas with surface flows within 4-8 km NE of Pu'u 'O'o Crater; smoke plumes from burning vegetation marked the most distal flows.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 August-18 August 2015 Citation IconCite this Report

HVO reported that seismicity at Kilauea remained at background levels during 12-18 August. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o. The June 27th NE-trending lava flow continued to be active in three areas with surface flows within 4-8 km NE of Pu'u 'O'o Crater; smoke plumes from burning vegetation marked the most distal flows.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 August-11 August 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 5-11 August. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o, including a small lava pond (40-50 m across and 21 m deep) in a collapsed pit. The June 27th NE-trending lava flow continued to be active with surface flows within 4-8 km NE of Pu'u 'O'o Crater; smoke plumes from burning vegetation marked the most distal flows.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 July-4 August 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 29 July-4 August. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o; for 45 minutes on 31 July a lava flow effused from a vent on the E part of the crater floor. The June 27th NE-trending lava flow continued to be active with surface flows within 4-8 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 July-28 July 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 15-22 July. The lava lake continued to circulate and spatter in the Overlook vent; occasional collapses of material briefly agitated the lake surface. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o. The June 27th NE-trending lava flow continued to be active within 4-8 km NE of Pu'u 'O'o Crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 July-21 July 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 15-22 July. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o. The June 27th NE-trending lava flow continued to be active with surface flows within 8 km NE of Pu'u 'O'o Crater; smoke plumes rose from burning forest at the most distant part of the flow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 July-14 July 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 8-14 July. The lava lake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o. The June 27th NE-trending lava flow continued to be active with surface flows within 8 km NE of Pu'u 'O'o Crater. Satellite images showed expansion of the flow field since 6 July, with gradual northward advancement of the most western and north-pointing branch of the flow field.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 July-7 July 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 1-7 July. The lava lake continued to be active in the deep pit within the Overlook vent, vigorously spattering. On 1 July part of the rim and wall of Overlook crater collapsed into the lava lake, starting at about 1430, producing an ashy plume, rapid oscillation of the lava lake, and intense spattering in the lake at the impact site. The June 27th NE-trending lava flow continued to be active with surface flows within 8 km NE of Pu'u 'O'o Crater. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 June-30 June 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit and upper East Rift Zone was at background levels during 24-30 June. The lava lake continued to be active in the deep pit within the Overlook vent, exhibiting vigorous spattering. The June 27th NE-trending lava flow continued to be active with surface flows within 8 km NE of Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 June-23 June 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 17-23 June. The lava lake continued to be active in the deep pit within the Overlook vent, exhibiting vigorous spattering. The June 27th NE-trending lava flow continued to be active with surface flows within 8 km NE of Pu'u 'O'o. A small-scale lava flow spilled onto the Pu'u 'O'o crater floor from a vent on the N side of the floor at 0130 on 19 June.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 June-16 June 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 10-16 June. The lava lake continued to be active in the deep pit within the Overlook vent, vigorously spattering. The June 27th NE-trending lava flow continued to be active with surface flows within 8 km NE of Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 June-9 June 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 3-9 June. The lava lake continued to be active in the deep pit within Halema'uma'u Crater (now called the Overlook vent); the lake level was about 62 m below the crater floor on 9 June. The June 27th NE-trending lava flow continued to be active with surface flows within 8 km NE of Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 May-2 June 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 27 May-2 June. The lava lake continued to be active in the deep pit within Halema'uma'u Crater; the lake level was about 44 m below the crater floor on 29 May and 73 m below the floor on 31 May. The June 27th NE-trending lava flow continued to be active with surface flows within 7.9 km NE of Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 May-26 May 2015 Citation IconCite this Report

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 20-26 May. The summit tiltmeter network recorded fluctuating inflationary and deflationary tilt from the typical Halema'uma'u source. Nighttime incandescence suggested an active lava pond in an isolated vent W of Pu'u 'O'o Crater. The June 27th NE-trending lava flow continued to be active with surface flows within 8.6 km NE of Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 May-19 May 2015 Citation IconCite this Report

HVO reported that the circulating lava lake in the pit within Kilauea's Halema'uma'u Crater started to drop on 9 May and as of 15 May was about 50 m lower than the raised vent rim. The lake-level drop was accompanied by a change from inflation of the summit area to deflation centered near Halema'uma'u Crater. In addition, on 13 May, the focus of deformation changed to the S part of Kilauea's summit caldera and upper Southwest Rift Zone (SWRZ), where rapid and localized inflationary tilt was recorded. Seismicity shifted from Kilauea's summit and the upper East Rift Zone (ERZ) to the S part of the summit; seismicity at the upper SWRZ continued. The number of earthquakes increased on 15 May. The data suggest that magma had moved into a shallow area beneath the S part of the caldera and upper SWRZ. During 16-18 May rates of tilting slowed, and seismicity at the summit and SWRZ remained above background levels but had decreased. By 19 May seismicity rates at the summit were normal and tilit had decreased slightly. The lava lake remained about 45-50 m below the crater floor.

Nighttime incandescence suggested an active lava pond in an isolated vent W of Pu'u 'O'o Crater. The June 27th NE-trending lava flow continued to have active surface flows within 8 km NE of Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 May-12 May 2015 Citation IconCite this Report

During 6-12 May HVO reported that the circulating lava lake occasionally rose and fell in the pit within Kilauea's Halema'uma'u Crater. Lava overflowed the rim multiple times almost daily, and since the first overflow on 28 April, had built up a rim that by 8 May was 10 m higher than the Halema'uma'u crater floor. Contemporaneously with deflation detected during 10-12 May, the lake receded, and by 12 May was barely visible from the Jaggar Museum.

At Pu'u 'O'o Crater, lava erupted from several vents multiple times onto the crater floor. An overflight on 8 May revealed an active lava pond in an isolated vent W of the main crater. The June 27th NE-trending lava flow continued to be active with three areas of breakouts within and along the flow-field margins, within 8 km NE of Pu'u 'O'o. Most of the surface flows were fed from the 21 February breakout and located less than 3 km from the NE rim of Pu'u 'O'o. Forest burned about 8 km NE of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 April-5 May 2015 Citation IconCite this Report

In a special statement on 29 April, HVO reported that beginning at 2140 the night before the lava lake in Kilauea’s Halema'uma'u Crater overflowed it's rim multiple times, sending lobate sheets of pahoehoe as far as 130 m across the crater floor. The report also noted that a few explosions in the lake triggered by falling wall rock had occurred; one at 1020 on 28 April ejected boulders of molten spatter (2 m in diameter) onto the rim of Halema'uma'u Crater, in the vicinity of the closed visitor overlook fence. Spatter also blanketed an area 100 m along the rim and 50 m back. This area had been closed to the public since 2007.

The accumulating lava had built up a rim around the lake that was a few meters above the crater floor. On 30 April the lava-lake surface was about 4 m below the new rim. During 1-2 May the lake level was near or at the rim, and overflowed onto the floor several times. During 2-3 May the lake surface was 3-5 m above the original, pre-flow crater floor. A collapse of a portion of the crater wall at 1320 on 3 May impacted the lake and triggered a small explosion, ejecting fist-sized clasts onto the crater rim. Lava overflowed the rim several times during 4-5 May.

During 29 April-5 May Kilauea’s 27 June NE-trending lava flow continued to be active with three areas of breakouts within and along the flow-field margins, within 8 km of Pu'u 'O'o. The three main areas of breakouts were the 21 February breakout on the flank of Pu'u 'O'o, the 9 March breakout near the forested cone of Kahauale'a, and a relatively small forked breakout 5-6 km farther NE of Pu'u 'O'o. Forest burned about 8 km NE of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 April-28 April 2015 Citation IconCite this Report

During 22-28 April HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with three areas of breakouts within and along the flow-field margins, within 8 km of Pu'u 'O'o. The three main areas of breakouts were the 21 February breakout on the flank of Pu'u 'O'o, the 9 March breakout near the forested cone of Kahauale'a, and a relatively small forked breakout 5-6 km farther NE of Pu'u 'O'o. Forest burned about 8 km NE of the crater. The thermal webcam recorded multiple incandescent outgassing vents in the crater. Lava that sporadically erupted from vents on the SE and S parts of Pu'u 'O'o's crater floor covered the floor.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. Abrupt inflation began at 1640 on 21 April; concurrently the lava lake rose and was 20 m below the crater floor on 23 April, the highest level since the eruption began in 2008. A small collapse from the overhanging W wall at about 0520 triggering a small explosive event that ejected spatter out onto the Halema'uma'u crater floor. The lake continued to rise and was 12 m below the floor on 25 April. Two collapses of the W crater wall each triggered explosions that ejected clumps of spatter (some 30 cm in diameter) up onto the rim of Halema'uma'u and dusted the Jaggar Museum area with ash. During 25-26 April the lava lake rose to within about 4 m of the crater floor. During 27-28 April the lava lake fluctuated but was mostly 3-4 m below the rim, and briefly reached the rim on 28 April at a time without spattering.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 April-21 April 2015 Citation IconCite this Report

During 15-21 April HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with three areas of breakouts within and along the flow-field margins. The three main areas of breakouts were the 21 February breakout on the flank of Pu'u 'O'o, the 9 March breakout near the forested cone of Kahauale'a, and a relatively small forked breakout 5-6 km farther NE of Pu'u 'O'o. The thermal webcam recorded multiple incandescent outgassing vents in the crater. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. On 16 April several small lava flows extruded from two S vents on Pu'u 'O'o's crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 April-14 April 2015 Citation IconCite this Report

During 8-14 April HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with three areas of breakouts within and along the flow-field margins. The three main areas of breakouts were the 21 February breakout on the flank of Pu'u 'O'o, the 9 March breakout near the forested cone of Kahauale'a, and a relatively small forked breakout 5-6 km farther NE of Pu'u 'O'o. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. A lava flow from a vent at the S edge of Pu'u 'O'o began at 1700 on 7 April and remained active through 9 April.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 April-7 April 2015 Citation IconCite this Report

During 1-7 April HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with three areas of breakouts within and along the flow-field margins. The three main areas of breakouts were the 21 February breakout on the flank of Pu'u 'O'o, the 9 March breakout near the forested cone of Kahauale'a (burning trees were visible), and a relatively small forked breakout 5-6 km farther NE of Pu'u 'O'o. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. During an overflight on 3 April geologists observed a small collapse pit had formed sometime since the previous overflight (possibly on 18 March based on tilt data) in the W portion of Pu'u 'O'o Crater. The opening was about 27 m in diameter but the chamber below was much larger. The floor of the collapse pit was about 80 m in diameter, about 24 m below the pit rim and hosted two active lava ponds.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 March-31 March 2015 Citation IconCite this Report

During 25-31 March HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with four separate breakouts in three areas within and along the flow-field margins. The three main areas of breakouts were the 21 February breakout on the flank of Pu'u 'O'o, the 9 March breakout near the forested cone of Kahauale'a (burning trees were visible), and a relatively small breakout 5-6 km farther NE of Pu'u 'O'o. On 25 March HVO lowered the Volcano Alert Level from Warning to Watch, noting that in recent weeks the Pu'u 'O'o lava flows nearest to the town of Pahoa were inactive. The Aviation Color Code remained at Orange. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 March-24 March 2015 Citation IconCite this Report

During 18-24 March HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with several small and scattered breakouts within the flow-field margins, upslope of the leading front. The three main areas of breakouts were the 21 February breakout on the flank of Pu'u 'O'o, the 9 March breakout near the forested cone of Kahauale'a (burning trees were visible), and a relatively small breakout 5 km farther NE of Pu'u 'O'o. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor. A small lava pond was visible in the central Pu'u 'O'o vent; on 23 March a tiny lava flow erupted from the vent. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 March-17 March 2015 Citation IconCite this Report

During 11-17 March HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with several small and scattered breakouts within the flow-field margins, upslope of the leading front. Most of the erupting lava was found in the two largest breakouts: the 21 February breakout on the flank of Pu'u 'O'o and the 9 March breakout near the forested cone of Kahauale'a. A third and relatively small breakout was 5 km farther NE of Pu'u 'O'o. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor. A small lava pond was visible in the S portion of the crater. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. During 12-13 March a tiny lava flow erupted from the NE edge of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 March-10 March 2015 Citation IconCite this Report

During 4-10 March HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with several small and scattered breakouts within the flow-field margins, upslope of the leading front. These breakouts included a lobe extending to the N, about 1.6 km upslope from Highway 130, and a lobe on the S side of the flow, about 870 m upslope of Malama Market. The most northern lobe of lava remained stalled, about 500 m above Highway 130, near police and fire stations. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 February-3 March 2015 Citation IconCite this Report

During 25 February-3 March HVO reported that Kilauea’s 27 June NE-trending lava flow continued to widen with several small breakouts across the interior and edges of the lobes, upslope of the leading front. These breakouts included a lobe extending to the N, which remained about 1.6 km upslope from Highway 130, and a lobe on the S side of the flow, about 870 m upslope of Malama Market. The most distal lobe of lava remained about 500 m above Highway 130, near police and fire stations. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor and minor lava flows within the crater were observed. During an overflight on 27 February volcanologists observed a few lava ponds in the vents. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 February-24 February 2015 Citation IconCite this Report

During 19-24 February HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with several small breakouts across the interior and edges of the lobes, upslope of the leading front. These breakouts included a lobe extending to the N, about 1.6 km upslope from Highway 130, and a lobe on the S side of the flow, about 870 m upslope of Malama Market. The most northern lobe of lava remained about 500 m above Highway 130, near police and fire stations. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 February-17 February 2015 Citation IconCite this Report

During 11-17 February HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with several small breakouts across the interior and edges of the lobes, upslope of the leading front. Small brush fires from the breakouts were noted about 3 km NE of Pu'u 'O'o Crater and in an area W of the Kaohe Homesteads. The most northern lobe of lava remained about 500 m above Highway 130, near police and fire stations. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of tephra onto nearby areas.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 February-10 February 2015 Citation IconCite this Report

During 4-10 February HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with several small breakouts across the interior and edges of the lobes, upslope of the leading front. The most northern lobe of lava remained about 500 m above Highway 130, near police and fire stations. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 January-3 February 2015 Citation IconCite this Report

During 28 January-3 February HVO reported that Kilauea’s 27 June NE-trending lava flow continued to widen and breakout lava flows continued upslope of the leading front. The most northern lobe of lava was about 500 m above Highway 130 by 3 February, near police and fire stations. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 January-27 January 2015 Citation IconCite this Report

During 21-27 January HVO reported that Kilauea’s 27 June NE-trending lava flow continued to widen and advance, with breakout lava flows upslope of the leading front. The most northern lobe of lava continued to advance and by 27 January the front was about 500 m above Highway 130, near police and fire stations. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 January-20 January 2015 Citation IconCite this Report

During 14-20 January HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with breakouts upslope of the leading front. A narrow lobe of lava that had broken away from the W edge of the flow field below the crack system stalled; by 20 January the front was about 650 m above Highway 130, near police and fire stations. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 January-13 January 2015 Citation IconCite this Report

During 7-13 January HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with breakout lava flows upslope of the leading front. On 13 January scientists conducted an overflight of the flow field and observed scattered breakouts along the distal part of the flow between 0.5 and 1 km upslope of the stalled flow front; a narrow lobe that had been advancing NNE was 700 m upslope of the stalled front. Additional breakouts were scattered from 1.7 to 3 km upslope of the flow tip and near the crack system.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas; smaller particles may have been dropped several kilometers away.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 December-6 January 2015 Citation IconCite this Report

During 30 December-6 January HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with breakout lava flows upslope of the leading front. A narrow lobe of lava that had broken away from the W edge of the flow field below the crack system stalled and by 30 December the front was about 800 m above the intersection of Pahoa Village Road and Highway 130, and 530 m from the Pahoa Marketplace.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 December-30 December 2014 Citation IconCite this Report

During 24-30 December HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. A narrow lobe of lava that had broken away from the W edge of the flow field below the crack system advanced, and by 30 December the front was about 800 m above the intersection of Pahoa Village Road and Highway 130, and 604 m from the Pahoa Marketplace.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 December-23 December 2014 Citation IconCite this Report

During 17-23 December HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. A narrow lobe of lava that had broken away from the W edge of the flow field below the crack system advanced and by 22 December the front was about 1 km above the intersection of Pahoa Village Road and Highway 130, near the Pahoa Marketplace.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 December-16 December 2014 Citation IconCite this Report

During 10-16 December HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. A narrow lobe of lava that had broken away from the W edge of the flow field below the crack system advanced at rates of several hundred meters per day; by 16 December the front was about 1.6 km above the intersection of Pahoa Village Road and Highway 130, near the Pahoa Marketplace.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 December-9 December 2014 Citation IconCite this Report

During 3-9 December HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. A narrow lobe of lava that had broken away from the W edge of the flow field below the crack system advanced at rates of several hundred meters per day; by 9 December the front was about 3.5 km above the intersection of Pahoa Village Road and Highway 130, near the Pahoa Marketplace.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 November-2 December 2014 Citation IconCite this Report

During 26 November-2 December HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. During an overflight on 1 December volcanologists observed a narrow lava flow that had originated from the W edge of the flow field and traveled 2.8 km N, burning vegetation along its path. They noted that weak surface activity was present in three areas upslope: the W side of the flow field that had produced the new lava flow, the E edge of the crack system, and at a breakout 3.5 km upslope of Pu'u 'O'o. They also measured a cross-sectional area of the lava stream within a tube near Pu'u 'O'o and found a 25% reduction in area compared to the previous week. The result was consistent with less lava flowing through the tube due to the summit deflation, which has been ongoing since 29 November.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 November-25 November 2014 Citation IconCite this Report

During 19-25 November HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. A satellite image acquired on 22 November showed that active breakouts were focused in two areas: in the upper part of the flow field about 4 km NE of Pu'u 'O'o, and above the ground crack system near an abandoned geothermal well site on Kilauea’s east rift zone. On 24 November slow-moving pahoehoe flows near the well site had advanced and were 5.7 km SW of the transfer station on Apa'a Street.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 November-18 November 2014 Citation IconCite this Report

During 12-18 November HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. On 15 November the closest active lava to Pahoa Village Road was about 630 m upslope of the road. Multiple breakouts were active upslope of Apa’a Street and Cemetery Road, including a breakout traveling along the S margin of the earlier flow that crossed Cemetery Road and burned the road surface. During an overflight on 17 November, scientists noted a marked decrease in the surface breakouts that have been active N of Kaohe Homesteads, and near Apa’a Street and the Pahoa Japanese Cemetery during the previous few weeks. This decrease in supply was caused by a large breakout from the lava tube at Pu’u Kahauale’a, near Pu'u 'O'o, which began overnight during 14-15 November. A report on 18 November noted that the lower portion of the lava flow, near the Kaohe Homesteads and Pahoa, had stalled, but breakouts remained active in the upslope portion of the flow between 1.6 km and 9 km NE of Pu'u 'O'o.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 November-11 November 2014 Citation IconCite this Report

During 5-11 November HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. Breakout lava flows behind the stalled leading edge continued to advance. On 10 November the closest active lava to Pahoa Village Road was about 450 m upslope of the road, on the N margin of the flow field. Multiple breakouts were active around Apa’a Street and Cemetery Road. Lava advanced to within 20 m of the transfer station fence and through residential property across the street; at 1155 an unoccupied home on that lot was ignited by advancing lava.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 October-4 November 2014 Citation IconCite this Report

During 29 October-4 November HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. Breakout lava flows behind the stalled leading edge continued to advance; during 30-31 October a lobe downslope of the Pahoa cemetery was active, burning trees in a forested area and causing numerous loud methane bursts. The lobe entered residential property at 1645 on 31 October, advanced along the N edge of the property, and then stalled on 4 November. The interior areas of the flows continued to inflate.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 October-28 October 2014 Citation IconCite this Report

During 22-28 October HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. On 22 October a narrow lava flow (less than 50 m wide) that had overtaken the flow front during the previous few days moved into a small gully; the advancement rate was variable and sometimes as high as 300 m/day. Another breakout upslope continued to advance at a slower rate. On 24 October HVO scientists aboard an overflight measured the cross sectional area of the lava tube feeding the flow; the measurement suggested that the volume of lava being supplied to the flow from the Pu'u 'O'o vent had slightly increased.

At approximately 0350 on 25 October lava crossed Apa’a Street and continued to advance towards Pahoa town. Throughout the morning the flow moved down the Pahoa cemetery driveway and then turned SE into adjoining pasture. At 0900 on 26 October the flow was an estimated 140 m wide. The next day it had narrowed to 100 m wide and was about 570 m from Pahoa Village Road. At about 0200 on 28 October the flow had reached the first occupied residential property. The leading edge of the flow was less than 50 m wide but increased to 150 m upslope. At 1730 the lava flow was 310 m in a straight-line distance from Pahoa Village Road and about 900 meters in a straight-line distance from Highway 130. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning.

According to news articles, Pahoa town, residence to 800-900 people, consists of small shops and homes. A school and a few roads were closed. Crews were building temporary access roads and trying to build berms to divert lava away from the highly traveled Highway 130.

The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); CBC; CNN


15 October-21 October 2014 Citation IconCite this Report

During 15-21 October HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

The 27 June NE-trending lava flow continued to be active, with several breakouts about 1.3 km upslope of the front, although it stopped advancing on 17 October. Along the S side of the main flow a narrow breakout flow traveled at a rate of 80 m/day. The leading edge of the flow remained 1.4 km upslope from Apa’a Street. Vegetation along the flow margins was burning. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 October-14 October 2014 Citation IconCite this Report

During 8-14 October HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of tephra onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

The 27 June NE-trending lava flow continued to advance. Volcanologists aboard an overflight on 13 October noted that the flow had advanced about 220 m since 10 October, with an average travel rate of approximately 75 m/day since 6 October. The leading edge of the flow was 1.4 km upslope from Apa’a Street. Vegetation along the flow margins was burning. An overflight on 14 October revealed that the flow had advanced an additional 40 m. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 October-7 October 2014 Citation IconCite this Report

During 1-7 October HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor.

The 27 June NE-trending lava flow remained active; flows that had broken out upslope from the leading but stalled front had overtaken that front by 1 October. By 6 October the115-m-wide flow was advancing at a rate of about 120 m/day and was 1.2 km upslope from Apa`a Street. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 September-30 September 2014 Citation IconCite this Report

During 23-30 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. Small collapses from the inner wall occasionally occurred and on 24 September produced a small brown plume from the vent. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor. Volcanologists on an overflight on 26 September observed sloshing lava in the pits.

The 27 June NE-trending lava flow remained active upslope from the leading edge. By 22 September the flow had extended 16.4 km from the vent (measured in a straight line), placing the active flow front within the NW portion of the Kaohe Homesteads, a vacant forested portion of the subdivision, 2.3 km upslope from Apa`a Street and 3.3 km from Pahoa Village Road. Two slow-moving lobes behind the flow front advanced; the nearest lobe was about 125 m behind the stalled front. During an overflight on 29 September volcanologists observed breakouts where the flow first entered the crack system about 8 km behind the stalled front, and where it exited the system about 3 km upslope from the front. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 September-23 September 2014 Citation IconCite this Report

During 17-23 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor. Two small lava ponds in the S pit were visible during the earlier part of the week, and small breakout flows near the crater burned adjacent forest.

The NE-trending lava flow had advanced at an average rate of 290 m/day between 15 and 17 September and 190 m/day between 17 and 19 September, and continued to cause localized fires as it spread through the forest. By 22 September the flow extended 16.4 km from the vent (measured in a straight line), placing the active flow front within the NW portion of the Kaohe Homesteads, a vacant forested portion of the subdivision. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 September-16 September 2014 Citation IconCite this Report

During 10-16 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining 50-60 m below the Overlook Crater rim. Elevated gas emissions were detected during the week of 9 September, with amounts of 3,300-6,700 tonnes per day, and persisted through this reporting period. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have fallen several kilometers away.

During 10-16 September little change was recorded from Pu`u `O`o; glow was visible overnight above several outgassing openings in the crater floor. By 16 September the NE-trending lava flow extended 15.5 km from the vent, placing the active flow front within the NW portion of the Kaohe Homesteads, a vacant forested portion of the subdivision. The flow had advanced at an average rate of 215 m/day between 12 and 15 September and continued to generate smoke and localized fires as it spread through the forest.

The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 September-9 September 2014 Citation IconCite this Report

During 3-9 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining 50-60 m below the Overlook Crater rim. Elevated gas emissions were detected on 2 September, 3,300-6,700 tonnes per day, and persisted through this reporting period. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have fallen several kilometers away.

During 3-9 September little change was recorded from Pu`u `O`o; glow was visible overnight above several outgassing openings in the crater floor. On 3 September HVO raised the Volcano Alert Level from Watch to Warning due to the advancement of the June 27th lava flow. By that afternoon the NE trending lava flow had reached ~13.2 km from the vent, placing the active flow front 1.3 km from the E boundary of the Wao Kele o Puna Forest Reserve. The lava flow continued to generate smoke and localized fires as it spread through the forest, and as of 9 September had advanced ~800 m.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 August-2 September 2014 Citation IconCite this Report

During 27 August-2 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.

During 27 August-2 September glow was visible overnight above several outgassing openings in Pu`u `O`o's crater floor. On 28 August there was a brief reduction in surface activity. On 1 September aerial views showed small lava ponds within the NE, SE, and N pits within the crater, and a crusted pond surface in the SE pit. The June 27th lava flow remained active. On 1 September active lava was 12.6 km from the vent, and about 1.9 km from the eastern boundary of the Wao Kele o Puna Forest Reserve. Lava a few hundred meters behind the front had flowed into a large ground crack and disappeared from view; a line of steam from the crack extended E. The most distant steaming along the crack was 12.8 km from the vent and 1.7 km from the Forest Reserve boundary. Small breakouts were active closer to Pu`u `O`o, about midway along the length of the June 27th flow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 August-26 August 2014 Citation IconCite this Report

During 20-26 August HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. On 23 August part of the deep inner ledge surrounding the lava lake collapsed, disrupting the lava lake surface for a short time.

During 20-26 August glow was visible overnight above several outgassing openings in Pu`u `O`o's crater floor and on 20-21 August glow was visible at skylights along the June 27th flow lava tube. On 22 August observations during a helicopter flight showed the June 27th flow had poured into a deep, large crack of Kilauea’s east rift zone and produced a line of steaming that advanced eastward. On 25 August an overflight confirmed that lava in the crack had returned to the surface, creating a small, isolated pad of lava. On 26 August the farthest portion of this new pad of lava was about 11.4 km from the vent on Pu`u `O`o and about 3.1 km from the eastern boundary of the Wao Kele o Puna Forest Reserve. A separate branch of the June 27th flow continued to advance into a different section of forest northeast of Pu`u `O`o and was 7.3 km from the vent on 25 August.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 August-19 August 2014 Citation IconCite this Report

During 13-19 August HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. On 15-18 August glow was visible during the night above outgassing pits on the northeast, south, and southeast edges of Pu`u `O`o's crater floor and at skylights along the June 27th flow lava tube. On 12 August these pits at the edges of the crater floor were identified in an overflight. The June 27th flow continued to advance into forest NE of Pu`u `O`o. The tube-fed flow slowed and widened over several days, and its distal tip was 9.4 km from the vent (straight-line distance) on 18 August. The flow also hosted a broad area of lava flow breakouts mid-way along its length that reached the forest about 5 km NE of the vent, on the N side of the current flow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 August-12 August 2014 Citation IconCite this Report

During 6-12 August HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. On 6 August a small collapse of the north rim and wall of Halema'uma'u Crater temporarily increased spatter on the lava lake surface.

On 6-12 August HVO reported one small lava pond on the S and glow along the S, SE, and NE edges of the crater floor of Pu?u ?O?o . On August 6 June 27th flow front had encroached on forest 7 Km ENE of Pu?u ?O?o . Monitoring of the volcanoes was disrupted by Hurricane Iselle on 7 August and HVO is working to fully recover from the impacts of the storm. In the interim, staff from the Alaska Volcano Observatory and from USGS Headquarters in Reston, VA have increased satellite monitoring for volcanoes in Hawai’i.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 July-5 August 2014 Citation IconCite this Report

During 30 July-5 August HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea’s Halema’uma’u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele’s hair onto nearby areas; smaller particles may have been deposited several kilometers away.

On 30 June the mapped June 27th flow front had reached 4.2 km from vent on northeast flank of Pu’u ‘O’o’. The flow front has continued to advance reaching about 5 km NE of Pu’u ‘O’o’ on 4 August. Two small lava ponds remained active on the south side of Pu’u ‘O’o’s crater. On 30 July-2 August small lava flows were fed by the eastern lava pond.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 July-29 July 2014 Citation IconCite this Report

During 23-29 July HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema`uma`u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. On 24 July a small explosion triggered by rockfalls from the southeast crater wall sent spatter onto the closed tourist overlook at Halema`uma`u; small rockfalls also disturbed the lava lake surface on 27 July.

Lava flows fed from a vent on Pu`u `O`o's northeast flank continued to advance slowly NE as two lobes that reached 2.4 km from the vent on 25 July. Lava was at or near the surface within the four pits on the crater floor and a small lava flow erupted from the southern pit during the night of 25-26 July. On 28 July there were a few small collapses around the edge of Pu`u `O`o's crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 July-22 July 2014 Citation IconCite this Report

During 16-22 July HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. A 27 June breakout of lava flowed in an incipient lava tube from the vent to the gentle break in slope at the base of Pu`u `O`o, and continued slowly moving in two main lobes that extended about 2 km NE. Two small lava ponds within cones are present within the two southeastern pits in the crater floor, and glow above two other pits indicated lava is near the surface.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 July-15 July 2014 Citation IconCite this Report

During 2-14 July HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema`uma`u Crater. The lava-lake level fluctuated between 30 and 45 m below the Overlook crater rim; on 13 July, the level dropped 45-50 m during periods of spattering. Weak inflation was measured at the summit during 2-8 July, deflation during 9-10 July, no significant deformation during 11-13 July, and slight inflation on 14 July. Gas emissions remained elevated; during the weeks ending on 1 and 8 July, the summit SO2 emission rates were 3,800-8,400 tonnes/day and 5,800-6,900 tonnes/day, respectively. Earthquakes during 2-7 July (11-21/day) and 8-14 July (5-27/day) were strong enough to be located beneath Kilauea. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.

On 3 July, the total SO2 emission rate from all East Rift Zone sources was 500 tonnes per day. During 2-14 July, four lava ponds within cones occupied the crater floor of Pu`u`O`o. The vent which opened on the NE flank of Pu`u`O`o on 27 June remained active and supplied a flow extending NE, constructing a lava shield that continued to expand until 10 July. This new flow cut off lava supply to the Kahauale`a 2 flow, which by 3 July was no longer active. The new shield developed a perched lava pond which crusted over and became quiescent when the pond spilled over on 11 July. Lava continued to erupt from the base of the structure, supplying flows that accumulated around the flat-lying terrain at the base of Pu`u`O`o until 14 July. Continuous deflation was measured at Pu`u`O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 June-1 July 2014 Citation IconCite this Report

During 25 June-1 July HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.

During 25-26 June, lava flows from the N and NE spatter cones at Pu'u 'O'o Crater were active and persistent glow emanated from spatter cones on the N, SE, and S portions of the crater floor, and from a small lava lake in the NE spatter cone. On 27 June the crater floor slowly subsided and new lava erupted on the N flank. During 27-30 June lava flowed from four locations on the NE flank, advancing to about 1 km NE. Spatter cones collapsed varying amounts. A 28 June satellite image showed that the 27 June lava flows had expanded in area and extended no more than 1.6 km NE of Pu'u 'O'o cone. During 25-27 June there were multiple active breakouts in the interior of the Kahauale`a 2 flow at the north base of Pu'u 'O'o and distant broad smoke plumes, with multiple glowing points visible at night from both near and distant breakouts. Only one stationary glowing spot was seen during 28-30 June on a nearby breakout from the Kahauale`a 2 flow, and little to no smoke from the distal end of that flow, suggesting that the flow was cutoff and dead.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 June-24 June 2014 Citation IconCite this Report

During 18-23 June HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema‘uma‘u Crater. The lava-lake level dropped several meters on 21 June then returned to an estimated 34-35 m below the floor of Halema‘uma‘u Crater by 22 June. Gas emissions remained elevated. The ambient SO2 concentrations near the vent varied greatly but remained higher than 10 ppm, and frequently exceeded 50 ppm (upper limit of the detector) during times with moderate trade winds. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.

At Pu‘u ‘O‘o Crater, glow emanated from spatter cones on the N, SE, and S portions of the crater floor, and from a small lava lake in the NE spatter cone. On 17 June geologists mapped five small breakouts as far as 7 km NE from Pu‘u ‘O‘o. The local webcam captured views of the active break-out flows at the N base of Pu‘u ‘O‘o cone as well as distant smoke plumes from the slow-moving lava flow burning vegetation along the NE margin of the Kahauale‘a 2 flow. Overall, however, this slow-moving flow has appeared to be weakening over the past few months.

The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 June-17 June 2014 Citation IconCite this Report

During 11-17 June HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N, SE, and S portions of the crater floor, and from a small lava lake in the NE spatter cone. On 22 May geologists mapped the farthest point of activity from the Kahauale’a 2 lava flow, 8.4 km NE of Pu’u 'O'o, and on 6 June they mapped four small breakouts as far as 6.5 km from Pu’u 'O'o. Smoke plumes rising from forested areas suggested advancing lava from a new 12 June breakout at the N base of the Pu’u 'O'o cone. Overall, however, this slow-moving flow has appeared to be weakening over the past few months.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 June-10 June 2014 Citation IconCite this Report

During 4-10 June HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N, SE, and S portions of the crater floor, and from a small lava lake in the NE spatter cone. On 22 May geologists mapped the farthest point of activity from the Kahauale’a 2 lava flow, 8.4 km NE of Pu’u 'O'o, and on 6 June they mapped four small breakouts as far as 6.5 km from Pu’u 'O'o. Smoke plumes rising from forested areas suggested advancing breakout flows.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 May-3 June 2014 Citation IconCite this Report

During 28 May-3 June HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N, NE, SE, and S portions of the crater floor. During 30 May-1 June the small lava lake in the NE spatter cone briefly overflowed its rim each morning. On 22 May geologists mapped the farthest point of activity from the Kahauale’a 2 lava flow, 8.4 km NE of Pu’u 'O'o; on 30 May they mapped three small breakouts 1.8-6.2 km from Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 May-27 May 2014 Citation IconCite this Report

During 21-27 May HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N, NE, SE, and S portions of the crater floor. The Kahauale’a 2 lava flow continued to advance, with breakouts from the main stalled lobe, and burn adjoining forest. On 22 May geologists mapped the farthest point of activity, 8.4 km NE of Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 May-20 May 2014 Citation IconCite this Report

During 14-20 May HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and from the lava pond in the NE spatter cone. Lava flows from the N spatter cone traveled short distances during 14-15 May. The Kahauale’a 2 lava flow continued to advance, with breakouts from the main stalled lobe, and burn adjoining forest. A satellite image acquired on 14 May showed that the farthest point of activity was 8.8 km NE of Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 May-13 May 2014 Citation IconCite this Report

During 7-13 May HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and from the lava pond in the NE spatter cone. The S spatter cone periodically erupted lava flows that overflowed on the N flanks and extended from the S base of the cone. The N cone ejected spatter. The Kahauale’a 2 lava flow continued to advance, with breakouts from the main stalled lobe, and burn adjoining forest. On 5 May geologists mapped the farthest point of activity, 8.6 km NE of Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 April-6 May 2014 Citation IconCite this Report

During 30 April-6 May HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and from the lava pond in the NE spatter cone. The S spatter cone periodically erupted lava flows that traveled N and SE beyond the crater rim. During 5-6 May the N cone ejected spatter and a small lava flow. The Kahauale’a 2 lava flow continued to advance, with breakouts from the main stalled lobe, and burned adjoining forest. On 5 May geologists mapped the farthest point of activity, 8.6 km NE of Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 April-29 April 2014 Citation IconCite this Report

During 23-29 April HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. During 28-29 April the lake level rose to an estimated 30 m below the crater floor, the highest level measured since February 2013.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and from the lava pond in the NE spatter cone. On 22 April, just before midnight, the N spatter cone produced a vigorous lava flow that traveled E across the crater floor in minutes, over the crater edge, and then down the NE flank of the cone along the Kahauale’a 2 lava flow tube. The flow continued to be sporadically active during the rest of this reporting period. The Kahauale’a 2 lava flow continued to advance, with breakouts from the main stalled lobe, and burn adjoining forest. On 28 April geologists mapped the farthest point of activity, 8.3 km NE of Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 April-22 April 2014 Citation IconCite this Report

During 16-22 April HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and from the lava pond in the NE spatter cone. The Kahauale’a 2 lava flow continued to advance, with breakouts from the main stalled lobe, and burn adjoining forest. On 18 April geologists noted that the farthest point of activity was 7.5 km NE of Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 April-15 April 2014 Citation IconCite this Report

During 9-15 April HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and from the lava pond in the NE spatter cone (during most of the reporting period). The Kahauale’a 2 lava flow continued to advance, with breakouts from the main stalled lobe, and burn adjoining forest. A satellite image acquired on 9 April showed the farthest point of activity was 8.3 km NE of Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 April-8 April 2014 Citation IconCite this Report

During 2-8 April HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and from the lava pond in the NE spatter cone. The Kahauale’a 2 lava flow continued to advance, with breakouts from the main stalled lobe, and burn adjoining forest. During an overflight on 7 April geologists observed that the farthest point of activity was 8.2 km NE of Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 March-1 April 2014 Citation IconCite this Report

During 26 March-1 April HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and from the lava pond in the NE spatter cone. The Kahauale’a 2 lava flow, fed by the NE spatter cone, continued to advance, with breakout lava flows from the main stalled lobe, and burn adjoining forest. A satellite image acquired on 27 March showed active breakouts 5.5 and 8 km NE of Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 March-25 March 2014 Citation IconCite this Report

During 19-25 March HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and from the lava pond in the NE spatter cone. Lava from the pond periodically spilled over the rim during 18-19 March. Breakouts from the main stalled lobe of the Kahauale’a 2 lava flow, fed by the NE spatter cone, continued to advance and burn adjoining forest. Overflight mapping on 21 March showed that the edge of the most distant breakout flow was 8.2 km NE of Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 March-18 March 2014 Citation IconCite this Report

During 12-18 March HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and from the lava pond in the NE spatter cone. On 12 March lava flowed S from the S cone. Once on 14 March and twice on 17 March lava from the pond rose and spilled over the rim.

Breakouts from the stalled main lobe of the Kahauale’a 2 lava flow continued to advance and burned adjoining forest. A satellite image from 11 March showed that the edge of the most distant breakout flow was 8 km NE of Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 March-11 March 2014 Citation IconCite this Report

During 5-11 March HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and from the lava pond in the NE spatter cone. The Kahauale’a 2 lava flow, fed by the NE spatter cone, continued to advance, with breakout lava flows from the main stalled lobe, and burn adjoining forest. A satellite image from 7 March showed that the edge of the most distant breakout flow was 7.9 km NE of Pu’u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 February-4 March 2014 Citation IconCite this Report

During 26 February-4 March HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor; the lava pond in the NE spatter cone was possibly crusted over. The 7.8-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, stalled in mid-January but remained active with scattered break-out flows behind the flow front that burned adjoining forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 February-25 February 2014 Citation IconCite this Report

During 19-25 February HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and a lava pond was active in the NE spatter cone. The 7.8-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, stalled in mid-January but remained active with scattered break-out flows behind the flow front that burned adjoining forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 February-18 February 2014 Citation IconCite this Report

During 12-18 February HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and a lava pond was active in the NE spatter cone. The 7.8-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows behind the flow front that burned the forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 February-11 February 2014 Citation IconCite this Report

During 5-11 February HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and a lava pond was active in the NE spatter cone. The 7.8-km-long Kahauale’a 2 lava flow (based on a satellite image from 2 February), fed by the NE spatter cone, was active with scattered break-out flows 4.8 and 6.9 km NE of Pu'u 'O'o that burned the forest.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 January-4 February 2014 Citation IconCite this Report

During 29 January-4 February 2014 HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. A lava pond was active in the NE spatter cone. The 7.8-km-long Kahauale’a 2 lava flow (based on a satellite image from 27 January), fed by the NE spatter cone, was active with scattered break-out flows 4.8 and 6.7 km NE of Pu'u 'O'o that burned the forest. On 31 January a few brief lava overflows occurred from two of the cones.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 January-28 January 2014 Citation IconCite this Report

During 22-28 January 2014 HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 7.8-km-long Kahauale’a 2 lava flow (based on mapping from 24 January), fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. On 23 January a small lava flow also oozed out of the SE spatter cone. During 23-26 January lava rose in the westernmost spatter cone and flowed down the N flank.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 January-21 January 2014 Citation IconCite this Report

During 15-21 January 2014 HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. A "deflation-inflation" event, or DI, began on 17 January and by 21 January the lava-lake level had dropped more than 20 m to about 70 m below the crater floor. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 7.5-km-long Kahauale’a 2 lava flow (based on a satellite image from 17 January), fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. On 19 January the N side of the NE spatter cone collapsed, possibly due to lower lava levels as a result of the DI event, exposing a small lava pond.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 January-14 January 2014 Citation IconCite this Report

During 8-14 January 2014 HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. Fed by the NE spatter cone, the Kahauale’a 2 lava flow had reached 7.5 km long by 9 January (based on a satellite image), and was active with scattered break-out flows that burned the forest N of Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 January-7 January 2014 Citation IconCite this Report

During 31 December 2013-7 January 2014 HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 6.3-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, remained active with scattered break-out flows that burned the forest N of Pu'u 'O'o. During 1-2 January the SE spatter cone erupted a total of five short lava flows, and on the morning of 6 January it ejected a small amount of lava.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 December-31 December 2013 Citation IconCite this Report

During 24-30 December HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 6.3-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 December-24 December 2013 Citation IconCite this Report

During 18-23 December HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 7.3-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o; the flow however was most active about 6 km NE of Pu'u 'O'o based on satellite images from 20 December.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 December-17 December 2013 Citation IconCite this Report

During 11-17 December HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 7.3-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. The flow was most active about 5 km NE of Pu'u 'O'o, based on satellite images from 10 December.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 December-10 December 2013 Citation IconCite this Report

During 4-10 December HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 7.3-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o; the flow however was most active about 5 km NE of Pu'u 'O'o based on a satellite images from 30 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 November-3 December 2013 Citation IconCite this Report

During 27 November-3 December HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 7.3-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o; the flow however was most active between 3.3 and 5.8 km NE of Pu'u 'O'o based on a satellite images from 30 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 November-26 November 2013 Citation IconCite this Report

During 20-26 November HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 7.3-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 November-19 November 2013 Citation IconCite this Report

During 13-19 November HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. On 18 November the southernmost spatter cone produced a lava flow that after a few hours burst out in a dome fountain; lava spread over much of the S crater floor before stopping about 30 minutes later. The 7.1-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 November-12 November 2013 Citation IconCite this Report

During 6-12 November HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. On 5 November a cone erupted a low fountain of lava which waned quickly; it was the first lava erupted in Pu'u 'O'o in several months.

The 6.4-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. On 7 November geologists confirmed that, after being active for more than two years and producing some memorable ocean entries, the Peace Day flow, to the SE of Pu'u 'O'o, was no longer active.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 October-5 November 2013 Citation IconCite this Report

During 30 October-5 November, HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The depth to the lake surface ranged between 44 and 53 m, and levels frequently corresponded to fluctuations in tilt measured at the summit. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 5.8-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. The Peace Day flow, fed by lava tubes extending from Pu'u 'O'o, showed little activity and may have ceased; only one breakout flow was mapped during fieldwork on 21 October, and thermal anomalies since that date have been minor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 October-29 October 2013 Citation IconCite this Report

During 23-29 October HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 5.8-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of a possible minor breakout above the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 October-22 October 2013 Citation IconCite this Report

During 16-22 October HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 5.8-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of a few breakouts; on 21 October geologists mapped a small breakout lava flow, with two lobes, about 3 km SE of Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 September-24 September 2013 Citation IconCite this Report

During 18-24 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 3.6-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of a few breakouts; during an overflight on 19 September geologists observed two small breakouts 2.7 km and 6 km SE of Pu'u 'O'o above the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 September-17 September 2013 Citation IconCite this Report

During 11-17 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 3.2-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakouts high on the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 September-10 September 2013 Citation IconCite this Report

During 4-10 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater; the lake level was 47-56 m below the Halema'uma'u crater floor. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. Short lava flows issued from one or more of the NE spatter cones four times during 8-9 September.

The 3.2-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakouts on the pali and coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 August-3 September 2013 Citation IconCite this Report

During 28 August-2 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater; the lake level was 45-52 m below the Halema'uma'u crater floor during 30-31 August and 2-3 September. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. A small and brief lava flow issued from the NE spatter cone on 30 August. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakouts on the pali and coastal plain. A brief plume near the ocean entry on 2 September possibly signified a small bench collapse.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 August-27 August 2013 Citation IconCite this Report

During 21-27 August HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater; the lake level was 35-39 m below the crater floor on most days. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. During 22 and 26-27 August two lava flows from the NE spatter cone were visible, and HVO noted that lava from the NW spatter cone had built a second, taller cone immediately to the E. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakouts on the pali and coastal plain, and an ocean entry outside of the National Park boundary to the E which was last visible on 23 August.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 August-20 August 2013 Citation IconCite this Report

During 14-20 August HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater; the lake level was as high as 36 m below the Halema'uma'u crater floor on 16 and 18 August. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. On 18 August on 1330 the E flank of the N spatter cone apparently burst, causing lava flows to sporadically rush from the cone and cover a large part of the crater floor by the next morning. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakouts on the pali and coastal plain, and an ocean entry outside of the National Park boundary to the E.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 August-13 August 2013 Citation IconCite this Report

During 7-13 August HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. The lake level rose during the week; the level was 49 m below the Halema'uma'u crater floor on 7 August and 37-39 m below the floor during 10-12 August. The level rose to 48 m below the floor during 12-13 August.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned forest N of Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, and an ocean entry outside of the National Park boundary to the E.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 July-6 August 2013 Citation IconCite this Report

During 31 July-6 August HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. The lake level was 51 m below the Halema'uma'u Crater floor on 5 August.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. The Kahauale’a 2 lava flow branches, fed by the NE spatter cone, were active as far NE as 3.2 km and as far NW as 2 km, and burned forest occasionally in two locations at the N edge of the 1983-1986 'a'a flows from Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, and an ocean entry outside of the National Park boundary to the E.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 July-30 July 2013 Citation IconCite this Report

During 24-30 July HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. The lake level receded during 25-26 July and was 75 km below the Halema'uma'u Crater floor on 26 July. The inner ledge, a long-time fixture within the vent, started collapsing at 2030 on 25 July; several pieces of the pit wall fell into the lake on both days. The lake level started to rise again and was 65 and 67 m below the crater floor on 28 and 29 July, respectively.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. The Kahauale’a 2 lava flow branches, fed by the NE spatter cone, were active as far NE as 3.2 km and as far NW as 2 km, and burned forest in two locations at the N edge of the 1983-1986 'a'a flows from Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, and an ocean entry outside of the National Park boundary to the E.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 July-23 July 2013 Citation IconCite this Report

During 17-23 July HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. On 19 July several pieces of the pit wall fell into the lake.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. The Kahauale’a 2 lava flow branches, fed by the NE spatter cone, were active as far N as 2.6 km and as far NNW as 1.9 km, and burned forest in both areas. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, and an ocean entry at a location E and outside of the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 July-16 July 2013 Citation IconCite this Report

During 10-16 July HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. The Kahauale’a 2 lava flow branches, fed by the NE spatter cone, were active as far N as 2.6 km and as far NNW as 1.9 km, and burned forest in both areas. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, and ocean entries at locations inside and outside the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 July-9 July 2013 Citation IconCite this Report

During 3-9 July HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. Branches of the Kahauale’a 2 lava flow, fed by the NE spatter cone, were active as far N as 2.6 km and as far NNW as 1.9 km, and burned forest in both areas. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, and ocean entries at locations inside and outside the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 June-2 July 2013 Citation IconCite this Report

During 26 June-2 July HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater but remained about 40-45 m below the crater floor. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. The Kahauale’a 2 lava flows (formerly known as the Kahauale’a II lava flow), fed by the NE spatter cone, were active as far N as 2.6 km and as far NNW as 1.9 km, and burned forest in both areas. At about 2230 on 18 June breakouts from the Kahauale’a 2 lava tube, near the NE spatter cone and high on the NE flank of Pu'u 'O'o cone, produced lava flows that traveled N down the flank. On 27 June the Kahauale’a 2 flow field was mapped and found to be 40 percent larger than when it was last mapped on 11 June.

Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, and ocean entries at locations inside and outside the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 June-25 June 2013 Citation IconCite this Report

During 19-25 June HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater but remained about 40-45 m below the crater floor. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. The Kahauale’a II lava flows, fed by the NE spatter cone, were active as far N as 2.5 km and as far NNW as 1.9 km, and burned forest in both areas. At about 2230 on 18 June breakouts from the Kahauale’a II lava tube, near the NE spatter cone and high on the NE flank of Pu'u 'O'o cone, produced lava that traveled N down the flank. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, and ocean entries at locations inside and outside the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 June-18 June 2013 Citation IconCite this Report

During 12-18 June HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. The lake level was about 45 m below the Halema'uma'u crater floor during 14-15 and 17-18 June.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. The Kahauale’a II lava flows, fed by the NE spatter cone, were active as far N as 2.5 km and as far NNW as 1.9 km, and burned forest in both areas. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, and ocean entries at locations inside and outside the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 June-11 June 2013 Citation IconCite this Report

During 5-11 June HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. The lake level was 45-46 m below the Halema'uma'u crater floor during 5-6 June.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor; the NE spatter cone produced a small lava flow on 5 June. The Kahauale’a II lava flows, fed by the NE spatter cone, were active as far N as 2 km and as far NNW as 1.6 km, and burned forest in both areas. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, and ocean entries at locations inside and outside the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 May-4 June 2013 Citation IconCite this Report

During 29 May-4 June HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. The Kahauale’a II lava flows traveled N from the base of Pu'u 'O'o cone. The most distal front of the flow was 1.8 km from its source at a spatter cone on the NE edge of Pu'u 'O'o's crater floor. At 0740 on 26 May lava began to spill from the N side of the NE spatter cone, feeding a new breakout on the N flank of Pu'u 'O'o. .

Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, but mainly flows entering the ocean at locations inside and outside the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 May-28 May 2013 Citation IconCite this Report

During 22-28 May HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. The Kahauale’a II lava flows traveled N from the base of Pu'u 'O'o cone. The most distal front of the flow was 1.8 km from its source at a spatter cone on the NE edge of Pu'u 'O'o's crater floor. At 0740 on 26 May lava began to spill from the N side of the NE spatter cone, feeding a new breakout on the N flank of Pu'u 'O'o.

Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, but mainly flows entering the ocean at locations inside and outside the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 May-21 May 2013 Citation IconCite this Report

During 15-21 May HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. Lava from base of Pu'u 'O'o cone traveled N and was named the Kahauale’a II flow. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of lava flows active on the coastal plain that were entering the ocean at a location outside the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 May-14 May 2013 Citation IconCite this Report

During 8-14 May HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. Lava from the E lava pond traveled down the N, NE, E, and S flanks, extending beyond the base of Pu'u 'O'o cone. During 10-11 May the SW spatter cone erupted lava, and during 11-12 May the SE spatter cone also produced flows.

Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of lava flows active on the pali and on the coastal plain. Lava also entered the ocean in at least two locations spanning the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 May-7 May 2013 Citation IconCite this Report

During 1-7 May HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. Small lava flows issued from the N spatter cone on 1 May and from the SW cone on 2 May. The lava pond overflowed during 3-4 and 6-7 May.

Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of lava flows active above the pali SE of Pu'u 'O'o, on the pali, and on the coastal plain. Lava also entered the ocean in at least two locations spanning the National Park boundary. On 3 May a breakout on the top of the pali produced a lava flow that traveled down to the coastal plain in about 1 hour. Branches from the flow advanced during 4-6 May.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 April-30 April 2013 Citation IconCite this Report

During 24-30 April HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 April-23 April 2013 Citation IconCite this Report

During 17-23 April HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the crater floor. Just before midnight on 19 April a vigorous lava flow gushed out of the N spatter cone and quickly covered the N portion of the crater floor, then went over the E rim. The lava pond on the NE crater's edge briefly overflowed. On 21 April the two spatter cones on the S portion of the crater floor produced lava flows.

Two lava flows (Peace Day and Kahauale'a) were fed by lava tubes extending from Pu'u 'O'o. Multiple lava flows from the NE spatter cone, collectively called the Kahauale'a flow, stopped advancing on 20 April, although a few breakout lava flows were observed during 20-22 April. Peace Day activity consisted of lava flows active above the pali (5 km SE of Pu'u 'O'o), on the pali, and on the coastal plain. Lava also entered the ocean at two or three locations spanning the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 April-16 April 2013 Citation IconCite this Report

During 10-16 April HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from four spatter cones on the crater floor. Two lava flows (Peace Day and Kahauale'a) were fed by lava tubes extending from Pu'u 'O'o. Multiple lava flows from the NE spatter cone, collectively called the Kahauale'a flow, traveled across the NE flank of Pu'u 'O'o cone to the cone's base and advanced more than 4.9 km NE over older flows. Peace Day activity consisted of lava flows active above the pali (5 km SE of Pu'u 'O'o), on the pali, and on the coastal plain. Lava also entered the ocean at two main locations spanning the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 April-9 April 2013 Citation IconCite this Report

During 3-9 April HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from four spatter cones on the crater floor. Two lava flows (Peace Day and Kahauale'a) were fed by lava tubes extending from Pu'u 'O'o. Multiple lava flows from the NE spatter cone, collectively called the Kahauale'a flow, traveled across the NE flank of Pu'u 'O'o cone to the cone's base and advanced more than 4.9 km NE over older flows. Peace Day activity consisted of lava flows active above the pali (5 km SE of Pu'u 'O'o), on the pali, and on the coastal plain. Lava also entered the ocean at two main locations spanning the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 March-2 April 2013 Citation IconCite this Report

During 27 March-2 April HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from four spatter cones on the crater floor. Two lava flows (Peace Day and Kahauale'a) were fed by lava tubes extending from Pu'u 'O'o. Multiple lava flows from the NE spatter cone, collectively called the Kahauale'a flow, traveled across the NE flank of Pu'u 'O'o cone to the cone's base and advanced more than 4.4 km NE over older flows. A branch also traveled S, just S of Pu'u Kahauale'a. Peace Day activity consisted of lava flows active above the pali (5 km SE of Pu'u 'O'o), on the pali, and on the coastal plain. Lava also entered the ocean at two main locations spanning the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 March-26 March 2013 Citation IconCite this Report

During 20-26 March HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from four spatter cones on the crater floor. Lava flowed from the cone on the NE edge of the crater on 23 March, the first lava activity in the crater in a month. Two lava flows (Peace Day and Kahauale'a) were fed by lava tubes extending from Pu'u 'O'o. Multiple lava flows from the NE spatter cone, collectively called the Kahauale'a flow, traveled across the NE flank of Pu'u 'O'o cone to the cone's base and advanced more than 4.4 km NE over older flows. A branch also traveled S, just S of Pu'u Kahauale'a. Peace Day activity consisted of lava flows active above the pali (5 km SE of Pu'u 'O'o), on the pali, and on the coastal plain. Lava also entered the ocean at two main locations spanning the National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 March-19 March 2013 Citation IconCite this Report

During 13-19 March HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. The lake level was 31 m below the Halema'uma'u crater floor on 14 March.

At Pu'u 'O'o Crater, glow emanated from four spatter cones on the crater floor. Multiple lava flows from the NE spatter cone, collectively and informally called the Kahauale'a flow, traveled across the NE flank of Pu'u 'O'o cone to the cone's base and advanced more than 4 km NE over older flows. A branch also traveled S, just S of Pu'u Kahauale'a. Lava flows were active above the pali (5 km SE of Pu'u 'O'o), on the pali, and on the coastal plain. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations. A second lava-flow branch was active near the coast and a third branch was active near the base of the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 March-12 March 2013 Citation IconCite this Report

During 6-12 March HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from four spatter cones on the crater floor. Multiple lava flows from the NE spatter cone, collectively and informally called the Kahauale'a flow, traveled across the NE flank of Pu'u 'O'o cone to the cone's base and advanced more than 3.5 km NE over older flows. A branch also traveled S, just S of Pu'u Kahauale'a, but possibly stalled at the end of the week. Lava flows were active above the pali (5 km SE of Pu'u 'O'o), on the pali, and on the coastal plain. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations. A second lava-flow branch was active near the coast and a third branch was active near the base of the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 February-5 March 2013 Citation IconCite this Report

During 27 February-5 March HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a perched lava lake on the NE part of the floor. Multiple lava flows from the NE spatter cone, collectively and informally called the Kahauale'a flow, traveled across the NE flank of Pu'u 'O'o cone to the cone's base and advanced 2.5 km NE over older flows. A branch also traveled S, just S of Pu'u Kahauale'a, and started fires in the kipuka. Lava flows were active above the pali (5 km SE of Pu'u 'O'o) and in a 1-km-wide area on the coastal plain. To the W, a 350-m-wide lava flow advanced towards the coast and produced scattered breakouts. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 February-26 February 2013 Citation IconCite this Report

During 20-26 February HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. The lake level was 35 m below the Halema'uma'u crater floor on 20 February.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a perched lava lake on the NE part of the floor. Multiple lava flows from the NE spatter cone, collectively and informally called the Kahauale'a flow, traveled across the NE flank of Pu'u 'O'o cone to the cone's base and continued to advance NE and SW over older flows. Lava flows were active above the pali (5 km SE of Pu'u 'O'o) and in a 1-km-wide area on the coastal plain. To the W, a 350-m-wide lava flow advanced towards the coast and produced scattered breakouts. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations. A few small bench collapses may have occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 February-19 February 2013 Citation IconCite this Report

During 13-19 February HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. The lake level was between 25-30 m below the Halema'uma'u crater floor during 13 and 15-17 February.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a perched crusted lava lake on the NE part of the floor. Lava flowed from the SE and S spatter cones on 13 February and from the SW cone on 17 February. On 19 February lava flowed from the SW and NE spatter cones. New breakouts occurred on the Kahauale'a lava tube high on the NE flank of Pu'u 'O'o cone.

Multiple lava flows, collectively called the Kahauale'a flow, from the lava lake (perched 5-6 m higher than the crater rim) traveled across the NE flank of Pu'u 'O'o cone to the cone's base and continued to advance N and E over older flows. Lava flows were active above the pali (5 km SE of Pu'u 'O'o) and in a 1-km-wide area on the coastal plain. To the W, a 350-m-wide lava flow advanced towards the coast and produced scattered breakouts. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 February-12 February 2013 Citation IconCite this Report

During 6-12 February HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. The lake level was 27 m below the Halema'uma'u crater floor on 6 February, 25-27 m below the floor on 7 February, and 31 m below the floor on 11 February.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a perched crusted lava lake on the NE part of the floor. Multiple lava flows from the lava lake (perched 5-6 m higher than the crater rim) traveled across the NE flank of Pu'u 'O'o cone to the cone's base and continued to advance over older flows. Lava flows were active on the pali and in a 1-km-wide area on the coastal plain. To the W, a 350-m-wide lava flow advanced more than 1.2 km from the base of the pali and remained active with scattered breakouts. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 January-5 February 2013 Citation IconCite this Report

During 30 January-5 February HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. The lake level was 32 m below the Halema'uma'u crater floor on 31 January.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a perched circulating lava lake on the NE part of the floor. Lava flows were active in a 1-km-wide area on the coastal plain. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations. Lava from the lava lake (perched 5-6 m higher than the crater rim) flowed across the NE flank of Pu'u 'O'o cone to the cone's base and continued to advance over older flows. On 31 January the N spatter cone gushed with lava; the flow quickly banked against the N crater wall, advanced E to the base of the perched pond at the NE edge, and W towards the W crater wall. On 4 February a minor amount of lava flowed out of the SW spatter cone, and a brief but voluminous lava flow gushed out of the NW spatter cone on 5 February.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 January-29 January 2013 Citation IconCite this Report

During 23-29 January HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. on 23 January a portion of the W vent wall fell into the lake. The lake level was 35 m below the Halema'uma'u crater floor on 23 January and 38 m below the floor on 28 January.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a perched circulating lava lake on the NE part of the floor. Lava flows were active in a 1-km-wide area on the coastal plain. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations. On most days lava flows from multiple vents were active on the crater floor. On 25 and 26 January pilots confirmed that a lava flow remained active on the E flank of Pu'u 'O'o cone.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 January-22 January 2013 Citation IconCite this Report

During 16-22 January HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. During 15-16 January rocks fell into and disrupted the lake surface. The lake level was 35 m below the Halema'uma'u crater floor on 16 January and 27 m below the floor on 19 January.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a circulating lava lake on the NE part of the floor. Lava flows were active in a 1-km-wide area that stretched from near the base of the pali to the coast. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations. Lava levels remained mostly high in the crater; several lava flows from multiple vents were active on the crater floor. The lava lake was perched several meters above the crater rim and sporadically issued lava that flowed outside the crater and onto the E flank of the cone.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 January-15 January 2013 Citation IconCite this Report

During 9-15 January HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. The lake level was 40-45 m below the Halema'uma'u crater floor during 9-10 January, 32 m below the floor on 14 January, and 25 m below the floor on 15 January (which was a little higher than the previous high point in late October 2012).

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a circulating lava lake on the NE part of the floor. Lava flows were active in a 1-km-wide area that stretched from near the base of the pali to the coast. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations. During 9-13 January the lava lake overflowed and occasionally fed larger flows on the crater floor and two small flows on the E flank of Pu'u 'O'o cone. Lava flowed from the SE spatter cone on 11 January and from the SW spatter cone the next day. Lava levels remained high in the crater during 14-15 January; several lava flows from multiple vents were active on the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 January-8 January 2013 Citation IconCite this Report

During 2-8 January HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. A few pieces of the inner ledge of the lake as well as several pieces of veneer on the walls of the conduit occasionally fell into the lake.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a circulating lava lake on the NE part of the floor. Lava flows were active in a 1-km-wide area that stretched from near the base of the pali to the coast. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations. On 4 January the N and W rims of the lava lake collapsed into the lake.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 December-1 January 2013 Citation IconCite this Report

During 26 December-1 January HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a circulating lava lake on the NE part of the floor. The lava lake briefly overflowed on 27 December. During 29-30 December lava flowed from the easternmost spatter cone in the S part of the crater floor. Lava flows were active in a 1-km-wide area that stretched from near the base of the pali to the coast. During 28-30 December web cameras recorded infrequent and weak steam plumes from lava sporadically entering the ocean at multiple locations.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 December-25 December 2012 Citation IconCite this Report

During 19-25 December HVO reported that on most days the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a circulating lava lake on the NE part of the floor. During 21-24 December a few brief and short lava flows issued from the spatter cones at the S edge of the crater floor. Lava flows were active in a 1-km-wide area that stretched from near the base of the pali to the coast. There were no webcam recordings of any ocean entry plumes or reports suggesting that lava had been entering the ocean since 17 December.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 December-18 December 2012 Citation IconCite this Report

During 12-18 December HVO reported that on most days the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a lava lake on the NE part of the floor which was mostly covered by a spatter cone. The lava lake overflowed during 12-13 December, and on 13 December lava flowed from the SW spatter cone. On 14 December the N rim of the NE spatter cone/lava lake collapsed and was followed by a brief overflow of the lake. A larger lava flow issued from a spatter cone on the N edge of the crater floor, followed by another smaller flow; both flows traveled W, then split and flowed N and S. Another rim collapse from the NE spatter cone/lava lake and small overflow were observed the next day.

Lava flows remained active in two branches on the coastal plain: a small W branch, and a larger E branch with scattered activity extending from the pali to the coast E of the easternmost boundary of Hawai'i Volcanoes National Park. An ocean entry was marked by a weak and variable plume near Kupapa'u, with lava entering the water in at least two different areas. A new lava flow at the top of the pali was observed on 11 December. On 15 December observers noted that lava flows were active in a 1-km-wide area that stretched from near the base of the pali to the coast. On 16 December HVO noted that a lava delta at the ocean entry had slowly grown to be 50 m wide.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 December-11 December 2012 Citation IconCite this Report

During 5-11 December HVO reported that on most days the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, lava circulated within the perched lava lake at the NE part of the crater, and glow emanated both from spatter cones on the SE part of the crater floor and from a spatter cone at the NW edge. The lava lake briefly overflowed on 5 December, and small, short-lived lava flows emanated from the spatter cones during 7-9 December. Through the week a spatter cone formed over the lava lake, covering the surface.

Lava flows remained active in two branches on the coastal plain: a small W branch, and a larger E branch with scattered activity extending from the pali to the coast E of the easternmost boundary of Hawai'i Volcanoes National Park. An ocean entry was marked by a weak and variable plume near Kupapa'u, with lava entering the water in at least two different areas.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 November-4 December 2012 Citation IconCite this Report

During 28 November-4 December HVO reported that on most days the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, lava circulated within the perched lava lake at the NE part of the crater, and glow emanated from spatter cones on the SE part of the crater floor and from a spatter cone at the NW edge. Lava overflowed the lava lake on 24 November and 2 December.

Lava flows remained active in two branches on the coastal plain: a small W branch, and a larger E branch with scattered activity extending from the pali to the coast E of the easternmost boundary of Hawai'i Volcanoes National Park. During 28-30 November steam plumes did not rise from the ocean entry point; on 30 November geologists confirmed that active lava flows were 100 m from the coast. Lava again entered the ocean during 1-2 and 4 December.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 November-27 November 2012 Citation IconCite this Report

During 21-27 November HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, lava circulated within the perched lava lake at the NE part of the crater, and glow emanated from vents at the S edge of the crater floor and from a spatter cone at the N edge. A small lava flow issued from the E vent at the S edge of the crater floor on 24 November.

The easternmost of two lava flows on the coastal plain entered the ocean on 24 November in an area 500 m E of the easternmost border of Hawai'i Volcanoes National Park. Steam plumes rose from the entry point during 25-26 November, suggesting lava continued to enter the ocean. A plume was absent on the morning of 27 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 November-20 November 2012 Citation IconCite this Report

During 14-19 November HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. Lava flows were active on the coastal plain, but were about 290 m from the coast.

Activity at Pu'u 'O'o Crater remained elevated. Lava circulated within the perched lava lake at the NE pit at Pu'u 'O'o Crater, and glow emanated from vents at the S edge of the crater floor and from a spatter cone at the N edge. Small lava flows issued a few times from the westernmost vent at the S edge of the crater floor during 17-18 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 November-13 November 2012 Citation IconCite this Report

During 7-13 November HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. Lava flows were active in the Royal Gardens subdivision and flowed across the coastal plain, but were about 500 m from the coast.

Activity at Pu'u 'O'o Crater remained elevated. Lava circulated within the perched lava lake at the NE pit at Pu'u 'O'o Crater, and glow emanated from vents at the S edge of the crater floor and from a spatter cone at the N edge. Small lava flows issued a few times from the westernmost vent at the S edge of the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 October-6 November 2012 Citation IconCite this Report

During 31 October-6 November HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. Lava flows were active in the Royal Gardens subdivision and flowed across the coastal plain, but were 1-1.3 km from the coast. The perched lava lake within the NE pit at Pu'u 'O'o Crater remained active, and glow emanated from sources at the S and N edges of the crater floor. Spatter from the N edge was observed. On 1 November geologists observed the perched lava lake and noted that it was a few meters above the Pu'u 'O'o Crater rim. During 2-3 November lava flowed from the spatter cone on the N part of the crater floor, and was accompanied by spattering.

During 4-5 November activity increased within Pu'u 'O'o Crater. A small amount of lava spilled out of the perched lava lake and from the easternmost of the two sources at the S edge of the crater floor; larger, episodic flows from the easternmost source at the S floor edge continued later. Spattering continued from the cone at the N floor edge.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 October-30 October 2012 Citation IconCite this Report

During 24-30 October HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter, Pele's hair, and rock from the vent wall onto nearby areas. Cracking noises, audible from the Jaggar overlook and caused by rocks of the vent wall fracturing from the heat, emanated sporadically from the vent. Occasional collapses of rock from the vent walls triggered bursts of spatter that deposited a small amount of ejecta on the floor of Halema'uma'u Crater. On 25 October the lake rose to a level 27 m below Halema'uma'u Crater floor.

Lava flows accumulated at the base of the pali in the Royal Gardens subdivision and flowed across the coastal plain, but were 1.3 km from the coast. Flows also remained active on the pali. Activity at Pu'u 'O'o Crater remained elevated: the lava lake in the NE pit overflowed its rim, the vent on the N part of the crater floor produced lava flows, and lava fountaining and lava flows from the S vent were observed. Spattering was recorded from sources at the S and N edges of the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 October-23 October 2012 Citation IconCite this Report

During 17-23 October HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. Cracking noises, audible from the Jaggar overlook and caused by rocks of the vent wall fracturing from the heat, emanated sporadically from the vent. On 18 October the lake rose to a level 42 m below Halema'uma'u Crater floor, and the next day the lake rose to 38 m below the floor. During 21-23 October the lake rose to within 33 m of the crater floor. Small collapses of rock into the N portion of the lava lake triggered small spatter explosions on 21 and 23 October.

Lava flows accumulated at the base of the pali in the Royal Gardens subdivision and flowed across the coastal plain, but were 1.4 km from the coast. Flows also remained active on the pali. At Pu'u 'O'o Crater, incandescence was visible from lava flows in the S pit, lava circulating in the NE pit, and from the W edge of the crusted N pit. Three small lava flows erupted from a spatter cone on the S side of the crater floor on 17 October. Two fuming hot vents in the same area were observed the next day. Activity at Pu'u 'O'o Crater was elevated during18-21 October; the lava lake in the NE pit overflowed its rim, the S pit produced three lava flows, and the spatter cone vigorously spattered.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 October-16 October 2012 Citation IconCite this Report

During 10-16 October HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas.

Lava flows accumulated at the base of the pali in the Royal Gardens subdivision and flowed across the coastal plain, but were 1.7 km from the coast on 10 October. Flows also remained active high on the pali. At Pu'u 'O'o Crater, incandescence was visible from lava flows in the S pit, lava circulating in the NE pit, and from the W edge of the crusted N pit. On 12 October lava erupted from an incandescence spatter cone at the W edge of the N pit, filling a low depression on the N side of the crater floor and extending almost to the NE pit and lava lake. Small flows erupted from a spatter cone in the S pit during 13-14 and 16 October.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 October-9 October 2012 Citation IconCite this Report

During 3-9 October HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. On 5 October geologists using a laser range-finder measured the high lava level at 52 m below the floor of Halema'uma'u Crater, which was a new maximum level.

Lava flows reached the base of the pali in the Royal Gardens subdivision and flowed across the coastal plain, but were 1.6 km from the coast. At Pu'u 'O'o Crater, incandescence was visible from lava flows in the S pit, lava circulating in the E pit, and from the W edge of the crusted N pit. An opening in the roof of the lava tube at the base of the SE flank of Pu'u 'O'o also continued to glow until nearly the end of the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 September-2 October 2012 Citation IconCite this Report

During 26 September-2 October HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Periodic measurments indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. Lava flows were active above the abandoned Royal Gardens subdivision and flowed down the pali. At Pu'u 'O'o Crater, incandescence was often visible from the S pit, from lava circulating in the E pit, and from the W edge of the crusted N pit. An opening in the roof of the lava tube at the base of the SE flank of Pu'u 'O'o also continued to glow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 September-25 September 2012 Citation IconCite this Report

During 19-25 September HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. Lava flows were active above the abandoned Royal Gardens subdivision and began to flow down the pali. At Pu'u 'O'o Crater, incandescence from the S and E pits on the crater floor, and from the W edge of the crusted N pit, was often visible. An opening in the roof of the lava tube at the base of the SE flank of Pu'u 'O'o also continued to glow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 September-18 September 2012 Citation IconCite this Report

During 12-18 September HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair, and possible crater wall veneer, onto nearby areas. Lava flows were active above the abandoned Royal Gardens subdivision. At Pu'u 'O'o Crater, incandescence from the S and E pits on the crater floor, and from the W edge of the crusted N pit, was often visible. An opening in the roof of the lava tube at the base of the SE flank of Pu'u 'O'o also continued to glow. On 14 September HVO geologists estimated that the lava lake in the E pit was about 10 m below the rim.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 September-11 September 2012 Citation IconCite this Report

During 5-11 September HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas.

On 4 September HVO geologists observed the Pu'u 'O'o Crater floor and noted lava ponds in the E and S pits, with the N pit being fully crusted over. During 5-11 September glow emanated from the E and S pit craters; lava in the N pit was crusted, but was periodically incandescent on the W edge. A collapse in the roof of the lava tube at the base of the SE flank of Pu'u 'O'o also continued to glow. Lava flows were active above and at the top of the pali. On 11 September a geologist confirmed that lava flows above the pali had advanced to the top of the abandoned Royal Gardens subdivision.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 August-4 September 2012 Citation IconCite this Report

During 28 August-4 September HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. On 28 August two major collapses of the inner wall significantly disrupted the lake's circulation.

Lava flows were periodically active on the pali and the coastal plain. At Pu'u 'O'o, a collapse of the crater floor just before 0400 on 30 August enlarged the newer pit crater at the S edge, making it appear slightly larger in the webcam views than the older, active, pit crater on the E edge. A new pit crater formed at the N edge of the floor after 1000, and by 1300 it was filled with lava. The N rim of the E pit crater fell into the lava lake there just before 1700. During 30-31 August incandescence emanated from the lava lake in the E pit crater but was absent from the S pit crater. A few scattered areas of flow activity on the coastal plain more than 2 km from the coast were visible on web cameras. On 1 September glow emanated from the E and S pit craters. Crusted lava filled the N pit crater and sagged, and a couple of small lava flows traveled from the edge onto the sagging crust. The N pit appeared to be a passive lava lake, without a direct source of magma underneath. A collapse in the roof of the lava tube at the base of the SE flank of Pu'u 'O'o continued to glow but was less bright the next day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 August-28 August 2012 Citation IconCite this Report

During 22-28 August HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent likely continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. There were no significant geologic changes in Pu'u 'O'o Crater; incandescence emanated from a lava lake in a pit on the NE part of the crater floor, from a pit crater on the S part of the crater floor, and from a vent at the base of the SE flank. The vent on the S part of the crater floor produced a small lava flow on 26 August. Lava flows were active on the pali and the coastal plain, and were as close as 2 km from the ocean on 28 August.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 August-21 August 2012 Citation IconCite this Report

During 15-21 August HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. There were no significant geologic changes in Pu'u 'O'o Crater; the glowing vent at the base of the SE flank continued to glow brightly, and incandescence emanated from a lava lake in a pit on the NE part of the crater floor. A small, new pit crater opened on the S crater floor on 17 August. Lava flows were active on the pali and the coastal plain. The active lava-flow front was about 2 km from the ocean on 18 August.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 August-14 August 2012 Citation IconCite this Report

During 8-14 August HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. There were no significant geologic changes in Pu'u 'O'o Crater; a few days before 11 August a new glowing vent SE of the crater appeared, probably from a newly-opened skylight in the lava-tube system feeding flows on the pali and coastal plain. Lava flows were active on the pali and the coastal plain. The active lava-flow front was about 2 km from the ocean on 14 August.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 August-7 August 2012 Citation IconCite this Report

During 1-7 August HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. Glow from the lava pond in a small pit on the E edge of the Pu'u 'O'o crater floor and two vents along the S edge of the floor was visible with the web cameras. Lava flows were active on the pali and the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 July-31 July 2012 Citation IconCite this Report

During 25-31 July HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. The lava pond in a small pit on the E edge of the Pu'u 'O'o crater floor and two vents along the S edge of the floor were visible with the web cameras. Lava flows were active on the pali and the coastal plain; the active lava-flow front was about 1.8 km from the ocean on 31 July.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 July-24 July 2012 Citation IconCite this Report

During 18-24 July HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. The lava pond in a small pit on the E edge of the Pu'u 'O'o crater floor and two vents along the S edge of the floor were visible with the web cameras. Lava flows were active on the pali and the coastal plain; the active lava-flow front was about 1.9 km from the ocean on 24 July.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 July-17 July 2012 Citation IconCite this Report

During 11-17 July HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. The lava pond in a small pit on the E edge of the Pu'u 'O'o crater floor was 7-8 m below the rim on 12 July. The pond and two vents along the S edge of the floor were visible with the web cameras. A vent on the W part of the crater was also briefly incandescent. Lava flows were active on the pali and the coastal plain; the active lava-flow front was about 1.3 km from the ocean.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 July-10 July 2012 Citation IconCite this Report

During 4-10 July HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. The lava pond in a small pit on the E edge of the Pu'u 'O'o crater floor and two vents along the S edge of the floor were visible with the web cameras. On most days lava flows were active on the pali, at the base of the pali and onto the coastal plain, and farther out on the coastal plain near the Royal Gardens/Hawai'i Volcanoes National Park boundary.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 June-3 July 2012 Citation IconCite this Report

During 27 June-3 July HVO reported that the lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and Pele's hair onto nearby areas. The lava pond in a small pit on the E edge of Pu'u 'O'o crater floor and two vents along the S edge of the floor were visible with the web cameras. Lava flows were active on the pali and coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 June-26 June 2012 Citation IconCite this Report

During 20-26 June HVO reported that the lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and Pele's hair onto nearby areas. The lava pond in a small pit on the E edge of Pu'u 'O'o crater floor and two vents along the S edge of the floor were visible with the web cameras. Lava flows were active on the coastal plain and traveled as far as 1 km from the ocean. Lava flows were also active on the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 June-19 June 2012 Citation IconCite this Report

During 13-19 June HVO reported that the lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and Pele's hair onto nearby areas. The lava pond in a small pit on the E edge of Pu'u 'O'o crater floor was visible with the web cameras, and on 15 June was 7-8 m below the rim. Incandescence emanated from two vents along the S edge of the crater floor, and a lava flow issued from a south-central vent on 14 June. Lava flows were active on the coastal plain and traveled as far as 1.1 km from the ocean. Lava flows were also sometimes active on the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 June-12 June 2012 Citation IconCite this Report

During 6-12 June HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, rising as high as the inner ledge about 60 m below the crater floor. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and Pele's hair onto nearby areas. The lava pond in a small pit on the E edge of Pu'u 'O'o crater floor was visible with the web cameras. Lava flows periodically issued from vents on the S and south-central parts of Pu'u 'O'o's crater floor. Lava flows were active on the coastal plain and traveled as far as 1.6 km from the ocean. Lava flows were also sometimes active on the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 May-5 June 2012 Citation IconCite this Report

During 30 May-5 June HVO reported that the circulating and spattering lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, rising as high as the inner ledge about 60 m below the crater floor. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and Pele's hair onto nearby areas. The level of the lava pond in a small pit on the E edge of Pu'u 'O'o crater floor rose back into view. Field geologists observed many lava flows coming down the pali and extending onto the coastal plain. A small new collapse pit in Pu'u 'O'o about 50 m west of the southern spatter cone was observed on 1 June; weak incandescence from this pit was visible in the thermal camera. On 5 June geologists observed a second small collapse pit near the south-central edge that had been covered by a small shield of lava while the lava pond in the E collapse pit had risen to within about 5 m of the rim.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 May-29 May 2012 Citation IconCite this Report

During 23-29 May HVO reported that the circulating and spattering lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Parts of the inner ledge and crater wall surrounding the lake occasionally collapsed into the lake. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, Pele's hair, and occasionally fresh spatter from the margins of the lava lake, onto nearby areas. The level of the lava pond in a small pit on the E edge of Pu'u 'O'o crater floor dropped out of view. A small lava flow erupted from a vent on the S part of the floor on 23 May. On 28 May HVO noted that lava-flow activity on the coastal plain SE of Pu'u 'O'o appeared to have stopped.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 May-22 May 2012 Citation IconCite this Report

During 16-22 May HVO reported that the circulating and spattering lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, and spilled over the deep inner ledge on multiple occasions. On 15 May laser measurements indicated that the lava-lake surface was about 65 m below the Halema'uma'u Crater floor, among the highest levels measured; the lake rose five more meters during 18-19 May. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, and occasionally fresh spatter from the margins of the lava lake, onto nearby areas. A lava pond in a small pit on the E edge of Pu'u 'O'o crater floor remained active with spattering. On 19 May a small collapse of the N rim of the pit slightly enlarged the pit and lava pond within. A small lava flow erupted from a vent on the S part of the floor. Lava flows were active on the pali and the coastal plain, and were about 750 m from the sea.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 May-15 May 2012 Citation IconCite this Report

During 9-15 May HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. On 14 May laser measurements indicated that the lava-lake surface was about 67 m below the Halema'uma'u Crater floor. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, and occasionally fresh spatter from an active source at the SE edge of the lava lake, onto nearby areas. Incandescence was visible from both a lava pond in a small pit on the E edge and a small spatter cone on the SE edge of the Pu'u 'O'o crater floor, and from two skylights on the uppermost part of the lava-tube system. Geologists observed slowly advancing lava flows on 13 May that were about 1.4 km from the coast. A short lava flow issued from an incandescent vent on the S part of Pu'u 'O'o's crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 May-8 May 2012 Citation IconCite this Report

During 2-8 May HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Frequent measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, and occasionally fresh spatter from an active source at the SE edge of the lava lake, onto nearby areas. Incandescence was visible from both a lava pond in a small pit on the E edge and a small spatter cone on the SE edge of the Pu'u 'O'o crater floor. Geologists observed slowly advancing lava flows on 4 May that were about 1.1 km from the coast, not reaching as far as previous flows on the coastal plain over the past month. On 5 May further collapse of the pit on the E edge of the Pu'u 'O'o crater floor led to much brighter incandescence from that area. Lava flows on the coastal plain stalled while new lava flows high on the pali formed on 5 May, vigorously advancing from the base of the pali to more than halfway across the flow field during 5-8 May.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 April-1 May 2012 Citation IconCite this Report

During 25 April-1 May HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Frequent measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, and occasionally fresh spatter, nearby. Incandescence was visible from both a lava pond in a small pit on the E edge and a small spatter cone on the SE edge of the Pu'u 'O'o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain, reaching about 900 m from the coast. New lava flows on the pali were observed on 30 April, while web cameras recorded decreasing incandescence on the coastal plain during 30 April-1 May.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 April-24 April 2012 Citation IconCite this Report

During 18-24 April HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, and occasionally fresh spatter, nearby. Incandescence was visible from both a lava pond in a small pit on the E edge and a small spatter cone on the SE edge of the Pu'u 'O'o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain, reaching about 1.1 km from the coast. During 19-20 April small lava flows issued from a vent on the SE edge of the Pu'u 'O'o crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 April-17 April 2012 Citation IconCite this Report

During 11-17 April HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, and occasionally fresh spatter, nearby. Incandescence was visible from both a lava pond in a small pit on the E edge and a small spatter cone on the SE edge of the Pu'u 'O'o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain, reaching about 1.4 km from the coast. On 11 and 13 April small lava flows issued from a vent on the SE edge of the Pu'u 'O'o crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 April-10 April 2012 Citation IconCite this Report

During 4-10 April HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, and occasionally fresh spatter, nearby. Incandescence was visible from both a lava pond in a small pit on the E edge and a small spatter cone on the SE edge of the Pu'u 'O'o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain, reaching about 1.6 km from the coast. During 6-9 April a small lava flow issued three times from a vent on the SE edge of the Pu'u 'O'o crater floor. The first two flows advanced N almost the entire width of the floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 March-3 April 2012 Citation IconCite this Report

During 28 March-3 April HVO reported that the lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash nearby. Incandescence was visible from both a small pit on the NE edge and a small spatter cone on the SE edge of the Pu'u 'O'o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain, reaching about 1.6 km from the coast. On 2 April a small lava flow issued from a vent on the S edge of the Pu'u 'O'o crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 March-27 March 2012 Citation IconCite this Report

During 21-27 March HVO reported that the lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. Incandescence was visible from both a small pit on the NE edge and a small spatter cone on the SE edge of the Pu'u 'O'o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 March-20 March 2012 Citation IconCite this Report

During 14-20 March, HVO reported that the lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. Incandescence was visible from both a small pit on the NE edge and a small spatter cone on the SE edge of the Pu'u 'O'o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain, and were about 2 km from the coast.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 March-13 March 2012 Citation IconCite this Report

During 7-13 March, HVO reported that the lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. Incandescence was visible from both a small pit on the NE edge and a small spatter cone on the SE edge of the Pu'u 'O'o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain. On 12 March the leading edge of the flows were 9 km SE of Pu'u 'O'o and about 2 km from the coast.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 February-6 March 2012 Citation IconCite this Report

During 29 February-6 March, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Web camera views and satellite images indicated that lava flows continued to advance, reaching more than 7.5 km SE of Pu'u 'O'o. Active flows were also visible at the top of the pali SE of Pu'u 'O'o. Incandescence was visible on the NE and SE edges of the Pu'u 'O'o crater floor and on the upper part of the lava-tube system on the E flank. According to a news article, the last house in the Royal Gardens subdivision was destroyed by a lava flow on 2 March.

Sources: Hawaii Tribune Herald; US Geological Survey Hawaiian Volcano Observatory (HVO)


22 February-28 February 2012 Citation IconCite this Report

During 22-28 February, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Web camera views and satellite images indicated that lava flows remained active within the abandoned Royal Gardens subdivision more than 7.5 km SE of Pu'u 'O'o. Lava flows also remained active high on the pali and across the December 2011 flows. Incandescence was visible on the NE and SE edges of the Pu'u 'O'o crater floor and on the upper part of the lava-tube system on Pu'u 'O'o's E flank during 23 and 26-28 February. On 22 February a small lava flow from the SE source was observed by the web camera. Two minor lava flows issued from the NE source on 26 February, and one lava flow issued from NE source on 27 February.

On 25 February HVO geologists aboard an overflight reported that the small cone on the NE source periodically ejected spatter, and the SE source fumed and produced a lava flow. They also noted that the flow advanced as two lobes; one lobe traveled along the E margin of the December 2011 flows and another advanced along the W margin of the December 2011 flows. During 27-28 February the web camera and satellite images indicated that both the E and W lobes continued moving down the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 February-21 February 2012 Citation IconCite this Report

During 15-21 February, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Strong incandescence was visible from the collapsed cone on the NE edge and weaker from a cone on the SE edge during 15-18 and 20 February. A web camera recorded strong incandescence above the pali during 15-16 February. Incandescence also emanated from two sources on the E flank on 19 and 21 February.

Web camera views and satellite images indicated that lava flows remained active within the abandoned Royal Gardens subdivision more than 6.5 km SE of Pu'u 'O'o during 15-21 February. The flows advanced down the pali along the E side of the December 2011 flows during the week and on 21 February advanced to the kipuka on the E. On 17 February a second smaller branch appeared on the W side of the December 2011 flows. Ground-based observers reported active lava flows at the top of the pali during 15-21 February.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 February-14 February 2012 Citation IconCite this Report

During 8-14 February, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Incandescence was visible on the NE and SE edges of the Pu'u 'O'o crater floor, and strongest from a small cone on the NE edge during 8-13 February. A web camera recorded incandescence above the pali on 8 and during 12-14 February. The SE vent issued short lava flows on 14 February.

In comparison to last week, thermal anomalies increased on the flow field during 8-9 February. HVO geologists aboard an overflight on 9 February reported that the small cone on the NE edge had collapsed and was venting hot gas, and the pit was filled with a stream of lava heading NE. Geologists mapped active flows on the flow field about 6 km SE of Pu'u 'O'o and above the abandoned Royal Gardens subdivision. Web camera and satellite images indicated that the flows remained active 6 km SE of Pu'u 'O'o and above the abandoned Royal Gardens subdivision during 10-14 February, and from the Kalapana (E side of the coastal plain) on 13 February. Ground based observers reported active lava at the top of the pali on 11 and 13-14 February.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 February-7 February 2012 Citation IconCite this Report

During 1-7 February, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). On 1 February lava ejections on the S edge rebuilt a low spatter cone. On 3 February two large rockfalls into the lake originated from the Halema'uma'u Crater floor. The first collapse from the N rim induced secondary collapses of the inner ledge and ejected spatter onto nearby portions of the Halema'uma'u Crater floor. The second collapse deposited large amounts of debris into the NE side of the lava lake.

At Pu'u 'O'o short lava flows issued from the SE vent during 1-2 February. Incandescence was visible on the NE and SE edges of the Pu'u 'O'o crater floor during 3-7 February and from a small cone on the NE edge during 5-7 February. The web camera showed incandescence reflected in the clouds above the pali on 2 and 4 February. During 1-7 February, thermal anomalies were seen in satellite imagery 4-5 km SE of Pu'u 'O'o cone.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 January-31 January 2012 Citation IconCite this Report

During 25-31 January, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. During 25-27 January lava ejections on the SE edge built a small spatter rampart and produced small lava flows on the inner ledge.

Incandescence was visible on the NE, SE, and W edges of the Pu'u 'O'o crater floor during 25-31 January. On 25 January lava started to fill a Pu'u 'O'o crater floor depression and continued episodically all week. Geologists on a 26 January overflight reported lava flows 4 km SE of Pu'u 'O'o. On 27 January the SE and NE vents started to effuse lava. During 24-31 January, thermal anomalies were seen in satellite imagery 3-4 km SE of Pu'u 'O'o cone.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 January-24 January 2012 Citation IconCite this Report

During 18-24 January, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby.

Incandescence was visible on the NE, SE, and W edges of the Pu'u 'O'o crater floor during 18-24 January. Incandescence emanated both from small lava flows which had issued from the NE and SE sources on 18 January, and from a long narrow lava flow that traveled W across the crater floor on 20 January. Minor surface flows were observed in satellite imagery on the upper flow field on 18 January, and during 19-23 January, small thermal anomalies were seen in satellite imagery on the upper E rift zone. Scientists on an overflight reported small active pahoehoe lobes about 4 km SE of the Pu'u 'O'o cone on 21 January.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 January-17 January 2012 Citation IconCite this Report

During 11-17 January, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby.

Incandescence was visible from small spatter cones on the E, S, and W edges of the Pu'u 'O'o crater floor during 11-17 January. Incandescence was also exhibited by short lava flows from the E pit on 13 January, small lava flows issuing from the SE spatter cone, and a small flow from the NE pit on 16 January. During 11-16 January a thermal anomaly about 2-4 km SE of Pu'u 'O'o cone was seen in satellite imagery. On 12 January, geologists on an overflight confirmed surface activity at this location. By 15 January the source of the thermal anomaly had extended to the coast.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 January-10 January 2012 Citation IconCite this Report

During 4-10 January, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby.

Incandescence was visible along the 21 September 2011 fissure on the SE flank of the Pu'u 'O'o cone during 4-5 January and from small spatter cones on the E, S, and W edges of the Pu'u 'O'o crater floor during 4-10 January. A web camera showed no activity on the flow field during 4-10 January; however clouds may have prevented views. On 6 January activity increased within a small pit that formed on the E edge of the crater during the previous week. The pit filled with lava and overflowed generating a small lava flow to the N within the crater. Activity continued within the pit during 7-8 January with short lava flows N and W. On 8 January thermal anomalies seen in satellite imagery were about 2-4 km SW of Pu'u 'O'o cone and observers on an overflight reported surface flows in the same area. On 9 January satellite imagery showed a weaker thermal anomaly.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 December-3 January 2012 Citation IconCite this Report

During 28 December-3 January, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby.

Incandescence was visible from small spatter cones on the E and S edges of the Pu'u 'O'o crater floor and along the 21 September 2011 fissure on the SE flank of the Pu'u 'O'o cone. Geologists on an overflight reported that pahoehoe lava flows were significantly broader (700-1,000 m) across the coastal plain and were entering the ocean along a 900 m wide area of the coast on 27 December. Lava flows continued to be active about 6.8 km SE of Pu'u 'O'o and entered the ocean W of Ka'ili'ili on 28 December. During 29 December-2 January a web camera showed no surface activity on the pali, weak sporadic flows near the coast, and weak plumes from the ocean entry. At night during 31 December-2 January incandescence was seen above the pali; on the night of 1 January ground based observers reported lava on the pali. Clouds prevented observations from a web camera on 3 January.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 December-27 December 2011 Citation IconCite this Report

During 21-27 December, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. On 22 December the SW vent wall collapsed into the lake, ejected lava onto the inner ledge, and caused an increased amount of ash in the plume.

Incandescence was visible from small spatter cones on the E and S edges of the Pu'u 'O'o crater floor. Pahoehoe lava flows, that were 300-400 m wide and fed by lava tubes from the fissure, continued to be active about 6.8 km SE of Pu'u 'O'o and entered the ocean W of Ka'ili'ili. During 25-26 December the tube appeared to be more robust and less surface flow activity was reported. Small plumes were observed from the ocean entry during 22-24 December and infrequent weak plumes were observed during 25-26 December. On 27 December a breakout of lava flows were visible on the pali (a fault scarp).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 December-20 December 2011 Citation IconCite this Report

During 14-20 December, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby.

Incandescence was visible along the 21 September fissure on the SE flank of Pu'u 'O'o cone, from a skylight on the lava tube, and from small spatter cones on the E and S edges of the Pu'u 'O'o crater floor. Pahoehoe flows that were 300-400 m wide, fed by lava tubes from the fissure, continued to be active about 6.8 km SE of Pu'u 'O'o and entered the ocean W of Ka'ili'ili. The lava delta now extends 15-20 m into the ocean at a point 6.4 km W of the Chain of Craters Road. During 17-20 December the lava flow branched, with lobes advancing NE and W into the ocean. Infrequent plumes were observed from the ocean entry during 18-20 December.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 December-13 December 2011 Citation IconCite this Report

During 7-13 December, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby.

Incandescence was visible along the E and W edges of the Pu'u 'O'o crater floor, along the 21 September fissure on the SE flank of Pu'u 'O'o cone, and from a skylight on the lava tube. Lava continues to erupt into the perched pond formed on 6 December. Pahoehoe flows, fed through lava tubes from the fissure, continued to be active about 6.8 km SE of Pu'u 'O'o based on intermittent views from satellite. Analysis of 10-12 December satellite images suggested that lava had reached the coast and was flowing into the ocean. During 11-12 December incandescence was observed from small spatter cones on the E and S edges of the Pu'u 'O'o crater floor; short lava flows issued from the E edge of the crater floor on 12 December.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 November-6 December 2011 Citation IconCite this Report

During 30 November-6 December, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. Incandescence was visible from the E and W edges of the Pu'u 'O'o crater floor, and from the 21 September fissure on the SE flank of Pu'u 'O'o cone.

On 2 December incandescence was seen from a new area low on the N flank of Pu'u'O'o. Pahoehoe flows, fed through lava tubes from the fissure, continued to be active about 6.8 km SE of Pu'u 'O'o based on intermittent views from satellite, ground observers and an overflight on 3 December. During 4-5 December the vent on the E edge of the crater produced lava flows that partially filled the depression left by the flank fissure eruption in September and a perched lava lake was built on 6 December.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 November-29 November 2011 Citation IconCite this Report

During 23-29 November, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. Incandescence was visible from the E and W edges of the Pu'u 'O'o crater floor, and from the 21 September fissure on the SE flank of Pu'u 'O'o cone. Pahoehoe flows, fed through lava tubes from the fissure, continued to be active about 5.7 km SE of Pu'u 'O'o based on intermittent views from satellite. Incandescence from a skylight on the lava tube was also observed. Short lava flows issued from the E edge of the crater floor on 23 November and from both the E and W edges of the crater floor on 27 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 November-22 November 2011 Citation IconCite this Report

During 16-22 November, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. Incandescence was visible from the E and W edges of the Pu'u 'O'o crater floor, and from the 21 September fissure on the SE flank of Pu'u 'O'o cone. Pahoehoe flows, fed through lava tubes from the fissure, continued to be active about 5 km SE of Pu'u 'O'o based on intermittent views from satellite. Incandescence from a skylight on the lava tube was also observed. During 18-19 November the vent on the E edge of the crater produced lava flows that partially filled the depression left by the flank fissure eruption in September. There were also two brief and small lava-flow effusions from the W edge vent. Intermittent lava flows continued from the E vent during 20-22 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 November-15 November 2011 Citation IconCite this Report

During 9-15 November, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. Incandescence emanated from the E and W edges of the Pu'u 'O'o crater floor and from the 21 September fissure on the SE flank of Pu'u 'O'o cone. Pahoehoe flows, fed through lava tubes from the fissure, continued to be active about 4.7 km SE of Pu'u 'O'o based on an overflight on 12 November and satellite images. Incandescence from a skylight on the lava tube was also observed.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 November-8 November 2011 Citation IconCite this Report

During 2-8 November, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. Incandescence emanated from the E and W edges of the Pu'u 'O'o crater floor and from the 21 September fissure on the upper E flank of the Pu'u 'O'o cone during most of the reporting period. Pahoehoe flows, fed through lava tubes from the fissure, continued to be active about 4.5 km SE of Pu'u 'O'o based on an overflight on 3 November and satellite images acquired during 4-7 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 October-1 November 2011 Citation IconCite this Report

During 26 October-1 November, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. Incandescence emanated from the E and W edges of the Pu'u 'O'o crater floor and from the 21 September fissure on the upper E flank of the Pu'u 'O'o cone. On 30 October incandescence was seen from a new area high on the W edge of a depression in the crater floor. Lava flows remained active to the SE of Pu'u 'O'o during 26-30 October, but were more sluggish during 31 October-1 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 October-25 October 2011 Citation IconCite this Report

During 19-25 October, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. At the E rift zone, incandescence emanated from the 21 September fissure on the upper E flank of the Pu'u 'O'o cone and lava flows remained active on the flow field to the SE of Pu'u 'O'o. Vents on the E and W edges of crater floor were incandescent.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 October-18 October 2011 Citation IconCite this Report

During 12-18 October, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby. At the E rift zone, the fissure that formed on 21 September on the upper E flank of Pu'u 'O'o continued to periodically feed lava flows to the NE and SE of the fissure that did not significantly advance. Vents on the E and W edges of Pu'u 'O'o Crater floor were incandescent.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 October-11 October 2011 Citation IconCite this Report

During 5-11 October, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby.

At the E rift zone, the fissure that formed on 21 September on the upper E flank of Pu'u 'O'o continued to feed slowly-advancing lava flows to the NE and SE of the fissure. During the beginning of the week, overall activity within and SE of Pu'u 'O'o Crater had slowed; only a few lava patches were visible in webcams. During 7-8 October lava began to flow from a vent at the E end of the crater floor and from an area at the W end the next day. Lava flows from the E-end source stalled on 10 October.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 September-4 October 2011 Citation IconCite this Report

During 28 September-4 October, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby.

At the E rift zone, the fissure that formed on 21 September on the upper E flank of Pu'u 'O'o continued to feed lava flows on 28 September that traveled along the edges of a low lava ridge. Most of the active lava spread out at higher elevations S and W of Pu'u Halulu (1.3 km NE of Pu'u 'O'o). Lava activity resumed from two sources on the E edge of the Pu'u 'O'o Crater floor and continued to spread W within the crater. During an overflight on 29 September, geologists observed that the fissure fed scattered active lava flows within 1.8 km on the SE flank of the cone. During 2-3 October lava from the E-crater floor source covered the crater floor. On 4 October active lava was confined to a small lake on the E side of the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 September-27 September 2011 Citation IconCite this Report

During 21-27 September, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby.

At the E rift zone, lava in the W lava lake in Pu'u 'O'o Crater fed a series of lava flows that traveled down the W flank of Pu'u 'O'o during 20-21 September. At about 0225 on 21 September activity in the crater and overflows to the W suddenly decreased, as lava broke through the upper E flank of Pu'u 'O'o, bypassing the crater. The new fissure fed a channelized 'a'a lava flow that advanced rapidly downslope 2.5 km SE. A second flow to the W of the first began the next day. In addition, a small pad of lava actively refilled the bottom of the drained E lava lake and small flows were barely active at the W edge of Pu'u 'O'o Crater. The channelized 'a'a lava flow reached 3.7 km long on 23 September and then stalled within the Kahauale'a Natural Area Reserve. Most of the active lava spread S and W of Pu'u Halulu (1.3 km NE of Pu'u 'O'o) during 23-27 September. Minor lava activity resumed within Pu'u 'O'o Crater with short lava flows issuing from the base of the E wall on 25 September and from the W wall base during 25-26 September. The crater floor of Pu'u 'O'o slowly subsided. Lava activity resumed within the E lake on 26 September. The floor of the crater continued to subside during 26-27 September, opening up cracks in the N crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 September-20 September 2011 Citation IconCite this Report

During 14-20 September, HVO reported that the level of the lava-lake surface in the deep pit within Kilauea's Halema'uma'u crater periodically fluctuated and circulated. Daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby.

At the E rift zone, lava in the E lava lake overflowed the E rim of Pu'u 'O'o crater on 13 September and advanced a few hundred meters. Lava erupted within the W lava lake and the next day overflowed the W edge of the crater through two broad gaps in Pu'u 'O'o cone, spreading up to several hundred meters downslope and mantling the W flank of Pu'u 'O'o. The flows had stopped by the evening of 15 September. During 15-16 September the level of the lava lakes had dropped 10-15 m. During 17-18 September the W lake was inactive and the E lake weakly bubbled and slowly circulated. Activity within the W lake increased abruptly on 19 September and, during 19-20 September, lava flowed across the W part of the crater floor. On 20 September lava refilled two perched lava ponds on the W edge of the crater, overflowed the southern-most pond, and produced a channelized lava flow that advanced 800 m down Pu'u 'O'o's W flank.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 September-13 September 2011 Citation IconCite this Report

During 31 August-6 September, HVO reported that the level of the lava-lake surface in the deep pit within Kilauea's Halema'uma'u crater periodically fluctuated and circulated. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby. At Pu'u 'O'o' crater, lava from E, W, and S-central sources on the crater floor fed an eastern and a western perched lava lake during 7-8 September. Lava also covered much of the crater floor, rising to within 5 m of a low point on the E crater rim. During 9-10 September a large amount of lava from a new source of effusion at the NE edge of the crater covered most of the crater floor. On 10 September a pilot confirmed that lava overtopped the E rim and fed a short lava flow. Not long after that the effusion rate decreased and lava fed only the two perched lava lakes. During 11-13 September the lava lakes mostly circulated and, by 12 September, had overflowed onto the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 August-6 September 2011 Citation IconCite this Report

During 31 August-6 September, HVO reported that the level of the lava-lake surface in the deep pit within Kilauea's Halema'uma'u crater periodically fluctuated but remained mostly stable below the inner ledge 75 m below the crater floor. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby. At Pu'u 'O'o' crater, lava from sources on the E portion of the crater floor fed a perched lava lake. Lava from a source at the W edge of the crater floor spread N and S along the base of the W crater wall and up to the base of the W, inactive wall of the perched pond. During 2-3 September a new perched pond fed from the W-edge source had formed.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 August-30 August 2011 Citation IconCite this Report

During 24-30 August, HVO reported that the level of the lava-lake surface in the deep pit within Kilauea's Halema'uma'u crater periodically fluctuated but remained below the inner ledge 75 m below the crater floor. At Pu'u 'O'o' crater, lava from sources on the E and S portions of the crater floor fed a lava lake that was formed during 25-26 August. A new source opened at the W edge of the crater floor during 29-30 August, and lava quickly spread N and S along the base of the W crater wall.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 August-23 August 2011 Citation IconCite this Report

During 17-23 August, HVO reported that lava continued to trickle onto the collapsed floor of Kilauea's Pu'u 'O'o' crater and some spattering occurred from various areas on the floor. The only activity on the W flank was observed during 17-20 August; a small lava flow from the base of the N pond rim near the Kamoamoa fissures and a larger flow from the N flow branch were both active. During 20-21 August a small amount of lava emitted from a vent on the S crater floor flowed a short distance. Later, lava started issued in larger quantities from another source on the S part of the floor that quickly filled in a low trench. Lava continued to flow onto the crater floor during the next two days.

During 17-18 August lava flowed onto the floor of the vent inset within the E wall of Halema'uma'u Crater. By the next day a persistent spattering source at the W edge of the cavity pushed the lava surface sluggishly from W to E. During 19-21 August drain-and-fill cycles were observed; the highest level of the lava surface was below the inner ledge 75 m below Halema'uma'u Crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 August-16 August 2011 Citation IconCite this Report

During 10-16 August HVO reported that Kilauea's summit lava lake was mostly crusted, but lava, possibly from a source higher on the SE wall, occasionally flowed over the surface. Small rockfalls from the vent walls were frequent, and the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby. During an overflight on 11 August, scientists observed an E-W trench in the deepest part of the cavity. Lava was upwelling from the E end and flowing W. During 14-15 August hot and possibly spattering vents were visible on the W part of the cavity floor.

At the E-rift zone, lava continued to trickle onto Pu'u 'O'o's collapsed crater floor and some spattering occurred from various sources the floor. The W-flank vents remained active and fed an elongated perched lava pond that extended to the SW, and also a small flow which advanced a short distance N. Small overflows or breaches from the elongated lake were occasionally active on the N side. During the 11 August overflight, scientists noted that the activity was less vigorous; the two channels that continued to feed the perched lake were crusted over and the W-flank vents were no longer spattering. The pond rims were higher and the pond was narrower, lava flows from the base of the pond were active on the N and W sides of the pond, and the S rim of the pond appeared to be slowly migrating S. The crater floor subsided a small amount on 15 August.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 August-9 August 2011 Citation IconCite this Report

HVO reported that on 3 August at 1402 the floor of Kilauea's Pu'u 'O'o crater, which had risen significantly over the past month, began to subside. At 1420 lava erupted from a vent low on the W flank of the Pu'u 'O'o cone, about halfway between Pu'u 'O'o Crater and the E end of the Kamoamoa fissure, and formed two branches. The weaker flow traveled N into a forested kipuka. The higher-volume S branch quickly advanced down Kilauea's S flank along the edge of flows erupted during 2002-2004. By 1515, the crater floor and perched lava lake began to collapse; the circulation in the lava lake was maintained as the crater floor dropped. Within a few hours the lava lake was no longer visible and the crater floor, which had dropped 75-85 m, was covered with rubble. Between 1530 and 1615, the preliminary sulfur dioxide emission rate from all east rift zone sources was as high as 7,000 tonnes/day. The rate decreased to 4,000 tonnes/day at about 1700. Also by that time the lava flow had advanced 3.6 km.

During 4-9 August lava continued to flow from multiple W-flank vents topped with spatter cones, ponding in a low area due to a decreasing effusion rate. The Pu'u 'O'o crater rim was extremely unstable; continued collapses along the crater walls sent blocks of rock onto the crater floor. Lava also slowly flowed back onto the collapsed crater floor.

During 3-9 August the level of the summit lava lake fluctuated deep in the 150-m-diameter vent inset within the E wall of Halema'uma'u Crater and circulated with various patterns. Overall, the lake level receded and on 6 August was about 75 m below the crater floor. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 July-2 August 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 27 July-2 August. The level of the summit lava lake fluctuated deep in the 150-m-diameter vent inset within the E wall of Halema'uma'u Crater and circulated with various patterns. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby.

Lava from the Puka Nui and MLK pits, smaller craters to the W of the main Pu'u 'O'o crater, continued to overflow to the SW, producing a tube-fed pahoehoe flow that had advanced about 700 m from the Puka Nui rim during 25-30 July. Lava from the base of the NE crater filled a trough between the crater wall and the perched lava lake. Uplift of the crater floor and lava lake continued until 30 July, when a breakout lava flow started along the base of the crater's S wall and the lake slowly subsided. Subsidence continued the next day but switched to inflation on 1 August. The preliminary sulfur dioxide emission rate from all east rift zone sources was calculated at 1,700, 1,000, and 800 tonnes/day on 29 and 30 July, and 1 August, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 July-26 July 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 20-26 July. The level of the summit lava lake fluctuated deep in the 150-m-diameter vent inset within the E wall of Halema'uma'u Crater and circulated with various patterns. Spattering occurred at locations along the edge of the lake. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby. At Pu'u 'O'o, lava from vents near the NE edge of the perched lava lake in the center of the crater floor continued to fill the circulating lake. The perched lake and crater floor continued to be uplifted and cracks on the doming crater floor were observed. Minor lava activity was noted in the Puka Nui and MLK pits, smaller craters to the W of the main Pu'u 'O'o crater. Based on several measurements throughout July, the crater floor was uplifted about 0.5-1 m per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 July-19 July 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 13-19 July. The level of the summit lava lake fluctuated deep in the 150-m-diameter vent inset within the E wall of Halema'uma'u Crater and circulated with various patterns. Spattering occurred at locations along the edge of the lake. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby.

The preliminary sulfur dioxide emission rate from all of the east rift zone sources was 1,500 tonnes/day on 12 July, the highest emission rate since the end of the Kamoamoa eruption in early March. At Pu'u 'O'o, lava from vents near the NE edge and, to a lesser degree, along the W edge of the perched lava lake in the center of the crater floor continued to fill the lake. The lake level fluctuated and flowed through rim breaches, sending lava onto the Pu'u 'O'o crater floor. The near-vertical rim of the perched pond continued to be uplifted until through 17 July; the crater floor and perched lake rims formed a nearly-continuous ramp sloping away from the lake. The lava lake surface of the perched lava lake was elevated about 6 m higher than the surrounding crater floor and the rim was a few meters higher than the surface; the crater floor was 19 m below the E crater rim. Since the last measurements on 29 June, the crater floor had been uplifted about 1 m per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 July-12 July 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 6-12 July. The level of the summit lava lake fluctuated deep in the vent inset within the E wall of Halema'uma'u Crater and circulated with various patterns. Spattering occurred at locations along the W edge of the lake. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash nearby. At Pu'u 'O'o, lava from vents near the NE edge and, to a lesser degree, along the W edge of the perched lava lake in the center of the crater floor continued to fill the lake. The lake level fluctuated and flowed through rim breaches, sending lava onto the Pu'u 'O'o crater floor. The near-vertical rim of the perched pond, which was elevated about 5 m higher than the surrounding sub-horizontal crater floor on the E side, continued to be uplifted; the crater floor and perched lake rims formed a nearly-continuous ramp sloping away from the lake.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 June-5 July 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 29 June-5 July. The level of the summit lava lake fluctuated deep in the vent inset within the E wall of Halema'uma'u Crater. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash nearby. At Pu'u 'O'o, lava from vents near the NE edge of the perched lava lake in the center of the crater floor continued to fill the lake. The lake level fluctuated and overflowed the edges or flowed through rim breaches, sending lava onto the Pu'u 'O'o crater floor. On 3 July inflation caused the crater floor and perched lake rim in the southern half of Pu`u `O`o Crater to rise; those areas continued to rise on 4 July until a large breach on the S rim of the lava lake occurred at midnight. Lava spilled onto the crater floor between the perched rim and the crater wall. The N rim rose briefly but rapidly between 5 and 10 minutes after midnight. The preliminary sulfur dioxide emission rate from all east rift zone sources was calculated at 700 tonnes/day on 30 June.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 June-28 June 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 22-28 June. The level of the summit lava lake fluctuated deep in the vent inset within the E wall of Halema'uma'u Crater. A gas plume from the vent drifted SW, depositing variable amounts of ash nearby. At Pu'u 'O'o, lava from vents near the NE edge of the perched lava lake in the center of the crater floor continued to fill the lake. The lake level fluctuated and overflowed the edges or flowed through rim breaches, sending lava onto the Pu'u 'O'o crater floor. A small shield had built up against the SW crater wall on the W side of the lake. On 23 June the rim of the perched lava lake was elevated 6-8 m higher than the surrounding crater floor; the crater floor was 35 m below the E crater rim. The preliminary sulfur dioxide emission rate from all east rift zone sources was calculated at 700 tonnes/day that same day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 June-21 June 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 15-21 June. The level of the summit lava lake fluctuated but remained mostly stable deep in the vent inset within the E wall of Halema'uma'u Crater. A gas plume from the vent drifted SW, depositing variable amounts of ash and fresh spatter nearby. On 17 June a heated brown plume rose from a spattering source on the SE edge of the lake; the ejecta were primarily fresh spatter bits suggesting that the plume derived from a partial collapse of the spattering source or a small rockfall.

At Pu'u 'O'o, lava from vents near the W and NE edges of the perched lava lake in the center of the crater floor continued to fill the lake. The lake level fluctuated and overflowed the edges or flowed through rim breaches, sending lava onto the Pu'u 'O'o crater floor. A small shield had built up against the SW crater wall on the W side of the lake. There was also minor lava activity from at least one source at the base of the SW crater wall.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 June-14 June 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 8-14 June. The level of the summit lava lake remained mostly stable deep in the vent inset within the E wall of Halema'uma'u Crater. Occasional increases in the lake level covered a vent on the south side wall; on other days lava from the vent cascaded down into the lake. A gas plume from the vent drifted SW. At Pu'u 'O'o, lava from vents near the W and NE edges of the perched lava lake in the center of the crater floor continued to fill the lake. The lake level fluctuated and infrequently overflowed the edges or flowed through a rim breach, sending lava onto the Pu'u 'O'o crater floor. There was also minor lava activity from at least one source at the base of the SW crater wall.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 June-7 June 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 1-7 June. The level of the summit lava lake remained mostly stable deep in the vent inset within the E wall of Halema'uma'u Crater. Occasional increases in the lake level covered a vent on the south side wall; on other days lava from the vent cascaded down into the lake. A gas plume from the vent drifted SW. The (preliminary) sulfur dioxide emission rate from all east rift zone sources was 1,100 tonnes/day on 3 June.

Lava from a vent near the W edge of the perched lava lake in the center of Pu'u 'O'o crater floor continued to fill the lake. The lake level fluctuated and occasionally overflowed the edges or flowed through rim breaches, sending lava onto the Pu'u 'O'o crater floor. The rim of the perched lava lake was elevated 2-3 m higher than the surrounding crater floor, which was 39 m below the E crater rim on 1 June.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 May-31 May 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 25-31 May. The level of the summit lava lake remained mostly stable deep in the vent inset within the E wall of Halema'uma'u Crater. An increase in the lake level covered the vent on the south side wall during 25-28 May. On other days lava from the vent cascaded down into the lake. A gas plume from the vent drifted SW. The (preliminary) sulfur dioxide emission rate from all east rift zone sources was 700 tonnes/day on 26 May; the emission rates were slowly increasing.

Lava from a vent near the W edge of the perched lava lake in the center of Pu'u 'O'o crater floor continued to fill the lake. The lake level fluctuated and occasionally overflowed the edges or flowed through rim breaches, sending lava onto the Pu'u 'O'o crater floor. The rim of the perched lava lake was elevated 10 m higher than the surrounding crater floor, which was 52 m below the E crater rim on 11 May. During 27-29 May lava from a vent at the base of the SW wall produced lava flows that slowly began filling the gap between the crater wall and the perched lake wall.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 May-24 May 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 18-24 May. The level of the summit lava lake remained mostly stable deep in the vent inset within the E wall of Halema'uma'u Crater. Lava from a vent above the south side cascaded down into the lake. A gas plume from the vent drifted SW and likely deposited very small amounts of ash nearby. At Pu'u 'O'o crater, lava mostly from a vent near the W edge of the perched lava lake in the center of the crater floor continued to fill the lake. The lake level fluctuated and occasionally overflowed the edges or flowed through rim breaches, sending lava onto the Pu'u 'O'o crater floor. The rim of the perched lava lake was elevated several meters higher than the surrounding crater floor, which was 52 m below the E crater rim on 11 May. On 20 May a small lobe of lava visible in the web camera appeared on the W edge of the crater floor. The (preliminary) sulfur dioxide emission rate from all east rift zone sources was 800 tonnes/day on 20 May; the emission rates were slowly increasing.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 May-17 May 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 11-17 May. The level of the summit lava lake fluctuated but remained mostly stable deep in the vent inset within the E wall of Halema'uma'u Crater. Lava from a vent above the south side cascaded down into the lake. A gas plume from the vent generally drifted SW or W and deposited very small amounts of ash nearby. At Pu'u 'O'o crater, lava mostly from vents near the W edge of the lake continued to fill in a perched lava lake in the center of the crater floor. The lake level fluctuated and occasionally overflowed the edges, sending lava onto the Pu'u 'O'o crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 May-10 May 2011 Citation IconCite this Report

HVO reported that two lava lakes at Kilauea were active during 4-10 May. The level of the summit lava lake fluctuated but remained mostly stable deep in the vent inset within the E wall of Halema'uma'u Crater. On 5 May the lava lake level dropped 10-20 m and lava from a vent well above the south side cascaded down into the lake. A gas plume from the vent drifted SW and deposited very small amounts of ash nearby. At Pu'u 'O'o crater, lava from vents near the W edge of the lake and near the base of the E crater wall continued to fill in a perched lava lake in the center of the crater floor. The lake level fluctuated and occasionally overflowed the edges and filled the entire bottom of Pu'u 'O'o crater floor. The crater had infilled about 70 m since the crater floor collapsed in March.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 April-3 May 2011 Citation IconCite this Report

During 27 April-3 May, HVO reported that the level of Kilauea's summit lava lake fluctuated but remained mostly stable deep in the vent inset within the E wall of Halema'uma'u Crater. A gas plume from the vent drifted SW and deposited very small amounts of ash nearby. At Pu'u 'O'o crater, lava from one or two vent sources continued to fill in a new lava lake in the center of the crater floor. Lava overflowed the edges of the lake, constructing a perched lava lake. During 30 April-1 May the overflows filled the entire crater floor before receding back within the boundaries of the perched lava lake.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 April-26 April 2011 Citation IconCite this Report

During 20-26 April, HVO reported that activity at Kilauea continued from the summit caldera and from Pu'u 'O'o crater. The level of the circulating lava-pool surface in a deep pit below the Halema'uma'u crater floor periodically fluctuated. A gas plume from the vent drifted mostly SW, and deposited very small amounts of ash nearby. At Pu'u 'O'o crater, central sources continuously erupted lava within a perched lava lake that was approximately half the diameter of the crater floor. The lava level fluctuated within the lake walls and episodically overflowed the rim. During 23-24 April lava from several central sources buried most of the perched lake and covered the crater floor. During 24-25 April several large draining events were characterized by a drop in the new lava-lake surface by several meters and minor collapses of the lake's rim.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 April-19 April 2011 Citation IconCite this Report

During 13-19 April, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. The level of the circulating lava-pool surface in a deep pit was approximately 100 m below the Halema'uma'u crater floor, and periodically rose and drained. A gas plume from the vent drifted NE and SW, and deposited very small amounts of ash nearby. On 16 April two collapses of interior vent walls covered most of the molten surface with rock debris and generated brown plumes. At Pu'u 'O'o crater, central sources continuously erupted lava within a perched lake that was approximately half the diameter of the crater floor. The lava level fluctuated within the lake walls and episodically overflowed the rim.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 April-12 April 2011 Citation IconCite this Report

HVO reported that lava in the deep pit within Kilauea's Halema'uma'u crater was visible on 5 April and rose, fell, and circulated within the pit during 6-12 April. At Pu'u 'O'o crater, the level of the lava lake rose and fell, and was fed from a source in the central portion of the lake. During 5-8 April a gas plume from the vent deposited very small amounts of ash nearby, derived from rockfalls and occasional spatter from the lake.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 March-5 April 2011 Citation IconCite this Report

HVO reported that lava in the deep pit within Kilauea's Halema'uma'u crater was visible on 5 April and rose, fell, and circulated within the pit during 6-12 April. At Pu'u 'O'o crater, the level of the lava lake fluctuated, and was fed from a source in the central portion of the lake. During 5-8 April a gas plume from the vent deposited very small amounts of ash nearby, derived from rockfalls and occasional lake spatter.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 March-29 March 2011 Citation IconCite this Report

HVO reported that at Kilauea's east rift zone small areas of incandescence in Pu'u 'O'o crater were visible through the web camera during 23-24 March. The lava lake in the deep pit within Halema'uma'u crater was crusted over; frequent rockfalls produced a few brown-tinged plumes. On 25 March the lava lake reappeared as lava streamed across and eventually covered the floor of the pit. The next day lava returned to Pu'u 'O'o crater about 20 days after the crater floor collapsed on 5 March. Lava slowly filled the deepest parts of the crater forming a lava lake. The lava lake within Halema'uma'u crater again crusted over. During 27-29 March the lava lake in Pu'u 'O'o crater circulated and was fed from two closely-spaced sources in the W center of the lake.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 March-22 March 2011 Citation IconCite this Report

HVO reported that at Kilauea's summit caldera a gas plume from the deep pit within Halema'uma'u crater drifted mainly SW during 16-22 March and deposited ash and fresh spatter nearby. The lava lake within the pit was mostly crusted over during 16-19 March but occasionally produced incandescence. The lake was visible during 20-22 March and periodically changed depth. At the east rift zone, small incandescent areas were visible in Pu'u 'O'o crater. The Kamoamoa fissure remained inactive. During 16-18 March the sulfur dioxide emission rate from all east rift zone sources was below the detection threshold of 20-30 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 March-15 March 2011 Citation IconCite this Report

HVO reported that on 9 March vigorous spattering as high as 50 m was noted from the W end of the Kamoamoa fissure, which had opened on 5 March, along Kilauea's east rift zone between Napau Crater and Pu'u 'O'o. Low lava fountains fed a channelized 'a'a lava flow, 80-290 m wide, that advanced at least 2.9 km to the SE. The lava flow waned starting at 1700 and spattering from the fissure stopped around 2230. The Volcano Alert Level was lowered to Watch and the Aviation Color Code remained at Orange.

During 9-10 March gas measurements showed a sulfur dioxide emission rate of about 4,400 tonnes/day from all east rift zone sources. The rate dropped to 350 tonnes/day on 10 March, and to 100 tonnes/day on 13 March, a value lower than those measured for the months before the Kamoamoa fissure eruption. Seismic tremor declined, but remained elevated above pre-Kamoamoa eruption levels at the summit and the eruption site. During 13-15 March incandescent areas were visible within Pu'u 'O'o crater.

At the summit caldera, a gas plume from the deep pit within Halema'uma'u crater drifted mainly SW during 9-15 March. The level of the lava in the pit was about 220 m below the crater floor, confirmed during an overflight on 9 March. It could not be observed during an overflight the next day because the bottom of the vent was obscured by rubble. Incandescence was occasionally seen in the web camera. An overflight on 14 March revealed that lava was present in the vent; the level slowly rose during the night. On 15 March tephra and fresh spatter was collected from an area beneath the plume.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 March-8 March 2011 Citation IconCite this Report

During 1-4 March, activity from Kilauea's summit caldera and east rift zone was similar to activity during the previous several weeks. The level of the circulating lava-pool surface in the deep pit within Halema'uma'u crater fluctuated and rose to at most 70 below the crater floor. Scattered surface flows were active on the pali and coastal plain, and lava covered large portions of Pu'u 'O'o's crater floor. An unusually high number of earthquakes were located at Kilauea; during 1-4 March a majority of the earthquakes were located at the upper east rift zone.

On 5 March at 1342 there was the onset of rapid deflation at Pu'u 'O'o and increased tremor along Kilauea's middle east rift zone, and at 1400 the summit began to deflate. Between 1416 and 1421 the floor of the Pu'u 'O'o crater began to collapse and within 10 minutes incandescent ring fractures opened on the crater floor. As the floor continued to drop, lava appeared in the center and the NE spatter cone collapsed. The collapse of a large block along the E crater wall produced an ash plume. The floor continued to drop as fume obscured the camera view at 1626. The Aviation Color Code was raised to Red and the Volcano Alert Level was raised to Warning. A later report indicated that the crater floor dropped a minimum of 115 m.

Coincident with the Pu'u 'O'o collapse, an earthquake swarm began along the east rift zone in the area of Maka'opuhi and Napau craters, WSW of Pu'u 'O'o. A fissure, ultimately 2.3 km long, opened along the east rift zone between Napau Crater and Pu'u 'O'o, erupting spatter up to 25 m high and lava that burned nearby vegetation. Lava on one side of the fissure flowed into a nearby deep parallel fissure and disappeared. Fissure activity had paused by 2155.

Kilauea's summit continued to deflate and the lava lake level within the Halema'uma'u crater vent dropped, facilitating rockfalls from the vent wall. On 6 March at 0703 the lake level to receded almost beyond the webcam view following a large collapse. Spattering from the fissure resumed and two more fissures opened that produced more gas than lava. Spatter was reaching heights of 40 m. The tiltmeter on the N flank of Pu'u 'O'o recorded over 150 microradians of deflation beginning at 1400 on 5 March that markedly slowed by the morning of 6 March. Rockfalls exposed incandescent areas within Pu'u 'O'o. Lava flows on the coastal plain and pali were less active. The average sulfur dioxide emission rate from all east rift zone sources was 10,000 tonnes/day on 6 March, 2011, the highest rate there since an eruptive surge in July 2008 produced an emission rate of 7,000 tonnes/day.

On 7 March the Aviation Color Code was lowered to Orange. Vigorous spattering from the W end of the fissure continued; spatter rose as high as 30 m. No active lava flows were observed on the pali or coastal plain. The lava lake surface in Halema'uma'u crater was 200 m below the crater floor, based on visual estimates. Rockfalls in the crater produced dusty-brown plumes during 7-8 March. Low fountains and spattering from the fissure fed several lava flows that advanced S.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 February-1 March 2011 Citation IconCite this Report

During 23 February-2 March, activity continued from the summit caldera and east rift zone. At the summit caldera, the level of the circulating lava-pool surface in the deep pit within Halema'uma'u crater fluctuated between 80 and 120 m below the crater floor. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent drifted in multiple directions and deposited ash and fresh spatter nearby. At the east rift zone, two branches of the 29 November lava flow (from a lava tube breach at 366 m elevation) produced scattered surface flows on the pali and coastal plain. In Pu'u 'O'o crater, lava periodically effused or spattered from a cone on the NE portion of the crater floor and from a vent in the E crater wall.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 February-22 February 2011 Citation IconCite this Report

During 16-22 February, activity continued from the summit caldera and east rift zone. At the summit caldera, the level of the circulating lava-pool surface in the deep pit within Halema'uma'u crater fluctuated between 70 and 125 m below the crater floor. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent drifted in multiple directions and deposited ash and fresh spatter nearby.

At the east rift zone, two branches of the 29 November lava flow (a lava tube breach at 366 m elevation) produced scattered surface flows on the pali and coastal plain. In Pu'u 'O'o crater, lava effused from a cone on the NE portion of the crater floor and from a vent in the E crater wall during most of 16-18 February, covering a large portion of the crater floor. After the lava effusion ceased, incandescence emanated from the cone and vent.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 February-15 February 2011 Citation IconCite this Report

During 9-15 February, activity continued from the summit caldera and east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater circulated and periodically changed depth. The highest level the lava rose to 72 m below the crater floor. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent drifted mostly W and deposited ash and fresh spatter nearby.

At the east rift zone, lava flows continued from one of the upper rootless shields, near the TEB vent. Two branches of the 29 November lava flow (a lava tube breach at 366 m elevation) produced scattered surface flows on the pali and coastal plain. In Pu'u 'O'o crater, incandescence emanated from a cone on the N portion of the crater floor, lava effused from a cone on the W edge of the floor, and spatter and lava flows were produced from a vent in the E crater wall. On 12 February increased activity from a cone on the N floor was characterized by lava flows and incandescent tephra ejected 40-50 m above the cone. During 14-15 February lava from a NE cone covered the E half of the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 February-8 February 2011 Citation IconCite this Report

During 2-8 February, activity continued from the summit caldera and east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater circulated and remained mostly stable at approximately 100 m below the crater floor, periodically rising or falling. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent that drifted mostly SW, W, and N deposited ash and fresh spatter nearby.

At the east rift zone, lava that broke out of the Quarry tube in a saddle between two rootless shields around 610 m elevation continued to advance both E and W, producing scattered surface flows. At the lowest elevation of the E branch, lava advanced along Highway 130 near Kalapana, periodically burning vegetation, and to the S towards the coast. On 4 February incandescence from the TEB vent and upper rootless shields visible on the web camera was later confirmed to be from spatter and lava flows. Lava continued to issue from each location during 5-8 February. Multiple small ocean entries were active on the W part of the Puhi-o-Kalaikini lava delta until 7 or 8 February.

In Pu'u 'O'o crater, incandescence emanated from the fuming vent in the E wall of the crater, and spatter and lava flows were produced from a cone on the N portion of the crater floor. On 7 February activity significantly increased; lava flowed from several vents including the vent on the E wall and multiple spatter cones on the N and NW areas of the floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 January-1 February 2011 Citation IconCite this Report

During 26 January-1 February, activity continued from the summit caldera and east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater circulated and remained mostly stable at approximately 125 m below the crater floor, periodically rising or falling. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent that drifted mostly SW deposited ash and fresh spatter nearby.

At the east rift zone, lava that broke out of the Quarry tube in a saddle between two rootless shields around 610 m elevation, continued to advance both E and W, producing scattered break-out flows. At the lowest elevation of the E branch, lava advanced along Highway 130 near Kalapana, periodically burning vegetation, and to the S towards the coast. Multiple small ocean entries were active on the W part of the Puhi-o-Kalaikini lava delta. Incandescence emanated from a spatter cone on the N portion of the Pu'u 'O'o crater floor and from the fuming vent in the E wall of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 January-25 January 2011 Citation IconCite this Report

HVO reported that the largest of about 36 rockfalls that occurred in the deep pit within Kilauea's Halema'uma'u crater on 17 January was followed by an explosive event, of a magnitude not seen since 2008, and felt locally. Ballistics up to 10 cm in diameter and hot tephra ejected from the pit were deposited on the rim of Halema'uma'u crater. Spatter up to 8 cm long was ejected onto the crater rim after collapses on 21 January.

During 19-25 January, activity continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater circulated and remained mostly stable at approximately 120 m below the crater floor, periodically rising or falling. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent that drifted mostly SW and W deposited ash and fresh spatter nearby.

At the east rift zone, lava that broke out of the Quarry tube, at a saddle between two rootless shields around 610 m elevation, continued to advance both E and W. At the lowest elevation of the E branch, lava advanced along Highway 130 near Kalapana, periodically burning vegetation. Steam sporadically rising near the ocean suggested that the lava entered the ocean, although not continuously. One part of the W branch stopped entering the ocean on 18 January, but remained active. Incandescence emanated from a spatter cone on the N portion of the Pu'u 'O'o crater floor and from the fuming vent in the E wall of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 January-18 January 2011 Citation IconCite this Report

During 12-18 January, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater circulated and remained mostly stable at approximately 120 m below the crater floor, periodically rising several meters higher. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent that drifted S, NE, and N deposited ash and fresh spatter nearby.

At the east rift zone, lava that broke out of the Quarry tube at a saddle between two rootless shields around 610 m elevation, continued to advance in two branches, E and W. At the lowest elevation of the E branch lava advanced along Highway 130 near Kalapana, set a kipuka on fire, and destroyed a structure. One part of the W branch entered the ocean at Ki, about 2 km SW of the end of Highway 130. A spatter cone on the N portion of the Pu'u 'O'o crater floor fed lava flows and incandescence emanated from the fuming vent in the E wall of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 January-11 January 2011 Citation IconCite this Report

During 5-11 January, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater circulated and remained mostly stable at approximately 120 m below the crater floor, periodically rising several meters higher. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent that drifted SW, NE, and N deposited ash and fresh spatter nearby.

At the east rift zone, lava that broke out of the Quarry tube at a saddle between two rootless shields around 610 m elevation, continued to advance in two branches, E and W. At the lowest elevation of the E branch lava advanced along Highway 130 near Kalapana. One part of the W branch entered the ocean on 6 January at a location about 2 km SW of the end of Highway 130. Lava flows fed by an 8-m-high cone on the N portion of the Pu'u 'O'o crater floor covered and recovered the E crater floor. The web camera also recorded incandescence from a small fume-producing vent in the E wall of the crater. On 10 January the sides of the cone seemingly gave way and lava poured into two active flows that traveled toward the W portion of the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 December-4 January 2011 Citation IconCite this Report

During 29 December-4 January, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater circulated and remained mostly stable at approximately 120 m below the crater floor, periodically rising several meters higher. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent that drifted mainly SW deposited ash and fresh spatter nearby.

At the east rift zone, lava that broke out of the Quarry tube onto the surface, at a saddle between two rootless shields at around the 610 m elevation, continued to advance in two branches. The lava flow at the lowest elevation advanced E beyond Kalapana by 3 January. Incandescence from a small spatter cone on the north-central part of Pu'u 'O'o crater floor continued. Lava from that cone flowed SE, NE, and W. Lava from a second spatter cone, located on the NW edge of the crater, was active on the crater floor. Weak incandescence was also visible from a small, fume-producing vent in the E wall of the crater, and from other various areas on the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 December-28 December 2010 Citation IconCite this Report

During 22-28 December, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable at approximately 125-130 m below the crater floor, periodically rising 20-30 m higher. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent that drifted NW, N, and NE deposited ash and fresh spatter nearby.

At the east rift zone, lava that broke out of the Quarry tube onto the surface, at a saddle between two rootless shields at around the 610 m elevation, continued to advance in two branches. The E branch advanced along the E edge of the Quarry flow to about 60 m elevation and burned small remnants of a forest. On 22 December a breakout lava flow from the 365-m elevation advanced 820 m. Multiple scattered breakout lava flows were observed during the reporting period. Incandescence from a small spatter cone on the north-central part of Pu'u 'O'o crater floor continued. Lava from a second spatter cone, located on the NW edge of the crater, advanced E on the crater floor and then stalled on 27 December.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 December-21 December 2010 Citation IconCite this Report

During 15-21 December, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable at approximately 130 m below the crater floor, periodically rising 20-30 m higher. Nighttime incandescence has been visible from the Jaggar Museum on the NW caldera rim since early 2010. A plume from the vent drifted SW and SE, when visible through fog, and deposited ash and fresh spatter nearby.

At the east rift zone, lava that broke out of the Quarry tube onto the surface at a saddle between two rootless shields at around the 610 m elevation, continued to advance in two branches. The E branch advanced along the E edge of the Quarry flow to about the 60-m elevation and burned small remnants of a forest. Incandescence from a prominent but small spatter cone on the north-central part of the Pu'u 'O'o crater floor continued. Lava from a second spatter cone, located on the NW edge of the crater, flowed across the W side of the crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 December-14 December 2010 Citation IconCite this Report

During 8-14 December, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable at approximately 130 m below the crater floor, periodically rising 15-20 m higher. Nighttime incandescence has been visible from the Jaggar Museum on the NW caldera rim since early 2010. A plume from the vent drifted in multiple directions and deposited ash and fresh spatter nearby.

At the east rift zone, lava flowed a short distance through the TEB lava-tube system before breaking out onto the surface at a saddle between two rootless shields at around the 610 m elevation, forming a lava pond atop a new shield. Two breakout lava flows traveled about 120 m down the pali. Lava flows from a small spatter cone on the Pu'u 'O'o crater floor continued. A small lava flow traveled W on 10 December. On 13 December lava flowed from a second spatter cone, located on the NW edge of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 December-7 December 2010 Citation IconCite this Report

During 1-7 December, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable at approximately 135 m below the crater floor, periodically rising about 15 m above that level. Nighttime incandescence has been visible from the Jaggar Museum on the NW caldera rim since early 2010. A plume from the vent mostly drifted SW and deposited ash and fresh spatter nearby.

At the east rift zone, lava flowed a short distance through the TEB lava-tube system before breaking out onto the surface at a saddle between two rootless shields at around the 610 m elevation on 1 December. Lava started to build a shield and also extended several hundred meters from both sides of the lava tube. A small breakout lava flow on top of the pali traveled 100 m downslope to within about 6 km of Kalapana Gardens. During 2-7 December, lava flows at the saddle area advanced W, N, and E. Lava was last observed entering the ocean at Puhi-o-Kalaikini during 29-30 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 November-30 November 2010 Citation IconCite this Report

During 24-30 November, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable between approximately 140 and 145 m below the crater floor, periodically rising about 20 m above that level. Nighttime incandescence has been visible from the Jaggar Museum on the NW caldera rim since early 2010. A plume from the vent mostly drifted SW and deposited ash nearby.

At the east rift zone, lava continued to flow through the TEB lava-tube system and fed surface flows on the coastal plain, breakout flows W and N of a county viewing area (located along Highway 130), and one or more ocean entries on the Puhi-o-Kalaikini delta W of Kalapana Gardens subdivision. A lava flow that broke out of the tube on 24 November advanced towards an abandoned house in Kalapana Gardens, and on 27 November, set fire to and destroyed the structure. Incandescence was visible from vents on the N part of the Pu'u 'O'o crater floor on 23 November before it started to spatter and feed a small lava flow. The lava flow continued to advance E during 24 November-1 December.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 November-23 November 2010 Citation IconCite this Report

During 17-23 November, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable approximately 150 m below the crater floor, periodically rising about 20 m above that level. Nighttime incandescence has been visible from the Jaggar Museum on the NW caldera rim since early 2010. A plume from the vent deposited ash nearby.

At the east rift zone, lava continued to flow through the TEB lava-tube system and fed small weakly active surface flows on the coastal plain, breakout flows W of a county viewing area (located along Highway 130), and a single ocean entry on the Puhi-o-Kalaikini delta W of Kalapana Gardens subdivision. Incandescence was visible from vents on the N part of the Pu'u 'O'o crater floor during 17-18 November. Spattering from the vent was seen during 18-19 November, and a slow-moving lava flow began at about noon on 19 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 November-16 November 2010 Citation IconCite this Report

During 10-16 November, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable at 155 m below the crater floor. Periodically the lava rose about 20 m above that level. Nighttime incandescence was seen from the Jaggar Museum on the NW caldera rim. A plume from the vent drifted SW and deposited ash nearby. At the east rift zone, lava continued to flow through the TEB lava-tube system and fed some small lava flows on the coastal plain and the Puhi-o-Kalaikini ocean entry. Incandescence was frequently visible from areaS on the N part of the Pu'u 'O'o crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 November-9 November 2010 Citation IconCite this Report

During 3-9 November, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable between 150 and 160 m below the crater floor. Periodically the lava rose about 20 m above that level, producing nighttime incandescence seen from the Jaggar Museum on the NW caldera rim. A plume from the vent drifted SW and deposited ash nearby.

At the east rift zone, lava continued to flow through the TEB lava-tube system and fed some small lava flows on the coastal plain and the Puhi-o-Kalaikini ocean entry. Some short-lived breakouts of lava occurred from the portion of the lava tube that crosses Highway 130, about 300 m SW of the current County Viewing Area. Incandescence was frequently visible from vents on the N part of the Pu'u 'O'o crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 October-2 November 2010 Citation IconCite this Report

During 27 October-2 November, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable between 160 and 170 m below the crater floor. Periodically the lava rose a few meters above that level, producing nighttime incandescence seen from the Jaggar Museum, on the NW caldera rim. A plume from the vent drifted SW and deposited ash nearby.

At the east rift zone, lava continued to flow through the TEB lava-tube system and fed two ocean entries at the Puhi-o-Kalaikini delta. On 27 October a small lava flow broke out of the lava tube and was active W of the end of Highway 130. A channelized 'a'a lava flow at the base of the pali began the next day. Lava flows were active on the coastal plain during 29-30 October and 1-2 November. Incandescence was frequently visible from vents on the N part of the Pu'u 'O'o crater floor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 October-26 October 2010 Citation IconCite this Report

During 20-26 October, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable; periodically the lava rose above that level, producing nighttime incandescence seen from the Jaggar Museum, on the NW caldera rim. A plume from the vent drifted mainly SW.

At the east rift zone, lava that flowed through the TEB lava-tube system fed at least one ocean entry at the Puhi-o-Kalaikini delta. Small surface flows on the coastal plain and pali were visible during 20-22 October. A vent on the N part of the Pu'u 'O'o crater floor ejected spatter on 20 October. Incandescence was visible from the vent the next day and from multiple vents during 22-23 October.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 October-19 October 2010 Citation IconCite this Report

During 13-19 October, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable between 155 and 160 m below the crater floor; periodically the lava rose 15-20 m above that level. Glow from the vent was also visible at night. A plume from the vent drifted mainly SW.

At the east rift zone, lava that flowed through the TEB lava-tube system fed small lava flows and at least one ocean entry at the Puhi-o-Kalaikini delta. A break-out lava flow began just west of the end of Highway 130 on 15 October. During 15-19 October the lava filled in low areas between the highway and the inactive flows that had stopped near Kalapana Gardens earlier in the year. A vent on the N part of the Pu'u 'O'o crater floor effused lava during 12-14 October and was incandescent during 15-19 October.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 October-12 October 2010 Citation IconCite this Report

During 6-12 October, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable between 150 and 160 m below the crater floor; periodically the lava rose 10-30 m above that level. Glow from the vent was also visible at night. A plume from the vent drifted mainly SW.

At the east rift zone, lava that flowed through the TEB lava-tube system mainly fed the Puhi-o-Kalaikini ocean entry. Break-outs of lava from a tube near the end of Highway 130 and NW of Kalapana on 4 October and other small break-outs during 6-12 October were noted. On 7 October another ocean entry point developed on the Puhi-o-Kalaikini delta, just W of the first entry.

Lava from a vent on the NW edge of Pu'u 'O'o crater flowed E across the crater floor during most of the reporting period. On 6 October a vent on the N floor of the crater opened and effused lava that buried the E portion of the crater with lava about 10 m thick. On 8 October, lava drained back into the vent on the N floor. Lava-flow activity on the crater floor was intermittent during 8-10 October. The next day the flows had stalled.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 September-5 October 2010 Citation IconCite this Report

During 29 September-5 October, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable at about 150 m below the crater floor; periodically the lava rose 15-35 m above that level. Glow from the vent was also visible at night. A plume from the vent drifted mainly SW and deposited ash nearby.

At the east rift zone, lava that flowed through the TEB lava-tube system mainly fed the Puhi-o-Kalaikini ocean entry. A lava flow that broke out of the lava-tube system W of the end of Highway 130 on 26 September produced a flow E toward Kalapana Gardens that stalled on 28 September. Two days later a new breakout lava flow began near the end of Highway 130, just west of Kalapana Gardens subdivision. The flow sparked fires in a small, sparsely forested kipuka, and remained active through 4 October.

During 29 September-4 October, incandescence was visible from a skylight on the lava tube downslope from the rootless shield complex. A large skylight on top of a rootless shield, built over the TEB lava tube mid-way between the top of the pali and the TEB vent, also showed incandescence. On 29 September, lava began to erupt from a vent on the NW edge of Pu'u 'O'o crater and flowed E across the floor. The lava flow in Pu'u 'O'o crater continued to be active through the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 September-28 September 2010 Citation IconCite this Report

During 22-28 September HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable around 160 m below the crater floor; periodically the lava rose 15-35 m above that level. Glow from the vent was also visible at night. A plume from the vent drifted SW and deposited ash nearby. At the east rift zone, lava that flowed through the TEB lava-tube system mainly fed the Puhi-o-Kalaikini ocean entry. Weak thermal anomalies detected in satellite imagery suggested little to no lava flow activity on the pali or the coastal plain. On 26 September lava broke out of the lava-tube system W of the end of Highway 130 and produced a flow E toward Kalapana Gardens. The next day lava, flowing at a slower rate, filled in low areas S of the Hawaii County lava viewing area.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 September-21 September 2010 Citation IconCite this Report

During 15-21 September HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within the Halema'uma'u crater remained mostly stable at about 160 m below the crater floor; periodically the lava rose 20-40 m above the stable surface level. Glow from the vent was also visible at night. A plume from the vent drifted SW and deposited ash nearby. At Pu'u 'O'o crater, incandescence emanated from a lava flow on the SW floor during 16-19 September. At the east rift zone, lava that flowed through the TEB lava-tube system mainly fed the Puhi-o-Kalaikini ocean entry. Weak thermal anomalies detected in satellite imagery during 17-19 September suggested little to no lava flow activity on the pali or the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 September-14 September 2010 Citation IconCite this Report

During 8-14 September HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent drifted SW and deposited ash, and occasionally Pele's hair and spatter, nearby. At Pu'u 'O'o crater, incandescence emanated from a lava flow on the SW floor on most nights. During an overflight on 9 September, geologists saw that the lava flow had ponded on the W side of the crater floor. At the east rift zone, lava that flowed through the TEB lava-tube system mainly fed the Puhi-o-Kalaikini ocean entry.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 September-7 September 2010 Citation IconCite this Report

During 1-7 September HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent drifted SW and deposited ash nearby. At Pu'u 'O'o crater, incandescence emanated from an active hornito on the N floor. On 4 September lava started to flow along the S margin of the crater floor and was active the next day. At the east rift zone, lava that flowed through the TEB lava-tube system fed minor surface flows on the coastal plain, as well as the Puhi-o-Kalaikini ocean entry.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 August-31 August 2010 Citation IconCite this Report

During 25-31 August HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent drifted SW. At Pu'u 'O'o crater, incandescence emanated from an active hornito on the N floor. At the east rift zone, lava that flowed through the TEB lava-tube system fed minor surface flows on the coastal plain, as well as two ocean entries at Puhi-o-Kalaikini, SW of Kalapana.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 August-24 August 2010 Citation IconCite this Report

During 18-24 August HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent mainly drifted SW. At Pu'u 'O'o crater, incandescence emanated from multiple areas on the N floor. At the east rift zone, lava that flowed through the TEB lava-tube system fed occasional surface flows on the pali and on the coastal plain NW and W of Kalapana Gardens, as well as the Puhi-o-Kalaikini ocean entry.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 August-17 August 2010 Citation IconCite this Report

During 11-17 August HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent mainly drifted SW, dropping small amounts of ash downwind. At Pu'u 'O'o crater, a small incandescent vent on the N floor that occasionally extruded lava flows was observed to be a hornito. At the east rift zone, lava that flowed through the TEB lava-tube system fed occasional surface flows at the base of the pali and on the coastal plain WNW and W of Kalapana Gardens, as well as the Puhi-o-Kalaikini ocean entry.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 August-10 August 2010 Citation IconCite this Report

During 4-10 August HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of a lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent mainly drifted SW, dropping small amounts of ash downwind.

At the east rift zone, lava flows that broke out of the TEB lava-tube system fed surface flows on the coastal plain, an inflating surface flow in Kalapana, and two ocean entries. The delta built by the W ocean entry named Puhi-o-Kalaikini was 900 m wide by 8 August. The less vigorous E entry, 'Ili'ili, remained active until 9 August. At Pu'u 'O'o crater, incandescence from small areas on the N crater floor was visible. During 9-10 August minor spattering from the area built a very small cone.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 July-3 August 2010 Citation IconCite this Report

During 28 July-3 August HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of a lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent mainly drifted SW, dropping small amounts of ash downwind.

At the east rift zone, lava flows that broke out of the TEB lava-tube system advanced NE over coastal highway 137 towards Kalapana Gardens subdivision. Two lava lobes that had overtopped the Hakuma horst, SW of Kalapana Gardens, flowed into the ocean. The first flow initially entered the ocean on 25 July and continued to build a small delta that was about 500 m wide by 3 August. On 28 July, the second flow entered the ocean, about 545 m E of the first ocean-entry point. In addition to the activity near the ocean, scattered small active lobes of lava were seen about 1 km W of the highway 130/137 intersection.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 July-27 July 2010 Citation IconCite this Report

During 21-27 July HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of a lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent mainly drifted SW.

At the east rift zone, lava flows that broke out of the TEB lava-tube system advanced E and NE along coastal highway 137 beginning on 17 July and expanded S, filling in the area between the highway and the N-facing scarp of the Hakuma horst. On 24 July, lava flowed N and by the next morning had destroyed a home in Kalapana Gardens. Advancing lava flowed over an area of the horst and on 25 July reached the ocean. On 26 July, lava caused small brush fires and methane explosions in a kipuka on the W edge of the Kalapana subdivision. By 1200 on 27 July, a second lava flow 500 m E of the ocean entry had advanced over the horst and was about 20 m from the ocean. At Pu'u 'O'o crater, intermittent incandescence from lava flows on the N crater floor was visible starting on 24 July.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 July-20 July 2010 Citation IconCite this Report

During 14-20 July HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of a lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent mainly drifted SW. At the east rift zone, two lava flows that broke out of the TEB lava-tube system advanced E through the coastal highway 130/137 intersection beginning on 17 July, and by 19 July were within 70 m of the nearest structure. A second set of active lava lobes were approximately 1 km to the NW and also advanced toward that general area. According to a news article, two people evacuated their home in Kalapana due to advancing lava flows.

Sources: Associated Press; US Geological Survey Hawaiian Volcano Observatory (HVO)


7 July-13 July 2010 Citation IconCite this Report

During 7-13 July HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of a lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent mainly drifted SW, dropping small amounts of tephra downwind. At the east rift zone, lava flows that broke out of the TEB lava-tube system built up a number of rootless shields between 580 and 395 m elevation. Thermal anomalies detected in satellite images and visual observations showed that minor lava flows originating from the shields traveled as far down as 60 m elevation near the base of the pali on 11 July.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 June-6 July 2010 Citation IconCite this Report

During 30 June-6 July HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of a lava-pool surface in the deep pit inset within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent mainly drifted SW, dropping small amounts of tephra, and occasionally fresh spatter, downwind.

At the east rift zone, lava flows that broke out of the TEB lava-tube system built up a number of rootless shields between 580 and 395 m elevation. Thermal anomalies detected in satellite images and visual observations showed that minor lava flows originating from the shields traveled as far down as 365 m elevation on 1 July. A gas vent on the E wall of Pu'u 'O'o crater was incandescent during most of the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 June-29 June 2010 Citation IconCite this Report

During 23-29 June HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of a lava-pool surface in the deep pit inset within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent mainly drifted SW, dropping small amounts of tephra, and occasionally fresh spatter, downwind. At the east rift zone, lava flows that broke out of the TEB lava-tube system built up a number of rootless shields between 580 and 520 m elevation. Satellite images showed thermal anomalies from minor lava flows originating from the shields. The Pu'u 'O'o web camera showed incandescence from a vent on the E wall of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 June-22 June 2010 Citation IconCite this Report

During 16-22 June HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of a lava-pool surface in the deep pit inset within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent mainly drifted SW, dropping small amounts of tephra, and occasionally fresh spatter, downwind.

At the east rift zone, lava flows that broke out of the TEB lava-tube system built up a number of rootless shields between 580 and 520 m elevation. Satellite images showed thermal anomalies from minor lava flows originating from the shields. The Pu'u 'O'o web camera views of a lava pond on the crater floor, that was an estimated 300 x 150 m in dimension, were often obscured by fumes. One small lava flow was seen on the crater floor on 18 June. Scientists saw a new gas vent on the E wall of the crater during an overflight on 21 June that had generated incandescence during the previous few days.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 June-15 June 2010 Citation IconCite this Report

During 9-15 June HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of a lava-pool surface remained mostly stable in the deep pit inset within the floor of Halema'uma'u crater; glow from the vent was visible. A plume from the vent mainly drifted SW, dropping small amounts of tephra downwind. Vigorous bubbling of the lava surface was seen during 14-15 June.

At the east rift zone, lava flows that broke out of the TEB lava-tube system at 580 m elevation built up rootless shields. Minor surface lava flows from the shields were often active on the pali and the coastal plain, and advanced along the W side of the TEB flow field towards the abandoned Royal Gardens subdivision. The Pu'u 'O'o web camera recorded a growing and sometimes circulating lava pond on the crater floor that was an estimated 300 x 125 m in dimension. The pond was fed predominantly from a source near the N rim of the Pu'u 'O'o, with some contributions from a source near the S shore.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 June-8 June 2010 Citation IconCite this Report

During 2-8 June HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of the circulating, crusting, and bubbling lava-pool surface remained mostly stable in the deep pit inset within the floor of Halema'uma'u crater; glow from the vent was visible. A plume from the vent drifted SW, dropping small amounts of ash and spatter downwind.

At the east rift zone, lava flows that broke out of the TEB lava-tube system at 580 m elevation built up rootless shields. Minor surface lava flows from the shields were active on the pali and the coastal plain. Lava stopped flowing into the ocean at the Ki entry sometime during 2-3 June. The Pu'u 'O'o' web camera recorded a growing and circulating lava pond on the crater floor that on 5 June was an estimated 300 x 125 m in dimension. A small spattering cone was seen on the floor to the N of the pond.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 May-1 June 2010 Citation IconCite this Report

During 26 May-1 June HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of the circulating, crusting, and bubbling lava-pool surface remained mostly stable in the deep pit inset within the floor of Halema'uma'u crater; glow from the vent was visible. On 31 May the surface rose to the highest level yet recorded, but was still more than 100 m below the Halema'uma'u crater floor.

At the east rift zone, lava flows that broke out of the TEB lava-tube system had advanced down the Pulama pali onto the coastal plain and headed S, entering the ocean at Ki. Other lava flows were active above the pali. On 27 May geologists noted a small rootless shield building up at a break-out point at 580 m elevation. Small lava flows issued from vents on Pu'u 'O'o's S crater wall during 26-27 May, and pooled on the crater floor at least through 31 May.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 May-25 May 2010 Citation IconCite this Report

During 19-25 May HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, occasional rising and falling of the circulating, crusting, and bubbling lava-pool surface continued at the deep pit inset within the floor of Halema'uma'u crater; glow from the vent was visible. The plume of gas from the summit vent drifted SW. Sulfur dioxide emission rates measured at the summit during 19-21 and 24 May were in the 800-1,200 tonnes/day range.

At the east rift zone, lava flows that broke out of the TEB lava-tube system had advanced down the Pulama pali onto the coastal plain and headed S, entering the ocean at Ki. Other lava flows were active on the flow field. A small lava flow issued from a vent on Pu'u 'O'o's S crater wall on 21 May.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 May-18 May 2010 Citation IconCite this Report

During 12-18 May HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, occasional rising and falling of the circulating lava-pool surface continued at the deep pit inset within the floor of Halema'uma'u crater; glow from the vent was visible. The plume of gas and ash from the summit vent drifted SW. On 14 May the sulfur dioxide emission rate measured at the summit was1,000 tonnes/day. The surface dimensions of the lava pool were an estimated 60 m by 90 m on 17 and 18 May.

At the east rift zone, lava flows that broke out of the TEB lava-tube system had advanced down the Pulama pali onto the coastal plain and headed S into the ocean. Geologists confirmed a collapse of a 17 m by 75 m sliver of Pu'u 'O'o crater's N rim that occurred on 11 May.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 May-11 May 2010 Citation IconCite this Report

During 5-11 May HVO reported that activity at Kilauea continued at the summit and the east rift zone. At the summit, episodic rising and falling of the lava-pool surface continued at the deep pit inset within the floor of Halema'uma'u crater; glow from the vent was visible. The plume of gas and ash from the summit vent drifted SW and W, dropping small amounts of ash, and occasionally Pele's hair and Pele's tears, downwind. The sulfur dioxide emission rate measured at the summit on 5 May was 880 tonnes/day.

At the east rift zone, lava flows that broke out of the TEB lava-tube system had advanced down the Pulama pali onto the coastal plain and headed S into the ocean. Lava also flowed along the highway, after covering the county viewing area on 5 May. Incandescence was sometimes seen from a vent low on the S wall of Pu'u 'O'o crater. On 9 May lava flows near the county viewing area stalled.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 April-4 May 2010 Citation IconCite this Report

During 28 April-4 May HVO reported that activity at Kilauea continued at the summit and the east rift zone. At the summit, episodic rising and falling of the lava-pool surface continued at the deep pit inset within the floor of Halema`uma`u crater; glow from the vent was visible. On most mornings the plume of gas and ash from the summit vent drifted NW, W, and SW. On 29 April small rockfalls disrupted the surface of the pond, producing "dusty" plumes. Sulfur dioxide emission rates measured at the summit during 28-29 April were in the 800-1,000 tonnes/day range.

At the east rift zone, lava flowed through tubes to supply a surface flow that had advanced down the Pulama pali, onto the coastal plain, heading S, and reached the ocean on 29 April. Lava continued to flow into the ocean, just W of the "old" coastal viewing area during the rest of the reporting period. Lava also flowed along the E margin, between the highway and the coast. Incandescence was sometimes seen from a vent low on the S wall of Pu'u 'O'o crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 April-27 April 2010 Citation IconCite this Report

During 21-27 April HVO reported that activity at Kilauea continued at the summit and the east rift zone. At the summit, episodic rising and falling of the lava column continued at the deep pit inset within the floor of Halema`uma`u crater; glow from the vent was often visible. On most mornings the plume of gas and ash from the summit vent drifted SW, depositing small amounts of tephra near the vent. Sulfur dioxide emission rates measured at the summit during 21-23 April were in the 630-770 tonnes/day range.

At the east rift zone, lava flowed through tubes to supply a surface flow that had advanced down the Pulama pali and onto the coastal plain, heading SE along the east margin of the TEB flow field. The lava flowed through vegetation, causing small brush fires and minor methane bursts. On 22 April a second lava flow to the W was also active. Two days later, the first lava flow appeared to have stalled. The W flow continued to advance, and by 27 April was within the County Viewing Area.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 April-20 April 2010 Citation IconCite this Report

During 14-20 April activity reported by HVO at Kilauea was continuing at the summit and the east rift zone. At the summit, episodic rising and falling of the lava column continued at the deep pit inset within the floor of Halema`uma`u crater. Cycles occurred every 10-20 minutes until becoming more sporadic the evening of 14 April. On 15-16 April there were only 1-2 cycles/day. Activity increased again on the 17th, with cycles every 10-30 minutes. Glow from the vent was visible when the rising and falling cycles were frequent. On most mornings the plume of gas and ash from the summit vent drifted SW, depositing small amounts of tephra near the vent. Sulfur dioxide emission rates measured at the summit on 12, 14, 15, and 19 April were in the 600-790 tonnes/day range.

At the east rift zone, lava flowed through tubes to supply surface flows that advanced down the Pulama pali towards the coastal plain; on 16 April those flows were within 300 m of the coastal plain. Sulfur dioxide emission rates from the summit and east rift zone vents remained elevated. Geologists in the field on 17 April reported that the flow front had reached the E margin of the older Thanksgiving Eve Breakout (TEB) flow field on the coastal plain. On 19 April the flow front headed SE along the east margin of the TEB flow field, just W of the end of the Kalapana access road, and was 380 m NW of the viewing area.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 April-13 April 2010 Citation IconCite this Report

During 7-13 April, HVO reported incandescence from a 60-m-wide active lava surface about 200 m below a 130-m-wide vent in the floor of Kilauea's Halema'uma'u crater. The lava surface circulated and both rose and drained through a pit in the cavity floor; a few times the level fluctuated between 235 and 260 m below the surface. Rocks from the vent walls fell into the pond, causing spattering. Plumes from the vent drifted mainly SW, dropping small amounts of ash, and occasionally Pele's hair and Pele's tears, downwind. Measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 600 and 500 tonnes per day were measured on 8 and 9 April, respectively.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed SE through the upper portion of a lava tube system and broke out onto the surface. Lava flows moved SE down Pulama pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 March-6 April 2010 Citation IconCite this Report

During 31 March-6 April, HVO reported incandescence from a 60-m-wide active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface circulated and both rose and drained through a pit in the cavity floor; a few times the level fluctuated between 235 and 260 m below the surface. Plumes from the vent drifted mainly SW, dropping small amounts of ash downwind. The sulfur dioxide emission rate at the summit on 31 March was 1,400 tonnes per day, the highest recorded in 2010. The rate on 1 and 2 April was 1,000 and 650 tonnes per day, respectively.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed SE through the upper portion of a lava tube system and broke out onto the surface. Lava flows advanced E, and then SE down Pulama pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 March-30 March 2010 Citation IconCite this Report

During 24-30 March, HVO reported incandescence from an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface circulated and both rose and drained through a pit in the cavity floor. Plumes from the vent drifted mainly SW, dropping small amounts of ash, and occasionally spatter, downwind. Gas measurements on 25 and 26 March indicated that the sulfur dioxide emission rate at the summit remained elevated at 600 and 800 tonnes per day, respectively. The 2003-2007 average rate was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed SE through the upper portion of a lava tube system and broke out onto the surface. Thermal anomalies detected by satellite, and visual observations, revealed active lava flows above the pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 March-23 March 2010 Citation IconCite this Report

During 17-23 March, HVO reported incandescence from an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface circulated and both rose and drained through a pit in the cavity floor. A plume from the vent drifted mainly SW, dropping small amounts of ash and spatter downwind. Measurements on 19 March indicated that the sulfur dioxide emission rate at the summit remained elevated at 500 tonnes per day. The 2003-2007 average rate was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed SE through the upper portion of a lava tube system and broke out onto the surface. Thermal anomalies detected by satellite, and visual observations, revealed active lava flows above the pali. Incandescence was sometimes seen from a vent low on the S wall of Pu'u 'O'o crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 March-16 March 2010 Citation IconCite this Report

During 10-16 March, HVO reported incandescence from an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface circulated and both rose and drained through a pit in the cavity floor towards the end of the reporting period. Lava fountaining from the N edge of the pit was also noted. A plume from the vent drifted mainly SW, dropping small amounts of ash downwind. Measurements on 11 March indicated that the sulfur dioxide emission rate at the summit remained elevated at 600 tonnes per day. The 2003-2007 average rate was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed SE through the upper portion of a lava tube system and broke out onto the surface. Thermal anomalies detected by satellite, and visual observations, revealed active lava flows on the pali and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 March-9 March 2010 Citation IconCite this Report

During 3-9 March, HVO reported an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface circulated and both rose and drained through a pit in the cavity floor. A plume from the vent drifted mainly SW, dropping small amounts of ash downwind. Measurements during 4-5 March indicated that the sulfur dioxide emission rate at the summit remained elevated at 700-800 tonnes per day. The 2003-2007 average rate was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed SE through the upper portion of a lava tube system and broke out onto the surface. Thermal anomalies detected by satellite, and visual observations, revealed active lava flows on the pali and on the coastal plain.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 February-2 March 2010 Citation IconCite this Report

During 24 February-2 March, HVO reported an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface circulated and both rose and drained through holes in the cavity floor. Low lava fountains rose from the south edge of the deep pit. A plume from the vent drifted mainly SW, dropping small amounts of ash downwind. Measurements on 25 February indicated that the sulfur dioxide emission rate at the summit remained elevated at 900 tonnes per day. The 2003-2007 average rate was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed SE through a lava tube system and broke out onto the surface. Thermal anomalies detected by satellite and visual observations revealed active lava flows on the pali and on the coastal plain. Incandescence was sometimes seen from a vent low on the S wall of Pu'u 'O'o crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 February-23 February 2010 Citation IconCite this Report

During 17-23 February, HVO reported an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface circulated and occasionally spattered, and both rose and drained through holes in the cavity floor. Bursting bubbles and low lava fountains were also noted. A plume from the vent drifted mainly SW, dropping small amounts of ash downwind. Measurements on 18 February indicated that the sulfur dioxide emission rate at the summit remained elevated at 600 tonnes per day. The 2003-2007 average rate was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed over 3 km SE through a lava tube system before breaking out onto the surface. Thermal anomalies detected by satellite and visual observations revealed active lava flows on the W side of the TEB flow field, on the pali, and on the coastal plain. Incandescence was sometimes seen from a vent low on the S wall of Pu'u 'O'o crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 February-16 February 2010 Citation IconCite this Report

During 10-16 February, HVO reported an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface occasionally spattered, and both rose and drained through holes in the cavity floor. A plume from the vent drifted mainly SW, dropping small amounts of ash, and occasionally fresh spatter, downwind. Measurements on 11 February indicated that the sulfur dioxide emission rate at the summit remained elevated at 900 tonnes per day. The 2003-2007 average rate was 140 tonnes per day. That same day a significant rockfall or collapse event was followed by a brown plume for several minutes.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed over 3 km SE through a lava tube system before breaking out onto the surface. Thermal anomalies detected by satellite and visual observations revealed active lava flows on the pali and on the coastal plain. Incandescence was sometimes seen from a vent low on the S wall of Pu'u 'O'o crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 February-9 February 2010 Citation IconCite this Report

During 3-9 February, HVO reported an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface occasionally spattered, and both rose and drained through holes in the cavity floor. A plume from the vent drifted mainly SW, dropping small amounts of ash, and occasionally fresh spatter, downwind. Measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 1,200 and 700 tonnes per day were measured on 4 and 8 February, respectively. The 2003-2007 average rate was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed over 3 km SE through a lava tube system before breaking out onto the surface. Thermal anomalies detected by satellite and visual observations revealed active lava flows above and on the pali, and on the coastal plain. By 8 February, pahoehoe lava flows had advanced 700 m from the base of the pali S onto the coastal plain. Incandescence was sometimes seen from a vent low on the S wall of Pu'u 'O'o crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 January-2 February 2010 Citation IconCite this Report

During 27 January-2 February, HVO reported an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface occasionally spattered, and both rose and drained through a hole in the cavity floor. A plume from the vent drifted N, NW, and W, dropping small amounts of ash, and occasionally fresh spatter, downwind. Measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 400 and 1,000 tonnes per day were measured on 28 January and 1 February, respectively. The 2003-2007 average rate was 140 tonnes per day.

Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed over 3 km SE through a lava tube system before breaking out onto the surface. Thermal anomalies detected by satellite and visual observations revealed active lava flows on top of and on the pali; lava burned forest on the W side of the TEB flows. Incandescence was seen from a vent low on the S wall of Pu'u 'O'o crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 January-26 January 2010 Citation IconCite this Report

During 20-26 January, HVO reported an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface occasionally spattered, and both rose and drained through a hole in the cavity floor. A plume from the vent drifted multiple directions, dropping small amounts of ash, and occasionally fresh spatter, downwind. Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed SE through a lava tube system. Thermal anomalies detected by satellite and visual observations revealed active lava flows on top of the pali from lava-tube breakouts.

During an overflight of Pu'u 'O'o crater on 19 January scientists saw a recent but inactive lava flow across the bottom of the crater. On 22 January a small part of the crater rim collapsed in front of the web camera, revealing an incandescent vent at the base of the E wall. During 23-26 January, incandescence was seen from the vent, as well as from high on the E wall, the crater floor, and low on the S wall.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 January-19 January 2010 Citation IconCite this Report

During 13-19 January, HVO reported an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface occasionally spattered, and both rose and drained through a hole in the cavity floor. A plume from the vent drifted mainly SW, dropping small amounts of ash, and occasionally fresh spatter, downwind. On 14 January, the lava surface suddenly rose to very high levels multiple times; the highest level was about 120 m below the floor of Halema'uma'u crater. Thermal anomalies from the areas above the pali, detected from satellites on the same day, indicated that lava emissions from the TEB vent had resumed. Lava flows were noted during 17-19 January.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 January-12 January 2010 Citation IconCite this Report

During 6-12 January, HVO reported that lava flows from Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex were seen above the pali by observers, or detected in satellite images. Lava did not enter the ocean at Waikupanaha. Incandescence was seen almost daily coming from multiple locations in Pu'u 'O'o crater. The vent in Halema'uma'u crater continued to produce a plume that drifted SW, N, and NE, dropping small amounts of ash, and occasionally fresh spatter, downwind. The NE-drifting plume resulted in poor air quality in some communities on 9 January. Incandescence originated from an active and sometimes sloshing lava surface within an opening on the deep floor of the vent cavity.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 December-5 January 2010 Citation IconCite this Report

During 30 December-3 January, HVO reported that lava flowed SE from beneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at Waikupanaha. Lava was not seen entering the ocean on 4 and 5 January. Thermal anomalies detected by satellite and occasional visual observations revealed active lava flows on the pali. Incandescence was seen almost daily coming from Pu'u 'O'o crater. During an overflight of Pu'u 'O'o crater on 29 December, geologists saw that a part of the high point of the W rim had collapsed, and a new gas vent had opened up at base of the N wall.

The vent in Halema'uma'u crater continued to produce a plume that drifted NE and NW, dropping small amounts of ash, and occasionally fresh spatter, downwind. Incandescence originated from an active and sometimes sloshing lava surface within an opening on the deep floor of the vent cavity.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 December-29 December 2009 Citation IconCite this Report

During 23-29 December, HVO reported that lava flowed SE from beneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at Waikupanaha. Thermal anomalies detected by satellite and visual observations revealed active lava flows on and at the base of the pali, and on the coastal plain. On 26 December, explosions at the ocean entry ejected material 15 m high. Incandescence was seen almost daily coming from Pu'u 'O'o crater. The vent in Halema'uma'u crater continued to produce a plume that drifted mainly SW, dropping small amounts of ash, and occasionally fresh spatter, downwind. Incandescence originated from a very active, sloshing lava surface within a single opening on the deep floor of the vent cavity. Parts of the opening rim periodically collapsed into the lava surface generating spatter that deposited on the floor and walls of the vent cavity.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 December-22 December 2009 Citation IconCite this Report

During 16-22 December, HVO reported that lava flowed SE from beneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at Waikupanaha. Incandescence was seen almost daily coming from Pu'u 'O'o crater. The vent in Halema'uma'u crater continued to produce an off-white plume that drifted E and SW, dropping small amounts of ash downwind. Incandescence originated from a few holes in the deep floor of the vent cavity. Occasionally, lava ponded on the floor of the cavity. Spatter originated from a small spatter cone on the E side of the vent cavity floor. Spatter from the opening frequently fed small lava flows that traveled down the flank of the cone. The sulfur dioxide emission rate at the summit remained elevated; 600 tonnes per day were measured on 18 December. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 December-15 December 2009 Citation IconCite this Report

During 9-15 December, HVO reported that lava flowed SE from beneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at multiple locations between Waikupanaha and areas farther to the W. Towards the beginning of the reporting period, thermal anomalies detected by satellite and visual observations revealed occasional active lava flows. Incandescence was seen almost daily from Pu'u 'O'o crater. The vent in Halema'uma'u crater continued to produce an off-white plume that drifted predominantly to the SW, dropping small amounts of ash downwind. Incandescence originated from a few holes in the deep floor of the vent cavity. On 13 December, lava ponded on the floor, crusted over, and blocked the holes. Incandescence was again visible the next night.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 December-8 December 2009 Citation IconCite this Report

During 2-8 December, HVO reported that lava flowed SE from beneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at multiple locations between Waikupanaha and an area 700 m farther to the W. Thermal anomalies detected by satellite and visual observations revealed active lava flows on the coastal plain. Incandescence was occasionally seen from Pu'u 'O'o crater; on 2 December, incandescence originated from vents on the E wall. The vent in Halema'uma'u crater continued to produce a white or off-white plume that drifted E, W, and SW, and dropped small amounts of ash downwind. Incandescence originated from multiple spattering holes in the deep floor of the vent cavity.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 November-1 December 2009 Citation IconCite this Report

During 25 November-1 December, HVO reported that lava flowed SE from beneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at multiple locations between Waikupanaha and an area 700 m farther to the W. A small bench collapse may have occurred on 27 November. Thermal anomalies detected by satellite and visual observations revealed active surface lava flows on the coastal plain. Incandescence was occasionally seen on the Pu'u 'O'o crater floor.

The vent in Halema'uma'u crater continued to produce a white or off-white plume that drifted mainly SW and dropped small amounts of ash downwind. Incandescence originated from a lava pond deep in the vent cavity floor; the lava pond circulated and spattered during 25-26 November and 1 December. Measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 1,000 tonnes per day were measured on 28 and 30 November. The 2003-2007 average rate was 140 tonnes per day.

According to a news article on 30 November, Hawaii county was declared a natural disaster area due to the negative impact that vog from Halema'uma'u crater has had on croplands and livestock.

Sources: Hawaii News Now; US Geological Survey Hawaiian Volcano Observatory (HVO)


18 November-24 November 2009 Citation IconCite this Report

During 18-24 November, HVO reported that lava flowed SE from beneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at multiple locations between Waikupanaha and an area 700 m farther to the W. Thermal anomalies detected by satellite and visual observations revealed active surface lava flows at locations on and at the base of the pali, at the TEB vent, and on the coastal plain. Incandescence was seen on the Pu'u 'O'o crater floor.

The vent in Halema'uma'u crater continued to produce a white or off-white plume that drifted mainly SW and dropped small amounts of ash downwind. Incandescence originated from a circulating and spattering lava pond that occasionally rose above and drained back below holes in the vent cavity floor. On 21 November, a sliver of the rim collapsed and was followed by an explosion that produced a dense brown plume that dissipated after a few minutes (http://hvo.wr.usgs.gov/kilauea/update/archive/2009/Nov/HMMvent_21Nov2009_x2speed.mov). Measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 700-1,100 tonnes per day was measured during 18-20 and 23 November. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 November-17 November 2009 Citation IconCite this Report

During 11-17 November, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at multiple locations between Waikupanaha and an area 700 m farther to the W. Thermal anomalies detected by satellite suggested active surface lava flows. Incandescence was seen on the Pu'u 'O'o crater floor and intermittently from an East wall vent. The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted W and SW. Incandescence originated from a spattering lava pond inside the vent cavity. Measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 600 tonnes per day was measured on 16 November. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 November-10 November 2009 Citation IconCite this Report

During 4-10 November, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry and a second location, 700 m farther to the W. Thermal anomalies detected in satellite images and visual observations revealed active surface lava flows. Breakout lava flows were located inland of the Waikpuanaha entry and also W of the County Public Viewing trail. The last remaining structure on the flow field burned on 3 November. Incandescence was seen from the Pu'u 'O'o crater floor and an East wall vent during 6-7 November.

The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted SW and likely produced some ashfall. Incandescence originated from a spattering lava pond inside the vent cavity. Preliminary measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 700 and 400 tonnes per day were measured on 6 and 9 November, respectively. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 October-3 November 2009 Citation IconCite this Report

During 28 October-3 November, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Lava began entering the ocean at a second location, 700 m farther to the W, on 31 October. Thermal anomalies detected in satellite images and visual observations revealed active surface lava flows. Breakout lava flows were located inland of the Waikpuanaha entry and also immediately W of the County Public Viewing trail. Intermittent incandescence was seen from the Pu'u 'O'o crater floor and an East wall vent.

The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted SW. Incandescence originated from occasionally spattering holes from a surface inside the vent cavity. On 3 November, a collapse of the surface revealed a circulating and spattering lava pond below. Preliminary measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 800 tonnes per day was measured on 30 October. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 October-27 October 2009 Citation IconCite this Report

During 21-27 October, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry on most days. Thermal anomalies detected in satellite images and visual observations revealed active surface lava flows. For a few days an active lava flow advanced on the coastal plain, burning vegetation and pavement along the former Kalapana access road. Intermittent incandescence was seen from the Pu'u 'O'o crater floor and an East wall vent.

The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted SW. Incandescence originated from occasionally spattering holes from a surface inside the vent cavity. Preliminary measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 560-1,400 tonnes per day was measured during 21-22 and 26 October. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 October-20 October 2009 Citation IconCite this Report

During 14-20 October, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Thermal anomalies detected in satellite images and visual observations revealed active surface lava flows on top and at the base of the pali. Intermittent incandescence was seen from the Pu'u 'O'o crater floor and an East wall vent.

The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted SW. Fresh Pele's Hair was collected near the summit on 16 October. Incandescence originated from sources inside the vent cavity; on 18 October a lava pond surface was seen, but then disappeared. Preliminary measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 690-940 tonnes per day was measured during 16-18 October. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 October-13 October 2009 Citation IconCite this Report

During 7-13 October, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Thermal anomalies detected in satellite images revealed active surface lava flows on top of the pali. Intermittent incandescence was seen from Pu'u 'O'o crater and the East wall vent during 7-10 October.

The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted mainly SW. Small amounts of ash were retrieved from collection bins placed near the plume. Incandescence originated from a source deep inside the vent cavity; on 13 October a crusted lava pond surface was seen. Preliminary measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 800 tonnes per day was measured on 11 October. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 September-6 October 2009 Citation IconCite this Report

During 30 September-6 October, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Thermal anomalies detected in satellite images revealed active surface lava flows on top of the pali. The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted SW. Small amounts of occasional fresh ash were retrieved from collection bins placed near the plume. During 30 September and 2, 4, and 5 October, a lava pond within the vent, about 200 m below the Halema'uma'u crater floor, rose and fell, circulated, and weakly spattered. Preliminary measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 410, 650, and 480 tonnes per day were measured on 30 September, 1 and 2 October, respectively. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 September-29 September 2009 Citation IconCite this Report

During 23-27 September, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Lava was not seen entering the ocean on 28 and 29 September. Visual observations and thermal anomalies detected in satellite images revealed active surface lava flows on most days. On 23 September, weak incandescence was detected from inside Pu'u 'O'o crater and from a gas vent in the E crater wall. Explosive activity at the ocean entry on 26 September was possibly caused by a small bench collapse.

The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted SW and W. Small amounts of ash were retrieved from collection bins placed near the plume. Weak incandescence from the vent, about 200 m below the Halema'uma'u crater floor, was visible at night. Rushing gas and rockfall sounds were occasionally heard in the vicinity of the vent. Preliminary measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 400, 700, and 665 tonnes per day were measured on 23, 24, and 28 September, respectively. The 2003-2007 average rate was 140 tonnes per day. On 26 September, a series of rockfalls accompanied an apparent collapse of the vent floor, causing the lava level to drop and the plume to turn "dusty brown" for several minutes. On 28 September, a spattering lava pond was seen inside the vent.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 September-22 September 2009 Citation IconCite this Report

During 16-22 September, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Visual observations and thermal anomalies detected in satellite images revealed active surface lava flows.

The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted mainly SW. Small amounts of ash were retrieved from collection bins placed near the plume. The sulfur dioxide emission rate at the summit remained elevated; 1,300, 1,000, and 400 tonnes per day were measured on 16, 17, and 18 September, respectively. The 2003-2007 average rate was 140 tonnes per day. During 16 and 17 September, two hybrid earthquakes were followed by 20-40 minutes of sustained tremor. The plume turned briefly "dusty" after the first event and incandescent tephra was ejected onto the rim after the second event; both produced glassy spatter.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 September-15 September 2009 Citation IconCite this Report

During 9-15 September, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Weak, sporadic explosions from the ocean entry were seen on 10 September. Occasional thermal anomalies detected in satellite images and visual observations revealed active surface lava flows.

The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted mainly SW. The plume briefly turned brown on 9 September from a rockfall. Small amounts of ash were retrieved from collection bins placed near the plume. Incandescence from small openings in the floor of the vent, about 200 m below the Halema'uma'u crater floor, was visible at night with varying intensity. During the night from 12 to13 September, spattering from the opening was seen on the web camera. The sulfur dioxide emission rate at the summit remained elevated; 900 tonnes per day was measured on 11 September. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 September-8 September 2009 Citation IconCite this Report

During 2-8 September, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Thermal anomalies detected in satellite images and visual observations revealed active surface lava flows in the abandoned Royal Gardens subdivision.

The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted mainly SW. Small amounts of ash-sized tephra were retrieved from collection bins placed near the plume. Degassing and rockfall sounds were occasionally heard in the vicinity of the vent. Incandescence from small openings in the floor of the vent, about 200 m below the Halema'uma'u crater floor, was visible at night. The sulfur dioxide emission rate at the summit remained elevated; 1,200 and 785 tonnes per day were measured on 2 and 3 September, respectively. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 August-1 September 2009 Citation IconCite this Report

During 26 August-1 September, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted mainly SW. Small amounts of ash-sized "rock dust" were retrieved from collection bins placed near the plume. Degassing sounds were occasionally heard in the vicinity of the vent. Incandescence from the floor of the vent was visible at night on the web camera, or from HVO. The sulfur dioxide emission rate at the summit remained elevated; 1,000 and 950 tonnes per day were measured on 26 and 27 August, respectively. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 August-25 August 2009 Citation IconCite this Report

During 19-25 August, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Thermal anomalies detected in satellite images and visual observations during 18-19 August revealed active surface lava flows. The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted mainly SW. Small amounts of ash-sized "rock dust" were retrieved from collection bins placed near the plume. Rushing gas sounds were occasionally heard in the vicinity of the vent. Incandescence from the floor of the vent was visible at night on the web camera. The sulfur dioxide emission rate at the summit remained elevated; 950-1,140 tonnes per day was measured during 19-21 August. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 August-18 August 2009 Citation IconCite this Report

During 12-18 August, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Thermal anomalies detected in satellite images and visual observations revealed active surface flows on the flow field.

The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted mainly SW. Small amounts of ash-sized "rock dust," were retrieved from collection bins placed near the plume; possibly fresh tephra, including Pele's Hair, was collected on 12 August. Rushing gas sounds were often heard in the vicinity of the vent. During 12-13 August, a new, brightly incandescent hole appeared on the floor of the vent. The vent increased in size and incandescence continued to be seen on the web camera during the reporting period. The sulfur dioxide emission rate at the summit remained elevated; 2,050 and 900 tonnes per day was measured on 12 and 14 August; respectively. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 August-11 August 2009 Citation IconCite this Report

During 5-11 August, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Thermal anomalies detected in satellite images and visual observations revealed active surface flows on the pali, and along the E and W TEB flow field. The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted mainly SW. Small amounts of ash-sized "rock dust," likely generated from small vent wall collapses, were retrieved from collection bins placed near the plume. The sulfur dioxide emission rate at the summit remained elevated; 1,800 tonnes per day was measured on 7 August. The 2003-2007 average rate was 140 tonnes per day. For the first time in weeks, on 10 August, incandescence from the vent was seen.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 July-4 August 2009 Citation IconCite this Report

During 29 July-4 August, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Thermal anomalies detected in satellite images and visual observations revealed active surface flows on the pali. The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted mainly SW. Small amounts of ash-sized "rock dust," likely generated from small wall collapses in the vent, were retrieved from collection bins placed near the plume. The sulfur dioxide emission rate at the summit remained elevated; 675 tonnes per day was measured on 31 July. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 July-28 July 2009 Citation IconCite this Report

During 22-28 July, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. Thermal anomalies detected in satellite images and visual observations revealed active surface flows at several locations on the pali. Explosions from the Waikupanaha ocean entry were reported on 22 July. The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted mainly SW. Small amounts of ash-sized "rock dust" were retrieved from collection bins placed near the plume during the reporting period. The sulfur dioxide emission rate at the summit remained elevated; measurements were 800, 500, and 950 tonnes per day on 22, 24, and 27 July, respectively. The 2003-2007 average rate was 140 tonnes per day; between the 30 June rockfall sequence and 19 July rates were 200-400 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 July-21 July 2009 Citation IconCite this Report

During 15-20 July, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Thermal anomalies detected in satellite images and visual observations revealed active surface flows at several locations on the pali, and on the TEB flow field. A structure in the abandoned Royal Gardens subdivision was destroyed on 16 July. Explosions from the Waikupanaha ocean entry were reported on 17 July. Lava was not seen entering the ocean on 21 July.

The vent in Halema'uma'u crater continued to produce a diffuse white plume that drifted mainly SW. No lava or incandescence from the crater had been seen since a "deflation-inflation" event on 4 July. Small amounts of ash-sized "rock dust" were retrieved from collection bins placed near the plume during the reporting period. The sulfur dioxide emission rate at the summit remained elevated; measurements were 400 and 1,100 tonnes per day on 17 and 20 July, respectively. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 July-14 July 2009 Citation IconCite this Report

During 8-14 July, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Thermal anomalies detected in satellite images and visual observations revealed active surface flows on the pali and on the TEB flow field. Explosions from both ocean entries were reported on 8 July; strong explosions ejected incandescent tephra up to 20 m high at the Waikupanaha entry.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. No lava or incandescence from the crater had been seen since a "deflation-inflation" event on 4 July. Small amounts of ash-sized tephra were retrieved from collection bins placed near the plume during the reporting period. The sulfur dioxide emission rate at the summit remained elevated; measurements were between 300 and 400 tonnes per day during 8-10 and 13 July. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 July-7 July 2009 Citation IconCite this Report

During 1-6 July, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Thermal anomalies detected in satellite images and visual observations revealed active surface flows on the pali and on the TEB flow field.

A sequence of rockfalls within the cavity on the floor of Halema'uma'u crater began at 1338 on 30 June. The first rockfall was followed by a loud explosion, and produced a M 2.4 equivalent earthquake felt at HVO and the adjacent Jaggar Museum. The gas plume turned brown for several minutes. Several more rockfall signals were detected by the seismic network; two more were felt locally. Booming sounds also accompanied several of the rockfalls. Chunks of the vent rim fell into the cavity. By 1600, more than 30 rim-collapse events had been recorded by seismometers, with a few more occurring on 1 July. Seismic tremor amplitudes decreased by more than 50 percent. By 1800, the levels were at their lowest values since 30 August 2007. On 1 July, scientists observed rocky rubble within the vent and no incandescence. Sporadic gas jetting noises were heard coming from the vent.

During 1-2 July, a few areas of incandescence were seen in the vent by the web camera. During 2-4 July, scientists observed a small ponded lava surface and weak spattering deep within the vent. The sulfur dioxide emission rate at the summit remained elevated; measurements were 360 and 200 tonnes per day on 3 and 5 July, respectively. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 June-30 June 2009 Citation IconCite this Report

During 24-30 June, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Thermal anomalies detected in satellite images and visual observations revealed active surface flows on the pali and on the TEB flow field. Explosions from both ocean entries were occasionally reported. On 28 June, officials reported a wide swath of lava flows descending the pali.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Small amounts of ash-sized tephra, including Pele's hair and fresh spatter, were retrieved from collection bins placed near the plume during the reporting period. A molten lava pool (54 m in diameter) near the base of the cavity, about 290 m below the floor of the crater, produced incandescence of variable brightness. The level of the lava pond rose periodically. Sounds resembling rushing gas and rockfalls were occasionally heard in the vicinity of the crater. The sulfur dioxide emission rate at the summit remained elevated; measurements were 800 tonnes per day on 24 and 26 June. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 June-23 June 2009 Citation IconCite this Report

Daily reports from HVO about Kilauea during 17-23 June indicated continuing visible glow from the Halema'uma'u vent. Molten lava remained in the neck of a funnel-shaped cavity in the floor of Halema'uma'u Crater. Webcam views showed the lava level rising several meters for brief periods before returning to depths of about 290 m below the crater rim and 205 m below the crater floor, as determined by laser-ranging measurements. Throughout the week lava from east rift zone vents flowed through tubes to the coast and entered the ocean at two locations west of Kalapana; active surface flows also continued on the pali within the abandoned Royal Gardens subdivision. Sulfur dioxide emission rates from the Halema`uma`u and Pu`u `O`o vents remained elevated. The plume continued to carry glassy bits of spatter and small amounts of ash. A deflation-inflation event began on 22 June and was continuing the next day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 June-16 June 2009 Citation IconCite this Report

During 10-16 June, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Thermal anomalies detected in satellite images and visual observations revealed active surface flows on the pali and on the TEB flow field. Explosions from the Waikupanaha ocean entry were reported on 13 June.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Small amounts of tephra, including Pele's hair and fresh spatter, were retrieved from collection bins placed near the plume during the reporting period. A molten lava pool near the base of the cavity, about 100 m below the floor of the crater, produced bright incandescence. The Halema'uma'u Overlook Vent webcam that has a view into the vent cavity showed a draining event from the actively bubbling lava pond on the evening of 12 June. Sounds resembling rushing gas and rockfalls were occasionally heard in the vicinity of the crater. The sulfur dioxide emission rate at the summit remained elevated; measurements were 1,100 and 1,000 tonnes per day on 11 and 12 June, respectively. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 June-9 June 2009 Citation IconCite this Report

During 3-9 June, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. The Kupapa'u ocean entry was again active starting on 4 or 5 June. Thermal anomalies detected in satellite images and visual observations revealed active surface flows above and in the abandoned Royal Gardens subdivision, and on the TEB flow field.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Small amounts of tephra, including Pele's hair and fresh spatter, were retrieved from collection bins placed near the plume during the reporting period. A molten lava pool near the base of the cavity, about 100 m below the floor of the crater, produced bright incandescence. Lava was clearly visible in the Halema'uma'u Overlook Vent webcam on 5 June. On 8 and 9 June, sounds resembling rushing gas and rockfalls were heard in the vicinity of the crater. The sulfur dioxide emission rate at the summit remained elevated; measurements were 700 and 800 tonnes per day on 4 and 5 June, respectively. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 May-2 June 2009 Citation IconCite this Report

During 27 May-2 June, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry. The Kupapa'u ocean entry was active until 31 May. On 30 May, a thermal anomaly on the upper TEB flow field was detected on satellite imagery. Pilot reports and satellite imagery analysis on 2 June confirmed active surface lava flows in this area. A small channelized 'a'a lava flow had stagnated above the top of the pali.

The vent in Halema'uma'u crater continued to produce a predominantly white plume, occasionally tinged brown, that drifted mainly SW. Small amounts of ash-sized tephra, including Pele's hair, Pele's tears, and fresh spatter, were retrieved from collection bins placed near the plume during the reporting period. A molten lava pool near the base of the cavity, deep below the floor of the vent, produced incandescence of variable intensity. Sounds resembling rushing gas were sometimes heard in the vicinity of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 May-26 May 2009 Citation IconCite this Report

During 20-26 May, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. The vent in Halema'uma'u crater continued to produce a predominantly white plume that rose 200-300 m. The plume drifted N, NE, and SW, and caused poor air quality in the summit region. Small amounts of usually ash-sized tephra, including Pele's hair, Pele's tears, and glassy spatter, were retrieved from collection bins placed near the plume during the reporting period. A molten lava pool near the base of the cavity, deep below the floor of the vent, produced incandescence of variable intensity. Sounds resembling rushing gas and rockfalls were heard in the vicinity of the crater on 26 May.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 May-19 May 2009 Citation IconCite this Report

During 13-19 May, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. The vent in Halema'uma'u crater continued to produce a predominantly white plume, occasionally tinged brown, that drifted mainly W. Various amounts of tephra, including Pele's hair and irregular pieces of vesicular glass, were retrieved from collection bins placed near the plume during the reporting period. A molten lava pool near the base of the cavity, deep below the floor of the vent, produced incandescence of variable intensity. Sounds resembling rushing gas and rockfalls were sometimes heard in the vicinity of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 May-12 May 2009 Citation IconCite this Report

During 6-12 May, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. On 6 May, a bench collapse from Kupapa'u was detected by seismic signals. Tour pilots reported an active surface lava flow above the pali that was less than half a kilometer long. A thermal anomaly corresponding to the flow was detected on satellite imagery. Geologists on an overflight on 7 May mapped a stalled 'a'a flow that broke out from the TEB lava tube and was being covered by pahoehoe from the breakout point. They also saw that the Waikupanaha delta had built out to the furthest point in its over 13-month history and that bus-sized chunks of delta were scattered on the beach fronting the Kupapa'u entry, as a result of the 6 May collapse. Some explosions occurred at the Waikupanaha ocean entry on 10 May.

The vent in Halema'uma'u crater continued to produce a white plume that that drifted W and SW. A molten lava pool near the base of the cavity, deep below the floor of the crater, produced the brightest incandescence from the summit vent since early December 2008. Sounds resembling rushing gas and falling rocks were sometimes heard in the vicinity of the crater. Fresh spatter was retrieved from collection bins placed near the plume during 6-7 May. The sulfur dioxide emission rate at the summit was elevated; measurements were 1,100 and 700 tonnes per day on 8 and 10 May, respectively. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 April-5 May 2009 Citation IconCite this Report

During 29 April-5 May, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Some explosions occurred at the Waikupanaha ocean entry. The vent in Halema'uma'u crater continued to produce a white plume that sometimes caused poor air quality in nearby areas. Sounds resembling rushing gas were sometimes heard in the vicinity of the crater. Various amounts of tephra, spatter, and ash were retrieved from collection bins placed near the plume during the reporting period. On 3 May, unusually bright incandescence seen from the vent on the web camera was accompanied by a decrease in summit tremor levels of about 40 percent. During 4-5 May, bright incandescence was again noted; summit tremor levels were variable but never exceeded moderate values.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 April-28 April 2009 Citation IconCite this Report

During 22-28 April, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Occasional explosions occurred from the Waikupanaha ocean entry, and on 22 April small littoral explosions continued to build up a steep-sided cone at the Kupapa'u entry. Surface flows were present on the coastal plain. The vent in Halema'uma'u crater continued to produce a white plume occasionally tinged brown that drifted SW, N, and NE. Poor air quality in nearby communities was sometimes caused by the plume. Incandescence was intermittently seen from the vent, and sounds resembling rushing gas or rockfalls were sometimes heard in the vicinity of the crater. Various amounts of tephra, including Pele's hair, spatter, and ash, were frequently retrieved from collection bins placed near the plume.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 April-21 April 2009 Citation IconCite this Report

During 15-21 April, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Occasional explosions occurred from the Waikupanaha ocean entry. Surface flows were present on the coastal plain and at the base of the pali. The vent in Halema'uma'u crater continued to produce a white plume occasionally tinged brown that drifted mainly SW. Incandescence was intermittently seen from the vent, and sounds resembling rushing gas or rockfalls were sometimes heard in the vicinity of the crater. Pele's hair, tiny glass spheres, and ash were frequently retrieved from collection bins placed near the plume. The sulfur dioxide emission rate at the summit was elevated, reaching 700 tonnes per day on 15 April; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 April-14 April 2009 Citation IconCite this Report

During 8-14 April, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Occasional explosions occurred from the Waikupanaha ocean entry. Surface flows on the coastal plain or from the Prince lobe were seen or detected by satellite imagery. The vent in Halema'uma'u crater continued to produce a white plume occasionally tinged brown that drifted mainly SW. Incandescence was intermittently seen from the vent. The sulfur dioxide emission rate at the summit was elevated; measurements were 1,000, 900, and 1,000 tonnes per day on 8, 9, and 13 April, respectively. The 2003-2007 average rate was 140 tonnes per day. On 13 April, Pele's hair, tiny glass spheres, and ash were retrieved from collection bins placed near the plume. On 14 April, ash was collected from the bins. Seismic instruments recorded a M 5 earthquake beneath the S flank, 12 km SE of the summit, at a depth of 10 km.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 April-7 April 2009 Citation IconCite this Report

During 1-7 April, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Surface flows on the coastal plain were seen or detected by satellite imagery. Occasional explosions occurred from the Waikupanaha ocean entry. On 2 April, geologists found that the surface lava flow feeding the Kupapa'u entry was 1 km (0.6 m) wide.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Incandescence was intermittently seen from the vent, and sounds resembling rushing gas were sometimes heard in the vicinity of the crater. Variable amounts of tephra including some Pele's hair, Pele's tears, and rock dust were retrieved daily from collection bins placed near the plume. During 31 March and 1 April, geologists utilizing an infrared camera to look into the vent saw a lava pond that rose and fell approximately every 3 minutes. During 2-3 April, the lava pond was replaced by a large hot opening; ejected spatter built up a rim. The sulfur dioxide emission rate at the summit was elevated; measurements were 550, 800, and 700 tonnes per day on 1, 2, and 3 April, respectively. The 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 March-31 March 2009 Citation IconCite this Report

During 24-31 March, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Daily thermal anomalies seen on satellite imagery suggested surface flows on the coastal plain.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Incandescence was intermittently seen from the vent, and sounds resembling rushing gas were sometimes heard in the vicinity of the crater. Variable amounts of tephra and some Pele's hair were retrieved almost daily from collection bins placed near the plume. On 24 March, a dusty brown plume rose from the vent. Geologists utilizing an infrared camera saw at least two spattering openings deep below the vent rim. On 25 March, two more brown plumes were emitted. A larger collapse was followed by a large, dense, brown plume, and several more brown plumes over the next two hours. The rockfalls within the vent covered the previously seen hot vents. During 26-28 March, infrared camera views revealed a rising and falling lava surface deep below the crater floor. The lava surface was static, but circulating on 29 March. The sulfur dioxide emission rate at the summit was 500, 900, and 1,000 tonnes per day on 25, 26, and 30 March, respectively; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 March-24 March 2009 Citation IconCite this Report

During 18-24 March, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Activity near the Prince Lobe was noted, and thermal anomalies seen on satellite imagery during most days suggested surface flows on the coastal plain. Explosions from the Waikupanaha ocean entry were seen on 19 March. During 19-20 March, the Kupapa'u bench was 450 m wide (along shore) and extended 70 m into the ocean.

The vent in Halema'uma'u crater continued to produce a predominantly white plume, occasionally tinged brown, that drifted mainly SW. Incandescence was intermittently seen from the vent, and sounds resembling rushing gas were sometimes heard in the vicinity of the crater. Tephra and some glassy spatter were retrieved almost daily from collection bins placed near the plume. On 20 March, geologists utilizing an infrared camera saw that a single small spattering vent (another was out of sight to the E) at the bottom of a large overhung cavity beneath the Halema'uma'u crater floor emitted gas and steam. The sulfur dioxide emission rate at the summit was 500 and 900 tonnes per day on 19 and 23 March, respectively; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 March-17 March 2009 Citation IconCite this Report

During 11-17 March, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry and occasionally producing explosions. Thermal anomalies noted during most days on the coastal plain suggested surface flows. During 11-13 March, scattered surface flows near the Prince lobe were noted. On 13 March, a 30-m-wide lava flow entered the ocean at Kupapa'u, a second ocean entry location to the W of Waikupanaha. Kupapa'u was active during 14-17 March.

The vent in Halema'uma'u crater continued to produce a predominantly white plume; southwesterly winds often caused poor air quality in communities to the N. Incandescence from the vent was seldom seen. On 12 March, seemingly fresh spatter was collected from bins placed near the plume; minimal amounts of ash were collected the next day. The sulfur dioxide emission rate at the summit was 1,000 tonnes per day on 13 March; the 2003-2007 average rate was 140 tonnes per day. Field visits to the caldera floor indicated that there was an ash emission event sometime before dawn on 15 March, possibly following a wall collapse within the Halema'uma'u vent. Ash coated several monitoring instruments and was detected in Volcano, about 6 km NE. On 16 March, the plume drifted N and dusted HVO with ash.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 March-10 March 2009 Citation IconCite this Report

During 4-10 March, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry and occasionally producing explosions. Thermal anomalies noted during most days on the coastal plain suggested surface flows. Scattered surface flows near the Prince lobe were noted on 5 and 9 March. The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW; incandescence was intermittently seen. Small amounts of newly ejected tephra were collected on 5, 6, and 10 March. Geologists utilizing an infrared camera on 3 March saw two spattering vents and a hot area about 100 m below the vent rim. Hot areas were also visible during 4-5 March, and on 6 March they saw an enlarged puffing vent. The sulfur dioxide emission rate at the summit was 700 tonnes per day on 5 and 6 March; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 February-3 March 2009 Citation IconCite this Report

HVO reported that during 25 February-3 March lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry and occasionally producing explosions. A sizable collapse of the Waikupanaha bench was seen by a visitor on 28 February. Thermal anomalies noted during most days on the coastal plain suggested surface flows.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW; incandescence was intermittently seen from the vent. Small amounts of ejected tephra, including Pele's hair, were routinely collected. On 26 February, geologists utilizing an infrared camera saw two spattering and episodically degassing vents about 100 m below the vent rim. The sulfur dioxide emission rate at the summit was 1,100 tonnes per day on 27 February and 1 March; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 February-24 February 2009 Citation IconCite this Report

HVO reported that during 18-24 February lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry and occasionally producing explosions. On 17 February, four large explosions that accompanied a collapse of the Waikupanaha bench ejected rocks and spatter 275 m inland. Lava also entered the ocean at Waha'ula during 18-20 February, and at a second point further E, named Poupou, starting on 18 February. Incandescence originated from the Prince lobe on 20 February. Thermal anomalies noted on the coastal plain suggested surface flows.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW; incandescence was intermittently seen from the vent. Small amounts of ejected tephra, including Pele's hair and some spatter, were routinely collected. Geologists utilizing an infrared imager during an overflight on 20 February saw a small, hot degassing vent deep below the vent rim. The sulfur dioxide emission rate at the summit was 1,400, 1,500, 1,300, and 900 tonnes per day on 17, 18, 19, and 20 February, respectively; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 February-17 February 2009 Citation IconCite this Report

HVO reported that during 11-17 February lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Waha'ula ocean entries. On most days, multiple explosions and spatter at the ocean entry were seen. On 11 February, geologists found a new littoral cone, on the edge of the bench, with a large crack running through it. Spatter on the cone and the bench behind it resulted from lava bubble bursts and steam jetting reported during the previous two days. A second crack between the cone and the sea cliff was also noted. The cracks suggested that the bench was slowly failing and did not collapse as reported a few days prior. Occasional incandescence originated from the Prince lobe, the flow that feeds the Waha'ula ocean entry. Thermal anomalies suggesting surface flows were noted on the coastal plain and on the pali.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW; incandescence was intermittently seen from the vent. Small amounts of tephra, including Pele's hair and some spatter, were routinely collected. Infrared images taken during an overflight on 11 February revealed the development of a small spattering cone over the conduit that hosted a lava pond the previous week. Images taken on 14 February indicated that the conduit had mostly crusted over; a small, puffing vent was visible. The sulfur dioxide emission rate at the summit was 800 tonnes per day on 12 February, and 500 tonnes on 13 February; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 February-10 February 2009 Citation IconCite this Report

HVO reported that during 4-10 February lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Waha'ula ocean entries. On 7 and 8 February, multiple explosions at the ocean entry were seen. On 9 February, booming noises and explosions were noted at the ocean entry; observers reported lava bubble bursts at 15-30 minute intervals. Seismicity and later observations indicated that the bench had collapsed. Incandescence originated from the Prince lobe, the flow that feeds the Waha'ula ocean entry. Thermal anomalies suggesting surface flows were noted on the coastal plain and on the pali.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW; the plume turned brown on 5 and 7 February. Small amounts of tephra were routinely collected. Incandescence was intermittently seen from the vent, and sounds resembling rushing gas and rockfalls were sometimes heard in the vicinity of the crater. Geologists looked into the vent on 4 and 6 February and saw lava rising and falling about 115-120 m below the vent rim. The sulfur dioxide emission rate at the summit was 900 tonnes per day on 4 and 9 February, and 500 tonnes on 5 February; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 January-3 February 2009 Citation IconCite this Report

HVO reported that during 28 January-3 February lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha and Waha'ula ocean entries. Explosions at the ocean entry were seen on 28 January. Incandescence originated from the Prince lobe, the flow that feeds the Waha'ula ocean entry. Thermal anomalies suggesting surface flows were noted on the coastal plain.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW; occasional shifts in the wind caused poor air quality at the summit and surrounding areas. Small amounts of newly ejected tephra, including rock dust, spatter, and Pele's hair, were collected. Incandescence was intermittently seen from the vent, and sounds resembling rushing gas and rockfalls were sometimes heard in the vicinity of the crater. The sulfur dioxide emission rate at the summit was 1,100 tonnes per day on 30 January and 1,500 tonnes on 2 February; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 January-27 January 2009 Citation IconCite this Report

HVO reported that during 20-27 January lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Explosions at the ocean entry were seen on 20, 21, and 26 January. On 22 January, the Prince lava flow, W of the main lava-tube system, entered the ocean at Waha'ula but was too small to generate a steam plume. Thermal anomalies suggesting surface flows were noted on the coastal plain and on the pali; geologists found active lava flows on the coastal plain on 26 January.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Small amounts of newly ejected tephra, including rock dust, spatter, and Pele's Hair, were collected. Incandescence was intermittently seen from the vent, and sounds resembling rushing gas, rockfalls, and rock impacts were sometimes heard in the vicinity of the crater. The sulfur dioxide emission rate at the summit was 900 tonnes per day on 22 and 23 January; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 January-20 January 2009 Citation IconCite this Report

HVO reported that during 14-20 January lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Surface flows were noted on the coastal plain and incandescence was seen on the pali. Explosions at the ocean entry were seen on 17 and 18 January. Variable winds caused the County Viewing Area to close during 14-16 January.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Variable winds occasionally caused poor air quality around the summit; on 16 January sulfur dioxide concentrations in the air reached unsafe levels. On 17 January, a geologist near the vent heard rockfalls, and rock impact and rushing sounds. Vent rim collapses the next day caused a dusting of fine tephra, and on 20 January faint incandescence from deep within the vent was noted.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 January-13 January 2009 Citation IconCite this Report

HVO reported that during 7-13 January lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Surface flows were noted on the coastal plain and incandescence was seen at the base of the pali. Explosions at the ocean entry were seen on 6, 8, and 11 January. A lobe of lava called the Prince lobe, to the W of Waikupanaha, advanced to within about 160 m of the coastline.

The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Tephra production had stopped; rockfalls inside the vent continued. An infrared camera showed that the vent conduit was closed by rubble deep beneath the floor of the crater. The sulfur dioxide emission rate at the summit was 800 tonnes per day on 7 January; above the 2003-2007 average rate of 140 tonnes per day. Variable winds periodically caused sulfur dioxide concentrations in the air to reach unsafe levels and effect nearby communities, and caused the Jaggar Museum to close on 12 January.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 December-6 January 2009 Citation IconCite this Report

HVO reported that during 31 December-6 January lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Surface flows were noted on the coastal plain and incandescence was seen at the base of the pali. Explosions at the ocean entry were seen on 31 December and 5 January.

Earthquakes strong enough to be located were variously scattered beneath the caldera, along the SW rift zone, and along the S-flank fault. The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Consistent with a decreasing trend of ash production since 15 December, the vent produced minimal amounts of fine tephra; essentially no tephra was collected during 5-6 January. Sounds resembling rockfalls were sometimes heard in the vicinity of the crater. The sulfur dioxide emission rate at the summit was 500 tonnes per day on 31 December and 2 January; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 December-30 December 2008 Citation IconCite this Report

HVO reported that during 24-30 December lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Thermal anomalies were detected on satellite imagery at the base of the pali and on the coastal plain. Explosions at the ocean entry were noted on 26 and 29 December.

Earthquakes were variously located beneath the caldera, along the S-flank fault, and along the SW rift zone. The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Following a decreasing trend since 15 December, the vent produced minimal amounts of tephra that mostly consisted of fine rock dust. The sulfur dioxide emission rate at the summit was 400 and 800 tonnes per day on 24 and 29 December, respectively; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 December-23 December 2008 Citation IconCite this Report

HVO reported that during 17-23 December lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Thermal anomalies were detected on satellite imagery at the base of the pali and on the coastal plain. During 19-20 December geologists reported explosions at the ocean entry. Earthquakes were variously located beneath the caldera and along the S-flank fault. The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW and deposited small amounts of tephra.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 December-16 December 2008 Citation IconCite this Report

HVO reported that during 10-16 December lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Incandescence was occasionally seen at the TEB vent, and surface flows were noted on and at the base of the pali, and on the coastal plain. A branch of lava previously seen traveling S towards the Hawai'i Volcanoes National Park boundary went about 55 m into the park. On 16 December, a Pu'u 'O'o Crater web camera was hit with a small amount of debris, suggesting a collapse in the crater.

Earthquakes were variously located beneath the caldera, along the SW rift zone, and along the S-flank fault. Beneath Halema'uma'u crater the number of earthquakes on 10 December ranged from 150 to 200, but were too small to be located more precisely (less than M 1.7 and recorded on fewer than four seismometers). The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW and deposited small amounts of tephra. Weak winds caused poor air quality at the summit. Sounds resembling rockfalls were sometimes heard in the vicinity of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 December-9 December 2008 Citation IconCite this Report

HVO reported that during 3-9 December lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Incandescence was occasionally seen at the TEB vent, and surface flows were noted on and at the base of the pali. On 6 December, a few explosions originated from the ocean entry. Observers reported that a small bench collapse that occurred sometime between 6 and 7 December sent boulders up to 0.5 m in diameter inland about 50-75 m.

Earthquakes were variously located beneath and to the S of the caldera, along the SW rift zone, and along the S-flank fault. The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW and deposited small amounts of tephra. Night-time incandescence was rarely seen at the base of the plume, and sounds resembling rockfalls were heard in the vicinity of the crater. During 2-4 December, the plume drifted NW and high concentrations of sulfur dioxide were measured at various locations. On 4 December, hybrid earthquakes were followed by several minutes of dense brown emissions. A vent rim collapse was seen on 5 December after rockfall and booming sounds were heard, and brown ash was emitted. The sulfur dioxide emission rate at the summit was 1,000 and 500 tonnes per day on 4 and 5 December, respectively; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 November-2 December 2008 Citation IconCite this Report

HVO reported that during 26 November-2 December lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Incandescence was seen at the TEB vent. Breakout lava flows low on the pali fed channelized flows that traveled S towards the Hawai'i Volcanoes National Park boundary. GPS stations spanning Pu'u 'O'o Crater recorded almost 4 cm of contraction during the previous 3 months. Earthquakes were variously located beneath and to the S of the caldera, and along the SW rift zone, the S-flank fault, and the Koa'e fault. The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW and deposited small amounts of tephra. Night-time incandescence was occasionally seen at the base of the plume. The sulfur dioxide emission rate at the summit was 500 tonnes per day on 26 November; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 November-25 November 2008 Citation IconCite this Report

HVO reported that during 19-25 November lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Incandescence and active surface flows were seen on and at the base of the pali (fault scarp), and at the TEB vent. Earthquakes were variously located beneath and to the S of the caldera, and along the S-flank fault. During 20-21 November, tremor levels increased to four times the background level. The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW and deposited small amounts of tephra. Night-time incandescence was occasionally seen at the base of the plume. The sulfur dioxide emission rate at the summit was 1,700 and 700 tonnes per day on 20 and 24 November, respectively; the 2003-2007 average rate was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 November-18 November 2008 Citation IconCite this Report

HVO reported that during 12-18 November lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Incandescence and active surface flows were seen on and at the base of the pali (fault scarp). Earthquakes were variously located beneath and to the S of the caldera, and along the S-flank fault. Beneath Halema'uma'u crater daily earthquakes ranged from 20 to 40 (background is about 40), but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW and deposited small amounts of tephra. Night-time incandescence was seen at the base of the plume on the web camera for the first time in about a month, and sounds resembling distant surf and rockfalls were heard in the vicinity of the crater. The sulfur dioxide emission rate was 1,200 and 800 tonnes per day on 14 and 17 November, respectively; the 2003-2007 rate average was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 November-11 November 2008 Citation IconCite this Report

HVO reported that during 5-11 November lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Thermal anomalies detected on satellite imagery indicated active surface flows. The sulfur dioxide emission rate at Pu'u 'O'o was 2,000 tonnes per day on 7 November, near the 2005-2007 average background rate of 1,700 tonnes per day.

During the reporting period, Kilauea earthquakes were variously located beneath and to the S of the caldera and along the S-flank fault. Beneath Halema'uma'u crater earthquakes ranged from 40 to 60 (background is about 40), but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a white plume that occasionally turned brown and drifted mainly SW. Night-time incandescence was intermittently seen at the base of the plume, and sounds resembling distant surf and rock clattering were heard in the vicinity of the crater. The sulfur dioxide emission rate was 900 tonnes per day on 7 November. The 2003-2007 rate average was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 October-4 November 2008 Citation IconCite this Report

HVO reported that during 29 October-4 November lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Thermal anomalies detected on satellite imagery indicated active surface flows, especially in the abandoned Royal Gardens subdivision. Explosive activity at the ocean entry was reported on 31 October and 1 November. The sulfur dioxide emission rate at Pu'u 'O'o was 1,200 and 1,700 tonnes per day on 30 October and 3 November, respectively, half of the background rate of the 2005-2007 average.

During the reporting period, Kilauea earthquakes were variously located beneath and to the S of the caldera and along the S-flank fault. Beneath Halema'uma'u crater earthquakes ranged from 40 to 60 (background is about 40), but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Night-time incandescence was intermittently seen at the base of the plume, and sounds resembling distant surf and rock clattering were heard in the vicinity of the crater. The sulfur dioxide emission rate was 500-700 tonnes per day during 29-31 October and 3 November. The 2003-2007 rate average was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 October-28 October 2008 Citation IconCite this Report

HVO reported that during 22-28 October lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Lava flow production possibly paused during 26-27 October. Multiple surface lava flows on the pali were noted. On 23 October, a plume drifted above the County Viewing Area near the ocean entry and rained acid droplets, causing a closure. Explosions at the ocean entry were reported on 24 October. The sulfur dioxide emission rate at Pu'u 'O'o was 1,000 tonnes per day on 23 and 24 October, half of the background rate of the 2005-2007 average. Weak winds caused the viewing area to close again on 25 October.

During the reporting period, Kilauea earthquakes were variously located beneath and to the S of the caldera, along the S-flank faults, and along the SW rift zone. Beneath Halema'uma'u crater earthquakes ranged from less than 30 per day to 70 (background is about 40), but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Night-time incandescence was intermittently seen at the base of the plume, and sounds resembling distant surf, rock clattering, and rock impacts were heard in the vicinity of the crater. Weak winds resulted in poor air quality at the summit during 21 and 25-28 October. During an overflight on 24 October, HVO geologists used a FLIR (Forward Looking InfraRed) camera to view the vent. The vent (about 80 m by 60 m) was wider than a lower orifice (about 30 m by 15 m), but narrower than a chamber above the orifice, resulting in an over-hanging vent rim prone to collapse. The sulfur dioxide emission rate was 500-900 tonnes per day during 22-24 October. The 2003-2007 rate average was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 October-21 October 2008 Citation IconCite this Report

HVO reported that during 15-21 October lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Multiple surface lava flows on the pali were noted; on 16 October a channelized 'a'a flow was active in the Royal Gardens subdivision and a pahoehoe flow was seen on the W side of the active flow field. Lava destroyed one of two remaining intermittently occupied structures in the subdivision. The sulfur dioxide emission rate at Pu'u 'O'o was 1,000 tonnes per day on 17 October, half of the background rate of the 2005-2007 average. Explosions at the ocean entry were reported on 19 October.

During the reporting period, Kilauea earthquakes were variously located beneath and to the S of the caldera, and along the S-flank faults. Beneath Halema'uma'u crater earthquakes ranged from 40 per day to more than 100 (background is about 40), but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a predominantly white plume, which was occasionally tinged brown in association with small local earthquakes or vent rim collapses, that drifted mainly SW. Night-time incandescence was intermittently seen at the base of the plume. Two vent explosions occurred on 14 October. The first was initiated by the collapse of a thin piece of the vent rim. The second explosion ejected molten spatter that fell within 100 m of the vent and produced an eruption plume that rose 2 km above the caldera rim. The sulfur dioxide emission rate was 600 and 900 tonnes per day on 16 and 17 October, respectively. The 2003-2007 rate average was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 October-14 October 2008 Citation IconCite this Report

HVO reported that during 8-14 October lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Multiple lava breakouts, including a small 'a'a flow E of the Royal Gardens subdivision, and points of incandescence on the pali were noted. The sulfur dioxide emission rate at Pu'u 'O'o was 1,400 tonnes per day on 12 October, below the background rate since early 2005. Explosions at the ocean entry were reported on 13 October.

During the reporting period, Kilauea earthquakes were variously located beneath and to the S of the caldera, and along the S-flank faults. Beneath Halema'uma'u crater earthquakes ranged from 40 per day to more than 80 (background is about 40), but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a predominantly white plume, which was occasionally tinged brown in association with small local earthquakes, that drifted mainly SW and S. Night-time incandescence was intermittently seen at the base of the plume. An explosion on 12 October produced pulsating ash-rich clouds with pulses of incandescent gas and tephra. Significant tephra deposits included frothy ejecta up to fist and grapefruit sizes. In a video of the eruption, incandescence in the plume appears to be well above the level of the crater rim (about 70 m above the vent). The sulfur dioxide emission rate was 1,200 tonnes per day on 10 October. The 2003-2007 rate average was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 October-7 October 2008 Citation IconCite this Report

HVO reported that during 1-7 October lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex. Lava that reached the ocean entry generated a steam plume during much of the reporting period; a plume was absent during 4-6 October. The sulfur dioxide emission rate at Pu'u 'O'o was 1,400 tonnes per day on 5 October, below the background rate as averaged over the past 25+ years.

During the reporting period, Kilauea earthquakes were variously located beneath and to the S of the caldera, along the S-flank faults, and along the SW rift zone. Beneath Halema'uma'u crater small earthquakes per day ranged from less than 40 to 100 (background is about 20-40), but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a predominantly white plume with occasional minor ash content that drifted mainly SW, but also in multiple other directions. Weak night-time incandescence was intermittently seen at the base of the plume. The sulfur dioxide emission rate was 900 and 1,100 tonnes per day on 3 and 5 October, respectively. The 2003-2007 rate average was 140 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 September-30 September 2008 Citation IconCite this Report

HVO reported that during 24-30 September, lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the ocean entry. Explosions at the ocean entry were noted on 25 and 27 September.

During the reporting period, Kilauea earthquakes were variously located beneath and to the S of the caldera, along the SW rift zone, and along the S-flank faults. Beneath Halema'uma'u crater, 40-100 small earthquakes per day (background is 20-40) also occurred but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a predominantly white plume with minor tephra content that drifted mainly SW. Weak night-time incandescence was intermittently seen at the base of the plume. The plume was occasionally tinged brown in association with small local earthquakes. During an overflight on 26 September, HVO geologists estimated that the surface of the lava pond was about 120-140 m below the crater floor, about 20-40 m lower than the previous pond surface observed on 5 September.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 September-23 September 2008 Citation IconCite this Report

HVO reported that during 17-23 September, lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. During 18-19 September, explosions from the base of the plume ejected debris into the air. The sulfur dioxide emission rate at Pu'u 'O'o was 1,700 tonnes per day on 21 September, near the background rate as averaged over the past 25 years.

During the reporting period, Kilauea earthquakes were variously located beneath and to the S of the caldera, and along the S-flank faults. Beneath Halema'uma'u crater, 40-80 small earthquakes per day (background is 20-40) also occurred but were too small to be located more precisely. On 19 September a M 4.3 earthquake, felt island-wide, was located at a depth of 9.7 km below the S flank. The vent in Halema'uma'u crater continued to produce a predominantly white plume with occasional minor ash content that drifted mainly SW. Weak night-time incandescence was intermittently seen at the base of the plume, and rock impact and rushing gas sounds were heard in the vicinity of the crater. The sulfur dioxide emission rate was 1,200 tonnes per day on 21 September. The pre-2008 background rate was 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 September-16 September 2008 Citation IconCite this Report

HVO reported that during 10-16 September, lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. On 9 September, geologists observed small littoral explosions that ejected debris 20 m into the air. Incandescence flashed from multiple sources within the central and western parts of Pu'u 'O'o crater were seen during 11-12 September.

During the reporting period, Kilauea earthquakes were variously located beneath Halema'uma'u crater, along the S-flank faults, and along the SW rift zones. Beneath Halema'uma'u crater, 50-100 small earthquakes per day (background is 20-40) also occurred but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a predominantly white plume with minor ash content that drifted mainly SW. The plume was occasionally tinged brown in association with small local earthquakes. Weak night-time incandescence was intermittently seen at the base of the plume, and rock impact sounds were heard in the vicinity of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 September-9 September 2008 Citation IconCite this Report

HVO reported that during 3-9 September, lava flowed SE through a lava tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry and one further to the E. On 5 September, geologists saw multiple surface flows during an aerial observation: four on the coastal plain, and a large 'a'a flow and a small pahoehoe flow in the abandoned Royal Gardens subdivision.

The vent in Halema'uma'u crater continued to produce a predominantly white plume with minor ash content that drifted mainly SW. The plume was occasionally tinged brown in association with small local earthquakes. Weak night-time incandescence was intermittently seen at the base of the plume, and rock impact sounds were heard in the vicinity of the crater. The sample collection bin contained tephra, Pele's hair, Pele's tears, and a variously shaped glass fragments. On 5 September, scientists saw the surface of a sloshing lava lake, 50 m in diameter, about 100 m below the vent rim while hovering over the vent in a helicopter. A second view revealed a roiling pond with multiple bursting bubbles that changed into a central upwelling circulation pattern. The level of the lake dropped slightly before the cycle restarted.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 August-2 September 2008 Citation IconCite this Report

HVO reported that during 27 August-2 September, lava flowed SE through a lava tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex and reached the Waikupanaha ocean entry. On 31 August, students from the University of Hawaii at Hilo reported low-level explosive activity at Waikupanaha.

A high number of Kilauea's earthquakes were centered in various locations along the Koa'e fault system, beneath the summit, N of Kupaianaha, along the S-flank faults, and along the E and SW rift zones. Beneath Halema'uma'u crater, more than 40 and up to 400 small earthquakes per day (background 40) also occurred but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a predominantly white plume with minor ash content that drifted mainly SW. The plume was occasionally tinged brown. Weak night-time incandescence was intermittently seen at the base of the plume, and rock impacts and muted rushing sounds were heard in the vicinity of the crater. During 26-27 August, multiple ash ejections were observed. On 27 August, the white plume was temporarily tinged brown and rose to a higher altitude following an explosive eruption (the fifth in 2008). Glass fragments and tephra up to 5 cm in diameter burned holes in a collection tarp placed near the overlook. Analysis of photos captured over the previous month showed that the vent had lengthened by almost 50 percent along the edge of the crater floor. On 29 August, the collection bin contained Pele's hair, Pele's tears, and a variety of other shapes of glass fragments.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 August-26 August 2008 Citation IconCite this Report

HVO reported that during 20-26 August, lava flowed SE through a lava tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. On 20 August, geologists observed bursting lava bubbles from an area E of Waikupanaha that threw molten fragments 10-20 m into the air. The sulfur dioxide emission rate at Pu'u 'O'o was 3,200 and 1,800 tonnes per day on 20 and 22 August, respectively; the average background rate is about 2,000 tonnes per day.

Kilauea earthquakes were centered in various locations along the Koa'e fault system, S and W of the caldera, beneath the summit, along the S-flank faults, and along the E and SW rift zones. Beneath Halema'uma'u crater, more than 40 small earthquakes per day (background 40) also occurred but were too small to be located more precisely. About 100 earthquakes were detected on 26 August. The vent in Halema'uma'u crater continued to produce a predominantly white plume with minor ash content that drifted mainly SW. The plume was occasionally tinged brown. Weak night-time incandescence was intermittently seen at the base of the plume, and rock impacts and muted rushing sounds were heard in the vicinity of the crater. On 21 August, an earthquake was accompanied by a 400-m-high jet of mostly gas that rose vertically, then drifted SW. The jet also contained some rock dust and bits of volcanic glass. Several small ash ejections occurred on 25 August. The sulfur dioxide emission rate was 600-1,000 tonnes per day during 20-25 August. The pre-2008 background rate was 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 August-19 August 2008 Citation IconCite this Report

HVO reported that during 13-19 August, lava flowed SE through a lava tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Incandescence was noted from the rootless shield complex during 13-15 August. Earthquakes were in various locations along the Koa'e fault system, S and W of the caldera, beneath the summit, along the S-flank faults, and along the E and SW rift zones. Beneath Halema'uma'u crater, around 40 small earthquakes per day (background is 20-40) also occurred but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a predominantly white plume with minor ash content that drifted mainly SW. The plume was occasionally tinged brown. Night-time incandescence was intermintently seen at the base of the plume, and rock impacts and rushing sounds were heard in the vicinity of the crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 August-12 August 2008 Citation IconCite this Report

HVO reported that during 6 and 9-12 August lava flowed SE through a lava tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Occasional explosions and surface lava flows were noted near the ocean entry. A small fountain in a lava pond at the top of one of the rootless shields was observed on 10 August. The sulfur dioxide emission rate at Pu'u 'O'o was 1,700 and 2,400 tonnes per day on 8 and 9 August, respectively; the average background rate is about 2,000 tonnes per day.

During the reporting period, Kilauea earthquakes were variously located beneath Halema'uma'u crater, along the Koa'e fault system, SE and W of the caldera, along the S-flank faults, and along the E and SW rift zones. Beneath Halema'uma'u crater, up to 100 small earthquakes per day (background is 20-40) also occurred but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a mainly white plume with minor ash content that drifted SW. The plume was occasionally tinged brown. Night-time incandescence was seen at the base of the plume rock-clattering sounds were heard in the vicinity of the crater. The sulfur dioxide emission rate was high at 900 tonnes per day on 7 August. The pre-2008 background rate was 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 July-5 August 2008 Citation IconCite this Report

HVO reported that during 30 July-5 August lava flowed SE through a lava tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Explosions from the ocean entry were noted on 30 July. On 31 July, about 2.3 acres (or 25 percent) of the bench E of the ocean entry collapsed. A small lava pond at the top of one of the rootless shields was observed during an overflight. The sulfur dioxide emission rate at Pu'u 'O'o was 1,800 tonnes per day on 31 July; the average background rate is about 2,000 tonnes per day.

During the reporting period, Kilauea earthquakes were variously located beneath Halema'uma'u crater, along the Koa'e fault system, N of the summit, along the S-flank faults, and along the E and SW rift zones. Beneath Halema'uma'u crater, 40 or fewer small earthquakes per day also occurred but were too small to be located more precisely.

The vent in Halema'uma'u crater continued to produce a mainly white plume with minor ash content that drifted SW, then occasionally rotated SE. During 1-3 August, seismic signals resembling those from explosions were accompanied an increase in plume vigor and by the color turning temporarily brown. An event on 1 August started with a collapse of a small portion of the vent rim and was followed by ejected incandescent tephra. Night-time incandescence was seen at the base of the plume. Rushing and rock-clattering sounds were heard in the vicinity of the crater. The sulfur dioxide emission rate was high at 800 and 700 tonnes per day, on 31 July and 4 August, respectively. The pre-2008 background rate was 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 July-29 July 2008 Citation IconCite this Report

Based on visual observations from HVO geologists, video footage, and web camera views, HVO reported that during 23-29 July, lava flowed SE through a lava tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. A bench collapse at the ocean entry occurred on 22 July. Pu'u 'O'o crater incandescence originated from vents on the crater floor and was reflected in a gas plume emitted from a vent on the E wall. A surface lava flow was seen behind the coastal bench on 28 July. The sulfur dioxide emission rate at Pu'u 'O'o was high at 4,700 and 5,400 tonnes per day on 24 and 26 July, respectively; the average background rate is about 2,000 tonnes per day.

During the reporting period, Kilauea earthquakes were variously located beneath Halema'uma'u crater, along the Koa'e fault system, beneath Makaopuhi crater, along the S-flank faults, and along the SW rift zone. Beneath Halema'uma'u crater, another 20-60 small earthquakes per day also occurred but were too small to be located more precisely. The vent in the crater continued to produce a white plume with minor ash content that drifted mainly SW. Night-time incandescence was seen at the base of the plume. Rock-clattering sounds were heard in the vicinity of Halema'uma'u crater. The sulfur dioxide emission rate was high and between 600 and 800 tonnes per day, during 24-26 July. The pre-2008 background rate was 150-200 tonnes per day. On 26 July, incandescent material was ejected from the vent in Halema'uma'u crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 July-22 July 2008 Citation IconCite this Report

Based on visual observations from HVO crews, video footage, pilot reports, and web camera views, HVO reported that during 16-22 July, lava flowed SE through a lava tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex. The lava flowed into the ocean at the Waikupanaha ocean entry resulting in occasional explosions and a vigorous steam plume from contact with the water. Lightning was sometimes seen in the steam plume. Incandescence was observed from the TEB vent, rootless shields, breakouts along the W margin of the TEB lava tube, and from vents and sporadic spatter in Pu'u 'O'o crater. The sulfur dioxide emission rate at Pu'u 'O'o was very high at 6,300 tonnes per day on 17 July; the average background rate is about 2,000 tonnes per day.

During the reporting period, Kilauea earthquakes were located beneath the summit area and beneath Halema'uma'u crater, along S-flank faults, and along the E and SW rift zones. Beneath Halema'uma'u crater, another 20-40 small earthquakes per day also occurred but were too small to be located. The vent in the crater continued to produce a white plume with minor ash content that drifted mainly SW. Night-time incandescence was seen at the base of the plume. Rock clattering, booming noises, and "rushing sounds" were heard in the vicinity of Halema'uma'u crater. The sulfur dioxide emission rate was high and between 700 and 800 tonnes per day, during 16-18 July. The pre-2008 background rate was 150-200 tonnes per day. On 19 July, incandescent material was ejected from the vent.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 July-15 July 2008 Citation IconCite this Report

During most of 9-15 July 2008 the Kilauea summit and Pu`u `O`o cone continued to deflate. Small amounts of ash and elevated amounts of sulfur dioxide gas continued to issue from the Halema`uma`u vent.

At the east rift eruption site, an unusually high amount of sulfur dioxide gas issued from Pu`u `O`o crater on 9 July. More lava than usual continued to erupt from the TEB vent area during 9-12 July and flowed into the tube system, feeding multiple short surface flows. Lava also resumed flowing into the ocean at Waikupanaha. Surface flows within the abandoned Royal Gardens subdivision were seen on the morning of 13 July; they may have reached the coastal plain the next day. Strong incandescence was seen from within Pu`u `O`o crater from the 10th through the 15th.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 July-8 July 2008 Citation IconCite this Report

Based on visual observations from HVO crews, video footage, pilot reports, and web camera views, HVO reported that during 2-8 July, lava flowed SE through a lava tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex. The TEB vent is located a little over 2 km NE of Pu'u 'O'o crater. During 2-6 July, lava flows reached the Waikupanaha ocean entry and created a steam plume from contact with the water. Incandescence was also seen from surface lava flows at multiple breakout points along the lava tube system. On 7 July, seismic tremor levels near the TEB vent abruptly doubled, corresponding to a substantial new breakout in the rootless shield area. The steam plume at the Waikupanaha ocean entry was also absent that day and the next. An overflight revealed that a lava fountain from one of the breakouts on rootless shield 3 (about 1 km SE of the TEB vent) was 12-15 m high and fed several lava flows. The lava fountain and a lava pond were active during 7-8 July and incandescence at shield 6 (about 2 km SE of the TEB vent) was noted.

At Pu'u 'O'o the sulfur dioxide emission rate fluctuated between 3,100 and 4,800 tonnes per day when measured during 4-6 July; the average background rate is about 2,000 tonnes per day. Incandescence from two distinct sources in the E and W ends of Pu'u 'O'o crater was observed on the web camera during 4-6 July. Diffuse incandescence was noted during 7-8 July.

During the reporting period, Kilauea earthquakes were located beneath the summit area, along S-flank faults, along the E and SW rift zones, beneath Halema'uma'u crater, and beneath the area where the Koa'e fault system joins the upper E rift zone. Beneath Halema'uma'u crater, another 20-100 small earthquakes per day also occurred but were too small to be located. The vent in the crater continued to produce a white plume with minor ash content that drifted mainly SW. Night-time incandescence was seen at the base of the plume. The sulfur dioxide emission rate was high, between 700 and 1,400 tonnes per day, during 2-7 July. The pre-2008 background rate was 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 June-1 July 2008 Citation IconCite this Report

Based on visual observations from HVO crews and web camera views, HVO reported that during 25 June-1 July, lava flowed SE through a lava tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. On 24 June, small episodic explosions at Waikupanaha propelled spatter about 50 m into the air; explosions were also noted on other days. The sulfur dioxide emission rate was 1,300 tonnes per day when measured on 24 June; the average background rate was about 2,000 tonnes per day. During 28 June-1 July, a small surface 'a'a lava flow near the E boundary of the Royal Gardens subdivision advanced E. During 30 June-1 July, several surface flows from multiple points along the lava tube system were noted.

During the reporting period, Kilauea summit earthquakes were located beneath the summit area, along S-flank faults, and along the E and SW rift zones. Another 20-60 small earthquakes per day also occurred but were too small to be located. The vent in Halema'uma'u crater continued to produce a white plume with minor ash content that drifted mainly SW. Night-time incandescence was seen at the base of the plume. Seismic tremor was elevated. The sulfur dioxide emission rate was 900 tonnes per day when measured on 26 June. The background rate is 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 June-24 June 2008 Citation IconCite this Report

Based on visual observations from HVO crews and web camera views, HVO reported that during 18-24 June, lava flowed SE through a lava tube system underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Incandescence was occasionally noted from the TEB vent area. The sulfur dioxide emission rate was 1,400 tonnes per day when measured on 18 June; the average background rate was about 2,000 tonnes per day.

During the reporting period, Kilauea summit earthquakes were located beneath Halema'uma'u crater, beneath the summit area, along the Koa'e and S-flank faults, and along the E and SW rift zones. About 100-140 small earthquakes (not located) were detected during 18-21 June. The vent in Halema'uma'u crater continued to produce white plumes with minor ash content that drifted mainly SW. Night-time incandescence was seen at the base of the plume. Seismic tremor was elevated. The sulfur dioxide emission rate was high and fluctuated between 400 and 1,100 tonnes per day when measured during 18-22 June. The background rate is 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 June-17 June 2008 Citation IconCite this Report

Based on visual observations from HVO crews, reports from county officials, and web camera views, HVO reported that during 11-17 June lava flowed SE through a lava tube system underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Incandescence was occasionally noted from the TEB vent area. Gas continued to jet from a vent about 30 m below Pu'u 'O'o crater's E rim.

During the reporting period, Kilauea summit earthquakes were located beneath HVO, beneath Puhimau Crater, N of Pu'u 'O'o, beneath the summit area, along the S-flank fault, and along the SW rift zone. An average of 10-40 small earthquakes (not located) were detected daily. The eruption from the vent in Halema'uma'u crater continued to produce white plumes with minor ash content that drifted mainly SW. Night-time incandescence was seen at the base of the plume. Seismic tremor was elevated. The sulfur dioxide emission rate was high and fluctuated between 420 and 800 tonnes per day when measured during 9-14 June. The background rate is 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 June-10 June 2008 Citation IconCite this Report

Based on visual observations from HVO crews and web camera views, HVO reported that during 4-10 June lava flowed SE through a lava tube system underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Incandescence was occasionally noted from the TEB vent area. Gas continued to jet from a vent about 30 m below Pu'u 'O'o crater's E rim. The sulfur dioxide emission rate was generally high and fluctuated between 1,530 and 3,080 tonnes per day when measured on 3, 5, 6, and 9 June. The background rate was about 2,000 tonnes per day when measured on 25 May and earlier.

During the reporting period, Kilauea summit earthquakes were located beneath the summit, along the S-flank fault, and along SW rift zones. An average of 10-20 small earthquakes (not located) were detected daily. The eruption from the vent in Halema'uma'u Crater continued to produce white plumes with minor ash content that drifted mainly SW. During the night incandescence was seen at the base of the plume. Seismic tremor was elevated. The sulfur dioxide emission rate was high and fluctuated between 680 and 1,160 tonnes per day when measured during 3-9 June. The background rate was 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 May-3 June 2008 Citation IconCite this Report

Based on visual observations from HVO crews and web camera views, HVO reported that during 28 May-3 June lava flowed SE through a lava tube system underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Incandescence was occasionally noted from the TEB vent area. Gas continued to jet from a vent about 30 m below Pu'u 'O'o crater's E rim. The sulfur dioxide emission rate was high and fluctuated between 2,740 and 4,700 tonnes per day when measured on 27 and 30 May. The background rate was about 2,000 tonnes per day when measured on 25 May and earlier.

During the reporting period, Kilauea summit earthquakes were located along the S-flank fault and along the E and SW rift zones. The eruption from the vent in Halema'uma'u Crater continued to produce white plumes with minor ash content that drifted mainly SW. During the night incandescence was seen at the base of the plume. Seismic tremor was elevated. The sulfur dioxide emission rate was high and fluctuated between 550 and 1,840 tonnes per day when measured during 27-31 May and 2 June. The background rate was 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 May-27 May 2008 Citation IconCite this Report

Based on observations during helicopter overflights, visual observations from HVO and National Park Service (NPS) crews, and web camera views, HVO reported that during 21-27 May lava flowed SE through a lava tube system underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Incandescence was occasionally noted from the TEB vent area. An overflight of Pu'u 'O'o crater on 23 May revealed that a new gas vent about 30 m below the E rim jetted gas at temperatures as high as 600 degrees Celsius.

During the reporting period, Kilauea summit earthquakes were located beneath the Halema'uma'u crater, S of the summit, along the S-flank and Koa'e faults, SW of Hi'iaka Crater, and along the SW rift zone. The eruption from the vent in Halema'uma'u Crater continued to produce white plumes with minor ash content that drifted mainly SW. During most nights incandescence was seen at the base of the plume. Seismic tremor was elevated. The sulfur dioxide emission rate was high and fluctuated between 990 and 1,540 tonnes per day when measured during 23-25 May. The background rate was 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 May-20 May 2008 Citation IconCite this Report

Based on visual observations from HVO and National Park Service (NPS) crews and web camera views, HVO reported that during 14-20 May lava flowed SE through a lava tube system underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Incandescence was occasionally noted from the TEB vent area. Spatter at the Waikupanaha ocean entry built a second littoral cone.

During the reporting period, Kilauea summit earthquakes were located beneath the Halema'uma'u crater, W of the summit, along the S-flank faults, and along the SW rift zone. The eruption from the vent in Halema'uma'u Crater continued to produce white plumes with minor ash content that drifted mainly NE and occasionally SW. During most nights incandescence was seen at the base of the plume. Seismic tremor was elevated. The sulfur dioxide emission rate was high and fluctuated between 1,320 and 680 tonnes per day when measured on 17 and 18 May, respectively. The background rate was 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 May-13 May 2008 Citation IconCite this Report

Based on observations during helicopter overflights, visual observations from HVO and National Park Service (NPS) crews, and web camera views, HVO reported that during 7-13 May lava flowed SE through a lava tube system underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Incandescence was occasionally noted from the TEB vent area. During 10-13 May, spatter at the Waikupanaha ocean entry was propelled 20-30 m high and built a littoral cone.

During the reporting period, Kilauea summit earthquakes were located beneath the Halema'uma'u crater, N of the summit, along the S-flank faults, and along the SW and E rift zones. The eruption from the vent in Halema'uma'u Crater continued to produce white plumes with minor ash content that drifted mainly SW. During most nights incandescence was seen at the base of the plume. Seismic tremor was elevated. During 11-12 May, the summit tiltmeter network recorded the tenth 'deflation-inflation' (DI) tilt event since the emergence of the new vent in Halema`uma`u Crater and the seventeenth so far in 2008.The sulfur dioxide emission rate was high and fluctuated between 590 and 1,100 tonnes per day during 6-12 May. The background rate was 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 April-6 May 2008 Citation IconCite this Report

Based on visual observations from HVO and National Park Service (NPS) crews and web camera views, HVO reported that during 30 April-6 May lava flowed SE through a lava tube system underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. On 4 May, lava flows from breakouts on the pali reached the coastal plain. Kilauea summit earthquakes were located beneath the Halema'uma'u crater, along the S-flank faults, and along the SW and E rift zones. The eruption from the vent in Halema'uma'u Crater continued to produce white plumes with minor ash content that drifted mainly SW. During most nights incandescence was seen at the base of the plume. Seismic tremor was elevated. The sulfur dioxide emission rate was high and fluctuated between 540 and 1,250 tonnes per day during 30 April-5 May. The background rate was 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 April-29 April 2008 Citation IconCite this Report

Based on observations during helicopter overflights, visual observations from HVO and National Park Service (NPS) crews, and web camera views, HVO reported that during 23-29 April lava flowed SE through a lava tube system underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Incandescence from breakouts along the lava-tube system was noted on 23 April.

During the reporting period, Kilauea summit earthquakes were located beneath the Halema'uma'u vent, beneath the S Kilauea caldera, NW of Pahala, along the S-flank faults, and along the SW rift zone. The eruption from the vent in Halema'uma'u Crater continued to produce white plumes with minor ash content that drifted mainly SW. During most nights incandescence was seen at the base of the plume. Seismic tremor was elevated.

Sulfur dioxide emission rates from the summit area have been elevated at 2-4 times background values since early January. On 28 April, the emission rate at the summit was 1,910 tonnes per day, compared to a background rate of 150-200 tonnes per day. According to news articles, Hawaii Volcanoes National Park closed during 24-25 April due to elevated levels of sulfur dioxide. About 2,000 people were evacuated from the Park.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); Associated Press


16 April-22 April 2008 Citation IconCite this Report

Based on observations during helicopter overflights, visual observations from HVO and National Park Service (NPS) crews, and web camera views, HVO reported that during 16-22 April lava flowed SE through a lava tube system underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entries. The Ki ocean entry was inactive during 19-22 April. Occasionally, incandescence from breakouts along the lava-tube system was noted.

During the reporting period, Kilauea summit earthquakes were located beneath Halema'uma'u Crater, beneath Napau Crater, along the S-flank faults, and along the upper E and SW rift zones. The eruption from the vent in Halema'uma'u Crater continued to produce white ash plumes that drifted mainly SW. During most nights incandescence was seen at the base of the plume. On 16 April, a small explosion from the vent ejected ash onto the overlook parking lot and on a portion of Crater Rim drive. Seismic tremor was elevated.

Sulfur dioxide emission rates from the summit area have been elevated at 2-4 times background values since early January. The emission rate fluctuated between 870 and 1150 tonnes per day during 15-21 April, compared to a background rate of 150-200 tonnes per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 April-15 April 2008 Citation IconCite this Report

Based on observations during helicopter overflights, visual observations from HVO and National Park Service (NPS) crews, and web camera views, HVO reported that during 9-15 April lava flow activity from Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex was mostly concentrated at multiple locations of the Waikupanaha and Ki ocean entries. Occasionally, incandescence from a skylight adjacent to the TEB vents and from breakouts along the lava-tube system was noted.

During the reporting period, Kilauea summit earthquakes were located beneath the summit, along the S-flank faults, and along the upper E rift zones. The eruption from the vent in Halema'uma'u Crater continued to produce white ash plumes that drifted mainly SW. During most nights incandescence was seen at the base of the plume. On 10 April, a small explosion from the vent ejected incandescent blocks to the rim of the crater, about 70 m above, and enlarged the vent by 5-10 ms. Seismic tremor was elevated.

Sulfur dioxide emission rates from the summit area have been elevated at 2-4 times background values since early January. The emission rate fluctuated between 575 and 890 tonnes per day during 10-14 April, compared to a background rate of 150-200 tonnes per day. At Pu'u 'O'o crater the emission rate was between 1,760 and 2,750 tonnes during 8-13 April. According to news articles, Hawaii Volcanoes National Park was closed during 8-9 April due to elevated levels of sulfur dioxide.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); Associated Press


2 April-8 April 2008 Citation IconCite this Report

Based on observations during helicopter overflights, visual observations from HVO and National Park Service (NPS) crews, and web camera views, HVO reported that during 2-8 April lava flow activity from Kilauea's Thanksgiving Eve Breakout (TEB) shield was mostly concentrated at the E Waikupanaha, W Waikupanaha, and Ki ocean entries. Spattering and small steam explosions were intermittently reported. Occasionally, incandescence from a skylight adjacent to the TEB vents and from breakouts along the lava-tube system was noted. Diffuse incandescence was seen on the web camera at Pu'u 'O'o crater during 2-4 and 7-8 April.

During the reporting period, Kilauea summit earthquakes were located beneath Halema`uma`u Crater, beneath the summit to the S and W, along the S-flank faults, and along the SW and E rift zones. The eruption from the vent in Halema'uma'u Crater continued to produce brown or white ash plumes that drifted mainly SW. During most nights incandescence was seen at the base of the plume and incandescent fragments were ejected from the vent. Based on pilot observations, the Washington VAAC reported that the plumes rose to altitudes of 3.4-3.8 km (11,200-12,500 ft) a.s.l. on 5 and 7 April. Seismic tremor was elevated.

Sulfur dioxide emission rates from the summit area have been elevated at 2-4 times background values since early January. The emission rate fluctuated between 480-800 tonnes per day during 2-7 April, compared to a background rate of 150-200 tonnes per day. At Pu'u 'O'o crater the emission rate was 1,300 tonnes on 5 April.

According to a news report, the Hawaii County Civil Defense issued a health advisory on 7 April for those living downwind of Halema'uma'u and Pu'u 'O'o craters. Residents of specified areas were then advised by the State Department of Health to evacuate because of projected dangerous level of sulfur dioxide. Residents of other areas were put on alert.

Sources: Washington Volcanic Ash Advisory Center (VAAC); Honolulu Advertiser; US Geological Survey Hawaiian Volcano Observatory (HVO)


26 March-1 April 2008 Citation IconCite this Report

Based on visual observations from HVO and National Park Service (NPS) crews as well as web camera views, HVO reported that during 26 March-1 April lava flow activity from Kilauea's Thanksgiving Eve Breakout (TEB) shield was mostly concentrated at multiple points along the Waikupanaha and Ki ocean entries. Incandescence from the TEB vent was noted. During 25-26 March, an active lava flow was spotted SE of Kalalua Cone. Diffuse incandescence was seen on the web camera in Pu'u 'O'o crater.

During the reporting period, Kilauea summit earthquakes were located beneath Halema`uma`u Crater, beneath the summit to the W, along the S-flank faults, and along the SW and E rift zones. The eruption from the vent in Halema'uma'u Crater continued to produce brown ash plumes that turned white for periods of time on 27, 28, and 31 March and on 1 April. Analysis of ash from the white plumes revealed that there was more volcanic glass than ash from the brown plumes. The plumes drifted mostly SW. Incandescence was seen at the base of the plume during the night. During 29 March-1 April, incandescent fragments were ejected from the vent.

Sulfur dioxide emission rates from the summit area have been elevated at 2-4 times background values since early January. The emission rate fluctuated between 700-1,500 tonnes per day during 26-31 March, compared to a background rate of 150-200 tonnes per day.

Sources: Washington Volcanic Ash Advisory Center (VAAC); US Geological Survey Hawaiian Volcano Observatory (HVO)


19 March-25 March 2008 Citation IconCite this Report

Based on visual observations from HVO and National Park Service (NPS) crews as well as web camera views, HVO reported that during 19-25 March lava flow activity from Kilauea's Thanksgiving Eve Breakout (TEB) shield was mostly concentrated in and near the Royal Gardens subdivision and at multiple points along the Waikupanaha and Ki ocean entries. Lava flows advanced eastward over an old sea cliff and onto the 1990 lava delta, and were 120 m W of the viewing area on 23 March. Flows through a kipuka produced fires during 18-22 March.

During the reporting period, Kilauea summit earthquakes were located beneath the S-half of the caldera, beneath Halema`uma`u Crater, N of Pu'u 'O'o, along the S-flank faults, and along the SW rift zone. At 0258 on 19 March, an explosion from Halema'uma'u Crater scattered debris over an area of about 75 acres (30 hectares), covering a portion of Crater Rim Drive and damaging the overlook. On Crater Rim Drive, the debris was up to 2 cm in diameter and increased in size and thickness towards the overlook. The largest block ejected during the explosion was about 1 cubic meter. Small impact craters from 30-cm-blocks were abundant in the overlook area. The event was the first explosive activity in the crater since 1924. During 19-24 March, seismic tremor levels were elevated above their already high pre-explosion levels and incandescence at the gas vent was intermittent. Small incandescent tephra particles erupted from the vent overnight during 23-24 March and were deposited on the rim of the crater. On 24 March, the gas plume from the vent became ash-laden and rose to an altitude of about 2.8 km (9,200 ft) a.s.l. The plumes drifted SW. Geologists found Pele's hair, Pele's tears, and spatter in the overlook area. The largest spatter was 10 cm in diameter. During 24-25 March, overnight observers reported incandescence at the base of the continuous ash plume. Based on a pilot observation, the Washington VAAC reported that ash plumes rose to an altitude of 2 km (6,500 ft) a.s.l. on 25 March and drifted SW. The eruption was the first to produce lava in Halema'uma'u since 1982.

Sulfur dioxide emission rates from the summit area have been elevated at 2-4 times background values since early January. The emission rate fluctuated between 1,200-2,200 tonnes per day during 18-23 March, compared to a background rate of 150-200 tonnes per day. On 23 March, the emission rate was 2,200 tonnes per day at Pu'u 'O'o. Sulfur dioxide concentrations were mostly below detection limits at the Jaggar museum and the Kilauea Visitors Center.

Sources: Washington Volcanic Ash Advisory Center (VAAC); US Geological Survey Hawaiian Volcano Observatory (HVO)


12 March-18 March 2008 Citation IconCite this Report

Based on visual observations from HVO and National Park Service (NPS) crews as well as web camera views, HVO reported that during 12-18 March lava flow activity from Kilauea's Thanksgiving Eve Breakout (TEB) shield was concentrated at rootless satellitic shields to the SE, in and near the Royal Gardens subdivision, and at ocean entries. During 12-13 March, lava flows entered the ocean at multiple locations on the Waikupanaha delta and at a new location 100 m E. A breakout from the E margin near the access road split into two lobes, surrounded and destroyed existing structures and covered the access road, and entered a nearby kipuka. On 14 March, lava entered the ocean at two primary Waikupanaha delta locations; the W delta was 600 m wide. An overflight revealed that the Kalalua flow (from the rootless shield complex to the E and SE of the TEB shield) advanced 240 m since 6 March. Lobes from the E-margin lava flows advanced SE into the kipuka and S of the access road, and entered the ocean during 14-15 March. Breakout lava flows were visible inland of the Waikupanaha and new ocean entires, at the base of Royal Gardens, and near the top of the pali. During 15-18 March, lava flows entered the ocean at multiple locations on the Waikupanaha delta and at a new location, 200 m W of the viewing area, named the Ki entry. On 17 March, breakouts and burned vegetation were visible within 1 km of the ocean entries.

During the reporting period, Kilauea summit earthquakes were located E of Halema'uma'u crater, along the S-flank faults, and along the SW and lower E rift zones. Sometime during 10-12 March, a new gas vent appeared just above the base of the E wall of Halema'uma'u crater. During 14-18 March, incandescence from the gas vent originated from a spot about 30 m wide within the rubble at the base of the E crater wall. Cracking rocks, possibly due to the heat, were heard by scientists at the Halema'uma'u overlook. On 17 March, the area of incandescence appeared slightly enlarged with a new area higher on the crater wall and to the N.

Sulfur dioxide emission rates from the summit area have been elevated at 2-4 times background values since early January. The emission rate abruptly increased on 12 March and fluctuated between 1,600-2,500 tonnes per day during 12-16 March, compared to a background rate of 150-200 tonnes per day. On 16 March, emission rates reached 2,500 tonnes per day, the highest recorded at Kilauea's summit since measurements began in 1979.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 March-11 March 2008 Citation IconCite this Report

Based on visual observations and web camera views when weather permitted, HVO reported that during 5-11 March lava flow activity from Kilauea's Thanksgiving Eve Breakout (TEB) shield was concentrated at rootless satellitic shields to the E and SE, in the Royal Gardens subdivision, and at two ocean entries. A lava flow from the rootless shield complex traveled E towards Kalalua. Earthquakes were located beneath Halema'uma'u crater, along the S-flank faults, beneath the summit, and along the SW rift zones.

During 4-6 March, the TEB flow expanded E above and within Royal Gardens, and also split into two 100-m-wide lobes (E and W) about 150 m N of the County access road. According to local sources, at about 2330 local time on 5 March the W lobe entered the ocean at the Waikupanaha entry, named for a nearby pond that was covered by lava in the 1990s. During 7-11 March, incandescence was visible from vents on top of two of the SE satellitic shields. On 8 March, the W lobe continued to build a delta; the E lobe was 470 m from the ocean. A public viewing area with excellent views of the pahoehoe flows opened. On 9 March, the Waikupanaha entry steamed from four points, but small streams of lava were only visible entering the ocean in the evening. The delta was 500 m wide and extended 100-150 m out into the ocean. During 9-10 March, smoke plumes and incandescence from Royal Gardens suggested that active breakouts from the tube system had possibly diminished the amount of lava arriving at the ocean. Diffuse incandescence was observed on the web camera in Pu'u 'O'o crater on 10 and 11 March.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 February-4 March 2008 Citation IconCite this Report

Based on observations during overflights, and web camera views when weather permitted, HVO reported that during 27 February-4 March activity from Kilauea's fissure segment D was concentrated at the Thanksgiving Eve Breakout (TEB) shield and satellitic shields to the E and SE. A pahoehoe flow ponded between the rootless shields and Kalalua Cone. Two lava flow lobes advanced through Royal Gardens subdivision and destroyed three abandoned homes by 28 February. One lobe reached the base of the Royal Gardens kipuka and Campout flow from early 2007.On 1 March the lobes merged and cut off the road access to the homes of the last two known residents. Incandescence from the TEB vent was noted during 29 February and 2-3 March.

Diffuse incandescence was observed in Pu'u 'O'o crater through the fume during 27 February and 1-3 March. Earthquakes were located beneath Halema'uma'u crater, along the S-flank faults, beneath the summit, N of Makaopuhi crater, and along the upper E and SW rift zones. Sulfur dioxide emission rates from the summit area were elevated at 2-4 times background values where levels have been since early January. The emission rate was about 970 tonnes per day on 3 March, compared to a background rate of 150-200 tons per day.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 February-26 February 2008 Citation IconCite this Report

Based on observations during overflights, and web camera views when weather permitted, HVO reported that during 20-26 February activity from Kilauea's fissure segment D was concentrated at the Thanksgiving Eve Breakout (TEB) shield and satellitic shields to the E and SE. A lava flow from the shields traveled E towards Kalalua. A pahoehoe lava flow from the SE rootless shield was observed 250 m S of the northern boundary of the Royal Gardens subdivision during an overflight on 20 February. During 25-26 February, lava flows advanced through the subdivision. Diffuse incandescence was observed in Pu'u 'O'o crater through the fume during 20-22 February. Earthquakes were located E of and beneath Halema'uma'u crater, along the S-flank faults, beneath the summit, N of the summit, and along the SW rift zones.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 February-19 February 2008 Citation IconCite this Report

Based on observations during overflights, and web camera views when weather permitted, HVO reported that during 13-19 February activity from Kilauea's fissure segment D was concentrated at the Thanksgiving Eve Breakout (TEB) shield and new satellitic shields to the E and SE. On 15 February, a broad pahoehoe flow traveled E from the main complex of shields. During 15-18 February, a lava flow traveled SE from a rootless shield (number 6) towards the N boundary of the Royal Gardens subdivision. Diffuse incandescence was observed in Pu'u 'O'o crater through the fume during 17-19 February. Earthquakes were located beneath Halema'uma'u crater, along the S-flank faults, beneath the summit, and along the E and SW rift zones.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 February-12 February 2008 Citation IconCite this Report

Based on field observations, and web camera views when weather permitted, HVO reported that during 6-12 February activity from Kilauea's fissure segment D was concentrated at the perched lava channel, the Thanksgiving Eve Breakout (TEB) shield, and satellitic shields to the SE. Lava flows issued from the tops and flanks of the shields. Lava in the original perched lava channel, formed from the 21 July fissure eruption, overflowed the NW and reached a forested area on 8 February; smoke was seen through the web camera. Incandescence was observed in Pu'u 'O'o crater for less than 10 minutes at a time every day during 6-8 February. A few earthquakes were located beneath the summit, the adjacent flank of Mauna Loa, and along the S-flank faults.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 January-5 February 2008 Citation IconCite this Report

Based on observations during overflights, and web camera views when weather permitted, HVO reported that during 30 January-5 February activity from Kilauea's fissure segment D was concentrated at the Thanksgiving Eve Breakout (TEB) shield and satellitic shields to the SE. Lava flows issued from the tops and flanks of the shields. Lava in the original perched lava channel, formed from the 21 July fissure eruption, overflowed the N end. On 30 January, the channelized 'a'a lava flow from a rootless shield that collapsed on 26 January advanced, burning small kipukas and another small area of the Royal Gardens subdivision. The lava flow was inactive the next day. During 30-31 February, the rootless shields at the SE end of the field (within 2 km of fissure D) issued abundant lava flows overnight. The lava pond within the Shield-4 collapse overflowed several times; lava flows advanced S.

Incandescence was observed in Pu'u 'O'o crater for less than 10 minutes at a time every day during the reporting period. A few small earthquakes were located beneath Halema'uma'u crater and along the S-flank faults, SW rift zone, and upper E rift zone.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 January-29 January 2008 Citation IconCite this Report

Based on observations during overflights, and web camera views when weather permitted, HVO reported that during 23-29 January activity from Kilauea's fissure segment D was concentrated at the Thanksgiving Eve Breakout (TEB) shield and satellitic shields to the SE. Lava flows issued from the tops and flanks of the shields. A crusted lava pond a few meters below the rim of the TEB shield was seen during an over flight on 25 January. A lava flow that advanced 1 km and started another rootless shield was also spotted during the aerial observations. On 28 January, low lava fountaining was seen from the TEB vent and a couple of the shields. The original perched lava channel formed from the 21 July fissure eruption refilled and overflowed the N end. On 29 January, a channelized 'a'a lava flow from a rootless shield that collapsed on 26 January advanced about 0.6 km into the Royal Gardens subdivision. The new 29 January flows mostly moved over older lava.

Incandescence was observed in Pu'u 'O'o crater for less than 10 minutes at a time every day during the reporting period. During 22-23 January, the summit tiltmeter network recorded the first DI (deflation-inflation) tilt event that coinciding with rain. A few small earthquakes were located along the S-flank faults and SW rift zone.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 January-22 January 2008 Citation IconCite this Report

Based on overflights and web camera views when weather permitted, HVO reported that during 16-22 January activity from Kilauea's fissure segment D was concentrated at the Thanksgiving Eve Breakout (TEB) shield and satellitic shields to the SE. Lava flows from the tops and flanks of the shields traveled S and E. During 16-19 January, incandescence was observed in Pu'u 'O'o crater for less than 10 minutes at a time. During 18-19 January, the summit tiltmeter network recorded the first DI (deflation-inflation) tilt event since October 2007. A few small earthquakes were located beneath the summit, Halema'uma'u crater, and Pulama pali, and along the upper and lower E rift zones and S-flank fault.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 January-15 January 2008 Citation IconCite this Report

Based on overflights and web camera views when weather permitted, HVO reported that during 2-8 January activity from Kilauea's fissure segment D was concentrated at the Thanksgiving Eve Breakout (TEB) shield and satellitic shields to the SE. Lava flows were noted from the tops and flanks of the shields and traveled S and E. On 8 January, the SE-most shield breached on the SE flank and issued a vigorous and channelized 'a'a lava flow. The 'a'a flow advanced SE during 8-10 January and stalled approximately 480-650 m from the upper reaches of the Royal Gardens subdivision on 10 January. On 13 January, one of four narrow and secondary lava flows initiated from the 8 January 'a'a flow, advancing along the E margin to 180 m N of the subdivision.

According to a news article, most of the upper portion of the Royal Gardens subdivision was abandoned after lava flows cut the highway that provided access to the subdivision during Kilauea's ongoing 25-year eruption. County officials later cleared a path through the cooled lava for a few remaining residents.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); The Honolulu Advertiser


2 January-8 January 2008 Citation IconCite this Report

Based on overflights and web camera views when weather permitted, HVO reported that during 2-8 January activity from fissure segment D from Kilauea's 21 July fissure eruption was concentrated at the Thanksgiving Eve Breakout (TEB) shield and two satellitic shields to the SE. Lava flows traveled S and stalled within 2.2 km SE of fissure D. From 21 July 2007 to 4 January 2008, the Pu'u 'O'o cone contracted about 0.45 m, based on interpretation of GPS data. Incandescent flashes at the top of the TEB shield were visible during 4-6 January and one short lava flow to the N was detected on 6 January. On 7 January, a lava pond was seen in a vent on top of the TEB shield during an overflight. During 7-8 January, brief flashes and one lava overflow at the top of the shield was seen on the web camera. Tremor remained low below Pu'u 'O'o crater. A few small earthquakes were located beneath the summit and along the S-flank fault.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 December-1 January 2008 Citation IconCite this Report

Based on overflights and web camera views when weather permitted, HVO reported that during 25 December -1 January activity from fissure segment D from Kilauea's 21 July fissure eruption was concentrated at the Thanksgiving Eve Breakout (TEB) shield and two satellitic shields to the SE. Short lava flows were noted to the SE and N. During 25-26 December, bursts of high-frequency tremor were noted every 70-90 minutes and interpreted as episodic spattering events near fissure D. Incandescence was visible from one of the lava seeps E of the perched lava channel on 1 January. Tremor remained low below Pu'u 'O'o crater. A few small earthquakes were located beneath the summit and along the S-flank fault, SW rift zone, and E rift zone.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 December-25 December 2007 Citation IconCite this Report

Based on overflights and web camera views, HVO reported that fissure segment D from Kilauea's 21 July fissure eruption continued to feed perched lava ponds within a lava flow that frequently overflowed their channel edges during 19-25 December. Lava flowed from the base and top of the Thanksgiving Eve Breakout (TEB) shield and crust overturned in multiple lava ponds. An overflight on 20 December revealed that lava from fissure D built up two more shields SE of the TEB shield. A few small earthquakes were located beneath the summit and Halema'uma'u crater, and along S-flank fault.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 December-18 December 2007 Citation IconCite this Report

Based on overflights and web camera views, HVO reported that fissure segment D from Kilauea's 21 July fissure eruption continued to feed perched lava ponds within a lava flow that frequently overflowed its channel edges during 12-18 December. An overflight on 13 December revealed that flows from the Thanksgiving Eve Breakout (TEB) were limited to breakouts at the base of the shield and were not active past 800 m from the source. Lava spattered and overturned in Pond 1 and overflowed the rim. On 16 December, a 4-5-m-high hornito at the summit of the TEB shield was active. On 17 December, lava from the TEB was about 1.1 km SE from fissure D and fume puffed from the top of the shield about every 15-20 minutes when visible. During 17-18 December, crust overturned in a new lava pond that had formed from a seep on the E side of Pond 3, and lava in the pond overflowed the margins. A few small earthquakes were located beneath the summit, and along the upper and lower E rift zones and S-flank fault.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 December-11 December 2007 Citation IconCite this Report

HVO reported that web camera views of fissure D from Kilauea's 21 July fissure eruption were mostly blocked by fog and fumes during 5-9 December. A brief view on 5 December revealed several overflows on the W side of Pond 1, a perched lava pond in the eruption channel formed by fissure D. A pilot report from an overflight on 6 December noted that all of the activity was close to fissure D and none of the SE Thanksgiving Eve breakout (TEB) flows traveled beyond 1.5 km. On 8 December, minor incandescence was observed in Pu'u 'O'o crater for the first time since 31 August, and was accompanied by a possible inflationary signal. Clear web camera views on 9 and 10 December revealed that the TEB shield continued to build vertically and was an estimated 15 m high. A few small earthquakes were located beneath the summit area and along the upper E rift zone and S-flank fault.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 November-4 December 2007 Citation IconCite this Report

Based on overflights and web camera views, HVO reported that fissure segment D from Kilauea's 21 July fissure eruption continued to feed a lava channel and perched lava ponds that occasionally overflowed their edges during 28 November-3 December. Views were blocked by fumes on 4 December. The small lava pond at the top of the Thanksgiving Eve Breakout (TEB) shield, built directly over the fissure, occasionally overflowed and fed lava flows in multiple directions. On 1 December, one of these flows was L-shaped and 2.1 km long, but mostly active within the upper 800 m. A few small earthquakes were located beneath Halema'uma'u crater and along the SW rift zone and S-flank fault.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 November-13 November 2007 Citation IconCite this Report

Based on overflights and web camera views, HVO reported that fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing lava flow that frequently overflowed its channel edges during 7-13 November. Lava tubes traveling E and S continued to burn kipukas N and SE of Pu'u Kia'i. Built-up and overturned crust in a lava pond nearest to the vent caused spattering to heights of 8-10 m during 10-11 November. A few small earthquakes were located beneath Halema'uma'u crater and along the S-flank fault during the reporting period. During 11-12 November, several earthquakes were located in an area between the Holei and Hilina palis.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 October-6 November 2007 Citation IconCite this Report

HVO reported that during 31 October-6 November fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing lava flow that frequently overflowed its channel edges. Small breakouts from a lava tube continued to slowly burn a kipuka about 1.2 km N of the main channel's end. An E-traveling lava tube supplied flows that burned into a small kipuka and forested areas. A few small earthquakes were located beneath the summit area, Halema'uma'u crater, and along the E rift zone and S-flank faults during the reporting period. During 3-4 November, an unusually large number of earthquakes were located beneath the S-flank faults. Tremor remained low below the summit and Pu'u 'O'o crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 October-30 October 2007 Citation IconCite this Report

HVO reported that during 24-30 October fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing lava flow that frequently overflowed its channel edges. Aerial observations on 26 October confirmed that a tube-fed pahoehoe flow along the N margin of the main channel advanced 2.4 km from the channel end. A few small earthquakes were located beneath Halema'uma'u crater, and along the lower SW rift zone and S flank faults during the reporting period. Tremor remained low below the summit and Pu'u 'O'o crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 October-23 October 2007 Citation IconCite this Report

HVO reported that during 17-23 October fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing lava flow that frequently overflowed its channel edges. Activity was concentrated at the NE end of the channel where 200-500-m-long pahoehoe lobes built out in a fan shape to the NW, N, and SE. On 23 October, a lava flow traveled 1.5 km and entered the remains of a kipuka along the N margin of the flow field. A few small earthquakes were located beneath Halema'uma'u crater and the S flank during the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 October-16 October 2007 Citation IconCite this Report

HVO reported that during 10-16 October fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing lava flow that occasionally overflowed its channel edges. Lava flows advanced NE and along the S margin of earlier flows. Aerial observations on 12 October revealed that the S margin of the flow field was mostly inactive. A few small earthquakes were located beneath Halema'uma'u crater and the S flank during the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 October-9 October 2007 Citation IconCite this Report

HVO reported that during 3-9 October fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing 'a'a lava flow that occasionally overflowed its channel edges. Lava flows advanced NE over earlier flows and along the S margin of earlier flows. On 3 October, aerial observations revealed that the lava flow along the S margin burned trees in a kipuka (an "island" of vegetation). A few small earthquakes were located beneath Halema'uma'u crater and the S flank during the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 September-2 October 2007 Citation IconCite this Report

HVO reported that during 26 September-2 October fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing 'a'a lava flow that occasionally overflowed its channel edges. Lava flows that were advancing E and NE from the lower section of the channel shifted S during 26-27 September and burned a bit of kipuka (an "island" of vegetation) during 28 September-1 October. A few small earthquakes were located beneath Halema'uma'u crater, the summit area, and the S flank during the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 September-25 September 2007 Citation IconCite this Report

HVO reported that during 19-25 September fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing 'a'a lava flow that occasionally overflowed its channel edges. Several of the lava flows that branched from the main channel continued to advance, widening and lengthening the flow field. A few small earthquakes were located beneath Halema'uma'u crater, the upper E rift zone, the S flank, and the lower SW rift zone during the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 September-18 September 2007 Citation IconCite this Report

HVO reported that during 12-18 September fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing 'a'a lava flow that frequently overflowed its channel edges. Several of the lava flows that branched from the main channel continued to advance, widening the flow field. An 'a'a flow that developed within the previous two weeks crusted over and pahoehoe breakouts issued from near the flow front on 14 September. A few small earthquakes were located beneath Halema'uma'u crater, the S flank, and the lower SW rift zone during the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 September-11 September 2007 Citation IconCite this Report

HVO reported that during 5-11 September fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing 'a'a lava flow that frequently overflowed its channel edges. Several of the lava flows that branched from the main channel continued to advance. A section of the lava flow's channel collapsed during 6-7 September, and several new lava flows branched away and advanced less than 1 km. On 8 September, the level of the lava in the channel was about 3-8 m below the previous level before the channel was breached. On 9 September, the channel was again full and overflowing. On 11 September, a breakout occurred at the fissure vent of segment D, sending a small lava flow to the S. A few small earthquakes were located beneath Halema'uma'u crater, the S flank, and the SW rift zone during the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 August-4 September 2007 Citation IconCite this Report

HVO reported that during 29 August-4 September fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing 'a'a lava flow that frequently overflowed its channel edges. During 29-30 August, a few small collapses within the Pu'u 'O'o' s crater were detected by seismometers. Incandescence in the crater was visible on the web camera on 31 August. Small earthquakes were located beneath Halema'uma'u crater, the lower SW rift zone, the N and W summit area, and the S flank during the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 August-28 August 2007 Citation IconCite this Report

HVO reported that fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing 'a'a lava flow during 22-28 August. In the last several weeks, four 'a'a flows had started from the open lava channel fed by Fissure D. From the second flow, each had advanced along the N edge of the previous one. The first two flows advanced a total of 6.3 km from the fissure source by 24 August. On 25 August, HVO geologists confirmed that the first three flows were inactive and the fourth flow had advanced 300 m and burned vegetation at the forest edge. During 25-26 August, the channel overflowed at a point about 1 km from the vent and spread along a section of the channel about 200-300 m long. During 27-28 August, the fourth flow was about 5.1 km from the vent and continued to advance.

Incandescence was visible on the web camera from E and W vents in Pu'u 'O'o's crater on 24 and 26 August. Small earthquakes were predominantly located beneath Halema'uma'u crater and the S flank during the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 August-21 August 2007 Citation IconCite this Report

HVO reported that fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing 'a'a lava flow during 15-21 August. Aerial observations on 17 August revealed that the first 'a'a flow had advanced 24 m since 13 August but was inactive. The second 'a'a channel had advanced 2.3 km along the N side of the first flow. Smoke from burning vegetation was visible near the flow front. On 18 August, a new and widening crack was seen on the rim of Pu'u 'O'o crater. A few small earthquakes were located beneath the summit, Halema'uma'u crater, and the S flank.

On 14 August, approximately 17.8 hectares (44 acres) of the East Lae'apuki bench collapsed, possibly due to a M 5.4 earthquake, high surf from hurricane Flossie, or a combination of both.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 August-14 August 2007 Citation IconCite this Report

HVO reported that fissure segment D from Kilauea's 21 July fissure eruption remained active during 8-14 August. The 'a'a flow from segment D advanced 760 m during 8-11 August and overflowed the N side of the channel multiple times during 10-12 August. On 13 August, an extension of the lava flow formed in an area of frequent overflows. Smoke from burning vegetation was visible near the flow front. Fissure segment C produced small lava flows during 8-10 August but only fumes during 11-14 August.

Incandescence was visible on the web camera from E and W vents in Pu'u 'O'o's crater on 11 August. A few small earthquakes were located beneath Halema'uma'u crater, the S flank, and the SW rift zone during 8-13 August. On 13 August, a M 5.4 earthquake was located beneath the S flank at a depth of 9 km.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 August-7 August 2007 Citation IconCite this Report

HVO reported that two of the four fissures from Kilauea's 21 July fissure eruption remained active during 1-7 August. The four fissures, A, B, C, and D, consecutively segment an approximately 2 km-long line that trends NE; fissure A is to the SE and fissure D is to the NE. During the reporting period, fissure C minimally fed a perched lava pond. Fissure D fed a NE-advancing 'a'a lava flow that was an estimated 3.5 km long on 1 August. The 'a'a flow entered the forest on 6 August as evident by smoke near the flow front.

Fuming was seen on Pu'u 'O'o's crater web camera images on 4, 5, and 7 August. A few small earthquakes were located beneath Halema'uma'u crater, the S flank, and an area offshore between Kilauea and Lo'ihi during 1-7 August.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 July-31 July 2007 Citation IconCite this Report

An important new eruption initiated at Kilauea very early on 21 July. It occurred along the E rift zone from fissures trending ENE for several kilometers from Pu'u O'o. The fissures caused drainage of both the West Gap lava lake and the Puka Nui pit. These and following events have come to be called the 21 July eruption and an associated fissure system by the same name.

As of 25 July, the 21 July eruption included instability at Pu'u 'O'o, fissuring along an NE-trending zone stretching a bit over 2 km in length, and lava flows over an area of a little over 1 km2.

A noteworthy feature of this eruption during the week 25-31 July was the formation of a series of perched ponds of lava. These formed as the edges of pools of lava hardened to create confining walls. These walls enable the pond's surface to be much higher--in some cases as much as 5 m (15 feet) higher than the surrounding land--like a volcanic above-ground swimming pool. During the 21 July eruption the walls of these perched ponds breached repeatedly, allowing lava to suddenly flood surrounding terrain. For example, at least three perched lava ponds breached by the 25th, each breakage spawning radially directed lava flows. Other small lava flows also emerged from fissures during the week as well.

The behavior of the perched ponds is difficult to judge and accordingly, around the start of this week the area was closed to the public. The eruption resided completely within the Kahauale'a Natural Area Reserve (just NE of the Hawai'i Volcanoes National Park).

On the morning of the 26th, an M 3.2 earthquake occurred on the lower E rift zone, beneath Pu'ulena crater, at a depth of 3 km (2 miles). Lava ponds again formed in the area surrounding the fissures but views of the process were hampered by foul weather. The HVO update for 31 July noted two prominent lava ponds then. In addition, one of the fissures fed an 'a'a flow advancing to the NE around the N side of Kupaianaha.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 July-24 July 2007 Citation IconCite this Report

During 18-21 July, the E vent and dominant W vent in Kilauea's Pu'u 'O'o produced lava flows. On 18 July, new vents opened in the Puka Nui pit, in the SSW area of Pu'u 'O'o crater, and produced lava flows that ponded. On 20 July, a vent high on the S crater wall, adjacent to the Puka Nui Gap pit, produced spatter and propelled lava bombs 10 m into the air. Meanwhile, the lava lake in the West Gap pit continued to fill, overturn, and occasionally overflow. The spatter cone that built up around the S wall vent in West Gap pit was submerged beneath the lava lake surface on 20 July. Uplift of the crater interior continued. Earthquakes occurred beneath the upper E rift zone, S flank, and Halema'umau crater.

On 20 July, just before midnight, Pu'u 'O'o's crater floor started to subside; a tiltmeter recorded a nearly 300 microradian tilt change. Just after midnight, on 21 July, the West Gap lava lake and Puka Nui pit drained. A new eruption initiated along a set of fissures that extended 1.7 km E from a point about 150 m E of the E rim of Pu'u 'O'o crater. Preliminary reports described two 600-800 m long, left-stepping fissures between Pu'u 'O'o and Kupaianaha. The easternmost fissure fed two lava flows; the farthest extent of the flow was 1-1.5 miles from the fissure in the SE direction.

On 22 July, HVO reported that the westernmost fissure was inactive by mid-morning on 21 July and the uppermost segment of the active lower fissure was completely sealed by mid-morning on 22 July. The rest of the fissure erupted lava, constructing several small perched ponds. A perched pond at the upper segment of the active fissure breached and produced an a'a' flow that traveled 300-400 m to the E. At Pu'u 'O'o crater, several new cracks were observed around its rim, parts of which had collapsed. During 23-24 July, lava ponds surrounding lower fissure segments grew in thickness and spilled lava over their edges.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 July-17 July 2007 Citation IconCite this Report

The W vent and dominant E vent in Kilauea's Pu'u 'O'o crater fed a growing lava lake during 11-13 July. Levees built up from overflows during 11-12 July. On the S wall of West Gap pit, intermittent incandescence and fuming from new vents that opened were observed during 13-14 July. On 14 July, the level of the lava lake dropped but remained active near the E vent. On 15 July, the E and W vents erupted small lava flows that drained onto the solidifying lava lake bed. Low lava fountains were observed from West Gap pit. During 15-17 July, lava filled the pit and overflowed into the main crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 July-10 July 2007 Citation IconCite this Report

On 2 July, HVO scientists confirmed new lava flows at the bottom of Kilauea's Pu'u 'O'o crater and raised the Volcanic Alert Level from Advisory to Watch and Aviation Color Code from Yellow to Orange. During 3-10 July, the lava lake grew and was active. On 6 July, two vents that fed the growing lava lake were identified: the W vent near the former Beehive location and the E vent near the former East Pond location. On 8 July, a small area of crust in the lava lake intermittently fumed.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 June-3 July 2007 Citation IconCite this Report

During 27 June-2 July, views of Kilauea's Pu'u 'O'o crater were obscured by steam. Active lava was not visible anywhere on the flow field or at the site of the 18-19 June eruption. Fuming from the W base of Kane Nui o Hamo and diffuse patches of rain-induced steaming were visible on the Mauna Ulu web camera.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 June-26 June 2007 Citation IconCite this Report

During 20-26 June, incandescence was not visible from the vents in Kilauea's Pu'u 'O'o crater. A tiltmeter at Pu'u 'O'o continued to show steady tilting inward toward the crater, and the crater floor was estimated to have subsided 100 m between 17 and 21 June.

On 19 June, new ground cracks were discovered in an area west of Mauna Ulu. On 20 June, HVO scientists measured sulfur dioxide concentrations greater than 10 parts per million (ppm) in a broad area adjacent to Halema'uma'u crater. Typical concentrations are generally negligible except for areas downwind of Halema'uma'u crater, where they can get up to 2.5 ppm in narrow zones. On 21 June, scientists confirmed that lava was not entering the ocean at the Poupou entry.

During 21-26 June lava was not visible anywhere on the flow field or at the site of the 18/19 June eruption. The crack W of Kane Nui o Hamo continued to emit steam and fume. The summit area continued to inflate very slowly and seismic tremor values at Pu'u 'O'o were below pre-June 17 levels. On 25 June, sulfur dioxide and carbon dioxide emissions were at approximately pre-June 17 levels after a gradual decline. HVO lowered the Volcanic Alert Level from Watch to Advisory and Aviation Color Code from Orange to Yellow. Aerial observation revealed that steaming from the site of the 18/19 June fissure eruption decreased, though the steaming cracks at the base of Kane Nui o Hamo were vigorously fuming. Ground-based mapping of the new lava flow was also completed; the eruption occurred from two places along the fissure, separated by about 40 m.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 June-19 June 2007 Citation IconCite this Report

During 13-19 June, lava from Kilauea flowed SE across a growing lava delta into the ocean at the Poupou entry. On 14 June, the Petunia flow went over the top of the Pulama pali. On 16 June, the front of the Petunia flow advanced down the Pulama pali and was about 90-180 m wide.

On 17 June, a swarm of earthquakes and rapid deflation began at 0215 in the upper E rift zone. The earthquakes were centered about 1 km SW of Mauna Ulu and about 1.5-3 km deep. About 70 earthquakes were recorded in the first 2 hours; at least 10 of those earthquakes were M 3 or greater. NPS crews evacuated visitors and closed the Chain of Craters road and the Crater Rim Drive between Jaggar museum and the Thurston lava tube parking lot. Fresh cracks about 2 cm wide opened in the Chain of Craters road near the Mauna Ulu turnoff. GPS receivers in the area of most intense seismic activity documented an approximate 10 cm of widening across the rift zone, near Makaopuhi crater. HVO observers noted rockfalls from the S wall of Pu'u 'O'o cone and collapse of the crater floor around the vents.

On 18 June, the earthquake swarm continued at a lower rate; about 10 to 15 small earthquakes per hour were recorded compared to more than about 100 per hour the morning of 17 June. Strong tremor beneath the summit was recorded and deflation continued. GPS receivers continued to show widening across the rift zone to more than 40 cm. According to a news article, Crater Rim drive and a few trails were re-opened to the public.

On 18 June, the earthquake swarm continued at a lower rate; about 10 to 15 small earthquakes per hour were recorded compared to more than about 100 per hour the morning of 17 June. Strong tremor beneath the summit was recorded and deflation continued. GPS receivers continued to show widening across the rift zone to more than 40 cm. According to a news article, Crater Rim drive and a few trails were re-opened to the public.

Seismicity decreased on 20 June and GPS receivers no longer showed extension on the rift zone. Aerial views of the crater floor and SW flank indicated more subsidence since 18 June.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); Associated Press


6 June-12 June 2007 Citation IconCite this Report

During 6-12 June, lava from Kilauea flowed SE across a growing lava delta into the ocean at the Poupou entry. Incandescence was visible from several vents in the Pu'u 'O'o crater and on 10 June from breakouts above the Pulama pali fault scarp and on 11 June at the base of the pali. An earthquake swarm that began on 12 May continued beneath the S flank and upper rift zones. Aerial observation and satellite imagery confirmed that the 2-km-long Petunia flow, initiating about 1 km S of Pu'u 'O'o crater, was somewhat active. Surface flow activity was seen inland of the Poupou entry on the E side of the flow field.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 May-5 June 2007 Citation IconCite this Report

During 30 May-5 June, lava from Kilauea flowed SE across a growing lava delta into the ocean at the Poupou entry. By 24 May, lava no longer entered the ocean at the Kamokuna entry. Incandescence was visible from several vents in the Pu'u 'O'o crater and from breakouts above the Pulama pali fault scarp. The earthquake swarm that began on 12 May continued S of Halema'uma'u and in the upper E rift zone. On 18 May, a large lava flow broke out of the PKK lava tube at the site of an old skylight named Petunia. By 4 June, the Petunia flow advanced 2 km. Also on 4 June, a M 3.8 earthquake occurred about 4 km NE of Pahala town. Surface flow activity was seen on the E flow-field between Royal Gardens subdivision and the coast.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 May-29 May 2007 Citation IconCite this Report

During 23-29 May, lava from Kilauea flowed SE across a growing lava delta into the ocean at the Poupou entry. By 24 May, lava no longer entered the ocean at the Kamokuna entry. Incandescence was visible from several vents in the Pu'u 'O'o crater and from breakouts above and at the base of the Pulama pali fault scarp. The earthquake swarm that began on 12 May continued S and E of Halema'uma'u, in the upper E rift zone, and at scattered locations in the S flank.

On 24 May, HVO recorded a M 4.7 earthquake at 0913, located beneath the upper E rift zone, near Puhimau crater, at a depth of 2 km. A M 4.1 aftershock occurred 20 minutes later and was located 1.5 km farther down-rift, beneath Koko'olau crater. A M 3.9 aftershock occurred at 1051 and was located another 2.5 km down-rift at a depth of 1 km. Since 1998, a few earthquakes with magnitudes greater than 4.0 have occurred at shallow depths beneath the upper E rift zone.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 May-22 May 2007 Citation IconCite this Report

During 16-22 May, lava from Kilauea continued to flow SE across a lava delta into the ocean at the Kamokuna entry. On 16 May, lava from the E arm of the Campout flow advancing along the coastal plain from the base of the Royal Gardens sub-division, reached the ocean at the newly-formed Poupou entry. On 18 May, field crews reported that the Poupou entry, about 1.6 km E of the Kamokuna entry, was 20 m wide and building a delta. Incandescence was visible from several vents in the Pu'u 'O'o crater and from breakouts on, above, and at the base of the Pulama pali fault scarp. Earthquake activity that initially increased on 12 May was scattered beneath the upper rift zone and S-flank areas.

According to a news article, new measurements revealed that the area of the 10 May bench collapse at East Lae'apuki lava delta was about 9.3 hectares (23 acres). Scientists reported that new cracks in the lava delta were observed within several hundred yards of the ocean's edge.

Sources: Honolulu Advertiser; US Geological Survey Hawaiian Volcano Observatory (HVO)


9 May-15 May 2007 Citation IconCite this Report

During 9-15 May, lava from Kilauea continued to flow SE across a lava delta into the ocean at the Kamokuna entry. Incandescence was visible from several vents in the Pu'u 'O'o crater and from breakouts on, above, and at the base of the Pulama pali fault scarp. Earthquake activity was scattered at the S edge of the summit, upper E rift zone between Puhimau and Pauahi craters, and S-flank areas. On 10 May, approximately 6.5 hectares (16 acres) of the East Lae'apuki bench collapsed, starting from the E-side and moving progressively westward. Each section of collapse generated a steam plume, occasionally blackened with rock dust, which rose to about 0.1-0.3 km (200-1,000 ft) a.s.l. The plumes resulted from the explosive interaction between seawater and incandescent rock exposed immediately after each section collapsed. On 11 May, HVO scientists surveyed the collapse and mapped cracks inland of the sea cliff. Rock fragments covered a 1.2 hectare (3 acre) area.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 May-8 May 2007 Citation IconCite this Report

During 2-8 May, lava from Kilauea continued to flow SE across a lava delta into the ocean at the Kamokuna entry. Incandescence was visible from several vents in the Pu'u 'O'o crater and from breakouts on, above, and at the base of the Pulama pali fault scarp. Earthquake activity was scattered at the summit, upper E rift zone, and S-flank areas. Tremor remained at moderate levels. During 3-4 May, large channelized a'a' flows descended down the pali on the Campout flow. On 4 May, a sheet flow ponded lava at the base of the Royal Gardens sub-division. On 8 May, HVO scientists reported that for the past several months, Kilauea caldera widened at a rate of 1.5 cm/month and Pu'u 'O'o cone was slowly collapsing, as indicated by new cracks on the S flank. Subsidence of the cone's N flank at a rate of 1 cm/month was also measured.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 April-1 May 2007 Citation IconCite this Report

During 25 April-1 May, lava from Kilauea continued to flow SE across a lava delta into the ocean at the Kamokuna entry, but lava was not seen entering the ocean at East Lae'apuki. Incandescence was visible from several vents in the Pu'u 'O'o crater and minimally visible from breakouts on the Pulama pali. On 28 April, a gas plume rose from an unidentified location above the pali. Earthquake activity was scattered at the summit, upper E rift zone, and S-flank areas. Tremor remained at moderate levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 April-24 April 2007 Citation IconCite this Report

During 18-24 April, lava from Kilauea continued to flow SE across a lava delta into the ocean at the Kamokuna entry, but lava was not seen entering the ocean at East Lae'apuki. Incandescence was intermittently visible from several breakouts on the Pulama pali and from several vents in the Pu'u 'O'o crater. Earthquake activity was scattered at the summit and S-flank areas. Tremor remained at moderate levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 April-17 April 2007 Citation IconCite this Report

On 11 April, lava from the E arm of Kilauea's Campout flow at the base of the long-abandoned Royal Gardens ignited fires within the subdivision. During 11-17 April, lava continued to flow across a lava delta into the ocean at the Kamokuna entry, but lava was not seen entering the ocean at East Lae'apuki. Incandescence was intermittently visible from several breakouts on the Pulama pali and from several vents in the Pu'u 'O'o crater. Earthquake activity was scattered at the summit and S-flank areas.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 April-10 April 2007 Citation IconCite this Report

During 4-10 April, lava from Kilauea continued to flow across a lava delta into the ocean at the Kamokuna entry. Lava was not seen entering the ocean at the East Lae'apuki entry. Incandescence was intermittently visible from several breakouts on the Pulama pali and from several vents in Pu'u 'O'o's crater. Earthquake activity was scattered at the summit and S-flank areas.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 March-3 April 2007 Citation IconCite this Report

During 28 March-3 April, lava from Kilauea continued to flow across a lava delta into the ocean at the Kamokuna entry. Lava was not seen entering the ocean at the East Lae'apuki entry. During 28-29 March, a more than usual number of earthquakes were located near the Halema'uma'u and Koko'olau craters and on the S flank. Incandescence was intermittently visible from several breakouts on the Pulama pali and from several vents in Pu'u 'O'o's crater. On 31 March, a major lava breakout from the Campout flow caused trees to ignite on a near-by kipuka (an "island" of vegetation) and produced small explosions from trapped gas.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 March-27 March 2007 Citation IconCite this Report

During 21-27 March, lava from Kilauea continued to flow across lava deltas into the ocean at the East Lae'apuki and Kamokuna entries. Incandescence was intermittently visible from several breakouts on the pali and from several vents in Pu'u 'O'o's crater. A few small earthquakes were located in the summit and Poliokeawe (South Flank) areas. On 27 March, a'a' flows were active on the pali. Tremor at Pu'u 'O'o' continued at moderate levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 March-20 March 2007 Citation IconCite this Report

During 14-19 March, lava from Kilauea continued to flow across lava deltas into the ocean at the East Lae'apuki and Kamokuna entries. Incandescence was intermittently visible from several breakouts on the pali and from several vents in Pu'u 'O'o's crater. On 14 March, 'a'a flows from the Campout flow were seen on the pali. Tremor at Kilauea's summit continued at low levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 March-13 March 2007 Citation IconCite this Report

During 7-13 March, lava from Kilauea continued to flow across lava deltas into the ocean at the East Lae'apuki and Kamokuna entries. On 10 March, lava no longer entered the ocean at East Ka'ili'ili and likely branched off W towards the Royal Gardens subdivision. Steam plumes at East Ka'ili'ili possibly from water washing onto hot rocks, were visible on subsequent days. Incandescence was intermittently visible from several breakouts on the pali and from several vents in Pu'u 'O'o's crater. Tremor at Kilauea's summit continued at low levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 February-6 March 2007 Citation IconCite this Report

During 28 February-6 March, lava from Kilauea continued to flow from lava deltas into the ocean at the East Lae'apuki, Kamokuna, and East Ka'ili'ili entries. Incandescence was intermittently visible from several breakouts on the pali and from several vents in Pu'u 'O'o's crater. Tremor at Kilauea's summit continued at low levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 February-27 February 2007 Citation IconCite this Report

During 21-27 February, lava from Kilauea continued to flow from lava deltas into the ocean at the East Lae'apuki, Kamokuna, and East Ka'ili'ili entries. Incandescence was intermittently visible from several breakouts on the pali and from several vents in Pu'u 'O'o's crater. On 22 February, HVO field crews reported gas jetting from vents on the S side of Pu'u 'O'o. Tremor at Kilauea's summit continued at low levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 February-20 February 2007 Citation IconCite this Report

During 14-20 February, lava from Kilauea continued to flow from lava deltas into the ocean at the East Lae'apuki, Kamokuna, and East Ka'ili'ili entries. Incandescence was intermittently visible from several breakouts on the pali and from several vents in Pu'u 'O'o's crater. On 15 February, breakout surface lava from the Campout flow produced seven lava falls over the seacliff behind the East Lae'apuki bench. Lava continued to flow over the seacliff in this area for the rest of the reporting period. Tremor at Kilauea's summit continued at low levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 February-13 February 2007 Citation IconCite this Report

During 7-13 February, lava from Kilauea continued to flow from lava deltas into the ocean at the East Lae'apuki, Kamokuna, and East Ka'ili'ili entries. Incandescence was seen from the Campout and PKK flows on the pali and from several vents in Pu'u 'O'o's crater. Tremor near Pu'u 'O'o continued at low levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 January-6 February 2007 Citation IconCite this Report

During 31 January-6 February, lava from Kilauea continued to flow from lava deltas into the ocean at the East Lae'apuki, Kamokuna, and East Ka'ili'ili entries. Incandescence was intermittently visible on the pali and from several vents in Pu'u 'O'o's crater. Tremor near Pu'u 'O'o continued at low levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 January-30 January 2007 Citation IconCite this Report

During 24-30 January, lava from Kilauea continued to flow from lava deltas into the ocean at the East Lae'apuki, Kamokuna, and East Ka'ili'ili entries. Incandescence was intermittently visible on the pali and from several vents in Pu'u 'O'o's crater. Breakout lava from the Campout flow advanced about 1.6 km per hour on 24 January. The USGS field crew noticed several small breakouts of lava from the Campout flow at the base of the pali that flowed E and burned trees near the long-abandoned Royal Gardens subdivision. Tremor near Pu'u 'O'o increased to a moderate level.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 January-23 January 2007 Citation IconCite this Report

During 17-23 January, lava from Kilauea continued to flow from lava deltas into the ocean at the East Lae'apuki, Kamokuna, and East Ka'ili'ili entries. Incandescence was intermittently visible on the pali and from several vents in Pu'u 'O'o's crater. Tremor near Pu`u `O`o continued at low levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 January-16 January 2007 Citation IconCite this Report

During 10-16 January, lava from Kilauea continued to flow from lava deltas into the ocean at the East Lae'apuki, Kamokuna, and East Ka'ili'ili entries. Incandescence was intermittently visible on the pali and from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater. On 12 January, the summit tilt network recorded the start of the tenth deflation-inflation (DI) event; after 7 microradians of deflation, inflation began on 13 January. Tremor near Pu'u 'O'o increased and decreased in response to the DI event.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 January-9 January 2007 Citation IconCite this Report

During 3-9 January, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki, Kamokuna, and East Ka'ili'ili entries. Incandescence was intermittently visible on the pali and from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater. Tremor near Pu`u `O`o continued at low levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 December-2 January 2007 Citation IconCite this Report

During 27 December-2 January, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Between those two entries, lava streams were visible on 27 and 28 December descending to the ocean to re-establish the Kamokuna entry. Incandescence was intermittently visible on the pali and from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater. Tremor near Pu`u `O`o continued at low levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 December-26 December 2006 Citation IconCite this Report

During 20-26 December, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Incandescence on the pali was visible during the reporting period. Intermittent incandescence was seen coming from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 December-19 December 2006 Citation IconCite this Report

During 13-19 December, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Incandescence on the pali was visible during the reporting period. Rare surface activity on the flow field was observed on 13 December. Incandescence was intermittently visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater. Tremor near Pu`u `O`o continued at moderate levels.

According to a news article, a three-year-long inflationary trend of Kilauea's summit and E and SW rift zones ceased in early October. Since the current on-going eruption began in 1983, a total of three such events have occurred.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); Honolulu Advertiser


6 December-12 December 2006 Citation IconCite this Report

During 6-12 December, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Incandescence on the pali was visible during the reporting period. A large breakout on Pulama pali on 5 December resulted in downed and burned trees. Incandescence was also intermittently visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 November-5 December 2006 Citation IconCite this Report

During 29 November-5 December, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. On 30 November and 5 December, incandescence was visible on the Pulama pali. Incandescence was intermittently visible from the East Pond and January vents, South Wall complex, and Drainhole and Beehive vents in Pu'u 'O'o's crater. The intensity of the incandescence was strongest at the E (East Pond) and diminished towards the W (Beehive).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 November-28 November 2006 Citation IconCite this Report

During 22-28 November, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. During 23 and 25-26 November, incandescence was visible on the Pulama pali and the coastal flats in the vicinity of the Campout flow. Incandescence was intermittently visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 November-21 November 2006 Citation IconCite this Report

During 15-21 November, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. During 15-18 November, break-out flows were visible on the Pulama pali. Incandescence was intermittently visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater. On 18 November, the Drainhole vent twice ejected spatter as high as 25 m above its rim. Summit inflation S of Halema'uma'u caldera continued. Tremor at Pu'u 'O'o remained at a typical moderate level.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 November-14 November 2006 Citation IconCite this Report

During 8-14 November, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. During 7-9 November, a break-out flow was visible about halfway down Pulama pali. Incandescence was intermittently visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater. Summit inflation S of Halema'uma'u caldera continued. Tremor at Pu'u 'O'o remained at a typical moderate level.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 November-7 November 2006 Citation IconCite this Report

During 1-7 November, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Break-out lava flows were visible along the Campout flow on and at the base of the Pulama pali. When weather permitted, incandescence was visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater. The summit continued to slowly inflate S of Halema'uma'u caldera.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 October-31 October 2006 Citation IconCite this Report

The summit of Kilauea continued to slowly inflate S of Halema'uma'u caldera during 25-31 October. Incandescence was intermittently but strongly visible from the East Pond and January vents, and occasionally dimly visible from South Wall complex and Drainhole vent in Pu'u 'O'o's crater. Lava from the Campout and PKK systems continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. On 25 October, two separate break-out lava flows were visible on Pulama pali. The upper flow at about 320 m (1,050 ft) elevation consisted of 'a'a and pahoehoe and the lower flow at 114 m (375 ft) was solely pahoehoe.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 October-24 October 2006 Citation IconCite this Report

During 18-24 October, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Incandescence was intermittently visible from the East Pond and January vents, South Wall complex, and Drainhole and Beehive vents in Pu'u 'O'o's crater. Summit inflation S of Halema'uma'u caldera continued. Weak incandescence was visible on the Pulama pali during 18-19 October. Tremor at Pu'u 'O'o remained at a typical moderate level.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 October-17 October 2006 Citation IconCite this Report

The summit of Kilauea continued to slowly inflate S of Halema'uma'u caldera during 11-17 October. Incandescence from surface flows was intermittently visible on the pali and at the base of the pali on 14 October. Lava from the Campout and PKK systems continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Two large earthquakes (largest, M 6.7) occurred on 15 October on the northwest side of Hawai'i Island. On 16 October, HVO reported that the earthquakes did not affect the Kilauea eruption.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 October-10 October 2006 Citation IconCite this Report

The summit of Kilauea continued to slowly inflate S of Halema'uma'u caldera during 4-5 October. Incandescence was intermittently visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater, when weather permitted. Lava from the Campout and PKK systems continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Incandescence from surface flows was intermittently visible on Pulama pali.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 September-3 October 2006 Citation IconCite this Report

Fountaining on 28 September was reported about 15 m inland of the W edge of the East Lae`apuki bench. Lava jetted about 30 m in the air accompanied by loud rumbling and jetting sounds. Over the next couple of days, 3-4 lava streams were visible on the W side of East Lae`apuki entry, as were incidents of tephra jetting and lava fountaining 15-23 m (50-75 ft) high. Glow had been visible from the East Lae`apuki entry and the Campout flow breakout on the pali, but not from the Ka`ili`ili entry. The consistent lack of visible glow from the Ka`ili`ili entry is due to its inability to build a very large bench, so its continuing activity remains hidden at the base of the seacliff.

Observers reported on 28 September that the floor of Drainhole vent had collapsed, and was replaced by an overturning lava pond. As of 29 September a new tube and flow were forming on the E side of the Campout flow. The USGS field crew also noticed a small stagnant breakout of lava at about 60 m (200 ft) elevation that flowed E to cover a little more of the long-abandoned Royal Gardens subdivision.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 September-26 September 2006 Citation IconCite this Report

Throughout 20-26 September Kilauea continued to erupt from the Pu`u `O`o vent on the East Rift Zone. Summit inflation centered in the south part of the caldera also continued. Lava was flowing through the PKK lava tube from its source on the SW flank of Pu`u `O`o to the ocean. About 1 km S of Pu`u `O`o, the Campout flow branches off from the PKK tube. The PKK and Campout systems feed two widely separated ocean entries named East Lae`apuki and East Ka`ili`ili, respectively. Activity during this period included numerous small breakouts from the Campout flow, new skylights along the PKK tube, and variable activity at the ocean entries. At Pu`u `O`o, intermittent lava incandescence reflected on gas plumes was visible from the usual four vents (East Pond, January, South Wall Complex, and Drainhole).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 September-19 September 2006 Citation IconCite this Report

The summit of Kilauea continued to slowly inflate S of Halema'uma'u caldera during 13-19 September. Incandescence was intermittently visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater. Lava from the Campout and PKK systems continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 September-12 September 2006 Citation IconCite this Report

During 6-12 September, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Incandescence was intermittently visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater. Summit inflation S of Halema'uma'u caldera continued. Tremor at Pu'u 'O'o remained at a typical moderate level.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 August-5 September 2006 Citation IconCite this Report

During 23-29 August, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. On 1 September, the area of the East Lae'apuki lava bench was an estimated 22 hectares (54 acres) and East Ka'ili'ili was an estimated 2.3 hectares (5.7 acres). Incandescence was visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater during the reporting period. Summit inflation S of Halema'uma'u caldera continued. Tremor at Pu'u 'O'o remained at a very typical moderate level.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 August-29 August 2006 Citation IconCite this Report

During 23-29 August, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Incandescence was visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater during the reporting period. Summit inflation S of Halema'uma'u caldera continued. Tremor at Pu'u 'O'o remained at a very typical moderate level.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 August-22 August 2006 Citation IconCite this Report

During 16-22 August, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Incandescence was visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater during most of the reporting period.

A recent leveling survey revealed an inflationary trend at the summit of Kilauea, in areas S of Halema'uma'u crater. Elevations have increased 11 cm in the past 6 months and continued to increase during the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 August-15 August 2006 Citation IconCite this Report

During 9-15 August, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Incandescence was visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater during most of the reporting period. Tremor remained at a very typical moderate level at Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 August-8 August 2006 Citation IconCite this Report

A 4-hectare (10-acre) area of the lava delta at Kilauea's East Lae'apuki collapsed into the ocean on 30 July. The collapse represented less than 15% of the delta's total area.

During 2-8 August, lava from the PKK lava tube flowed into the ocean at two entries on the SE flank, East Lae`apuki and about 3.5 km E at East Ka`ili`ili. Tilt at the Pu`u `O`o cone displayed a saw tooth pattern and tremor remained at a moderate level.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); The Honolulu Advertiser


26 July-1 August 2006 Citation IconCite this Report

During 26 July-1 August, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki entry. Incandescence was strongly visible from East Pond and January vents, moderately visible from the South Wall complex, and dimly visible from the Drainhole vent in Pu'u 'O'o's crater during most of the reporting period. Tremor remained at a very typical moderate level at Pu'u 'O'o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 July-25 July 2006 Citation IconCite this Report

During 19-24 July, incandescence from Kilauea was observed due to reflections from the fumes over East Pond and January vents and the South Wall complex. On 21 July, the terminus of the Campout flow was ~1.7 km from the sea at Ka'ili'ili, about 440 m from the observed terminus on 14 July. Pu'u 'O'o tremor remained at a moderate level.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 July-18 July 2006 Citation IconCite this Report

During 14-18 July, small areas of incandescence were observed from Kilauea's Campout flow on Pulama pali. Lava continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. Seismicity levels were low at the summit and moderate at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 July-11 July 2006 Citation IconCite this Report

During 5-11 July, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. Background volcanic tremor was at normal levels at Kilauea's summit, with small shallow earthquakes occurring. Volcanic tremor remained at a very typical moderate level at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 June-4 July 2006 Citation IconCite this Report

During 28 June-4 July, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. On 30 June, surface lava flows originating from the Campout lava tube were visible on the upper part of the Pulama pali fault scarp, which had not been the case since 8 February. Incandescence was visible from Drainhole vent in Pu`u `O`o's crater during most of the reporting period. Tremor remained at a very typical moderate level at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 June-27 June 2006 Citation IconCite this Report

During 21-27 June, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. On 24 June, lava that flowed over a 67 m wide sea cliff was fed from a breakout point about 50 m inland from the cliff on the W surface of the delta. The area of East Lae`apuki lava delta was estimated to be 20.5 hectares. On 24 June, the floor of Drainhole vent in Pu`u `O`o's crater collapsed and produced a 30 m by 25 m lava pond with dynamically active lava on the SE side of the pit. Lava from the Campout flow and tube, located on the E margin of the PKK shield, advanced 1.2 km towards the Pulama pali approximately during 19-24 June.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 June-20 June 2006 Citation IconCite this Report

During 14-20 June, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. Incandescence was visible from Drainhole vent in Pu`u `O`o's crater during the reporting period. Tremor remained at a very typical moderate level at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 June-13 June 2006 Citation IconCite this Report

During 7-13 June, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. Incandescence was visible from Drainhole vent during the reporting period. Tremor remained at a very typical moderate level at Pu`u `O`o. The summit of Kilauea slowly inflated.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 May-6 June 2006 Citation IconCite this Report

During 31 May to 5 June, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. Incandescence was visible from East Pond Vent, January Vent, Drainhole, and South Wall Complex when weather permitted observations. Incandescence high up on the PKK lava tube was observed on 4 June from the ground and by GOES satellite.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 May-30 May 2006 Citation IconCite this Report

During 24-30 May, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. Incandescence was visible from East Pond Vent, January Vent, and Drainhole during 24-30 May, and from South Wall Complex on 24 and 30 May. Tremor remained at a very typical moderate level at Pu`u `O`o. Small amounts of inflation and deflation occurred during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 May-23 May 2006 Citation IconCite this Report

Small lava flows were visible on 19 May and minor incandescence was observed on 21-22 May at Kilauea's East Lae`apuki lava delta. Seismicity levels were low at the summit and moderate at Pu`u `O`o. After 16 May, there was very little change in deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 May-16 May 2006 Citation IconCite this Report

During 15-16 May, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. No surface lava flows were visible on the Puluma pali fault scarp, as has been the case since 8 February. Kilauea's summit began to deflate on 14 May. On 16 May, inflation occurred that was accompanied by an abrupt drop in volcanic tremor at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 May-9 May 2006 Citation IconCite this Report

During 4-8 May, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. No surface lava flows were visible on the Puluma pali fault scarp, as has been the case since 8 February. Low-level volcanic tremor was recorded at Kilauea's summit, accompanied by a few small earthquakes. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 April-2 May 2006 Citation IconCite this Report

During 26 April to 2 May, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. No surface lava flows were visible on the Puluma pali fault scarp, as has been the case since 8 February. Continuous low-level volcanic tremor was recorded at Kilauea's summit, accompanied by a few small earthquakes. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 April-25 April 2006 Citation IconCite this Report

During 20-24 April, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. No surface lava flows were visible on the Puluma pali fault scarp, as has been the case since 8 February. Continuous low-level volcanic tremor was recorded at Kilauea's summit, accompanied by a few small earthquakes. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 April-18 April 2006 Citation IconCite this Report

During 13-17 April, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. Background volcanic tremor was at normal levels at Kilauea's summit, with small shallow also earthquakes occurring. Volcanic tremor reached moderate levels at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 April-11 April 2006 Citation IconCite this Report

During 5-11 April, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. Background volcanic tremor was at normal levels at Kilauea's summit. Small, shallow earthquakes continued beneath the summit area and upper E rift zone. Volcanic tremor reached moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 March-4 April 2006 Citation IconCite this Report

During 29 March to 3 April, lava from Kilauea flowed off of a lava delta into the ocean at the East Lae`apuki entry. Background volcanic tremor was at normal levels at Kilauea's summit. Small, shallow earthquakes continued beneath the summit area and upper E rift zone at a fluctuating rate. Volcanic tremor reached moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 March-28 March 2006 Citation IconCite this Report

During 22-28 March, lava from Kilauea flowed off of a lava delta into the ocean at the East Lae`apuki entry. Background volcanic tremor was at normal levels at Kilauea's summit. Small, shallow earthquakes continued beneath the summit area and upper east rift zone, often occurring in bursts but, they were less numerous than during the previous week, and much less than a month ago. Volcanic tremor reached moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 March-21 March 2006 Citation IconCite this Report

During 15-22 March, lava flowed off of a lava delta into the ocean at the East Lae`apuki entry and surface lava flows were occasionally visible. Background volcanic tremor was at normal levels at Kilauea's summit, with shallow earthquakes continuing to occur beneath the summit area and the upper E rift zone. Volcanic tremor reached moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 March-14 March 2006 Citation IconCite this Report

During 9-13 March, lava flowed off of a lava delta into the ocean at the East Lae`apuki entry. Background volcanic tremor was at normal levels at Kilauea's summit, with shallow earthquakes continuing to occur beneath the summit area and the upper east rift zone. Volcanic tremor reached moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 March-7 March 2006 Citation IconCite this Report

During 2-7 March, no surface lava flows were visible on Kilauea's Pulama pali fault scarp, which had been the case since 8 February. Lava flowed into the ocean at the East Lae`apuki entry. Beginning on 1 March, lava emerged from the PKK lava tube between the 45- and 75-m elevations, and lava streams extended 200-400 m downstream from this point. Background volcanic tremor was at normal levels at Kilauea's summit, with shallow earthquakes continuing to occur beneath the summit area and the upper east rift zone. Volcanic tremor reached moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 February-28 February 2006 Citation IconCite this Report

During 27-28 February, no surface lava flows were visible on Kilauea's Pulama pali fault scarp, which had been the case since 8 February. Lava flowed into the ocean at the East Lae`apuki entry. Background volcanic tremor was at normal levels at Kilauea's summit, with shallow earthquakes continuing to occur beneath the summit area and the upper east rift zone. Volcanic tremor reached moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 February-21 February 2006 Citation IconCite this Report

During 16-20 February, no surface lava flows were visible on Kilauea's Pulama pali fault scarp, which had been the case since 8 February. Several streams of lava poured into the sea from the lava delta at the East Lae`apuki entry. Background volcanic tremor was at normal levels at Kilauea's summit, with shallow earthquakes continuing to occur beneath the summit area and the upper east rift zone. Volcanic tremor reached moderate levels at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 February-14 February 2006 Citation IconCite this Report

During 8-14 February, surface lava flows were not visible on Kilauea's Pulama pali fault scarp due to lava traveling underground through the PKK lava tube until reaching the East Lae`apuki lava delta and flowing into the sea. Observations on 7 February revealed that the lava delta had broadened 120 m westward since 30 January. During the report period, background volcanic tremor was near normal levels at Kilauea's summit, with numerous sporadic shallow earthquakes continuing to occur at the summit and upper E rift zone. Volcanic tremor reached moderate levels at Pu`u `O`o. Slow, steady inflation continued at Kilauea's summit as it has more-or-less since mid-January.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 February-7 February 2006 Citation IconCite this Report

During 2-7 February, lava from Kilauea continued to enter the sea at the East Lae`apuki area and surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kilauea's summit, with numerous shallow earthquakes continuing to occur at the summit and upper E rift zone. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 January-31 January 2006 Citation IconCite this Report

During 30-31 January, lava from Kilauea continued to enter the sea at the East Lae`apuki area, building a new lava delta. Surface lava flows were visible on the Pulama pali fault scarp. On 31 January, the lava delta was 615 m long and 140 m wide. Background volcanic tremor was near normal levels at Kilauea's summit, with numerous shallow earthquakes occurring at the summit and upper E rift zone during several days. Volcanic tremor reached moderate levels at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 January-17 January 2006 Citation IconCite this Report

During 11-14 January, lava from Kilauea continued to enter the sea at the East Lae`apuki area, building a new lava delta. Surface lava flows were visible on the Pulama pali fault scarp. On 10 January the summit deflation switched abruptly to inflation after a loss of 5.2 microradians. Relatively high tremor occurred at this time. Tremor quickly dropped, becoming weak to moderate when deflation ended, with seismicity punctuated by a few small earthquakes. By 13 January, background volcanic tremor was near normal levels at Kilauea's summit and reached moderate levels at Pu`u `O`o. On 14 January, the lava delta was about 500 m long (parallel to shore) and still only 140 m wide.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 January-10 January 2006 Citation IconCite this Report

During 4-9 January, lava from Kilauea continued to enter the sea at the East Lae`apuki area, building a new lava delta. Surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of deformation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 December-3 January 2006 Citation IconCite this Report

During 28 December to 3 January, lava from Kilauea continued to enter the sea at the East Lae`apuki area and surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of deformation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 December-27 December 2005 Citation IconCite this Report

During 22-27 December, lava from Kilauea continued to enter the sea at the East Lae`apuki area and surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of deformation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 December-20 December 2005 Citation IconCite this Report

During 15-20 December, lava from Kilauea continued to enter the sea at the East Lae`apuki area and surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of deformation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 December-13 December 2005 Citation IconCite this Report

During 9-12 December, lava from Kilauea continued to enter the sea at the East Lae`apuki area and surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of deformation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 November-6 December 2005 Citation IconCite this Report

A lava bench collapse in the East Lae`apuki area on 29 November lasted several hours, sending the 34-acre bench plus another 10 acres of adjacent cliff into the sea. This was the largest bench collapse of the current eruption, which began in January 1983. The collapse left a 20-m-high cliff exposed, from which a 2-m-thick stream of lava was emitted from an open lava tube. Cracks had been observed on the inland portion of the bench several months earlier; visitors are not allowed near the bench, but a viewing area is provided about 3 km away. Growth of the new delta at East Lae`apuki was continuing as of 6 December. At that time breakouts were also active on Pulama Pali.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); Honolulu Advertiser


23 November-29 November 2005 Citation IconCite this Report

During 23-29 November, lava from Kilauea continued to enter the sea at the East Lae`apuki area and surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of deformation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 November-22 November 2005 Citation IconCite this Report

During 18-22 November, lava from Kilauea continued to enter the sea at the East Lae`apuki area and surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of deformation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 November-15 November 2005 Citation IconCite this Report

On 14 November, lava from Kilauea continued to enter the sea at the East Lae`apuki area. Surface lava flows were visible on the Pulama pali fault scarp although surface activity had decreased in comparison to the previous week. Background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 November-8 November 2005 Citation IconCite this Report

During 2-7 November, lava from Kilauea continued to enter the sea at the East Lae`apuki area, and surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 October-1 November 2005 Citation IconCite this Report

During 26-31 October, lava from Kilauea continued to enter the sea at the East Lae`apuki area, and surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 October-25 October 2005 Citation IconCite this Report

During 19-25 October, surface lava flows at Kilauea were occasionally visible along the E branch of the PKK flow. Lava flows continued to enter the sea at East Lae`apuki area, mostly NE of the point of the lava delta. Background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor was at moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 October-18 October 2005 Citation IconCite this Report

On 18 October, weak surface lava flows were visible at Kilauea and one cascade of lava flowed off of the western front of the East Lae`apuki delta. Background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor was at moderate levels at Pu`u `O`o. During 11-18 October, small amounts of inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 October-11 October 2005 Citation IconCite this Report

During 10-11 October, lava from Kilauea continued to enter the sea at the East Lae`apuki area, and surface lava flows were visible along the PKK lava flow. During the report period, background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor was at moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 September-4 October 2005 Citation IconCite this Report

During 28 September- 2 October, lava from Kilauea continued to enter the sea at the East Lae`apuki area, and surface lava flows were visible on the Pulama Pali fault scarp. During the report period, background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 September-27 September 2005 Citation IconCite this Report

During 22-27 September, lava from Kilauea continued to enter the sea at the East Lae`apuki area, and surface lava flows were visible on the Pulama Pali fault scarp. During the report period, background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 September-20 September 2005 Citation IconCite this Report

During 14-19 September, lava from Kilauea continued to enter the sea at the East Lae`apuki area, and surface lava flows were visible on the Pulama Pali fault scarp. During the report period, background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Around 19 September, several small shallow earthquakes occurred along the Kao`iki fault system or the adjacent upper southwest rift zone. Small amounts of inflation and deflation occurred at the volcano during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 September-13 September 2005 Citation IconCite this Report

During 7-12 September, lava from Kilauea entered the sea at the East Lae`apuki area, and surface lava flows were visible on the Pulama Pali fault scarp. Lava filled a collapse scar left by a lava-bench (land built out from the sea cliff) collapse that occurred on 27 August. On 6 September, piecemeal collapse of the lava bench removed much of the central part of the new fill. During the report period, background volcanic tremor was around normal levels at Kilauea's summit. Volcanic tremor was at moderate levels at Pu`u `O`o. On 11 September, substantial deflation at the volcano was followed by sharp inflation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 August-6 September 2005 Citation IconCite this Report

During 1-5 September, lava from Kilauea entered the sea at the East Lae`apuki area, and surface lava flows were visible on the Pulama Pali fault scarp. On 27 August, part of a lava bench (land built out from the sea cliff) collapsed. During the report period, background volcanic tremor was around normal levels at Kilauea's summit. Volcanic tremor was at moderate levels at Pu`u `O`o. Small periods of inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 August-30 August 2005 Citation IconCite this Report

During 25-29 August, lava from Kilauea entered the sea at the East Lae`apuki area, and surface lava flows were visible on the Pulama Pali fault scarp and the coastal flat. Background volcanic tremor was around normal levels at Kilauea's summit. Volcanic tremor was at moderate levels at Pu`u `O`o. Small periods of inflation and deflation occurred at the volcano during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 August-23 August 2005 Citation IconCite this Report

During 17-22 August, lava from Kilauea entered the sea at the East Lae`apuki area, and surface lava flows were sometimes visible on the Pulama Pali fault scarp and the coastal flat. By 22 August, surface lava on the W branch of the PKK lava flow was no longer visible. Background volcanic tremor was around normal levels at Kilauea's summit. Volcanic tremor was at moderate levels at Pu`u `O`o. Small periods of inflation and deflation occurred at the volcano during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 August-16 August 2005 Citation IconCite this Report

During 15 and 16 August, surface lava at Kilauea was visible on the W and E branches of the PKK lava flow, and lava continued to enter the sea at the East Lae`apuki entry. Background volcanic tremor was near normal levels at Kilauea's summit and at moderate levels at Pu`u `O`o cone. There were small periods of inflation and deflation at Kilauea's summit and Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 August-9 August 2005 Citation IconCite this Report

Up to seven ocean-entry points were visible off the W-facing front of the East Lae`apuki lava delta during 3-9 August; others were hidden from view off the E-facing front. On Pulama pali, the W branch of the PKK flow reached its greatest extent of the week on 5 August, when it broadened to include a couple of hundred meters of scattered breakouts and reached from about the 1,500-foot elevation down to about 850 ft. Background volcanic tremor was about normal at Kilauea's summit. Volcanic tremor was at a moderate level at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 July-2 August 2005 Citation IconCite this Report

On 30 July, small areas of surface lava were visible along Kilauea's PKK lava flow on the Pulama pali fault scarp. Background volcanic tremor was at normal levels at Kilauea's summit, and at moderate levels at Pu`u `O`o cone. There were periods of inflation and deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 July-26 July 2005 Citation IconCite this Report

During 21-26 July, lava from Kilauea continued to enter the sea at the East Kamoamoa and East Lae`apuki entries. Small areas of surface lava were occasionally visible along the PKK lava flow. Background volcanic tremor was well above normal levels at Kilauea's summit and at moderate levels at Pu`u `O`o cone. An M 4.5 earthquake occurred on 25 July at 2208 along the SE edge of Kilauea's SW rift zone at a depth of ~30 km.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 July-19 July 2005 Citation IconCite this Report

During 13-18 July, lava from Kilauea continued to enter the sea at the East Kamoamoa and East Lae`apuki entries. East Lae`apuki was larger, with lava spilling into the sea at several entry points. Surface lava was visible along the PKK lava flow. Background volcanic tremor remained above normal levels at Kilauea's summit and at moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 July-12 July 2005 Citation IconCite this Report

During 6-11 July, lava from Kilauea continued to enter the sea at the East Kamoamoa and East Lae`apuki entries. East Lae`apuki was much larger, with several entry points. East Kamoamoa barely emitted a glow from the incandescent lava. Surface lava was visible along the PKK lava flow. Background volcanic tremor remained above normal levels at Kilauea's summit and at moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 June-5 July 2005 Citation IconCite this Report

Lava from Kilauea entered the sea during 4-5 July, and few surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor remained above normal levels at Kilauea's summit and at moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano. According to a news report, around 3 July a lava-viewing area was closed at Kilauea due to the increased chance of a 10-hectare size lava bench (land built out from the sea cliff) in the vicinity collapsing without warning.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); Associated Press


22 June-28 June 2005 Citation IconCite this Report

On 22 June lava in the west branch of the current flow descended onto the coastal flat for the first time in several months. Volcanic tremor remains above normal levels at Kilauea's summit. On 24 June it was noted that Kilauea's summit continued its inflation, while Pu`u `O`o was deflating during the same period. On 27 June part of the active East Lae`apuki lava delta collapsed. Lava stored within the delta gushed out onto the surface of the delta and thence into the water. Fountains of lava reported to be about 25 m high spurted from the central part of the delta soon afterward.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 June-21 June 2005 Citation IconCite this Report

On 21 June lava from Kilauea continued to enter the sea and there was a small number of surface lava flows on the Pulama pali fault scarp. Background volcanic tremor remained above normal levels at Kilauea's summit and at moderate levels at Pu`u `O`o. There was no significant change in deformation at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 June-14 June 2005 Citation IconCite this Report

Lava entered the sea at two points along Kilauea's S flank during 8-12 June, and at three points on 13 June. During the report period, surface lava flows were visible on the Pulama pali fault scarp. Volcanic tremor remained above normal levels at Kilauea's summit and at moderate levels at Pu`u `O`o. Small amounts of deformation were recorded during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 June-7 June 2005 Citation IconCite this Report

Lava entered the sea at three points along the S flank of Kilauea during 1-4 June, and then at only two points through 7 June. Small surface lava flows were visible on the Pulama pali fault scarp and the coastal flat. Background volcanic tremor remained above normal levels at Kilauea's summit and at moderate levels at Pu`u `O`o. Small amounts of deformation occurred during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 May-31 May 2005 Citation IconCite this Report

On 31 May, three ocean entries were active at Kilauea and surface lava flows traveled down the Pulama pali fault scarp. Background volcanic tremor remained above normal levels at Kilauea's summit and at moderate levels at Pu`u `O`o. No deformation was recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 May-24 May 2005 Citation IconCite this Report

On 18 May lava from Kilauea continued to enter the sea at three areas. Surface lava flows were visible on the coastal plain and on the Pulama pali fault scarp. Volcanic tremor remained above background levels at Kilauea’s summit and at moderate levels at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 May-17 May 2005 Citation IconCite this Report

Ocean entries remained active during 11-17 May in the East Lae`apuki and Kamoamoa areas. By 16 May the East Lae`apuki and East Kamoamoa entries both had benches ~350 m long and up to 75 m wide. A large plume from West Highcastle on 10 May probably recorded a collapse of part of that lava delta, which has been inactive for the past several weeks following growth in March and April. The middle branch of the PKK flow remained active and extending down Pulama Pali. The east branch reached out farther but was narrower and contained fewer breakouts. The west branch was reduced to a cluster of breakouts about halfway down the pali. Glow was seen throughout the report period from all of the Pu`u `O`o crater vents, as well as the MLK vent at the SW foot of the cone. Background seismicity, both tremor and long-period earthquakes, remained above the norm at Kilauea's summit. Volcanic tremor is at a moderate level at Pu`u `O`o. Tilt at the summit was relatively flat, while Pu`u `O`o showed its usual ups and downs.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 May-10 May 2005 Citation IconCite this Report

A third ocean entry, in the East Lae`apuki area, became active on 5 May. That entry and the Far East Lae`apuki entry were both being fed by lava falls down the old sea cliff and were relatively small. Based of the brighter glow, the Kamoamoa entry was thought to be more substantial. By the morning of 9 May lava was treaming over the old sea cliff in four locations; two falls fed ocean entries and two were falling onto an old delta. The branch of the PKK flow feeding East Lae`apuki was full of breakouts on 9 May. The next day the middle branch of the PKK flow developed an open-channel stream on the Pulama pali 10-20 m wide, 500-600 m long, and moving rapidly. Volcanic tremor remained at moderate levels at Pu`u `O`o. Episodes of inflation and deflation occurred during the week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 April-3 May 2005 Citation IconCite this Report

During 27 April to 3 May, lava entered the ocean at the Kamoamoa entry. Numerous surface lava flows were visible on the coastal flat. Seismicity remained above background levels at Kilauea's summit, consisting of both tremor and long-period earthquakes. Volcanic tremor remained at moderate levels at Pu`u `O`o. Episodes of inflation and deflation occurred during the week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 April-26 April 2005 Citation IconCite this Report

During 21-25 April, there were fewer surface lava flows visible at Kilauea than during the previous week. On 24 April a small amount of lava began to enter the sea. Seismicity remained above background levels at Kilauea's summit, consisting mainly of tremor and some long-period earthquakes. Volcanic tremor was at moderate levels at Pu`u `O`o. Episodes of inflation and deflation occurred during the week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 April-19 April 2005 Citation IconCite this Report

During 14-19 April, surface lava flows from Kilauea were visible on the Pulama pali fault scarp and lava was not seen entering the ocean. Seismicity remained above background levels at Kilauea's summit, consisting mainly of tremor and some long-period earthquakes. Volcanic tremor was at moderate levels at Pu`u `O`o. Episodes of inflation and deflation occurred during the week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 April-12 April 2005 Citation IconCite this Report

During 6-11 April, lava from Kilauea continued to flow into the ocean at several points. Seismicity remained above background levels at Kilauea's summit, consisting mainly of tremor and some long-period earthquakes. Volcanic tremor was at moderate levels at Pu`u `O`o. Episodes of inflation and deflation occurred during the week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 March-5 April 2005 Citation IconCite this Report

Lava from Kilauea continued to flow into the ocean at several points during 1-4 April. Seismicity remained above background levels at Kilauea's summit, consisting mainly of tremor and some long-period earthquakes. Volcanic tremor was at moderate levels at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 March-29 March 2005 Citation IconCite this Report

On 29 March lava from Kilauea entered the ocean at five ocean entries. The largest, named Kamoamos, consisted of six or more places where lava entered the water along the front of a growing lava delta. A cascade of lava streamed down the old sea cliff at one of the two Highcastle entries. Bright glow came from Ka`ili`ili entry, and weak glow from East Highcastle entry. Seismicity remained above background levels at Kilauea's summit, consisting mainly of tremor and some long-period earthquakes. Volcanic tremor was at moderate levels at Pu`u `O`o. Surface waves from a M 8.7 earthquake on 28 March off Sumatra, Indonesia disturbed tilt measurements at Kilauea, otherwise the tilt change was small.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 March-22 March 2005 Citation IconCite this Report

During 16-21 March, lava from Kilauea's PKK lava flow continued to travel down the Pulama pali fault scarp and onto the coastal flat. Lava entered the ocean at the Ka`ili`ili and East Lae`apuki entries. Seismicity at Kilauea's summit was above background levels and tremor at Pu`u `O`o was at moderate levels. Slow deflation occasionally occurred at Kilauea's summit and Pu`u `O`o during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 March-15 March 2005 Citation IconCite this Report

On 15 March only small areas of surface lava flows at Kilauea were visible on the Pulama pali fault scarp, and the amount of lava in the three branches of the PKK lava flow continued to decrease. Lava continued to enter the ocean at the Ka`ili`ili and East Lae`apuki ocean entries. Only a few small earthquakes occurred below the volcano's S flank. The level of volcanic tremor was low at the summit and moderate at Pu`u `O`o. Small amounts of deflation occurred at Kilauea's summit and Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 March-8 March 2005 Citation IconCite this Report

During 3-7 March, lava from Kilauea continued to enter the ocean at the Ka`ili`ili and East Lae`apuki ocean entries; there were no signs of activity at the West Highcastle entry. Surface lava flows were visible on the Pulami pali fault scarp and the coastal flat. Small earthquakes occurred at Kilauea's summit, and no tremor was recorded. Tremor remained at moderate levels at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 February-1 March 2005 Citation IconCite this Report

During 23-26 February, lava from Kilauea entered the sea at three ocean entries that were located along 4.7 km of the island's SE coast. Lava may have stopped flowing into the sea at the westernmost entry, West Highcastle, on the 26th. The number of surface lava flows diminished in comparison to the previous week. Small earthquakes occurred at Kilauea's summit, and no tremor was recorded. Tremor remained at moderate levels at Pu`u `O`o. As of 28 February, deflation had occurred at Pu`u `O`o for more than a week, and at the summit since 24 February.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 February-22 February 2005 Citation IconCite this Report

On 21 February a new ocean entry, named East Lae`apuki, started at Kilauea. The entry was located between the other two ocean entries (Ka`ili`ili and West Highcastle) that had been active since 31 January 2005. This was the first time there had been three ocean entries active since early 2003. During 17-22 February, surface lava flows were visible on the volcano. A few small earthquakes occurred at Kilauea's summit, and no tremor was recorded. Tremor was at moderate levels at Pu`u `O`o. Small amounts of deformation occurred during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 February-15 February 2005 Citation IconCite this Report

During 9-15 February, Kilauea's PKK lava flow continued to enter the sea and surface lava was visible on the Pulama pali fault scarp. A few small earthquakes occurred at Kilauea's summit and no tremor was recorded there. Volcanic tremor remained at moderate levels at Pu`u `O`o. A small amount of deformation was recorded at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 February-8 February 2005 Citation IconCite this Report

Lava from Kilauea began to enter the ocean on 31 January at two entry points. The Ka`ili`ili entry to the E of the flow field was the largest and was fed by the large eastern arm of the PKK lava flow. The West Highcastle ocean entry was supplied by the W branch of the W arm of the PKK lava flow. On 7 February lava continued to enter the ocean and surface lava flows were visible on the Pulama pali fault scarp and on the coastal flat. A few small earthquakes were recorded at Kilauea's summit. No tremor was recorded at the summit, and volcanic tremor at Pu`u `O`o remained at a moderate level. Small amounts of deformation were recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 January-1 February 2005 Citation IconCite this Report

During 26-29 January, surface lava was visible at various spots along the PKK lava flow. All of the vents in the crater of Pu`u `O`o were visible at times. Small earthquakes were recorded at Kilauea's summit and decreased near the end of the report period. Slight tremor was recorded at the summit, and volcanic tremor at Pu`u `O`o remained at moderate levels. Small amounts of deformation was recorded at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 January-25 January 2005 Citation IconCite this Report

During 19-25 January, surface lava from Kilauea was visible along the arms of the PKK lava flow traveling down the Pulama pali fault scarp, over Paliuli, and onto the coastal flat. Lava did not enter the sea. Seismicity at Kilauea's summit was relatively low during the report period, except during the morning of 25 January when quick inflation was accompanied by long-period earthquakes. Seismicity abruptly returned to background levels when the inflation ended.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 January-18 January 2005 Citation IconCite this Report

During 12-18 January, surface lava flows were visible at Kilauea along the arms of the PKK lava flow on the Pulama pali fault scarp. No lava was visible near the coastline. Summit seismicity remained low with only a few long-period earthquakes recorded per day, and weak-to-absent background tremor. At Pu`u `O`o cone, volcanic tremor remained at moderate levels. Pu`u `O`o exhibited periods of slight inflation and deflation during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 January-11 January 2005 Citation IconCite this Report

During 5-11 January, surface lava flows were visible at Kilauea along the PKK lava flow on the Pulama pali fault scarp and on the coast. Summit seismicity remained low on both days with only a few long-period earthquakes recorded per day, and weak-to-absent background tremor. At Pu`u `O`o cone, volcanic tremor remained at moderate levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 December-4 January 2005 Citation IconCite this Report

During 3-4 January, surface lava flows were visible at Kilauea along the PKK lava flow on the Pulama pali fault scarp and on the coast. Summit seismicity remained low on both days with only a few long-period earthquakes recorded per day, and weak-to-absent background tremor. At Pu`u `O`o cone tremor remained at moderate levels, with periods of slight inflation and deflation recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 December-28 December 2004 Citation IconCite this Report

During 22-28 December, several areas of surface lava were visible at Kilauea along the PKK lava flow on the coastal flat, and along the Pulama pali fault scarp. Overall seismicity at the summit was low, but a few long-period earthquakes continued to occur. Tremor was essentially absent at the summit and moderate at Pu`u `O`o cone. On 26 December, surface ground motion from a deadly M 9 earthquake just W of Sumatra was picked up by all tiltmeters at Kilauea. During the report period, small periods of inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 December-21 December 2004 Citation IconCite this Report

During 19-21 December, lava flows from Kilauea did not enter the ocean. Several areas of surface lava were visible on the coastal flat, and on and above the Pulama pali fault scarp. Overall seismicity at the summit was low, but long-period earthquakes continued to occur. Tremor was essentially absent at the summit and moderate at Pu`u `O`o. Small periods of inflation and deflation occurred at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 December-14 December 2004 Citation IconCite this Report

During 8-14 December, surface lava flows were visible along all three arms of the PKK lava flow, from high on the Pulama pali fault scarp and on the coastal flat. By 13 December, lava entered the sea at the E Lae`apuki delta. During the report period, all vents were incandescent in the crater of Pu`u `O`o. Overall seismicity at the summit was low, but long-period earthquakes continued to occur. Tremor was essentially absent at the summit and moderate at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 December-7 December 2004 Citation IconCite this Report

During 1-6 December, surface lava flows were visible at Kilauea. Only a few areas of surface activity were visible along the PKK lava flow on 1 December. On 2 December surface flows were visible along all three arms of the PKK flow. All vents in the crater of Pu`u `O`o were incandescent, except for the South Wall Complex. The ocean entry at eastern Lae`apuki had not been active since 27-28 November. During the report period, overall seismicity at the summit was low, but long-period earthquakes continued to occur. Tremor was essentially absent at the summit and moderate at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 November-30 November 2004 Citation IconCite this Report

Surface lava flows at Kilauea were visible along two to three arms of the PKK lava flow on the Pulama pali fault scarp during 24-30 November. Most vents in the crater of Pu`u `O`o were incandescent. Lava entered the ocean through 26 November. On 30 November, seismicity at Kilauea's summit was low, with a few long-period earthquakes continuing to occur. Tremor was essentially absent at the summit and moderate at Pu`u `O`o. About 7 microradians of inflation occurred at Pu`u `O`o on 29 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 November-23 November 2004 Citation IconCite this Report

Lava from Kilauea's PKK flow continued to enter the sea at the newly formed lava delta at eastern Lae`apuki delta during 17-23 November. Fieldwork on 18 November determined that the new lava delta is 260 m long and extends about 80 m beyond pre-existing land (the front of the old Lae`apuki delta). The area of the delta is about 1.2 ha. One entry point was on the far west end of the delta, but most of the activity was east of center. During 17-23 November, all vents in the crater of Pu`u `O`o were incandescent. Seismicity at Kilauea's summit increased during the report period, with numerous small long-period earthquakes coming from the southern and southeastern parts of the caldera. Tremor remained low to absent, however. The tremor at Pu`u `O`o remained at moderate strength. No significant deformation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 November-16 November 2004 Citation IconCite this Report

Lava from Kilauea's PKK flow continued to enter the sea during 10-16 November at a newly formed lava delta at the eastern Lae`apuki entry area. On 16 November the delta grew along a wide front, mostly near and W of the most seaward point. A new arm of the delta-feeding flow had formed ~100 m farther E. Two vigorously active tips of this new arm were within 180 m of the sea cliff just E of the new delta, and at their current rate of advance they could enter the sea within a day. All vents in the crater of Pu`u `O`o were incandescent during this period. Seismicity was weak at Kilauea's summit, with essentially no tremor recorded. Tremor was at moderate levels at Pu`u `O`o. No significant deformation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 November-9 November 2004 Citation IconCite this Report

Lava from Kilauea's PKK flow entered the sea during the evening of 4 November. This was the first time lava had entered the sea since the Banana lava delta ceased operation in early August 2004. On the morning of 5 November, the entry was small, but vigorous. The width of the feeding lava flow was ~30 m and the new delta just starting to form seaward of the Lae`apuki delta was at most 70 m long and 8 m wide perpendicular to the shoreline. By 8 November the new lava delta was ~100 m wide along the shore and reached as far as 15 m seaward from the front of the old Lae`apuki delta. During 4-8 November, all vents in the crater of Pu`u `O`o were incandescent. Seismicity was weak at Kilauea's summit, with essentially no tremor recorded. Tremor was at moderate levels at Pu`u `O`o. No significant deformation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 October-2 November 2004 Citation IconCite this Report

During 28-31 October, surface lava was visible on the PKK lava flow on the Pulama pali fault scarp and all vents in the crater of Pu`u `O`o were incandescent. Seismicity was weak at Kilauea's summit and essentially no tremor was recorded. Tremor remained at moderate levels at Pu`u `O`o. During the report period, no significant deformation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 October-26 October 2004 Citation IconCite this Report

During 21-24 October, patches of incandescent lava were visible on the PKK lava flow on the Pulama pali fault scarp and all vents in the crater of Pu`u `O`o were incandescent. Seismicity was at low levels at Kilauea's summit and essentially no tremor was recorded there. Tremor was at moderate levels at Pu`u `O`o. During the report period, there were episodes of inflation and deflation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 October-19 October 2004 Citation IconCite this Report

During 13-18 October, surface lava flows were visible on the PKK lava flow on the Pulama pali fault scarp and all vents in the crater of Pu`u `O`o were incandescent. Tremor remained at moderate levels at Pu`u `O`o and essentially no tremor was recorded at Kilauea's summit. A M 4.5 earthquake on 13 October at 1318 occurred about 6 km S of Pu`u `O`o at a depth of ~9 km. The earthquake permanently offset the Pu`u `O`o tiltmeter and several others on the volcano. During the report period, little deformation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 October-12 October 2004 Citation IconCite this Report

On 11 and 12 October, patches of incandescent lava were visible on the PKK lava flow on the Pulama Pali fault scarp and all vents in the crater of Pu`u `O`o were incandescent. Tremor was at moderate levels at Pu`u `O`o. Essentially no tremor was recorded at Kilauea's summit. A M 4.0 earthquake occurred at Kilauea's summit at a depth of ~32 km on 11 October at 1030 that affected tilt meters. Taking earthquake- and rainfall-induced tilts into account, the volcanic tilt was minor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 September-5 October 2004 Citation IconCite this Report

During 30 September to 5 October, patches of incandescence were visible at the PKK lava flow on the Pulama pali scarp and all vents in the crater of Pu`u `O`o were incandescent. During the report period, seismicity was weak at Kilauea's summit, with essentially no tremor recorded. Tremor was moderate at Pu`u `O`o. In addition, small amounts of inflation and deflation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 September-28 September 2004 Citation IconCite this Report

During 22-27 September, all vents in Kilauea's Pu`u `O`o cone were incandescent. After several days of absence, lava was again visible on the Pulama pali fault scarp beginning on the 23rd. The lava was at the tip of the western branch of the PKK flow. During the report period, seismicity was weak at Kilauea's summit, with essentially no tremor. Tremor was at moderate levels at Pu`u `O`o. In addition, periods of inflation and deflation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 September-21 September 2004 Citation IconCite this Report

HVO reports noted that all vents in Pu`u `O`o's crater were incandescent during this period, and glow was frequently observed from the upper reaches of the PKK flow. As of the 20th seismicity was weak at Kilauea's summit, with essentially no tremor recorded, and tremor was moderate at Pu`u `O`o. Small episodes of deflation-inflation-deflation were also recorded during 15-21 September.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 September-14 September 2004 Citation IconCite this Report

During 9-12 September, a small amount of surface lava was visible atop Kilauea's Pulama pali and all vents in the crater of Pu`u `O`o were incandescent. Seismicity at Kilauea's summit was low and tremor at Pu`u `O`o was moderate. Small episodes of deflation and inflation occurred during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 September-7 September 2004 Citation IconCite this Report

During 2-6 September, surface lava flows were visible at Kilauea on the Pulama pali fault scarp, and all vents in the crater of Pu`u `O`o were incandescent. Seismicity was weak beneath Kilauea's summit and tremor was at moderate levels at Pu`u `O`o'. Small amounts of deformation occurred during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 August-31 August 2004 Citation IconCite this Report

During 25-31 August, surface lava flows were visible at Kilauea on the Pulama pali fault scarp, and all vents in the crater of Pu`u `O`o were incandescent. Seismicity was weak beneath Kilauea's summit. There was no tremor beneath Kilauea, and it was at moderate levels at Pu`u `O`o'. Small inflation and deflation events occurred during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 August-24 August 2004 Citation IconCite this Report

During 21-24 August, surface lava flows were visible at Kilauea on the Pulama pali fault scap and all vents in the crater of Pu`u `O`o were incandescent. Seismicity was weak beneath Kilauea's summit. There was no tremor beneath Kilauea and it was at moderate levels at Pu`u `O`o'. There was a small deflation-inflation-deflation deformation event during 21-22 August.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 August-17 August 2004 Citation IconCite this Report

During 11-17 August surface lava flow were visible on Pulama pali, and the vents in the crater of Pu`u `O`o were incandescent. Lava had not entered the sea since 4 August. Seismicity was weak beneath Kilauea's summit, and tremor was at moderate-to-high levels at Pu`u `O`o. There were periods of small inflation and deflation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 August-10 August 2004 Citation IconCite this Report

At Kilauea during August 5-9, no lava entered the sea. Surface lava flows were active on the coastal flat and the Pulama pali fault scarp over 5-6 August. During the report period, seismicity was weak beneath Kilauea's summit and tremor was at moderate-to-high levels at Pu`u `O`o. In addition, there were small periods of inflation and deflation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 July-3 August 2004 Citation IconCite this Report

An episode of deformation consisting of deflation, inflation, then deflation began at Kilauea on the morning of 27 July. It was accompanied by increased surface activity at several places. During inflation, seismicity greatly increased below Kilauea's caldera. Field observers reported that deformation may have occurred at the S flank of Pu`u `O`o. Several surface lava flows were visible on the coastal flat during 28 July to 2 August, and lava continued to flow into the sea. Aside from the deflation-inflation-deflation event, seismicity was weak beneath Kilauea's summit and tremor at Pu`u `O`o was at moderate-to-high levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 July-27 July 2004 Citation IconCite this Report

Several surface lava flows were visible at Kilauea during 22-26 July, and all vents in the crater of Pu`u `O`o were incandescent. Seismicity was weak beneath Kilauea's summit and tremor at Pu`u `O`o was at moderate-to-high levels. During 22-25 July, deflation occurred at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 July-20 July 2004 Citation IconCite this Report

Several surface lava flows were visible at Kilauea during 15-19 July, and all vents in the crater of Pu`u `O`o were incandescent. Seismicity was weak beneath Kilauea's summit and tremor at Pu`u `O`o was at moderate-to-high levels. Small amounts of deflation and inflation were recorded during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 July-13 July 2004 Citation IconCite this Report

Lava continued to flow through lava tubes from the Pu`u `O`o vent 12 km to the sea during 7-13 July. Lava spilled onto the surface from several skylights along the path of the tube system and spread across the slowly growing lava delta along the volcano's south shoreline. Volcanic tremor at Pu`u `O`o was at moderate-to-high levels, but no tremor was recorded at the summit. A relatively large deflation event at Pu`u `O`o on 11 July produced no apparent change in lava discharge.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 June-6 July 2004 Citation IconCite this Report

During 29 June to 6 July, lava continued to flow down the Pulama pali scarp and small amounts flowed into the sea. In addition, vents at Pu`u `O`o cone were incandescent. A few small earthquakes continued beneath Kilauea's summit, but no tremor was recorded. Tremor at Pu`u `O`o was at moderate-to-high levels. A relatively large deflation event occurred on 29 June, with no obvious accompanying changes in eruptive activity.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 June-29 June 2004 Citation IconCite this Report

During 24-28 June, lava continued to flow down the Pulama Pali scarp, Paliuli, and into the sea. In addition, vents at Pu`u `O`o cone were incandescent. A few small earthquakes continued beneath Kilauea's summit, but no tremor was recorded. Tremor at Pu`u `O`o was at moderate-to-high levels. During the report period, small periods of inflation and deflation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 June-22 June 2004 Citation IconCite this Report

During 16-22 July at Kilauea, lava continued to flow into the ocean and vents in the crater of Pu`u `O`o were active. Surface lava flows were visible descending the Pulama pali scarp and Paliuli, a steep slope and cliff below Pulama pali and just above the coastal flat. A few small earthquakes were recorded beneath Kilauea's summit, but no tremor was recorded. Tremor at Pu`u `O`o was at moderate-to-high levels. Episodes of inflation and deflation occurred during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 June-15 June 2004 Citation IconCite this Report

On 13 June, two collapses occurred at Kilauea's western lava delta, sending sizable chunks of the delta into the sea. On 14 June, most lava was being supplied to the ocean through lava tubes, but several surface lava flows were visible on the delta and traveling down the old sea cliff behind the Wilipe`a delta. The larger eastern lava delta had several active lava entries into the ocean, mostly larger than those on the western delta. All vents were active in the crater of Pu`u `O`o. A few small earthquakes were recorded beneath the summit of Kilauea and no tremor was detected. Tremor at Pu`u `O`o was at a moderate-to-high level.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 June-8 June 2004 Citation IconCite this Report

Lava from Kilauea continued to enter the ocean at several points throughout the reporting week, culminating in several new lava deltas. Some small littoral explosions were reported on 6 June, but otherwise the ocean entry was passive. Many small lava flows were observed in the area of the ocean entries, on the coastal flat, in the Paliuli area, and in the Kuhio area. Incandescence and some minor spattering was observed at Pu`u `O`o throughout the week. Seismicity at Pu`u `O`o was moderate to high, but the overall seismicity at Kilauea was low. Several episodes of inflation and deflation were recorded during the week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 May-1 June 2004 Citation IconCite this Report

Kilauea's Banana lava flow reached the sea on 30 May near the eastern end of the Wilipe`a lava delta. This was the first time lava had reached the sea since July 2003. The interaction of the water and lava was not explosive. During 26-31 May, low-frequency earthquakes and no noticeable tremor occurred at Kilauea's summit. Tremor at Pu`u `O`o was at its typical moderate level.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 May-25 May 2004 Citation IconCite this Report

During 19-21 May, the Banana lava flow traveled toward down the Pulama pali toward the sea, reaching within ~200 m of the sea cliff before stopping on the morning of 21 May. Around this time, a few incandescent areas were visible along the flow. During 19-23 May, tremor was at low levels at Kilauea's summit and at moderate levels at Pu`u `O`o. There were small episodes of inflation and deflation at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 May-18 May 2004 Citation IconCite this Report

On 12 May, the Banana lava flow at Kilauea stopped moving toward the sea. There were several incandescent areas along the route of the flow from Paliuli to the top of Pulama pali. During the report period, tremor was at low levels at Kilauea's summit and at moderate levels at Pu`u `O`o. A deflation-inflation-deflation event occurred at Kilauea's summit on 15 May.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 May-11 May 2004 Citation IconCite this Report

During 5-11 May, lava from Kilauea continued to flow down the Pulama Pali and incandescence was observed in the crater of Pu`u `O`o. On 8 May the lava-flow front was ~430 m from the ocean. During the report period, tremor was at low levels at Kilauea's summit and at moderate levels at Pu`u `O`o. Small episodes of inflation and deflation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 April-4 May 2004 Citation IconCite this Report

During 28 April to 4 May, lava from Kilauea continued to flow down the Pulama Pali and incandescence was observed in the crater of Pu`u `O`o. On 2 May, lava from the recently named Banana flow began pouring over Paliuli and advanced onto the coastal flat. By 4 May the lava-flow front was ~1 km from the ocean, the closest proximity to the coast since the fall of 2003. During the report period, tremor was at low levels at Kilauea's summit and at moderate levels at Pu`u `O`o. Small episodes of inflation and deflation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 April-27 April 2004 Citation IconCite this Report

During 22-27 April, lava from Kilauea continued to slowly flow down the Pulama Pali and incandescence was observed in the crater of Pu`u `O`o. During most of the report period, tremor was at low levels at Kilauea's summit. Tremor was at moderate levels at Pu`u `O`o. Small episodes of inflation and deflation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 April-20 April 2004 Citation IconCite this Report

During 14-20 April, lava from Kilauea continued to slowly flow down the Pulama Pali and incandescence was observed in the crater of Pu`u `O`o. Tremor was at low levels at Kilauea's summit and moderate levels at Pu`u `O`o. Small episodes of inflation and deflation occurred during the reporting week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 April-13 April 2004 Citation IconCite this Report

During 7-12 April, incandescence was visible in the crater of Pu`u `O`o cone and to its S. No tremor or low-frequency earthquakes were recorded at Kilauea, and tremor at Pu`u `O`o remained at typical moderate levels. There were small periods of inflation and deflation during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 March-6 April 2004 Citation IconCite this Report

During 31 March to 5 April, surface lava flows were visible at the southern part of Kilauea's rootless-shield complex, which is along the Mother's Day lava tube several hundred meters S of Pu`u `O`o cone. Incandescence was also visible from several vents in the crater of Pu`u `O`o. Seismicity was at low levels at Kilauea's summit, and tremor at Pu`u `O`o remained moderate. During the report period, there were episodes of inflation and deflation at Uwekahuna and Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 March-30 March 2004 Citation IconCite this Report

During 24-30 March, two surface lava flows were active at the southern part of Kilauea's rootless-shield complex: the MLK flow and the Kuhio flow. The summit-deflation event that began on 20 March ended on 23 March, with only minor inflation and deflation events recorded after 23 March. A weak swarm of low-frequency earthquakes and a 2-hour period of moderate-to-strong volcano-tectonic earthquakes were recorded during 24-25 March. Overall, seismicity was at low levels during the reporting period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 March-23 March 2004 Citation IconCite this Report

During 17-23 March, there were surface lava flows at the southern part of Kilauea's rootless-shield complex, which is along the Mother's Day lava tube S of Pu`u `O`o cone. A deflation-inflation-deflation event on 20 March culminated in lava emerging from the S base of Pu`u `O`o cone. No surface lava had been added to the crater floor over the previous couple of weeks. During the report period, very weak background tremor continued at Kilauea's summit along with brief periods of long-period earthquakes. Volcanic tremor at Pu`u `O`o remained at moderate levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 March-16 March 2004 Citation IconCite this Report

During 11-15 March most lava flows at Kilauea were emitted from the lower and upper ends of the rootless shield complex, which is along the Mother's Day lava tube south of Pu`u `O`o cone. On 4 March, a lava flow began to issue from vents at the S base of Pu`u `O`o and traveled ~3 km S. This flow was sporadically active through 15 March. During the report period, very weak background tremor continued at Kilauea's summit along with a few long-period earthquakes. Tremor at Pu`u `O`o remained at moderate levels. Small periods of inflation and deflation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 March-9 March 2004 Citation IconCite this Report

During 5-8 March at Kilauea, incandescence revealed surface lava flows in the Pu`u `O`o crater and at the southern part of the rootless shield complex (an area ~0.5 km SW of Pu`u `O`o). Very weak background tremor continued at Kilauea's summit along with a few long-period earthquakes. Tremor at Pu`u `O`o remained at moderate levels. Small periods of inflation and deflation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 February-2 March 2004 Citation IconCite this Report

During 26 February to 1 March at Kilauea, incandescence revealed surface lava flows in the southern part of the rootless shield complex (an area ~0.5 km SW of Pu`u `O`o) and in Pu`u `O`o's crater. Very weak background tremor continued at Kilauea's summit, and volcanic tremor at Pu`u `O`o was at moderate levels. There were periods of inflation and deflation at Pu`u `O`o and Kilauea's summit.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 February-24 February 2004 Citation IconCite this Report

During 19-23 February, lava mainly erupted from the S side of Kilauea's Pu`u `O`o crater. A large deflation event on 21 February during 0711 to 1413 amounted to 10.9 microradians of deformation. Weak background tremor continued at Kilauea's summit along with a few long-period earthquakes. Tremor at Pu`u `O`o was at moderate levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 February-17 February 2004 Citation IconCite this Report

During 12-17 February, lava flows and incandescence were sometimes visable in Pu`u `O`o's crater, the rootless shield complex (an area ~0.5 km SW of Pu`u `O`o), and the upper area of the Mother's Day lava tube (SW of Pu`u `O`o). Weak background tremor occurred at Kilauea's summit along with a few long-period earthquakes. Tremor at Pu`u `O`o was at moderate-to-low levels. Small deflation and inflation events occurred at the summit and at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 February-10 February 2004 Citation IconCite this Report

During 5-10 February, lava flows and incandescence were sometimes visable in Pu`u` O`o's crater and at the rootless shield complex (an area ~0.5 km SW of Pu`u `O`o). Weak background tremor occurred at Kilauea's summit along with a few long-period earthquakes. Tremor at Pu`u `O`o was at moderate-to-low levels. Small deflation and inflation events occurred at the summit and at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 January-3 February 2004 Citation IconCite this Report

During 29 January to 1 February mild volcanic activity occurred at Kilauea, with incandescence visible at vents in Pu`u `O`o's crater and small surface flows on the central or southern part of the rootless shield complex, an area ~0.5 km SW of Pu`u `O`o. Starting on 18 January, when the MLK vent formed, the distance across the summit caldera decreased significantly, ending a period of increasing extension rate since the Mother's Day event in May 2002. During the report period, weak tremor occurred at Kilauea's summit along with a few long-period earthquakes. Tremor at Pu`u `O`o remained moderate. Small deflation and inflation events occurred at the summit and at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 January-27 January 2004 Citation IconCite this Report

On 22 January lava was emitted from the vent that formed at Kilauea on 19 January (the vent and lava flow S of Pu`u `O`o cone were named MLK in honor of the activity that began on Martin Luther King Jr.'s birthday). There were also surface lava flows at the W side of the Amalgamated Bend shield SW of Pu`u `O`o. By 26 January there were no surface lava flows at the MLK vent, and incandescence was only visible at the S part of the rootless shield complex. On 23 January moderate-to-strong tremor beneath Kilauea's caldera stopped, while it lessened at Pu`u `O`o. On 26 January deflation that began on 18 January ended at Pu`u `O`o after reaching 24.7 microradians. This was probably the largest deflation event since early 1997.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 January-20 January 2004 Citation IconCite this Report

On 18 January during 0550 to 0830 a large period of deflation occurred at Kilauea's Pu`u `O`o cone, amounting in 18.1 microradians of net deflation. During this period a fissure opened at the SE base of Pu`u `O`o, trending approximately radial to the cone. Lava was emitted from the fissure and from three to four vents nearby. The initial flow reached about 1.5 km S of the cone. The S side of Pu`u `O`o was cut by many new fractures. The longest fracture constituted the N boundary of a shallow graben (a linear trough bounded by faults) that was ~75 m long and up to 1 m deep. Surface lava flows were emitted from the E end of the graben, at the base of Pu`u `O`o. The area S of Pu`u `O`o cone appeared to be quite unstable, so HVO scientists warned that no one should venture into the area. Seismicity at Kilauea's summit during 15-20 January was at low levels, while tremor at Pu`u `O`o was continuous and at moderate levels. The tremor picked up during the formation of the graben on 18 January. As of 20 January tilt continued to steadily decline following the 18 January deflation event.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 January-13 January 2004 Citation IconCite this Report

Volcanic activity continued at Kilauea's Pu`u `O`o crater during 8-12 January. Observers confirmed that most of the cones in the crater grew during the previous week and most cones were incandescent. Some days much lava was emitted from the West Gap vent, and the West Gap lava shield (a pile of lava flows built over a lava tube rather than over a conduit feeding magma) continued to expand. At Kilauea's summit few earthquakes and little, if any, volcanic tremor occurred. Volcanic tremor at Pu`u `O`o was continuous and at moderate levels. During the report period, small episodes of inflation and deflation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 December-6 January 2004 Citation IconCite this Report

During 30 December to 5 January, volcanic activity continued at Kilauea's Pu`u `O`o crater, but surface lava flows were not observed on Pulama pali or the coastal flat below Paliuli and no lava entered the ocean. During 30 and 31 December, much lava was emitted from vents on the W side of Pu`u `O`o's crater floor. Nearly the entire W part of the crater floor was covered by new lava flows. Above the Pulama pali fault scarp, SW of Pu`u `O`o, several active shields (a pile of lava flows built over a lava tube rather than over a conduit feeding magma) were seen in the upper rootless shield complex on 31 December and spatter cones were seen at the top of West Gap shield on 5 January. During the report period, few earthquakes occurred at Kilauea's summit and volcanic tremor at Pu`u `O`o continued at moderate levels. In addition, small amounts of inflation and deflation were recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 December-30 December 2003 Citation IconCite this Report

During 24-30 December, no active lava flows were observed on Pulama pali or the coastal flat below Paliuli and no lava entered the ocean. Eruptive activity continued at the Pu`u `O`o vent. Few earthquakes occurred at Kilauea's summit, only steady weak tremor was recorded. Volcanic tremor at Pu`u `O`o continued at moderate levels. Deflation of the volcano during 24-28 December signified relatively rapid extrusion.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 December-23 December 2003 Citation IconCite this Report

During 18-22 December, eruptive activity at the Pu`u `O`o vent of Kilauea continued unabated. Fresh lava from the southwestern vents within Pu`u `O`o coated a quarter of the crater floor. No active flows were observed on Pulama pali or the coastal flat below Paliuli and no lava entered the ocean. As of 18 December surface lava flows at high elevations along the Mother's Day lava-tube system ignited trees. A few small earthquakes were recorded at Kilauea's summit along with steady weak tremor. Volcanic tremor continuously occurred at moderate levels at Pu`u `O`o and small amounts of inflation and deflation were detected during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 December-16 December 2003 Citation IconCite this Report

During 10-16 December, eruptive activity continued at Kilauea's Pu`u `O`o vent. Various vents within Pu`u `O`o were occasionally active and new lava flows covered parts of the crater floor. No surface lava flows were visible on the coastal flat or Pulama pali. During 15-16 December, only steady weak tremor was recorded at Kilauea's summit, tremor at Pu`u `O`o was at moderate levels, and slight deformation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 December-9 December 2003 Citation IconCite this Report

During 3-9 December, incandescence and surface lava flows were observed in the upper flow field at Kilauea. Seismicity was low with weak tremor in the caldera interspersed with rare earthquakes. The swarm of shallow long-period earthquakes reported last week is over. Short periods of inflation and deflation occurred throughout the week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 November-2 December 2003 Citation IconCite this Report

During 30 November to 2 December, incandescence was visible from lava in the upper flow field. Surface lava flows were not seen on the coastal flat or Pulama pali. At Kilauea, relatively strong shallow long-period seismicity at Halemaumau crater on 29 November decreased the following day. On these days a few deeper long-period earthquakes were recorded. On 29 November small amounts of inflation and deflation occurred, followed by very little deformation on 30 November.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 November-25 November 2003 Citation IconCite this Report

Minor surface lava flows were observed upslope of Kilauea's coastal plain the week of 19-25 November. Small amounts of inflation and deflation were recorded through the week with sharp deflation beginning at both Uwekahuna and Pu`u O`o early on the morning of 25 November. Moderate, shallow seismicity was recorded beneath the summit, and moderate-to-high seismicity occurred beneath Pu`u O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 November-18 November 2003 Citation IconCite this Report

During 12-17 November, areas of surface lava were visible upslope of Kilauea's coastal flat. Seismicity at Kilauea's summit continued at moderate levels, with one or two small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger earthquakes at depths of a few kilometers. Also, during the report week small amounts of inflation and deflation occurred, including inflation on 17 November that started when the surface waves from a M 7.5 earthquake at Rat Island in the Aleutians reached Kilauea. The inflation was small, about 0.5 microradians at Pu`u `O`o tilt station and 0.3 microradians at Uwekahuna station.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 November-11 November 2003 Citation IconCite this Report

Tiltmeters located on the NW side of Kileauea's caldera rim (Uwekahuna) and on the NW flank of the active vent along the East rift zone (Pu`u `O`o cone) showed several microradians of radial tilt, but the week's patterns were complex and plagued by instrument problems.

Moderate seismicity at the summit of Kilauea continued. Many small, low frequency earthquakes have taken place at shallow depths beneath the summit caldera. The tiny earthquakes happened at the rate of about 1-2 per minute. As has been typical of the ongoing swarm for the past several weeks, some larger earthquakes also occurred, these coming from depths of a few kilometers. Little or no volcanic tremor accompanied the swarm at the summit. In contrast, as is the norm, volcanic tremor at Pu`u `O`o remained moderate to high.

On 5 November, two small breakouts occurred. The freshly escaping lava was seen on the Kohola arm of the Mother's Day flow just below the top of the steep cliffs called Pulama pali. Observers watching a 30-40 m diameter crater located on the SW side of Pu`u `O`o crater noted a new lava pond, a new lava flow, and a fuming cone-pit. Visits to active flow fields on 7 November resulted in observations of hornitos, a 200-m-wide rootless shield, and the leading edge of 45-m-wide flow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 October-4 November 2003 Citation IconCite this Report

During 29 October to 3 November, areas of surface lava were visible upslope of Kilauea's coastal flat. Seismicity at Kilauea's summit continued at moderate levels, with one to two small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger earthquakes at depths of a few kilometers. Also, during the report week small amounts of inflation and deflation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 October-28 October 2003 Citation IconCite this Report

During 22-28 October, areas of surface lava were visible upslope of Kilauea's coastal flat. Seismicity at Kilauea's summit continued at moderate levels, with one to two small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger earthquakes at depths of a few kilometers. Also, during the report week small amounts of inflation and deflation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 October-21 October 2003 Citation IconCite this Report

During 15-20 October, a few areas of surface lava were visible upslope of Kilauea's coastal flat. Seismicity at Kilauea's summit continued at moderate levels, with one to two small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger earthquakes at depths of a few kilometers. Also, during the report week small amounts of inflation and deflation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 October-14 October 2003 Citation IconCite this Report

During 8-14 October, a few areas of surface lava were visible upslope of Kilauea's coastal flat. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger earthquakes at depths of a few kilometers. Also, there were small inflation and deflation events during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 October-7 October 2003 Citation IconCite this Report

During 1-7 October, surface lava flows were sometimes visible on Kilauea's coastal flat and upslope areas. On 2 October lava began to flow westward after filling West Gap Pit on the W flank of Pu`u `O`o cone. Fairly vigorous spattering was visible in the pit, but died to only sporadic bursts later in the day. The flow appeared to have stopped by 4 October when no glow was observed coming from the pit. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger earthquakes at depths of a few kilometers. Also, there were small inflation and deflation events during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 September-30 September 2003 Citation IconCite this Report

During 24-30 September, surface lava flows were sometimes visible on Kilauea's coastal flat and upslope areas. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger earthquakes at depths of a few kilometers. There was very little deformation during the report week until small events occurred on 27 September.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 September-23 September 2003 Citation IconCite this Report

During 17-23 September, surface lava flows were sometimes visible on Kilauea's coastal flat and upslope areas. Surface lava flows were about 800 m inland of the coast on 21 September. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger earthquakes at depths of a few kilometers. Small inflation and deflation events occurred during the week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 September-16 September 2003 Citation IconCite this Report

During 10-16 September, surface lava flows were sometimes visible on Kilauea's coastal flat and upslope areas. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger earthquakes at depths of a few kilometers. Small inflation and deflation events occurred during the week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 September-9 September 2003 Citation IconCite this Report

During 4-9 September, surface lava flows were sometimes visible on the coastal flat and in areas upslope. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger events at depths of a few kilometers. Small inflation and deflation occurred during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 August-2 September 2003 Citation IconCite this Report

A M 5.0 earthquake occurred 10 km beneath Kilauea's central S flank on 26 August at 2024. It was the largest earthquake since 2 April 2000, an event that occurred in almost exactly the same spot. No significant damage was done, no cracks or rockfalls were seen, and there was no change in the eruption. During 27 August to 1 September, surface lava flows were sometimes visible on the coastal flat and upslope on Pulama pali. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger events at depths of a few kilometers. Small inflation and deflation occurred during the report week.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); Associated Press


20 August-26 August 2003 Citation IconCite this Report

During 20-25 August at Kilauea, surface lava flows were visible on the coastal flat and upslope on the Holei Pali. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger events at depths of a few kilometers. Small inflation and deflation occurred several times during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 August-19 August 2003 Citation IconCite this Report

During 13-18 August at Kilauea, surface lava flows were visible on the coastal flat, in some areas flowing to within 500 m of the sea. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger events at depths of a few kilometers. Small inflation and deflation occurred during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 August-12 August 2003 Citation IconCite this Report

Surface lava flows were visible on Kilauea's coastal flat and at several areas upslope during 6-12 August. Deflation that began on 8 August amounted to about 1.8 microradians at Uwekahuna tiltmeter and 4 microradians at Pu`u `O`o tiltmeter, both located at the volcano's summit. The deflation was accompanied by a drop in the level of lava in a lava tube, as seen by field workers at midday. Then, inflation began later that day at 1928, and in ~3.5 hours there was ~3.5 microradians of inflation at Uwekahuna and ~6 microradians at Pu`u `O`o. A lava breakout occurred on 9 August between 0200 and 0300, about 1.3 km SE of the center of Pu`u `O`o cone. A very large sheet flow emerged from a point on the uptube side of a rootless shield that was formed on 21 January. Observers saw a lava stream, up to 40 m wide. By 0600 the area of the flow was about 5.2 hectacres (0.052 square km). During the report week, seismicity at Kilauea's summit continued at moderate levels, with many small, low-frequency earthquakes continuing at shallow depths beneath the summit caldera every 1-2 minutes. During the deflation on 8 August, there was an increase in such earthquakes and changes in their frequency content. Some larger events occurred at depths of a few kilometers, as had been the case during the previous several weeks

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 July-5 August 2003 Citation IconCite this Report

During 30 July- 5 August at Kilauea, surface lava flows were visible on the coastal flat and upslope on the Pulama pali and beginning around 3 August at the Holei pali. Surface lava flowed to within 1.1 km of the sea. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger events at depths of a few kilometers. Small inflation and deflation occurred during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 July-29 July 2003 Citation IconCite this Report

During 23-28 July at Kilauea, surface lava flows were visible on the coastal flat and upslope on the Pulama pali. No lava flowed into the sea. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger events at depths of a few kilometers. Small inflation and deflation occurred during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 July-22 July 2003 Citation IconCite this Report

During 16-22 July at Kilauea, surface lava flows were visible on the coastal flat and upslope on the Pulama pali and Paliuli. No lava flowed into the sea. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger events at depths of a few kilometers. Small inflation and deflation occurred during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 July-15 July 2003 Citation IconCite this Report

During 12-15 July at Kilauea, surface lava flows were occasionally visible on the coastal flat and upslope on the Pulama pali fault scarp and Paliuli. Seismicity continued at moderate levels at Kilauea's summit, with small low-frequency earthquakes persisting at shallow depths at a rate of about 1-2 per minute. Volcanic tremor at Pu`u `O`o remained at moderate-to-high levels, as is the norm recently. Small periods of inflation and deflation occurred during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 July-8 July 2003 Citation IconCite this Report

During 2-8 July at Kilauea, surface lava flows were occasionally visible on the coastal flat and upslope on the Pulama pali fault scarp. Small amounts of lava continued to flow into the ocean at the Highcastle ocean entry. Seismicity continued at moderate levels at Kilauea's summit, with small low-frequency earthquakes persisting at shallow depths at a rate of about 1-2 per minute. Volcanic tremor at Pu`u `O`o remained at moderate-to-high levels, as is the norm recently. Small periods of inflation and deflation occurred during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 June-1 July 2003 Citation IconCite this Report

During 25-30 June at Kilauea, surface lava flows were occasionally visible on the coastal flat and upslope on the Pulama pali fault scarp, but diminished by 29 June. Seismicity continued at moderate levels at Kilauea's summit, with many small low-frequency earthquakes continuing at shallow depths at a rate of about 1-2 per minute. Volcanic tremor at Pu`u `O`o remained at moderate-to-high levels, as is the norm. Small periods of inflation and deflation occurred during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 June-24 June 2003 Citation IconCite this Report

During 18-24 June at Kilauea, lava continued to weakly enter the sea at the Highcastle entry and surface lava flows were occasionally visible on the coastal flat and upslope on the Pulama pali fault scarp. Seismicity continued at moderate levels at Kilauea's summit, with many, small, low-frequency earthquakes continuing to occur at shallow depths at a rate of about 1-2 per minute. Volcanic tremor at Pu`u `O`o remained at moderate-to-high levels, as is the norm. Small periods of inflation and deflation occurred during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 June-17 June 2003 Citation IconCite this Report

At Kilauea lava continued to enter the sea mainly at the Highcastle ocean entry during 11-17 June and surface lava flows were visible on the coastal flat and Pulama pali. Seismicity at the summit was at moderate-to-high levels, with many small, low-frequency earthquakes occurring at shallow depths beneath the summit caldera for the past two weeks. Little or no volcanic tremor accompanied the swarm, however. Volcanic tremor at Pu`u `O`o remained at moderate-to-high levels, as is the norm. A quasi-cyclic tilt pattern ended at Kilauea's summit and Pu`u `O`o on the 13th after lasting about a week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 June-10 June 2003 Citation IconCite this Report

Small amounts of lava continued to flow into the sea at the Highcastle entry during 4-10 June, and lava flows were sometimes visible on Pulama pali and the coastal flat. Seismicity at the summit of Kilauea continued at moderate-to-high levels, with many small, low-frequency earthquakes occurring at shallow depths beneath the summit caldera for more than a week. The tiny earthquakes occurred at the notably high rate of 2-4 per minute. Little or no volcanic tremor accompanied the swarm, however. Volcanic tremor at Pu`u `O`o remained moderate to high, as is the norm. Almost cyclic inflation and deflation occurred during the report week, but did not culminate in significant overall tilt.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 May-3 June 2003 Citation IconCite this Report

During 27 May to 2 June, lava continued to flow down Kilauea's SE flank, with surface lava flows occasionally visible on the coastal flat and upslope at Pulama pali, and Paliuli. Small amounts of lava continued to flow into the sea at Highcastle beach. A fire started by lava flows the previous week continued to burn W of the flow field. Seismicity at Kilauea's summit was at moderate-to-high levels around 1 June, with many small, low-frequency earthquakes occurring at shallow depths beneath the summit caldera. There were small episodes of inflation and deflation during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 May-27 May 2003 Citation IconCite this Report

During 21-26 May, surface lava flows were visible on Kilauea's coastal flat and the Pulama Pali fault scarp. Small amounts of lava began to flow into the sea on 21 May. Generally, seismicity was at normal levels, with little or no volcanic tremor occurring at Kilauea's summit. A swarm of small, low-frequency earthquakes occurred during 23 May until at least 26 May. The swarm occurred at shallow depths below the caldera floor and was the second such swarm in a 10-day period. No significant deformation occurred during the report period.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 May-20 May 2003 Citation IconCite this Report

During 14-19 May, lava flows continued to travel down Kilauea's S flank. Surface lava flows were visible on the coastal flat and the Pulama Pali fault scarp. Lava trickled into the sea at the West Highcastle entry on the 14th and then ceased thereafter. Generally, seismicity was at normal to below normal levels, with a few earthquakes and no tremor at Kilauea's summit. There were several small periods of inflation and deflation at Kilauea's summit and Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 May-13 May 2003 Citation IconCite this Report

Lava continued to flow down Kilauea's S flank, with small surface flows visible. On 12 May lava began to enter the sea again at the West Highcastle lava delta. Generally, seismicity was at normal to below normal levels, with very few earthquakes. Volcanic tremor at Pu`u `O`o remained at moderate-to-high levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 April-6 May 2003 Citation IconCite this Report

Lava flows continued to descend the S flanks and pour into the sea. Distances measured across Kilauea caldera between two points ~10 km apart, remained stable as they have since early 2003. There had been consistent progressive lengthening of this distance during late 2001 through mid-2002, and some minor fluctuations after that. In general, tilt during late April through 2 May changed little at Uwekahuna station (W side of the caldera), and showed a progressive decline at Pu`u `O`o station (E of the caldera). In the first few days of May slight inflationary tilt appeared at both stations.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 April-29 April 2003 Citation IconCite this Report

For the week ending 29 April eruptive activity continued unabated from the Pu`u `O`o vent of Kilauea. The flows on Pulama pali were frequently visible at night as streams of incandescence from the top of the pali down to the coastal flats. Late in the previous week and early in this week, the east arm of the Mother's Day flow split in two with the western segment being more active. A new ocean entry near Lae`apuki only lasted a day before the flow stagnated. Scattered surface breakouts were seen throughout the inflating Kohola flow, especially on its W side. The National Park Service has marked trails out to the closest activity. As of 24 April, lava entered the ocean at two point along the West Highcastle delta.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 April-22 April 2003 Citation IconCite this Report

During the week ending 22 April, Kilauea continued to erupt, sending lava down its SE flank either traveling over the land surface or through tubes. Lava entered the sea at the West Highcastle entry; activity there was sometimes weak, though one or more glowing areas were typically seen.

On 16 April a large tract of land not over-run by surrounding lava (a kipuka or ahu in the local parlance) remained within the Kohola lava flow, still ~30 cm above the top of inflated lavas that surround it. On the eastern margin of the swath of lava flows going down the steep slopes of Pulama pali, one partly crusted-over lava stream was highly visible. The crater of Pu`u `O`o was dark and obscured by fume. The previous day ended with a small inflation-deflation event recorded at both Kilauea's summit and Pu`u `O`o. These tilt changes began at Uwekahuna.

During 16-17 April, the Uwekahuna tiltmeter at Kilauea's summit recorded three small inflations, the last apparently right at its crest. Pu`u `O`o has generally followed suit, though in this case showing only two of the inflations very well. These tilts are not major but continue to illustrate the clear connection between Kilauea's summit, where most tilt events start, and Pu`u `O`o, 20 km away, where the tilt events follow a few minutes later.

Seismicity during the week was at low to normal levels. Instruments continued to register the summit swarm of long-period earthquakes and tremor, which began last June. Volcanic tremor at Pu`u `O`o remained elevated, as has been the norm for more than a week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 April-15 April 2003 Citation IconCite this Report

Lava continued to enter the ocean at the West Highcastle entry at Kilauea during 10-14 April. Surface lava flows were visible on the Kohala flow and the easternmost stream of the Mother's Day flow. Generally, seismicity remained at normal levels, with a swarm of long-period earthquakes and tremor continuing to occur. Volcanic tremor was recorded at Pu`u `O`o for more than a week and there were small deformation events at Kilauea's summit and at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 April-8 April 2003 Citation IconCite this Report

Lava continued to enter the ocean at the West Highcastle entry at Kilauea during 1-8 April. Surface lava flows were visible on the Kohala lava flow and Pulama pali. During the beginning of the report period, lava traveled over the Chain of Craters Road. The lava cooled and ceased flowing over the road by the 3rd. Generally, seismicity remained at normal to below-normal levels. The summit swarm of long-period earthquakes and tremor, which began last June, was weak, with scattered earthquakes and sparse low-frequency tremor. Volcanic tremor at Pu`u `O`o was relatively high during the last few days of the report period. Small deformation changes occurred mostly at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 March-1 April 2003 Citation IconCite this Report

During 26-30 March at Kilauea, moderate amounts of lava continued to enter the sea at the West Highcastle entry. Surface lava flows were visible along the Kohala lava flow and on Pulama pali. Generally, seismicity was at normal to below-normal levels. The summit swarm of long-period earthquakes and tremor, which began last June, was weak, with scattered earthquakes and sparse low-frequency tremor. Small episodes of inflation and deflation occurred at Kilauea's summit and Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 March-25 March 2003 Citation IconCite this Report

During 20-25 March at Kilauea, lava continued to enter the sea at the West Highcastle entry at moderate levels. Surface lava flows were visible along the Kohala lava flow and on Pulama pali. Generally, seismicity remained at normal levels, with the long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continuing at moderate levels. Small episodes of inflation and deflation occurred at Kilauea's summit and Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 March-18 March 2003 Citation IconCite this Report

During 11-18 March at Kilauea, lava flowed into the sea at moderate levels at the West Highcastle entry. Many surface lava flows were visible along the Kohala lava flow. Tongues of lava were visible traveling down Pulama pali that were a part of the activity that began on 12 May 2002 (named the Mother's Day flow). Generally, seismicity remained at normal levels, with the long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continuing at moderate levels. Only small deformation changes were recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 March-11 March 2003 Citation IconCite this Report

During 4-9 March at Kilauea, lava entered the sea at moderate rates at the West Highcastle entry. Small surface lava flows were scattered across the Kohala lava flow, and surface lava flows were visible above Pulama pali. By 5 March the Kohala lava flow was traveling very slowly towards the sea, to about 30 m away from the sea cliff. Generally, seismicity remained at normal levels, with the long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continuing at low-to-moderate levels. Moderate tremor was recorded by the nearest seismometer to Pu`u `O`o until the seismometer broke on 5 March. Moderate deflation occurred on 8 March first at the Uwekahuna tiltmeter and then at the Pu`u `O`o tiltmeter. According to a news report, a member of a tour group suffered burns on 10 March when he fell on hot lava while hiking near Chain of Craters road.

Sources: Honolulu Advertiser; US Geological Survey Hawaiian Volcano Observatory (HVO)


26 February-4 March 2003 Citation IconCite this Report

During 26 February to 3 March at Kilauea, lava continued to enter the sea at the West Highcastle entry and the lava-flow rate was reduced to a small trickle at the Kohala entry. Small surface lava flows occurred along the W edge of the Kohala lava flow and surface lava flows were visible above the Pulama pali fault scarp. Generally, seismicity remained at normal levels, with the long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continuing at low-to-moderate levels. Moderate tremor was recorded by the nearest seismometer to Pu`u `O`o. Small inflations and deflations occurred at the volcano around 1 March, but no significant deformation was recorded afterwards.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 February-25 February 2003 Citation IconCite this Report

During 20-24 February at Kilauea, a small amount of lava entered the sea at the West Highcastle entry, and W of there lava flowed into the sea at the Kohala entry (an event that began on 15 February). Fresh lava oozed out of the cooling Kohala lava flow, both within the body of the flow and along its E margin. During the report period, lava continued to cross the Chain of Craters Road. Generally, seismicity remained at normal levels, with the long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continuing at low-to-moderate levels. Moderate tremor was recorded by the nearest seismometer to Pu`u `O`o. During 17-21 February, several small periods of inflation and deflation, which were consistent with each other in magnitude and patterns, were recorded at Uwekahuna and Pu`u `O`o tiltmeters.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 February-18 February 2003 Citation IconCite this Report

During 12-19 February at Kilauea, lava continued to flow into the sea at the West Highcastle entry. Lava flowed through lava tubes down Pulama pali and Paliuli as it traveled to the sea. Surface lava flows continued to travel through vegetation, igniting fires and causing methane explosions. Rangers' office huts, restrooms, and signs were moved out of the path of the lava flow, which reached the Chain of Craters Road on 19 February at 1005. Generally, seismicity remained at normal levels, with the long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continuing at low-to-moderate levels. Small periods of inflation and deformation, which were consistent in magnitude and patterns, were recorded at Uwekahuna and Pu`u `O`o tiltmeters during the report period.

Sources: Honolulu Advertiser; US Geological Survey Hawaiian Volcano Observatory (HVO)


5 February-11 February 2003 Citation IconCite this Report

During 5-11 February at Kilauea, lava continued to enter the sea at the West Highcastle entry and surface lava flows traveled down the Pulama pali fault scarp. The Chain of Craters road, which provides access to a lava-viewing area, was closed due to a wildfire that was started by lava flows. Generally, the long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continued at low levels. On 9 and 10 February short, small, periods of deflation and inflation occurred at the Uwekahuna and Pu`u `O`o tiltmeters.

Sources: Associated Press; US Geological Survey Hawaiian Volcano Observatory (HVO)


29 January-4 February 2003 Citation IconCite this Report

During 29 January to 3 February at Kilauea, lava continued to enter the sea at the West Highcastle entry. Around 28 January a large lava breakout occurred from the West Highcastle lava tube about 170 m inland from the old sea cliff. As of 2 February the area of the new breakout was about 6.15 hectares. During the report period, seismicity was at background levels at Kilauea. The long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continued at low-to-moderate levels. No significant deformation was recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 January-28 January 2003 Citation IconCite this Report

During 20-27 January, lava continued to enter the ocean at the West Highcastle entry. Kilauea's summit began to deflate on 20 January at 1710, and Pu`u `O`o began to deflate a few tens of minutes later. Both areas deflated well into the next day. On the 21st at 1610 rapid, brief inflation began at the summit. The inflation and preceding deflation were centered near the NE corner of Halemaumau Crater, the normal center of small deformation events. Seismicity increased with the deformation events, returning to normal levels afterwards. Relatively large surface lava flows were visible starting on 21 January around 2035. By 22 January seismicity had returned to its normal level, with the long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continuing at weak-to-moderate levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 January-21 January 2003 Citation IconCite this Report

During 15-20 January at Kilauea, lava continued to flow into the sea at the West Highcastle entry. Most of the surface lava flows on the coastal flat crusted over, so that less incandescence was visible than the previous week. At Kilauea seismicity generally remained at background levels. The long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continued at moderate levels. Volcanic tremor was relatively strong at Pu`u `O`o during the report week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 January-14 January 2003 Citation IconCite this Report

During 8-13 January at Kilauea, lava continued to flow into the sea at the West Highcastle entry. Surface lava flows were visible on the coastal flat and upslope of it on Paliuli. Generally, seismicity was at background levels at Kilauea. The long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continued at low-to-moderate levels. No significant deformation was recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 December-6 January 2003 Citation IconCite this Report

During 31 December to 5 January, lava continued to enter the sea at several entry points along three deltas, though by the end of the report week only two were active. Surface lava flows were visible on the coastal flat and upslope on Pulama pali. Generally, seismicity continued at background levels at Kilauea. The long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continued at low levels. No significant deformation was recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 December-30 December 2002 Citation IconCite this Report

During 26-29 December at Kilauea, lava continued to enter the sea at several points along the coast at three lava deltas. Surface lava flows were visible on the coastal flat, and upslope at Paliuli, and on the Pulama pali. On 28 December moderate collapses occurred at the Wilipe`a lava delta, apparently in the area of the 15 December collapse. None came anywhere close to the rope barrier, and no explosion debris reached this area. Generally, seismicity continued at background levels at Kilauea. The long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continued at moderate levels. During 27-28 December, slight deflation occurred at the Uwekahuna and Pu`u `O`o tiltmeters.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 December-24 December 2002 Citation IconCite this Report

During 18-22 December, lava continued to enter the sea at several points along the coast at three lava deltas. Surface lava flows were visible along the E arm that feeds a new lava delta, and sporadically along Paliuli. Generally, seismicity was at normal levels. The swarm of long-period earthquakes and tremor beneath Kilauea's caldera, occasionally seismically active since June, continued at a relatively low level. No significant deformation was recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 December-17 December 2002 Citation IconCite this Report

During 10-17 December, lava continued to enter the sea at several points along the coast. On 15 December, shortly after 0700, the Wilipe'a lava delta partially collapsed, losing about 1/3 of its area. The tip of the delta retreated shoreward about 260 m and most of the collapse was in the central part of the delta. Around the 15th and 16th a substantial collapse occurred at the West Highcastle delta. Generally, seismicity was at normal levels. The swarm of long-period earthquakes and tremor beneath Kilauea's caldera, occasionally seismically active since June, continued at a relatively low level. The Pu`u `O`o tiltmeter showed deflation for about one week until the 17th. No other significant deformation was recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 December-10 December 2002 Citation IconCite this Report

During 4-10 December, lava continued to flow into the sea at entry points from two lava deltas. Moderate-to-large littoral explosions tossed spatter onto the front of the West Highcastle delta. Surface lava flows were visible on the coastal flat. Generally, seismicity was at normal levels. The swarm of long-period earthquakes and tremor beneath Kilauea's caldera, occasionally seismically active since June, continued to show some short bursts of tremor interspersed with small earthquakes. Small inflation and deflation events occurred at Pu`u` O`o and Uwekahuna tilt meters.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 November-3 December 2002 Citation IconCite this Report

During 26 November-2 December at Kilauea, lava continued to flow into the ocean at low-to-moderate levels at the West Highcastle and Wilipe`a entries. West Highcastle was the more active of the two lava deltas, with sporadic explosions coming from one of its entry points. Several surface lava flows were visible on the coastal flat. Generally, seismicity was at normal levels. A swarm of long-period earthquakes and tremor beneath Kilauea's caldera, occasionally active since June, continued to show short bursts of tremor interspersed with numerous small earthquakes. During the report week, small inflation and deflation events occurred at Pu`u `O`o and Uwekahuna tilt meters.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 November-26 November 2002 Citation IconCite this Report

During 21-24 November at Kilauea, lava continued to enter the sea at several points along two lava deltas (West Highcastle and Wilipe`a), although to a lesser extent than the previous week. Small-to-moderate littoral explosions were common at the entry point near the tip of the West Highcastle delta. Surface flows were visible extending from Paliuli to the coast. Generally, seismicity was at normal levels. Swarms of long-period earthquakes and tremor have been detected since June beneath Kilauea's caldera. During the report week, numerous short bursts of tremor were interspersed with numerous small earthquakes. Besides gentle deflation at Pu`u `O`o, no other significant deformation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 November-19 November 2002 Citation IconCite this Report

During 13-18 November at Kilauea two lava deltas were active, with lava entering the ocean at times. Only a small amount of incandescence was visible above Paliuli. Generally, seismicity was at normal levels. The swarm of long-period earthquakes and tremor beneath Kilauea's caldera, occasionally active since June, continued to show short bursts of tremor interspersed with numerous small earthquakes. Besides gentle deflation at Pu`u `O`o, no other significant deformation occurred.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 November-12 November 2002 Citation IconCite this Report

During 6-11 November at Kilauea, lava continued to flow into the sea at moderate rates from two lava deltas, as it has for several weeks. Spots of incandescence were visible on Paliuli, on the gentle slope below Pulama pali, and above Pulama pali. Surface lava flows were visible on the coastal flat at times. Generally, seismicity was at normal levels. The swarm of long-period earthquakes and tremor beneath Kilauea's caldera, occasionally active since June, was rather weak. Short bursts of tremor were interspersed with small earthquakes. Small deflation may have occurred at the Uwekahuna and Pu`u `O`o tiltmeters on the 10th, otherwise no significant deformation was recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 October-5 November 2002 Citation IconCite this Report

During 30 October to 4 November at Kilauea lava continued to enter the sea from two deltas, as it has for several weeks. Surface lava flows were visible extending from the top of Paliuli to the top of Pulama pali, but were not seen on the coastal flat. Generally, seismicity was at normal levels beneath Kilauea's caldera. Some small bursts of tremor occurred that were interspersed with tiny earthquakes. Inflation and deflation were recorded at times at Uwekahuna and Pu`u `O`o tiltmeters.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 October-29 October 2002 Citation IconCite this Report

During 23-29 October at Kilauea, lava continued to enter the sea from two deltas as it has for several weeks. Surface lava flows were not visible on the coastal flat or Paliuli, and were occasionally seen near Pulama pali. Generally, seismicity was at normal levels beneath Kilauea's caldera. A swarm of long-period earthquakes and tremor beneath the caldera occasionally occurred. A small deflation event began on the 28th that was recorded at Uwekahuna and Pu`u `O`o tiltmeters.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 October-22 October 2002 Citation IconCite this Report

During 16-21 October at Kilauea, lava continued to flow into the sea at points along two active lava deltas. Surface lava flows were visible on the coastal flat, Pulama pali, and Paliuli. Generally, seismicity was at normal levels beneath Kilauea's caldera. A swarm of long-period earthquakes and tremor beneath the caldera occasionally occurred. In addition, numerous small bursts of tremor were interspersed with tiny earthquakes. Periods of deflation and inflation occurred at Pu`u `O`o and Uwekahuna.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 October-15 October 2002 Citation IconCite this Report

During 9-14 October at Kilauea, lava continued to flow into the sea at points along two active lava deltas. Surface lava flows were visible on the coastal flat, and sporadically on Pulama pali and Paliuli. Generally, seismicity was at normal levels at Kilauea. A few small swarms of long-period earthquakes and tremor occurred beneath the volcano's caldera. Regular deflation occurred at the Pu`u `O`o tiltmeter, while no significant deformation was recorded elsewhere.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 October-8 October 2002 Citation IconCite this Report

During 1-6 October at Kilauea, lava entered the sea at several points along two active lava deltas (Middle Highcastle and Wilipe`a). No surface flows were visible on the deltas; lava either entered the water via lava tubes or inflated the delta underneath the surface. Several surface flows were visible on the coastal flat, while no incandescence was seen on Paliuli and only a few glowing spots were visible on Pulama pali. On the 3rd, the swarm of long-period earthquakes and tremor beneath Kilauea's caldera that was first active beginning in June, picked up strongly, with numerous long-period events persisting for about a day. Elsewhere there was no unusual seismicity. Around the time of increased seismicity, small periods of inflation and deflation occurred at Pu`u `O`o and Uwekahuna. Otherwise, tiltmeters recorded no unusual deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 September-1 October 2002 Citation IconCite this Report

During 25-30 September at Kilauea, lava continued to travel SE down Paliuli and Pulama pali, and surface lava flows were visible on the coastal flat. Lava entered the sea at multiple points along the fronts of two lava deltas and visitors saw several sudden collapses of the front of the bench (land built out from the sea cliff). Generally, seismicity was at normal levels. The swarm of long-period earthquakes and tremor beneath Kilauea's caldera that originally began in June was fairly weak. Periods of small deflation and inflation occurred at Uwekahuna and Pu`u `O`o tiltmeters, but no significant deformation was recorded elsewhere.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 September-24 September 2002 Citation IconCite this Report

During 17-22 September, at Kilauea lava continued to travel SE down Paliuli and Pulama pali, and surface lava flows were visible on the coastal flat. Lava also continued to flow into the sea. Generally, seismicity was at normal levels. For several days before the 18th, there was a period of repetitive inflation and deflation. After the 18th no significant deformation was recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 September-17 September 2002 Citation IconCite this Report

During 11-16 September, lava continued to travel SE down Paliuli and Pulama pali, and many surface lava flows were visible on the coastal flat. Lava flowed onto the Wilipe`a bench directly seaward of the end of the Chain of Craters Road. Lava entered the sea at several points on the NE portion of the front of the bench. Generally, seismicity was at normal levels. There were short periods of inflation and deflation at Uwekahuna and Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 September-10 September 2002 Citation IconCite this Report

During 3-9 September, lava continued to flow SE down Paliuli and Pulama pali, and many surface lava flows were visible on the coastal flat. Lava began to enter the ocean on 3 September. Seismicity was generally at normal levels. The swarm of long-period earthquakes and tremor that had been occurring since early June returned to moderate-to-low levels. There were small episodes of inflation and deflation at Uwekahuna and Pu`u `O`o for several days.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 August-3 September 2002 Citation IconCite this Report

During 27 August to 2 September, lava flowed down Paliuli and Pulama pali, and many surface lava flows were visible on the coastal flat. Seismicity was generally at normal levels, with the swarm of long-period earthquakes and tremor that has been occurring since early June fluctuating. There were small episodes of inflation and deflation at Uwekahuna and Pu`u `O`o for several days. By 2 September Pu`u `O`o was slowly deflating.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 August-27 August 2002 Citation IconCite this Report

During 21-26 August, surface lava flows continued to travel on Kilauea's coastal flat, and down Paliuli, and Pulama pali. On the 21st lava entered the sea near the Highcastle stairs (the more easterly ocean entry), but by the 25th no lava was entering the sea. Generally, seismicity was at normal levels with the swarm of long-period earthquakes and tremor fluctuating but typically remaining at high levels. Deformation was nearly flat, or continued long-term trends.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 August-20 August 2002 Citation IconCite this Report

During 14-19 August, lava flows from Kilauea sporadically entered the sea, traveling to the coast through lava tubes and also on the land surface. On the morning of the 18th several people saw part of a lava bench collapse into the sea. For most of the report period seismicity was at normal levels, with a decrease in the amount of long-period earthquakes and tremor that had been occurring since early June. On the morning of the 18th the amount of long-period seismicity increased. No significant deformation was recorded at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 August-13 August 2002 Citation IconCite this Report

During 7-13 August, surface lava flows continued to travel down Kilauea's flank into the sea at the Wilipe`a entry and on 7 August at 1427 the W Highcastle lobe reached the sea. On the evening of the 7th several littoral explosions occurred on the E side of the most seaward tip of the lava bench, spraying spatter and solid rocks back onto the bench. No visitors were in the prohibited area. A lava bench began to grow near the W Highcastle flow 10 m from the shoreline and was 30 m long parallel to the sea cliff by 11 August. Surface lava flows also cascaded down Paliuli at times. Generally, seismicity was at normal levels, except for the continued swarm of long-period earthquakes and tremor that has been taking place since early June. There were no signs of significant deformation at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 July-6 August 2002 Citation IconCite this Report

By 6 August, only the the Wilipe`a entry was active at Kilauea, with five or six spigots sending lava off the leading edge of the bench into the water. The West Highcastle bench was steaming but had no lava. At the Highcastle kipuka, two actively advancing lobes of lava were found, one 160 m and the other 170 m from the western and eastern remnants, respectively, of the Chain of Craters Road, themselves only 40-60 m from water. Each lobe was moving very slowly.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 July-30 July 2002 Citation IconCite this Report

Hundreds of spectators flocked to Kilauea to see the spectacular show of lava flowing into the sea at the end of easily accessible Chain of Craters Road. Surface lava flows were visible traveling down Pulama pali, Paliuli, and on the coastal flat. Generally, seismicity was at normal levels, except for the continued swarm of long-period earthquakes and tremor that has been ongoing since early June. The swarm increased slightly in the last several days of the report period. Brief inflation occurred at Pu`u` O`o on 26 July.

Sources: Associated Press; US Geological Survey Hawaiian Volcano Observatory (HVO)


17 July-23 July 2002 Citation IconCite this Report

During 16-22 July, surface lava flows were visible traveling on the coastal flat, down the Pulama pali scarp, and down Paliuli, the steep slope and cliff below Pulama pali and just above the coastal flat. On 20 July at 1900 part of the westernmost lava flow reached Chain of Craters road, and by 0445 the next day it was entering the sea in two areas. The active flow front moved relatively quickly for lava at Kilauea on nearly flat ground; the lava flow moved 610 m in 18 hours (35 m/h). Generally, seismicity was at normal levels, except for the continued swarm of long-period earthquakes and tremor that has been ongoing since early June. The swarm increased slightly in the last several days of the report period. Slow deflation occurred at Pu`u` O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 July-16 July 2002 Citation IconCite this Report

During 10-15 July, surface lava flows were visible travelling down the Pulama pali scarp and Paliuli, the steep slope and cliff below Pulama pali and just above the coastal flat. Generally, seismicity was at normal levels, except for the continued swarm of long-period earthquakes and tremor that has been taking place since early June. The only significant deformation was recorded on the 9th when deflation began at Pu`u `O`o. It ended by the 13th.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 July-9 July 2002 Citation IconCite this Report

During 3-9 July, surface lava flows were sometimes visible on Kilauea. Seismicity was at normal levels, except for the continued swarm of long-period earthquakes and tremor that has been occurring since early June. Slow deflation was recorded at Pu`u `O`o from 4 July until 6 July when inflation began. Slow inflation continued until at least 9 July.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 June-2 July 2002 Citation IconCite this Report

During 25-30 June, surface lava flows were visible on Kilauea's SW flank. Mild deflation, totaling 0.9 microradians, occurred at Pu`u `O`o on 26 June around 2130. No other significant deformation was recorded during the report period. Seismicity was at normal levels, except for the continued swarm of long-period earthquakes and tremor that has been occurring below Kilauea's caldera since early June.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 June-25 June 2002 Citation IconCite this Report

Incandescent surface lava flows were sometimes visible at Kilauea during 19-24 June. Generally, seismicity was at background levels, except at Kilauea's crater where a swarm of long-period earthquakes that began on 5 June continued. In addition, moderate tremor occurred at Pu`u `O`o. Tiltmeters showed no unusual deformation, with overall deflation occurring at Pu`u `O`o and Kilauea's summit during the week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 June-18 June 2002 Citation IconCite this Report

During 12-17 June, several surface lava flows were visible at Kilauea. Generally, seismicity was at background levels, except at the crater where a swarm of long-period earthquakes occurred since 5 June. Moderate tremor occurred at Pu`u `O`o. After about 2 microradians of deflation at Pu`u `O`o during 11-12 June, no significant deformation was recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 June-11 June 2002 Citation IconCite this Report

Surface lava flows were visible above, traveling down, and below the Pulama pali scarp. One flow was 1.7 km from the end of the Chain of Craters Road and 1.5 km from the nearest point along the coastline. Swarms of long-period earthquakes occurred in Kilauea's caldera during 5-10 June and moderate tremor occurred at Pu`u `O`o. Slow, uneven deflation started at Pu`u `O`o on 2 June, then inflation began during the evening of 5 June. The fires ignited by a lava flow that began on 12 May had been 65% contained by 10 June and Chain of Craters road was open to the public during the evening.

Sources: US Hawaii Volcanoes National Park; US Geological Survey Hawaiian Volcano Observatory (HVO)


29 May-4 June 2002 Citation IconCite this Report

Three main surface lava flows were visible at Kilauea during 29 May-2 June. The front of one flow was ~1.8 km from the coast. As of 2 June fires continued to burn that were ignited by a lava flow that began on 12 May. On 29 May the front of the fire was 800 m from Chain of Craters road, which was closed on 1 June after 1,530 acres burned overnight. By 1 June at 0700, when the fire was 15 days old, a total of 2,588 acres had burned downwind of the lava flow. Generally, seismicity across the volcano was at background levels. Volcanic tremor at Kilauea's summit was low, broken occasionally by short-lived long-period earthquakes. Pu`u `O`o had weak-to-moderate tremor. There were no signs of significant deformation at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 May-28 May 2002 Citation IconCite this Report

During 23-24 May, surface lava flows were visible on Kilauea's coastal flat. For several preceding days an intense swarm of small, shallow, long-period earthquakes occurred beneath Kilauea's caldera, at a rate of about one earthquake every 30 seconds. The swarm abruptly ended on 22 May. By the 24th seismicity at Kilauea was at normal background levels. In addition, tiltmeters recorded no unusual deformation, with Pu`u `O`o slowly inflating.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 May-21 May 2002 Citation IconCite this Report

Surface lava flows were visible at Kilauea during 15-17 May. The front of one flow was about 2.5 km from the ocean. Following the 12 May inflation event, the level of volcanic tremor and long-period earthquakes at Kilauea's summit was moderate, as was the level of tremor at Pu`u `O`o. No significant deformation was recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 May-14 May 2002 Citation IconCite this Report

An extremely large deflation episode began at Kilauea's Pu`u `O`o cone on 12 May at about 0720. By 1500 Pu`u `O`o had deflated about 16.5 microradians. Following the onset of deflation at Pu`u `O`o, there was slight deflation at Kilauea's caldera. No new eruptive activity was visible in Pu`u `O`o 's crater. Within a couple of hundred meters of the SW base of Pu`u `O`o, two large ~3-m-wide lava flows were visible that apparently broke out of the upper lava-tube system. By 13 May Pu`u `O`o had deflated 18 microradians, tremor at Pu`u `O`o was higher than preceding the deflation and was accompanied by small earthquakes, background tremor and long-period earthquakes increased at the summit, and no significant deformation was recorded at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 May-7 May 2002 Citation IconCite this Report

During 1-7 May at Kilauea, activity occurred at the rootless shields and surface lava flows were visible low on the Pulama pali scarp. None of the pits and craters at the foot of Pu`u `O`o were active, although incandescence was visible in some areas. By 7 May lava had poured over the Pulama pali scarp and flowed slowly eastward along the base of the pali. Generally, tremor at Pu`u `O`o was low and steady. Low-level tremor occurred at the caldera as well as a number of small earthquakes. There were no signs of significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 April-30 April 2002 Citation IconCite this Report

On 23 April inflation occurred at Pu`u `O`o , with no change in seismicity at Kilauea. Observations on the 24th revealed that the January 2002 cone continued to emit lava onto the Pu`u `O`o crater floor. During 24-29 April, no surface lava was visible on Pulama pali. Fairly rapid deflation occurred on the 28th. During the report period, tremor at Pu`u `O`o was at low levels, and only a few small earthquakes and low-level tremor occurred at Kilauea's caldera.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 April-23 April 2002 Citation IconCite this Report

During 18-22 April, surface activity was visible at a minimum of two vent areas of Pu`u` O`o's crater and at the rootless shields. No surface lava flows were visible on Pulama pali. Generally, tremor at Pu`u` O`o was low and only a few small earthquakes and low-level tremor occurred at Kilauea's caldera. During the report period, slow, small deflations occurred at Pu`u` O`o and the caldera.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 April-16 April 2002 Citation IconCite this Report

During 10-15 April, observers saw small surface lava flows descending along the path of the lava-tube system that drains the rootless shield area. These flows were sometimes visible above and on the Pulama pali scarp. Activity occurred at the rootless shields, and lava was visible in parts of Pu`u `O`o crater. Generally, seismicity and tilt were at normal levels. Tremor at Pu`u `O`o was low-to-moderate and low-level tremor and a few small earthquakes occurred at Kilauea's caldera. Pu`u `O`o slowly inflated following relatively slow deflation during 13-14 April; otherwise, there were no signs of significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 April-9 April 2002 Citation IconCite this Report

During 4-6 April, a remarkable series of deflation and inflation events occurred at Kilauea. Beginning on 4 April around 2100, Kilauea's summit deflated and 30 minutes later Pu`u `O`o followed. The summit deflated ~1.7 microradians and Pu`u` O`o dropped ~9 microradians. On 5 April rapid inflation began at 1600 at the summit and 12-13 minutes later at Pu`u` O`o. Inflation ended at the summit at 1700, when the summit abruptly deflated, and at Pu`u` O`o at 1800. Then, tilt at Pu`u` O`o oscillated three times between rapid deflation and slower inflation. After the tilt temporarily settled down, on 6 April at 0508 another oscillatory period commenced. Following 4.5 oscillations, tilt resumed slow, bumpy inflation after 1200 that same day.

During the period of deflation and inflation, long-period earthquakes increased at the summit, while tremor remained steady at Pu`u` O`o until it slightly increased on 6 April. Small surface lava flows were seen on the lower portion of Pulama pali and the upper part of the lava fan. During a brief trip to Pu`u` O`o on the morning of the 6th, scientists saw that the crater lake had risen ~8 m since 29 March (the lake surface was 17 m below the E rim), several cones were active, and lava was flowing into the lava lake from two vents. By the 7th activity had calmed down; tilt was relatively steady, volcanic tremor at Pu`u` O`o was at moderate levels, and tremor at the summit was at low-to-moderate levels. On the 8th there was activity at the rootless shields. Incandescence was not visible at Pu`u` O`o, which possibly means that lava lake activity was waning or had ended.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 March-2 April 2002 Citation IconCite this Report

During 27 March-2 April at Kilauea, activity continued at the rootless shields and surface lava flows were visible low on the Pulama pali scarp. On 27 March, just after 0300, a small earthquake beneath the caldera triggered more than 30 minutes of increased tremor and small earthquakes. Sharp deflation at Pu`u `O`o on 28 March accompanied a change in eruptive activity at the cone. Observations from a helicopter overflight revealed that new lava was visible just W of the main crater, as well as fountaining, and a circulating pond. By 31 March a lava flow was visible on the floor of Pu`u `O`o's crater and several vents were incandescent. On the 31st volcanic tremor was at low-to-moderate levels at Pu`u `O`o and weak tremor continued below Kilauea's caldera that was occasionally broken by small, long-period earthquakes. Tilt across the volcano was flat or only changed slightly.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 March-26 March 2002 Citation IconCite this Report

During 20-25 March, the rootless shields remained active at Kilauea and small surface lava flows were visible at the base of the lava fan and on the adjacent coastal flat. Generally, volcanic tremor remained at moderate levels at Pu`u `O`o, and long-period earthquakes and weak tremor continued below Kilauea's caldera. During 21-24 March a small amount of inflation was recorded at Pu`u `O`o, but during most of the report period no deformation was recorded at the volcano.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 March-19 March 2002 Citation IconCite this Report

During 12-19 March, bright glow was visible over Kilauea emanating from Pu`u `O`o crater and the rootless shield near 665-m elevation. The glow was widely visible in the Puna district. The most intense surface activity at the volcano occurred at the rootless shield. At Pu`u `O`o crater, HVO staff saw several incandescent vents mostly in the crater's S wall. By 18 March a lava flow had flooded the floor of Pu`u `O`o crater. During the week, lava flowed through lava tubes down the Pulama pali scarp, surfacing on the coastal flat below. Surface lava flows, which have been active for more than a month, spread on the lower fan and adjacent coastal flat. The fronts of the lava flows were ~2.3 km away from the coast. Generally, volcanic tremor remained at moderate levels at Pu`u `O`o. Long-period earthquakes and weak tremor continued below Kilauea's caldera. Tiltmeters across the volcano showed no evidence of significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 March-12 March 2002 Citation IconCite this Report

During 6-12 March, lava was visible near the base of the lava fan and on the nearby coastal flat at Kilauea. At times several rootless shields (a pile of lava flows built over a lava tube rather than over a conduit feeding magma) were active. Generally, volcanic tremor was at moderate levels at Pu`u `O`o and long-period earthquakes and weak tremor continued at Kilauea's caldera. Tiltmeters across the volcano showed no evidence of significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 February-5 March 2002 Citation IconCite this Report

Lava flowed down Pulama pali, and slowly advanced across the lava fan and adjacent coastal flat. Generally, volcanic tremor remained moderate at Pu`u `O`o, and long-period earthquakes and weak tremor continued at Kilauea's caldera. Tiltmeters across the volcano showed no evidence of significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 February-26 February 2002 Citation IconCite this Report

Surface lava flows were visible atop the Pulama pali scarp and at its base. Activity occurred at rootless shields (a pile of lava flows built over a lava tube rather than over a conduit feeding magma) located between 680- and 640-m elevations. Generally, volcanic tremor remained at moderate levels at Pu`u `O`o, and long-period earthquakes and weak tremor continued below Kilauea's caldera. Tiltmeters across the volcano showed no evidence of significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 February-19 February 2002 Citation IconCite this Report

During 13-19 February, a small surface lava flow was visible at Kilauea on the Pulama pali scarp. No lava has reached the coastal plain or the ocean since the Kamoamoa and E Kupapa`u entries stopped in late January. Generally, volcanic tremor remained at moderate levels at Pu`u `O`o and long-period earthquakes and weak tremor continued below Kilauea's caldera. Tiltmeters across the volcano showed no evidence of significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 February-12 February 2002 Citation IconCite this Report

Surface lava flows along the Kamoamoa lava tube system were visible extending from atop the Pulama pali scarp, down to its base. Generally, volcanic tremor remained at moderate levels at Pu`u `O`o and long-period earthquakes continued below Kilauea's caldera. Tiltmeters across the volcano showed no evidence of significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 January-5 February 2002 Citation IconCite this Report

On 3 and 4 February lava flows were visible atop Pulama pali, along the Kamoamoa flow. Generally, volcanic tremor remained at moderate levels at Pu`u `O`o and long-period earthquakes below Kilauea's caldera continued, though at greatly reduced amplitudes compared to the previous week. Tiltmeters across the volcano showed no evidence of significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 January-29 January 2002 Citation IconCite this Report

During 23-29 January lava entered the sea at the W portion of the Kamoamoa entry, and to a lesser extent at the E Kupapa`u entry. Surface lava flows emerging along the Kamoamoa lava tube system traveled down the Pulama pali scarp. On 22 January a lava flow was visible on Pu`u `O`o's crater floor. Generally, volcanic tremor remained moderate at Pu`u `O`o. The swarm of long-period earthquakes at Kilauea's summit were less regular than they had been for more than a month. Tiltmeters across the volcano showed no evidence of significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 January-22 January 2002 Citation IconCite this Report

Lava entered the ocean at multiple locations along the Kamoamoa entry, while the amount of lava entering the ocean at the E Kupapa`u entry was small. Surface lava flows were visible on both the upper portion of the flow field above the Pulama pali scarp and spreading out on the coastal flat. On 18 January at 0118 a 9.1-km-deep M-4.1 earthquake occurred about 4 km SSE of Pu`u `O`o. Generally, volcanic tremor remained moderate-to-strong at Pu`u `O`o for several days and the ongoing swarm of small long-period earthquakes continued at Kilauea's summit. Tiltmeters across the volcano showed no evidence of significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 January-15 January 2002 Citation IconCite this Report

Lava entered the ocean at multiple locations along the Kamoamoa ocean entry, while the amount of lava entering the ocean at the E Kupapa`u entry was very small. A broad, 1.5- to 2-km-long surface flow was visible on the upper portion of the flow field above the Pulama pali scarp and surface flows that emanated from the Kamoamoa lava tube system were seen on the coastal flat. Generally, volcanic tremor was moderate-to-strong at Pu`u `O`o for several days and the ongoing swarm of small long-period earthquakes continued at Kilauea's summit. Following minor deflation on 11 January, tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 January-8 January 2002 Citation IconCite this Report

During the week lava continued to flow into the ocean at the Kamoamoa ocean entry. Surface lava was visible on the coastal flat and lava that began to flow on the W side of Kamoamoa caused the lava bench to grow. Slow deflation at the summit (up to 2.3 microradians) occurred on 1 December during noon to around 2300. The next day during 1210-1950 the summit inflated 1.6 microradians. The deformation was not accompanied by a change in seismicity. Generally, volcanic tremor was moderate at Pu`u `O`o and the ongoing swarm of small long-period earthquakes continued at Kilauea's summit. After the period of deflation and inflation no significant deformation was recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 December-1 January 2002 Citation IconCite this Report

Lava continued to flow into the ocean at the Kamoamoa ocean entry. Surface lava flowed along the Kamoamoa lava tube system, extending from above the Pulama pali scarp down to the lava fan. Generally, volcanic tremor was moderate at Pu`u `O`o and there were many small long-period earthquakes at Kilauea's summit, as there have been for 2 weeks. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 December-25 December 2001 Citation IconCite this Report

Lava entered the ocean at two areas along the Kamoamoa entry and surface lava flows were visible along the track of the Kamoamoa lava tube. Generally, volcanic tremor was moderate at Pu`u `O`o and there were many small long-period earthquakes at Kilauea's summit. Brief, barely discernable deflation at the volcano's summit on 25 December was the only deformation recorded.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 December-18 December 2001 Citation IconCite this Report

Lava continued to enter the ocean at the Kamoamoa and E Kupapa`u entries and surface lava flows were observed on the coastal flat. Generally, seismicity was at normal levels; volcanic tremor at Pu`u `O`o was low-to-moderate and small long-period earthquakes were recorded at Kilauea's summit. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 December-11 December 2001 Citation IconCite this Report

Lava continued flowing into the ocean at the Kamoamoa and E Kupapa`u ocean entries, and surface lava flows were visible at spots along the Kamoamoa lava tube system. Volcanic tremor was at low-to-moderate levels at Pu`u `O`o and low at Kilauea's summit, with weak long-period earthquakes occurring frequently. On 8 December rapid deflation (~2.4 microradians) occurred at Kilauea's summit, followed shortly thereafter by deflation (~1.9 microradians) at Pu`u `O`o cone. On 9 December abrupt inflation at Kilauea's summit (>6 microradians) was followed by much slower and lesser inflation at Pu`u `O`o. Strong earthquakes and tremor accompanied the inflation. A shallow M 3.4 earthquake was registered in the SE part of the caldera. By 10 December, seismicity had returned to normal levels at the summit, and tremor at Pu`u `O`o remained at a moderate level.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 November-4 December 2001 Citation IconCite this Report

Volcanic activity at Kilauea remained similar to the previous week, with lava flowing into the ocean at the Kamoamoa and E Kupapa`u ocean entries and surface lava flows at spots along the Kamoamoa lava tube system. Generally, seismicity was normal at the volcano; volcanic tremor was at low-to-moderate levels at Pu`u `O`o and low at Kilauea's summit. Tiltmeters along the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 November-27 November 2001 Citation IconCite this Report

Lava continued to flow into the ocean at the Kamoamoa and E Kupapa`u entries. HVO personnel confirmed that the Kupapa`u entry was inactive, as was reported the previous week. Surface lava flows were visible near the E Kupapa`u entry and at spots above, on, and below the Pulama pali scarp along the Kamoamoa lava tube system. Generally, volcanic tremor remained at low-to-moderate levels at Kilauea's summit and Pu`u `O`o. The level of tremor was relatively low at the summit, but the number of small earthquakes remained well above average. Tremor at Pu`u `O`o varied in amplitude. Tiltmeters along the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 November-20 November 2001 Citation IconCite this Report

Lava continued to flow into the sea at the E Kupapa`u and Kamoamoa lava entries. The Kupapa`u entry appeared to be inactive by 18 November. Lava was mostly confined to the lava tube systems, with patches of incandescent lava visible above Pulama pali. Generally, volcanic tremor remained at low-to-moderate levels at Kilauea's summit and Pu`u `O`o. Tremor at the summit was relatively low. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 November-13 November 2001 Citation IconCite this Report

Lava continued to flow into the sea at the Kamoamoa, Kupapa`u, and E Kupapa`u entries. Surface lava flows were visible along the Kamoamoa lava tube system and just inland from the Kupapa`u entry. Generally, volcanic tremor remained at low-to-moderate levels at Kilauea's summit and Pu`u `O`o. Tremor was relatively low at the summit, but a fairly large number of tiny earthquakes occurred. Bursts of higher-amplitude tremor were interspersed with more continuous tremor at Pu`u `O`o. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 October-6 November 2001 Citation IconCite this Report

During 30 October to 5 November lava continued to flow into the sea at the Kamoamoa and E Kupapa`u entries. On 30 October a new entry located directly off the former Kupapa`u Point was observed. Surface lava flowed above and down Pulama pali along the trace of the Kamoamoa lava tube system. There were possible surface flows at the western portion of the Kamoamoa entry, while surface activity ended at the eastern portion. Generally, volcanic tremor remained at low-to-moderate levels at Kilauea's summit and Pu`u `O`o. Tremor was relatively low at the summit; tiny earthquakes occurred that were strongest during the beginning of the week. Bursts of higher amplitude tremor were interspersed with more continuous tremor at Pu`u `O`o. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 October-30 October 2001 Citation IconCite this Report

Surface lava flows were visible above and on Kilauea's Pulama pali scarp and on the coastal flat. Lava continued to flow through lava tubes, entering the sea at the E Kupapa`u and Kamoamoa entries. By 28 October the rapidly growing lava bench at Kamoamoa was 120 m seaward of the old sea cliff in comparison to 80-100 m the previous week. Generally, volcanic tremor remained at low-to-moderate levels at both Kilauea's summit and Pu`u `O`o. On 24 October short bursts of relatively high amplitude tremor returned to Pu`u `O`o after being nearly absent for 2-3 days. During 23-24 October tiltmeters at the summit and Pu`u `O`o recorded slow deflation. No significant deformation was recorded during the rest of the week.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 October-23 October 2001 Citation IconCite this Report

During the week, surface lava flows were visible on Kilauea's Pulama pali scarp and lava continued to enter the ocean at the E Kupapa`u and Kamoamoa entries. On 21 October the lava bench at the Kamoamoa entry extended approximately 80-100 m seaward from the old sea cliff. Generally, volcanic tremor remained at low-to-moderate levels at Kilauea's summit and Pu`u `O`o. Tremor at the summit was relatively low. Tremor at Pu`u `O`o became rather continuous by 21 October and was no longer broken by brief episodes of stronger events. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 October-16 October 2001 Citation IconCite this Report

Lava continued to enter the ocean at the E Kupapa`u and Kamoamoa entries. Surface lava flows occurred along the course of the lava tube systems. Generally, volcanic tremor remained at low-to-moderate levels at Kilauea's summit and Pu`u `O`o. Background tremor at Pu`u `O`o was interrupted, at intervals of ten's of minutes to an hour or two, by short-lived bursts of relatively vigorous tremor. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 October-9 October 2001 Citation IconCite this Report

During the week, lava continued to flow into the ocean at the E Kupapa`u ocean entry and at the new Kamoamoa entry and surface lava flows were visible above and on the Pulama pali. The overall size of the E Kupapa`u entry diminished, while activity was divided into two distinct areas at the Kamoamoa entry; one to the E and one to the W. By 8 October lava was only emitted from the W Kamoamoa entry area. Generally, volcanic tremor remained at moderate-to-low levels at Kilauea's summit and Pu`u `O`o. Background tremor at Pu`u `O`o was interrupted at intervals of ten's of minutes to an hour or two, by short-lived bursts of relatively vigorous tremor. Besides small deflation at Kilauea's summit on 28 September, tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


26 September-2 October 2001 Citation IconCite this Report

Lava flows from the W of the active flow field began to enter the ocean at a new area during the evening of 28-29 September. The ocean entry was located S of the former site of Komoamoa camping area. By 30 September a new lava bench and an adjacent black sand beach had begun to form. Lava continued to flow into the ocean at the E Kupapa`u entry, although the overall size of the entry had diminished. Surface lava flows were visible above and on the Pulama pali scarp. The lava flows W and E of the flow field that had been active for the past couple of weeks had mostly crusted over. Generally, volcanic tremor remained at moderate-to-low levels at Kilauea's summit and Pu`u `O`o. Background tremor at Pu`u `O`o was interrupted at intervals of ten's of minutes to an hour or two, by short-lived bursts of relatively vigorous tremor. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


19 September-25 September 2001 Citation IconCite this Report

Lava continued to enter the ocean at the E Kupapa`u ocean entry. Lava flowed down the Pulama pali scarp W and E of the active flow field. The western flow was mainly `a`a. The more vigorous eastern flow had been active for more than two weeks. Surface lava flowed within about 0.6 km of the coastline about 1.8 km W of the E Kupapa`u ocean entry. Generally, volcanic tremor remained at moderate-to-low levels at Kilauea's summit and Pu`u `O`o. Background tremor at Pu`u `O`o was interrupted at intervals of ten's of minutes to an hour or two, by short-lived bursts of relatively vigorous tremor. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


12 September-18 September 2001 Citation IconCite this Report

Lava continued to flow down the Paluma pali scarp, across the coastal flat, and into the ocean at the E Kupapa`u ocean entry. Generally, volcanic tremor remained at low-to-moderate levels at Kilauea's summit and Pu`u `O`o. During 12 and 13 September very slight deflation occurred at Kiliauea's summit. During the rest of the week tiltmeters across the volcano showed no significant deformation. On 17 September at Pu`u `O`o, background tremor was interrupted at intervals of ten's of minutes to an hour or two, by short-lived bursts of relatively vigorous tremor.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


5 September-11 September 2001 Citation IconCite this Report

Lava continued to flow down the Paluma pali scarp, across the coastal flat, and into the ocean at the E Kupapa`u ocean entry. The lava flow that began to cover a County lava-viewing road on 1 September ceased flowing by 5 September. Generally, volcanic tremor remained at low levels at Kilauea's summit and Pu`u `O`o. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 August-4 September 2001 Citation IconCite this Report

Lava continued to enter the sea at the E Kupapa`u entry. Surface lava flows were visible on Pulama pali and the coastal flat. By 1 September a surface lava flow that broke out of the ocean-entry tube on the coastal plain during mid-August flowed across a County lava-viewing road. The unpaved section of Highway 130 had been open for less than 2 weeks before the narrow lava flow crossed it. Generally, volcanic tremor remained at low-to-moderate levels at Kilauea's summit and Pu`u `O`o. Tiltmeters across the volcano showed no significant deformation.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); The Honolulu Advertiser


22 August-28 August 2001 Citation IconCite this Report

Lava continued to flow down the Pulama pali, and into the ocean at the E Kupapa`u entry. On 25 August a small amount of sharp, short-lived inflation occurred at Pu`u `O`o cone and an hour later at Kilauea's summit. No change in volcanic or seismic activity accompanied the inflation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 August-21 August 2001 Citation IconCite this Report

Lava continued to enter the sea at the E Kupapa`u entry. Surface lava flows were visible on the coastal plain in both the E and W branches of the current flow field. A short, stubby surface flow was visible halfway down the Pulama pali scarp. On 15 August volcanic tremor abruptly increased at Kilauea's summit and at Pu`u `O`o, but it reached only moderate-to-low levels. Generally, weak, rather steady tremor and a few small earthquakes continued beneath Kilauea's caldera. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


8 August-14 August 2001 Citation IconCite this Report

Small amounts of lava continued to enter the ocean at the E Kupapa`u entry. Surface lava flows were observed issuing from the eastern tube of the current flow field. One of the lobes of lava reached ~1.1 km short of the coast. Generally, weak, rather steady tremor and a few small earthquakes continued beneath Kilauea's caldera. Near Pu`u `O`o, continuous tremor occurred at weak-to-moderate levels. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 August-7 August 2001 Citation IconCite this Report

Moderate amounts of lava continued to flow into the sea at the E Kupapa`u entry. Surface lava flows were occasionally visible to the E and W of the current lava flow field. Pahoehoe lava was visible slowly spreading on the coastal flat seaward of the base of the Pulama pali scarp. Generally, weak, rather steady tremor and a few small earthquakes continued beneath Kilauea's caldera. Near Pu`u `O`o, continuous tremor occurred at weak-to-moderate levels. Elsewhere, seismicity was at normal levels. Tiltmeters across the volcano showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 July-31 July 2001 Citation IconCite this Report

During the week small-to-moderate levels of lava entered the ocean at the E Kupapa`u entry. During 26-28 July a stream of `a`a lava continuously advanced down the Pulama pali scarp to the coastal flat on the E side of the current lava flow field. Generally, weak, rather steady tremor and a few related long-period earthquakes continued beneath Kilauea's caldera. Near Pu`u `O`o the tremor also became weak and continuous. Elsewhere, seismicity was at normal levels. Tiltmeters across the volcano indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 July-24 July 2001 Citation IconCite this Report

During the week lava entered the sea at a moderate rate at the E Kupapa`u entry. On 18 July at 1803 a M 3.5 earthquake rattled though the lower east rift zone of Kilauea. Surface flows were vigorous in two areas of the current lava flow field; one in the E branch of the flow field at the base of the Pulama pali scarp, and the other just SE of the shatter ring in the W branch of the flow field. Generally, weak, steady tremor and a few related long-period earthquakes continued beneath Kilauea's caldera. Near Pu`u `O`o, the tremor alternated from weak, to moderate, to strong over periods of several hours. Elsewhere, seismicity was at normal levels. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 July-17 July 2001 Citation IconCite this Report

At Kilauea small surface lava flows traveled along the E and W branches of the lava flow field active during the last 6 months and moderate amounts of lava entered the sea at the E Kupapa`u entry. Generally, weak, steady tremor and related long-period earthquakes continued beneath Kilauea's caldera. Near Pu`u `O`o, the tremor alternated from weak, to moderate, to strong over periods of several hours. Elsewhere, seismicity was at normal levels. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 July-10 July 2001 Citation IconCite this Report

Small surface flows of pahoehoe lava were located in the W and E branches of the lava flow field. Like the previous week, lava poured into the sea at the E Kupapa`u ocean entry. Generally, weak, steady tremor and related long-period earthquakes continued beneath Kilauea's caldera. Tremor remained weak to moderate near Pu`u `O`o and seismicity was at normal levels elsewhere. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 June-3 July 2001 Citation IconCite this Report

Small surface flows of pahoehoe lava were visible on the coastal flat below Pulama pali, clustered near the E edge of the flow field and to the W. Lava poured into the sea at two main sites along the eastern third of the E Kupapa`u bench. On 26 June from about noon until the evening, less than 1 microradian of deflation occurred at the summit, and about 0.5 microradian of deflation occurred at Pu`u `O`o. Generally, weak, steady tremor and related long-period earthquakes continued beneath Kilauea's caldera. Earthquake activity remained slightly above average at the summit. Tremor remained weak to moderate near Pu`u `O`o and seismicity was at normal levels elsewhere. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 June-26 June 2001 Citation IconCite this Report

Weak glow was visible in the area where lava entered the sea at the E Kupapa`u entry. Small lava flows were active on the coastal flat at the base of the Pulama pali scarp. Generally, weak, steady tremor and related long-period earthquakes continued beneath Kilauea's caldera. Tremor remained weak to moderate near Pu`u `O`o and seismicity was at normal levels elsewhere. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 June-19 June 2001 Citation IconCite this Report

Small surface pahoehoe lava flows were visible on the W end of the flow field. Lava entered the sea at the E Kupapa`u ocean entry. Generally, weak, steady tremor and related long-period earthquakes continued beneath Kilauea's caldera. On 18 June for several hours there was a slight increase in long-period earthquakes near the caldera. Tremor remained weak to moderate near Pu`u `O`o and seismicity was at normal levels elsewhere. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 June-12 June 2001 Citation IconCite this Report

A small number of surface lava flows was visible along the W and E lava tube systems. Generally, weak tremor and related long-period earthquakes continued at a relatively steady rate beneath Kilauea's caldera. Tremor remained weak to moderate near Pu`u `O`o. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


30 May-5 June 2001 Citation IconCite this Report

During the beginning of the week lava flowed down Pulama pali and entered the ocean at two areas. By 3 June there were few surface flows with most of the lava traveling in lava tubes and entering the ocean sporadically. On 3 June a pause in volcanic activity may have begun at about 0900 with slow deflation (~2.6 microradians) occurring at the tiltmeter closest to HVO. The inflation ended around 2400 and on 4 June at 0125 rapid inflation (~2.7 microradians) began, most occurred in about 55 minutes. On 3 June at 1015 slow deflation (0.9 microradians) began at Pu`u `O`o and ended at about 2200. Slow inflation occurred at least until 4 June. Background volcanic tremor at Kilauea's summit gradually increased on 3 June starting at mid-morning, after the deflation had begun. There was no significant change in the tremor at Pu`u `O`o.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


23 May-29 May 2001 Citation IconCite this Report

The tilt event that began on 20 May ended the following day and HVO reported that the precursory deflation, remarkably rapid inflation of 10-11 microradians in one hour, and then the slow relaxation of the summit presumably recorded a pulse of magma supplied to the summit reservoir complex. The pulse was then transferred to the Pu`u `O`o area where it is currently stored. Lava continued to flow into the ocean at the SE corner of the lava flow field. On 23 May surface lava flows were visible. On 26 May tremor occurred at low-to-moderate levels beneath Pu`u `O`o, earthquake swarms occurred beneath Kilauea caldera, and background tremor was low. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


16 May-22 May 2001 Citation IconCite this Report

Lava continued to flow down Pulama pali and was observed entering the sea at the SE corner of the lava flow field. On 20 May the largest tilt event to occur at Kilauea in more than 4 years took place. Beginning at 0500 the volcano's summit began to slowly deflate (~2 microradians) until about 1630 when it very abruptly began to inflate (~10 microradians). The inflation peaked at 1735, and deflation began at 1750. The event was accompanied by strong tremor, which ended a prolonged period of small earthquakes that had lasted, with a 9-hour break on the night of 18 May, for several days. At about 1920 a lava pond was observed forming in Pu`u `O`o crater. Observations the next day revealed that the pond had drained, leaving only a few spattering vents.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


9 May-15 May 2001 Citation IconCite this Report

Surface lava flows were visible traveling down Pulama Pali. Three ocean-entry benches were seen along the SE corner of the active lava flow field. The active lava flow was 300-500 m from the nearest house in the Royal Gardens subdivision, but the homes may be protected from the lava by a barrier of `a`a deposited in 1983. Volcanic tremor was higher than normal during 12 and 13 May and small earthquakes were recorded in the caldera. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


2 May-8 May 2001 Citation IconCite this Report

Small streams of lava traveled down the Pulama Pali fault scarp. On 6 May lava was visible entering the sea at three locations and producing small steam plumes. The swarm of long-period earthquakes that occurred beneath the caldera the previous week came to an end. Generally, earthquake activity and volcanic tremor near Pu`u `O`o and in Kilauea's caldera were at low levels. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


25 April-1 May 2001 Citation IconCite this Report

Lava continued to flow down the Pulama pali and across the coastal flat. On 25 April a small stream of lava reached the sea for the first time since late January. The lava stopped trickling into the sea on 29 April. On that day an unstable block of the lava bench fell into the sea, producing a loud noise and generating an explosion that tossed rocks onto dry land. A M 4.4 earthquake on the afternoon of 25 April was followed by a few small aftershocks during the rest of the week. A swarm of long-period earthquakes that began on 18 April continued through at least 27 April. The tilt at the summit was neither flat nor consistently in one direction or the other. Tiltmeters along the east rift zone indicated that there was no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


18 April-24 April 2001 Citation IconCite this Report

Surface lava flows were visible above the Pulama Pali and traveling down it without reaching the coast. The lava flows were predominately pahoehoe with minor `a`a. Generally, volcanic tremor near Pu`u `O`o cone and in Kilauea's caldera was at low levels, although a swarm of long-period earthquakes occurred beneath the caldera from 18 to at least 24 April. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


11 April-17 April 2001 Citation IconCite this Report

After phases of deflation, inflation, and increased seismicity last week, volcanic activity at Kilauea returned to normal levels. Lava flowed down the Pulama pali and several surface flows were visible on the coastal flat. By 15 April surface lava flows seemed to diminish. Generally, volcanic tremor near Pu`u `O`o cone and in Kilauea's caldera was at a low levels. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


4 April-10 April 2001 Citation IconCite this Report

Moderate eruptive activity was visible during most of the week, but during 7-9 April Kilauea also went through phases of deflation, inflation, and increased seismicity. On 7 April, lava flowed down the Pulama Pali in two surface streams. At 0300 on 7 April summit tiltmeters began to show deflation, and starting at ~0620 volcanic tremor and long-period earthquakes increased. The phase ended in the early afternoon with a total of 3 microradians of deflation. By 8 April there was no glow from surface flows on or above Pulama Pali, which indicated that an apparent pause in the eruption occurred the previous day. At ~0200 on 8 April the summit began to inflate and about an hour later the amplitude of tremor and the rate of long-period earthquakes began to decline for about 2 hours. The inflation ended at about 1000, regaining up to 2.5 microradians at the summit. By 9 April surface lava flows traveled down Pulama Pali, seismic activity returned to normal levels, and all tiltmeters showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 March-3 April 2001 Citation IconCite this Report

The HVO reported on 2 April that surface lava flows confined to a single flow in the E branch of the flow field continued to travel down the Pulama Pali. In addition, lava flows were still visible on the coastal plain and were 400-450 m from the coast. Overall, volcanic tremor near Pu`u `O`o cone was at low-to-moderate levels and at Kilauea's caldera tremor was low. Tiltmeters in the summit area and along the east rift zone showed no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 March-27 March 2001 Citation IconCite this Report

Lava continued to flow down the Pulama Pali and across the coastal flat, but has not yet entered the ocean. During the past few weeks, the flows have covered about 230 m of the private access road to Royal Gardens and are now farther east than any active flows since 1992. Activity is robust on the coastal flat near the truncated road that formerly accessed Royal Gardens but that has long since been cut off by lava. Flows in the area were observed in the last few days to be feeding dozens of breakouts and to be rapidly inflating. Ground observers can often hear methane explosions from burning vegetation along the base of Pulama pali. This activity is part of the "east flow," but lava in the old "west flow" reappeared on the morning of 28 March. Overall, volcanic tremor near Pu`u `O`o was low-to-moderate and tremor at Kilauea's caldera was low. For approximately the previous 2 weeks, small low-frequency earthquakes occurred below the caldera. Tiltmeters in the summit area and along the east rift zone are showing no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 March-20 March 2001 Citation IconCite this Report

Lava continued to flow down the Pulama Pali and across the coastal flat as it has for the past 2.5 months. By the end of the week the front of the lava flow was within 300 m of the coast. During the previous couple of weeks, the lava flows had traveled farther E than any active flows since 1992. Overall, volcanic tremor near Pu`u `O`o was low-to-moderate and tremor at Kilauea's caldera was low. For approximately the previous 2 weeks, small low-frequency earthquakes occurred below the caldera. Tiltmeters in the summit area and along the E rift zone showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 March-13 March 2001 Citation IconCite this Report

Lava slowly flowed SE down the Pulama pali and across the coastal plain in a broad flow front, ~1.5 km wide. Much of the flow front was within 1-1.3 km of the coastline, with the closest point ~700 m from the coast. Overall, volcanic tremor near Pu`u `O`o was low-to-moderate and tremor at Kilauea's caldera was low. Tiltmeters in the summit area and along the E rift zone showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


28 February-6 March 2001 Citation IconCite this Report

Lava continued to flow down Pulama pali without reaching the sea. Overall, volcanic tremor near Pu`u `O`o was low-to-moderate and tremor at Kilauea's caldera was low. Tiltmeters in the summit area and along the E rift zone showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


21 February-27 February 2001 Citation IconCite this Report

Lava continued to flow SE down the Pulama pali and across the coastal plain to within 1 km of the coast. At 1317 on 20 February a M 3.7 earthquake occurred that was centered about 5 km SE of Halemaumau Crater at a very shallow depth. Brief summit deflation occurred on 24 February, but ended the next day with no corresponding period of inflation following it. NE of Kilauea at Mauna Kea volcano, a swarm of earthquakes occurred during 22-24 February on Mauna Kea's NE flank. The earthquakes were all approximately M 3 and occurred at 2-12 km depth. Swarms occasionally occur in this area of Mauna Kea.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


14 February-20 February 2001 Citation IconCite this Report

Lava flows continued to travel down the Pulama pali and across the coastal flat without entering the sea. During 17 and 19 February a weak swarm of shallow earthquakes occurred within the caldera. The HVO reported that the swarm was not unusual and appeared to be dying off by the end of the report period. Overall, volcanic tremor near Pu`u `O`o was at low-to-moderate levels. Tiltmeters in the summit area and along the E rift zone showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


7 February-13 February 2001 Citation IconCite this Report

Surface flows continued to travel down the Pulama pali, with no lava entering the sea. A tiltmeter near the HVO showed a small (about 0.4 microradian) deflation shortly before 1230 on 10 February. After 10 February, tiltmeters in the summit area and along the E rift zone showed flat signals. Volcanic tremor near Pu`u `O`o and in Kilauea's caldera was at low-to-moderate levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 January-6 February 2001 Citation IconCite this Report

The HVO reported that lava had not entered the sea since 29 January. Surface lava flow activity occurred primarily on the E branch of the flow on the Pulama pali, with some breakouts occurring along the trace of the W branch of the flow. Overall, volcanic tremor near Pu`u `O`o and in Kilauea's caldera was at low-to-moderate levels. Tiltmeters in the summit area and along the E rift zone showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 January-30 January 2001 Citation IconCite this Report

Surface lava flow activity on Pulama pali gradually declined during 27 and 28 January, with only two flows near the E and W sides of the flow field. By 29 January, the area where lava entered the ocean was relatively large and a small bench (land built out from the sea cliff) was being constructed. Overall, volcanic tremor near Pu`u `O`o and in Kilauea's caldera was at low-to-moderate levels. Tiltmeters in the summit area and along the east rift zone showed no deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 January-23 January 2001 Citation IconCite this Report

According to HVO, a broad lava flow traveled down Pulama pali as a continuation of the series of lava lobes that developed and descended the pali for the previous 2-3 weeks. In addition, a surface breakout E of the main flow traveled down the forested slope. Small volumes of lava began to enter the sea on 21 January, while most of the lava flowed at the surface and stopped short of the coastline. Overall, volcanic tremor near Pu`u `O`o and in Kilauea's caldera was at low-to-moderate levels. Tiltmeters in the summit area and along the east rift zone showed no deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 January-16 January 2001 Citation IconCite this Report

According to HVO, surface flows on Pulama pali diminished after 9 January. Activity continued on the morning of 10 January from both the W and E tongues. Each was incandescent near the top, and on the lower fourth, of the pali. The much larger W tongue was burning trees along its upper E edge. By the early morning of 11 January, the only incandescence was in the W tongue. Fires continued along the E side of the upper W tongue. The crater of Pu`u `O`o was dimly glowing both mornings. By the morning of 16 January, one flow extended more than halfway down the pali, with patchy incandescence near the base. Glow above the pali and E of the flow on the pali moved eastward overnight; this glow has been there for about a week and indicates uncrusted surface lava or a fire. Lava continued to pond, thicken, and gradually spread seaward on the coastal flat below the pali. Only the faintest of glows came from the July 2000 pit on 16 January. Volcanic tremor at Pu`u `O`o and in Kilauea's caldera continued through this period at a low to moderate level, but bursts of strong tremor lasted about 30 minutes on the morning of the 11th and less than an hour on the 15th.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


3 January-9 January 2001 Citation IconCite this Report

According to HVO, lava flows continued to travel down the Pulama Pali and across the coastal flat. The flows progressed no farther than ~2 km inland from the sea as they had for the previous two weeks. By the end of the report week, surface lava flows were sparse, and only incandescent patches remained on the Pali and coastal flats. During 6 to 8 January, Kilauea's summit and Pu`u `O`o went through periods of deflation and inflation that were accompanied by increased volcanic tremor. Refer to the US Geological Survey Hawaiian Volcano Observatory update for details about the event. By 8 January the tilt at the summit and Pu`u `O`o, and the seismicity appeared to have returned to background levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


27 December-2 January 2001 Citation IconCite this Report

Surface lava flows continued to travel down Pulama Pali and across the coastal flat to within about 2 km inland from the sea. Overall, seismic tremor was weak-to-moderate near Pu`u `O`o and was weak beneath Kilauea caldera. The tiltmeters at Kilauea's summit and along the east rift zone showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


20 December-26 December 2000 Citation IconCite this Report

During the week surface lava flows continued to flow down Pulama pali, with the lava flow front more than 2 km inland from the sea. Overall, seismic tremor was weak to moderate near Pu`u `O`o and was weak beneath Kilauea caldera. The tiltmeters at Kilauea's summit and along the east rift zone showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


13 December-19 December 2000 Citation IconCite this Report

Lava flowed into the sea at the Kamokuna entry until 17 December. From the 17th until the 19th of December (the end of the report period) no lava was observed flowing into the sea. During the week several `a`a flows were visible traveling down Pulama pali. Overall, earthquake activity was low across the island. Volcanic tremor was at normal levels near Pu`u `O`o and beneath Kilauea caldera. A tiltmeter near HVO showed slight deflation the morning of 19 December, while all other tiltmeters on Kilauea showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


6 December-12 December 2000 Citation IconCite this Report

A small flow of lava entered the sea at the Kamokuna entry and no surface activity was observed on Pulama pali (a fault scarp) or the coastal flat. Overall, earthquake activity was low across the island. Tremor and a few shallow earthquakes continued to be detected at Kilauea's summit; the tremor local to the summit that was particularly noticeable last week decreased in intensity on ~8 December. The tilt-meters at Kilauea's summit and along the east rift zone showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


29 November-5 December 2000 Citation IconCite this Report

Lava continued to flow into the ocean at the Kamokuna entry. Overall, earthquake activity was low across the island. Tremor and a few shallow earthquakes continued to be detected at Kilauea's summit; the tremor local to the summit was particularly noticeable. The tilt-meters at Kilauea's summit and along the east rift zone showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


22 November-28 November 2000 Citation IconCite this Report

Lava continued to flow through the tube system, entering the sea at the Kamokuna entry. Overall, earthquake activity was low across the island. Volcanic tremor near Pu`u `O`o vent remained at a moderate level, while tremor and a few shallow earthquakes were detected at Kilauea's summit. The tilt-meters at Kilauea's summit and along the east rift zone showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


15 November-21 November 2000 Citation IconCite this Report

Lava continued to flow across the coastal flat and into the sea near the Kamokuna entry. Surface flows were visible sporadically during the week. At 1408 on 16 November tour pilots observed a large collapse of the bench (land built out from the sea cliff) at Kamokuna that sent ~30 % of the bench into the sea in ~6 seconds. The large explosion that followed the collapse produced a large amount of spatter and a big, billowing, mostly white plume that rose to 600-1,800 m a.s.l. None of the spatter was directed inland. Overall, volcanic tremor at Pu`u `O`o vent remained at a moderate level. Earthquake activity related to volcanism was low across the island, but for several hours on the night of 15 November a giant earthquake (M 8) in New Ireland, Paupau New Guinea caused slow, peak-to-peak oscillations at Kilauea's summit seismometer and set off alarms at two tiltmeters. Otherwise, the tiltmeters at Kilauea's summit crater and along the east rift zone showed flat signals.

Sources: US Geological Survey Earthquake Hazards Program; US Geological Survey Hawaiian Volcano Observatory (HVO)


8 November-14 November 2000 Citation IconCite this Report

Lava continued to flow across the coastal flat and into the sea at the Kamokuna entry. Overall, volcanic tremor near Pu`u `O`o vent remained at a moderate level and earthquake activity was low across the island. The tilt-meters at Kilauea's summit and along the east rift zone showed flat signals.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


1 November-7 November 2000 Citation IconCite this Report

The HVO reported that lava continued to enter the ocean at the Kamokuna entry as it has since late September 2000. Surface lava flows were visible sporadically through the week. Overall, volcanic tremor near Pu`u `O`o vent was moderate and earthquake activity was low across the island. Tilt measured at Kilauea's summit was rather flat, as it was elsewhere along the E rift zone, continuing the long-term slow deflation underway since the eruption began in 1983.

On 5 November the bodies of two hikers who died on 3 November were found on Kilauea. According to an Associated Press article, a National Park Service Ranger stated that the hikers suffered severe burns, cuts, and abrasions. Authorities believed the hikers may have bypassed warning signs and hiked beyond the recommended area. The cause of their deaths was not known as of 7 November, but it was thought that they may have been struck by lightning or scalded by lava-heated sea water while they were on the active bench (land built out from the sea cliff). Refer to the Hawaiian Volcano Observatory website for more details.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO); Associated Press


Bulletin Reports - Index

Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

08/1968 (CSLP 28-68) Eruption from Hiiaka Crater produces lava fountains

09/1968 (CSLP 28-68) Details of Upper East Rift Zone eruption during August 1968

10/1968 (CSLP 48-68) Lava fountaining from fissure eruption floods Napau Crater

11/1968 (CSLP 48-68) Minor fountaining resumes east of Napau Crater

02/1969 (CSLP 16-69) Fissure eruption begins on 22 February on the upper east rift

03/1969 (CSLP 16-69) Fountaining resumed on 25 February; lava cascades into Alae Crater

05/1969 (CSLP 16-69) Eruption sends lava flows into Aloi and Alae craters

06/1969 (CSLP 16-69) Lava fountaining in mid-June

07/1969 (CSLP 16-69) Eruption on 15 July

08/1969 (CSLP 16-69) Alae Crater fills, then drains; lava fountaining

09/1969 (CSLP 16-69) Strong eruption from vent between Aloi and Alae craters

10/1969 (CSLP 16-69) Lava fountains low but continuous

11/1969 (CSLP 16-69) Summary of east rift zone activity since August 1968

02/1970 (CSLP 14-70) Summit deflation followed by moderate lava emission

04/1970 (CSLP 14-70) Lava fills Aloi Crater and overflows S toward the coast

12/1970 (CSLP 14-70) Summary of activity since May 1969 that has formed broad shield named Mauna Ulu

04/1971 (CSLP 14-70) Divers observe underwater lava flow

08/1971 (CSLP 81-71) Summit eruption from four fissures with lava fountaining

10/1971 (CSLP 81-71) Summary of 25-29 September eruption

02/1972 (CSLP 09-72) Mauna Ulu erupts in early February; new lava lake and fountains

05/1973 (CSLP 59-73) Eruption on 5 May opens 600-foot-long fissure; high lava fountains

11/1973 (CSLP 59-73) Mauna Ulu crater overflows; fountaining from fissures around Pauahi Crater

01/1975 (CSLP 04-75) Lava fountains from a fissure eruption send flows 12 km

11/1975 (SEAN 01:02) Lava fountains following a severe earthquake

01/1976 (NSEB 01:04) Slow inflation and two earthquakes

11/1976 (NSEB 01:14) Summit deflation

04/1977 (NSEB 02:04) Monitoring data from 8-9 February magma intrusion event

09/1977 (NSEB 02:09) Fissure eruption begins on the East Rift near Kalalua Crater

10/1977 (NSEB 02:10) Eruption near the Kalalua cone ends on 1 October

11/1979 (SEAN 04:11) Brief eruption from upper east rift zone

03/1980 (SEAN 05:03) Two intrusions into the upper east rift

08/1980 (SEAN 05:08) Intrusion into the upper east rift zone

10/1980 (SEAN 05:10) Two intrusions into the upper east rift

05/1981 (SEAN 06:05) Intrusion into the southwest rift

06/1981 (SEAN 06:06) Small shallow intrusion under SE part of caldera

07/1981 (SEAN 06:07) Intrusion under S summit area and SW rift zone

08/1981 (SEAN 06:08) More information on SW Rift intrusion

03/1982 (SEAN 07:03) Small intrusions into E and SW rifts

04/1982 (SEAN 07:04) Small fissure eruption in summit caldera

06/1982 (SEAN 07:06) Intrusion into the SW rift

09/1982 (SEAN 07:09) Fissure eruption in summit caldera

11/1982 (SEAN 07:11) Intrusion into upper E rift

01/1983 (SEAN 08:01) Major eruption in middle E Rift Zone

02/1983 (SEAN 08:02) Renewed fountaining and lava flow production on E Rift

03/1983 (SEAN 08:03) Eruption continues in middle east rift zone

04/1983 (SEAN 08:04) Lava effusion stops; low level harmonic tremor, local incandescence, and extension continue

05/1983 (SEAN 08:05) Incandescent vents, harmonic tremor, and dilation across fissure system continue, then lava extrusion resumes

06/1983 (SEAN 08:06) Lava flows and spatter cones produced by two new phases of E rift zone eruption

07/1983 (SEAN 08:07) Lava flows move ENE along east rift for 4 days

08/1983 (SEAN 08:08) 7th, 8th, and 9th major episodes produce lava flows extending NE and S from spatter cone

09/1983 (SEAN 08:09) 8th-10th major phases of E Rift Zone eruption

10/1983 (SEAN 08:10) 10th and 11th major phases of E Rift Zone eruption

11/1983 (SEAN 08:11) 11th and 12 major phases of East Rift Zone eruption

12/1983 (SEAN 08:12) Episode 12 described; tremor and inflation continue; new ground cracks

01/1984 (SEAN 09:01) 13th-15th major episodes of East Rift Zone eruption include lava fountains to 300 m and temperatures to 1,147°C

02/1984 (SEAN 09:02) 15th and 16th major episodes; lava fountains to 320 m; large tephra fall

03/1984 (SEAN 09:03) Episodes 16 and 17 include strong fountaining, tephra, and the longest flow of the 1983-84 eruption

04/1984 (SEAN 09:04) 18th episode; four lava flows, longest flow of 1983-84 eruption

05/1984 (SEAN 09:05) 19th and 20th episodes; gas-piston activity

06/1984 (SEAN 09:06) Episodes 20-22; highest lava fountains of 1983-84 eruption

07/1984 (SEAN 09:07) Episodes 22-23 of 1983-84 E Rift Zone eruption

08/1984 (SEAN 09:08) Episode 24; high fountains; thin tephra blanket

09/1984 (SEAN 09:09) Episode 25; highest fountains of 1983-84 eruption; tephra

10/1984 (SEAN 09:10) Episode 26; shortest of 1983-84 eruption

11/1984 (SEAN 09:11) Episodes 27 and 28 of 1983-84 middle E Rift Zone eruption

12/1984 (SEAN 09:12) Episodes 28 and 29 are one-day eruptions with fountains to 450 m

01/1985 (SEAN 10:01) Episodes 29-30; fountains to 460 m; heavy tephra fall

02/1985 (SEAN 10:02) 30th episode lasts about 21 hours; tephra falls in Hilo

03/1985 (SEAN 10:03) Episode 31; lava flows into subdivision; tephra builds Pu`u `O`o

04/1985 (SEAN 10:04) Episode 32 of 1983-85 middle E Rift Zone eruption

05/1985 (SEAN 10:05) Summit inflation and low-level harmonic tremor continue; episode 33 of 1983-85 eruption

06/1985 (SEAN 10:06) Episodes 33 and 34; aa lava flows SE

07/1985 (SEAN 10:07) Continuing lava production from new fissures uprift of active vent

08/1985 (SEAN 10:08) Fissure activity ends; new episode three weeks later

09/1985 (SEAN 10:09) Episode 37 of the 1983-85 East Rift Zone eruption

10/1985 (SEAN 10:10) Episodes 37, 38, and 39 of 1983-85 eruption

11/1985 (SEAN 10:11) Episode 39 includes S-flank vent activity

12/1985 (SEAN 10:12) 40th episode marks end of 3rd year of East Rift eruption

01/1986 (SEAN 11:01) Episodes 40 and 41 of East Rift Zone eruption

02/1986 (SEAN 11:02) 42nd episode of East Rift Zone eruption

03/1986 (SEAN 11:03) Two brief episodes of high lava fountains feed short flows

04/1986 (SEAN 11:04) Episode 44 included lava production from new vent

05/1986 (SEAN 11:05) Episodes 45 and 46 of East Rift eruption

06/1986 (SEAN 11:06) Intermittent activity precedes episode 47

07/1986 (SEAN 11:07) Episode 48 from three new fissures

08/1986 (SEAN 11:08) Lava shield continues to grow

09/1986 (SEAN 11:09) Lava tubes feed flow complex; continued lava shield growth

10/1986 (SEAN 11:10) Continued lava production builds shield; flows burn forest

11/1986 (SEAN 11:11) 12-km-long lava flow destroys 11 houses, enters ocean

12/1986 (SEAN 11:12) Lava destroys more homes

01/1987 (SEAN 12:01) Activity confined to shield area, new tube system

02/1987 (SEAN 12:02) New outbreaks along lava tube system stagnate

03/1987 (SEAN 12:03) Lava flow enters ocean; more coastal destruction

04/1987 (SEAN 12:04) Lava advance continues, three more houses destroyed

05/1987 (SEAN 12:05) Lava enters ocean from underwater tubes and surface flows

06/1987 (SEAN 12:06) Lava flow builds coast, destroys house; inflation resumes

07/1987 (SEAN 12:07) Tube system blockage changes shield, lava flows

08/1987 (SEAN 12:08) Lava production continues; deep tremor

09/1987 (SEAN 12:09) Lava destroys seven more houses

10/1987 (SEAN 12:10) Lava flows into ocean

11/1987 (SEAN 12:11) Lava flows into ocean, destroys house

12/1987 (SEAN 12:12) Lava flows into sea, destroys more houses

01/1988 (SEAN 13:01) Increased lava production; activity resumes at Pu`u `O`o

02/1988 (SEAN 13:02) Lava continues to enter ocean; littoral cones and tephra

03/1988 (SEAN 13:03) Lava flows into ocean; littoral explosions

04/1988 (SEAN 13:04) Lava production resumes after a one-week hiatus

05/1988 (SEAN 13:05) Lava destroys houses, re-enters ocean

06/1988 (SEAN 13:06) Tube system feeds lava into ocean

07/1988 (SEAN 13:07) Lava bench collapse at seacoast

08/1988 (SEAN 13:08) Coastal lava benches build and collapse

09/1988 (SEAN 13:09) Littoral explosions and lava bench collapse

10/1988 (SEAN 13:10) Repeated collapse of new coastal lava benches

11/1988 (SEAN 13:11) Lava benches form and collapse at coast

12/1988 (SEAN 13:12) Continued lava flow into sea; tube breakouts upslope

01/1989 (SEAN 14:01) Lava flow remains active at seacoast and upslope

02/1989 (SEAN 14:02) Lava enters sea through tubes; surface breakouts upslope

03/1989 (SEAN 14:03) Breakouts upslope slow lava bench growth at coast

04/1989 (SEAN 14:04) Lava flows threaten houses

05/1989 (SEAN 14:05) Surface activity destroys four houses

06/1989 (SEAN 14:06) Earthquake causes bench collapse; no effect on eruption

07/1989 (SEAN 14:07) High surface activity, new flow enters ocean

08/1989 (SEAN 14:08) Lava continues to enter the ocean at several sites

09/1989 (SEAN 14:09) Coastal lava entries active; breakouts from tube system

10/1989 (SEAN 14:10) Lava flows into sea at three sites; breakouts from lava tubes

11/1989 (SEAN 14:11) Three ocean lava entries remain active; littoral explosions

12/1989 (SEAN 14:12) Two ocean entries remain active; littoral explosions

01/1990 (BGVN 15:01) Lava production stops for three days but resumes with more vigor; seismicity suggests E Rift crustal adjustment

02/1990 (BGVN 15:02) Eruption stops, then resumes with vigorous surface activity; two new ocean entries

03/1990 (BGVN 15:03) Eruption stops briefly then resumes after seismic swarm; lava destroys house

04/1990 (BGVN 15:04) E Rift lava flows destroy dozens of homes

05/1990 (BGVN 15:05) E Rift eruption pauses briefly, then lava destroys more homes

06/1990 (BGVN 15:06) Vigorous East Rift lava production resumes after brief pause; lava pond recedes

07/1990 (BGVN 15:07) Lava flow destroys two homes, re-enters ocean

08/1990 (BGVN 15:08) Continued East Rift lava production; two houses destroyed; three brief eruptive pauses

09/1990 (BGVN 15:09) Continued east rift lava production; lava extending hundreds of meters into ocean

10/1990 (BGVN 15:10) Lava continues to flow into sea; more homes destroyed

11/1990 (BGVN 15:11) E rift lava continues to flow into sea; earthquake swarm

12/1990 (BGVN 15:12) East rift lava continues to enter sea; briefly increased lava lake activity after seismic swarm

01/1991 (BGVN 16:01) Continued lava flow into sea; increased summit seismicity

02/1991 (BGVN 16:02) Lava flows build more new land at coast

03/1991 (BGVN 16:03) Lava continues to enter ocean; upper east rift magma intrusion

04/1991 (BGVN 16:04) Lava breakout from tube system feeds new ocean entry

05/1991 (BGVN 16:05) E rift lava continues to flow through tubes into the ocean

06/1991 (BGVN 16:06) E rift lava continues to enter the ocean

07/1991 (BGVN 16:07) Continued E rift lava production; summit earthquake swarm

08/1991 (BGVN 16:08) Continued lava flow into sea; lava pond overflows; magma intrusion

09/1991 (BGVN 16:09) Numerous surface flows break out from tubes, then lava stops entering ocean; lava lake active

10/1991 (BGVN 16:10) New east rift fissure vents

11/1991 (BGVN 16:11) Lava from new east rift fissure vents

12/1991 (BGVN 16:12) Small lava flows emerge from tube system; new lava covers Pu`u `O`o Crater floor

01/1992 (BGVN 17:01) Lava from new fissure; continued lava pond activity; lava production ends from shield vent

02/1992 (BGVN 17:02) Continued lava production from East rift fissure vents; magma intrusion into upper East rift

03/1992 (BGVN 17:03) Continued lava production from East rift fissure vent

04/1992 (BGVN 17:04) East rift lava production from fissure vent continues, but with brief pauses

05/1992 (BGVN 17:05) Lava production from episode-51 vent interrupted by brief pauses; lava lake in nearby crater

06/1992 (BGVN 17:06) Continued east rift lava production

07/1992 (BGVN 17:07) Lava flows south from East-rift vents

08/1992 (BGVN 17:08) Continued East-rift lava extrusion interrupted by brief pauses

09/1992 (BGVN 17:09) New vent opens after M 4.5 earthquake

10/1992 (BGVN 17:10) Lava flows into ocean

11/1992 (BGVN 17:11) Lava flows extend 350 m into the ocean

12/1992 (BGVN 17:12) Lava continues to flow into sea as East rift zone eruption enters 11th year

01/1993 (BGVN 18:01) Lava flowing through tube system continues to enter the sea

02/1993 (BGVN 18:02) Episode 53 begins; lava flows from tube breakout reach Kamoamoa delta

03/1993 (BGVN 18:03) Lava continues to flow into ocean; phreatic explosion kills one

04/1993 (BGVN 18:04) Lava continues to enter the ocean

05/1993 (BGVN 18:05) Lava continues to enter the ocean; bench collapses cause explosions

06/1993 (BGVN 18:06) Ocean entries remain active; bench collapses continue

07/1993 (BGVN 18:07) New lava breakout on the Kamoamoa delta reaches the ocean

08/1993 (BGVN 18:08) Lava enters ocean along both sides of the Kamoamoa delta

09/1993 (BGVN 18:09) Lava from tubes enters ocean; lava pond remains active

10/1993 (BGVN 18:10) Ocean entries remain active; partial collapse at episode-53 vent

11/1993 (BGVN 18:11) Lava bench collapse with vigorous explosive activity

12/1993 (BGVN 18:12) New collapse area engulfs much of the episode-53 cone

01/1994 (BGVN 19:01) New skylights open; W ocean entry remains active

02/1994 (BGVN 19:02) Three lava bench collapses, littoral cones, and a M 5.2 earthquake

03/1994 (BGVN 19:03) New lava flows, bench collapse, and postulated water entry into lava tubes

04/1994 (BGVN 19:04) Lava escaping from an active tube feeds aa flows

05/1994 (BGVN 19:05) Littoral explosions as lava continues to enter the ocean

06/1994 (BGVN 19:06) A few lava flows break out of tubes onto the surface; banded tremor continues

07/1994 (BGVN 19:07) Bench collapses and littoral explosions occur as lava flows continue to enter the ocean

08/1994 (BGVN 19:08) New lava flow advances over a fault scarp; ocean entries remain active

09/1994 (BGVN 19:09) One active ocean entry; small breakouts on E side of flow field

10/1994 (BGVN 19:10) Laeapuki ocean entries still active and new lava flow reaches ocean

12/1994 (BGVN 19:12) Lava-flow breakouts cover new land and reach the ocean

01/1995 (BGVN 20:01) Lava flows active on coastal plain and at ocean entries

02/1995 (BGVN 20:02) Lava flows on coastal plain; four active ocean entry points

04/1995 (BGVN 20:04) Lava flows, breakouts, tremor, and more

05/1995 (BGVN 20:05) Lava flows and ocean entries very active in the Highcastle area

07/1995 (BGVN 20:07) Continued collapse of the Pu`u `O`o cone; lava flows and ocean entries

09/1995 (BGVN 20:09) Numerous lava flows upslope and on the coastal plain; new ocean entry formed

12/1995 (BGVN 20:11) Surface lava flows, lava tubes, and ocean entries still active

01/1996 (BGVN 21:01) Eruptive pulse on 1 February almost results in a summit eruption

03/1996 (BGVN 21:03) Heightened activity on 1-4 February followed by 10-day pause; bench construction

05/1996 (BGVN 21:05) Surface flows, ocean entries, and bench collapses; summit inflation episode

07/1996 (BGVN 21:07) Surface flows, ocean entries, and bench collapses; continued eruption tremor

09/1996 (BGVN 21:09) Eruptive activity continues; ocean entry and lava bench collapses

11/1996 (BGVN 21:11) Eruptive activity continues; lava-bench collapses

01/1997 (BGVN 22:01) New, short-lived eruptive episode (54) in Napau Crater; Pu`u `O`o pauses

02/1997 (BGVN 22:02) Lava returns to Pu`u `O`o

03/1997 (BGVN 22:03) Lava flows outside of Pu`u `O`o for the first time since 31 January

04/1997 (BGVN 22:04) Lava issuing from three sites; Pu`u `O`o lava lake 20 m from W crater rim

07/1997 (BGVN 22:07) Fountaining from Pu`u `O`o vents; lava flows reach ocean again

09/1997 (BGVN 22:09) Lava effusion and overflows

11/1997 (BGVN 22:11) Bench collapse and pit formation; lava flows continue to reach the coast

12/1997 (BGVN 22:12) Surge in activity on 15 January

01/1998 (BGVN 23:01) Surface flows; 27 January earthquake swarm

02/1998 (BGVN 23:02) Steady, low activity during February

03/1998 (BGVN 23:03) Steady eruption but low seismicity, sparse surface flows

04/1998 (BGVN 23:04) Brief magma surge on 5 April, bench collapse 13-14 April

06/1998 (BGVN 23:06) Pause in lava flow during May; benches collapse during May-July

08/1998 (BGVN 23:08) Eruptive pause (No. 20) followed by a new pahoehoe flow to the sea

10/1998 (BGVN 23:10) Lava from Pu`u `O`o continues to build bench

11/1998 (BGVN 23:11) Continuing flow from Pu`u `O`o; major bench collapse

01/1999 (BGVN 24:01) Pause in eruption leads to new surface flows

03/1999 (BGVN 24:03) Large delta collapse on 8 March nearly claims victims

05/1999 (BGVN 24:05) Bench collapse on 13 April; a 33-hour eruptive pause on 5 May

09/1999 (BGVN 24:09) Abrupt changes in tilt, tremor, and extrusive output due to an inferred intrusion

01/2000 (BGVN 25:01) Ground deformation continues through June; earthquake swarms begin in December

04/2000 (BGVN 25:04) An eruptive pause occurred in September; intrusion of magma in February

06/2000 (BGVN 25:06) During May-July 2000, continued frequent surface flows and earthquakes

10/2000 (BGVN 25:10) Continued lava production during late-July to mid-November; two hikers dead

09/2001 (BGVN 26:09) Branching lava flows, ocean entries, and elevated seismicity into September 2001

12/2001 (BGVN 26:12) Low-to-moderate tremor, surface lava flows and ocean entry through early 2002

03/2002 (BGVN 27:03) Lava stops entering sea during January, tilting in late March-April 2002

05/2002 (BGVN 27:05) New lava flows during early May burn over 1,000 hectares of forest

08/2002 (BGVN 27:08) Lava flowed over land and poured over the sea cliff during parts of mid-2002

11/2002 (BGVN 27:11) Inflation-deflation episodes and lava flows through 2 December 2002

05/2003 (BGVN 28:05) Continued lava flows during December 2002-June 2003 enter the ocean

09/2003 (BGVN 28:09) Active surface lava flows from June through mid-October

11/2003 (BGVN 28:11) Moderate seismicity and minor activity on the lava-flow field

02/2004 (BGVN 29:02) Activity through April 2004 focuses in upper flow field (maps and diagrams)

06/2004 (BGVN 29:06) Surface lava flows and renewed ocean entries; lava tubes in June

09/2004 (BGVN 29:09) June-October 2004 period has lava entering ocean and ample lava flows

06/2005 (BGVN 30:06) During November 2004-January 2005 lava flows continued to enter the sea

04/2006 (BGVN 31:04) Maps of past year's surface lava flows and photos of lava entering the sea

08/2006 (BGVN 31:08) Lava entering the sea at E Lae`apuki; small bench collapse on 30 July 2006

10/2006 (BGVN 31:10) PKK lava tube active August-November 2006; 10 October collapse pit at Pu`u `O`o

05/2007 (BGVN 32:05) Lava flows entering the ocean between December 2006 and March 2007

06/2007 (BGVN 32:06) April to June 2007 activity; rift zone earthquakes and extension

03/2009 (BGVN 34:03) June to December 2007 activity; multiple fissure eruptions

01/2010 (BGVN 35:01) 2008 highlights: Thanksgiving Eve Breakout continues, Halema'uma'u Crater vent opens

02/2013 (BGVN 38:02) 2009 highlights: Waikupanaha ocean entry ceases, lava enters Halema`uma`u

05/2013 (BGVN 38:05) Summary of highlights for 2010-2012

05/2014 (BGVN 39:05) During 2013, a summit lava lake and lava flows on slopes and into ocean

09/2014 (BGVN 39:09) 1 January-26 June 2014: Waning stages of the Kahauale'a 2 lava flow

12/2014 (BGVN 39:12) 27 June-30 December 2014: Birth and rapid advance of the June 27th lava flow

07/2015 (BGVN 40:07) Lava lake in Halema'uma'u Crater overflows its rim; lava front from Pu'u 'O'o stalls near Pahoa village

02/2016 (BGVN 41:02) Breakouts continue from the June 27th lava flow; new incandescent vent opens on the flank of Pu'u 'O'o cone.

08/2016 (BGVN 41:08) June 27th flow ceases; new flow from Pu'u 'O'o Crater's E flank heads SE

08/2017 (BGVN 42:08) New flow from Pu'u 'O'o reaches the sea on 26 July; Kamokuna delta collapses on 31 December 2016

11/2017 (BGVN 42:11) Episode 61g lava flow continues with many breakouts; firehose enters the sea at Kamokuna ocean entry

03/2018 (BGVN 43:03) Activity continues at Halema'uma'u lava lake, and at the East Rift Zone 61g flow, July-December 2017

07/2018 (BGVN 43:07) Overflows of lava lake in Halema'uma'u crater; Pu'u 'O'o crater floor collapses 30 April 2018; inflation and increased seismicity

10/2018 (BGVN 43:10) Twenty-four fissures open on the lower East Rift Zone in May 2018; at least 94 structures destroyed

12/2018 (BGVN 43:12) Lava fountains on the Lower East Rift Zone build 50-m-high pyroclastic cone and 13-km-long lava flow that engulfs Kapoho Bay during June 2018; 533 homes destroyed since 1 May

01/2019 (BGVN 44:01) Fissure 8 lava flow continues vigorously until 4 August, ocean entry ends in late August, last activity at fissure 8 cone on 5 September 2018

03/2021 (BGVN 46:03) New eruption in December 2020 with an active lava lake, lava flows, spattering, and a dome fountain

06/2021 (BGVN 46:06) Active lava lake, lava flows, and spattering during February-May 2021

01/2022 (BGVN 47:01) New eruption in the lava lake at Halema’uma’u during September-December 2021

08/2022 (BGVN 47:08) Lava effusions persisted in the lava lake at Halema’uma’u during January-June 2022




Information is preliminary and subject to change. All times are local (unless otherwise noted)


August 1968 (CSLP 28-68)

Eruption from Hiiaka Crater produces lava fountains

Card 0014 (26 August 1968) Eruption from Hiiaka Crater produces lava fountains

The following information was reported by the Associated Press on 22 August 1968. "Kīlauea volcano on the island of Hawaii erupted today with fountains up to 75 feet in height. Activity broke out in Hiiaka Crater about 0645. About four miles south of Kīlauea-iki off the Chain of Craters road. Records of the Hawaii Volcanoes National Park indicate that Hiiaka Crater had not previously erupted in historical time."

Information Contacts: Howard Powers, Hawaiian Volcano Observatory (HVO), U.S. Geological Survey.


September 1968 (CSLP 28-68)

Details of Upper East Rift Zone eruption during August 1968

Card 0030 (03 September 1968) Details of Upper East Rift Zone eruption during August 1968

"An eruption along the upper east rift of Kīlauea started with a swarm of earthquakes at 0249, 22 August 1968. Collapse of the summit began recording on the Uwekahuna tiltmeters almost simultaneously. By daylight, 0530, clouds of fume were issuing from a line of new cracks that intercepted the Chain of Craters Road, crossed through Hiiaka pit and a half across the Old Keauhou Wagon Road at B.M. 3270. Lava vents appeared in the bottom of Hiiaka Crater about 0645 and rapidly fed a lake that deepened to about 100 feet and reached a diameter at "shore line" of about 300 feet. Drainback started conspicuously while some continued another half hour leaving only a thin plaster of new lava covering the funnel-shaped bottom walls of Talus. During the early part of the Hiiaka eruption, another small flow was erupted from one fissure a mile east of Hiiaka.

"During the next four days (through 26 August 1968) cracks opened progressively eastward as far as about 13.5 miles from Hiiaka; first at three miles, next at 12 miles, and finally at 13.5 miles, somewhat E of Kalalua Crater. Violent emission of hot gas with no outpouring of lava took place from the western set of cracks; small amounts of rampart spatter and short, stubby, listless flows issued from the more distant groups of cracks.

"Collapse at the caldera totaled about 60 µrad on the rim stations during the first 36 hours, and reversed to a steady but moderate inflation Sunday and Monday. Level stations on the floor of the caldera dropped a little more than half a foot during this period.

"The earthquake swarm ceased within about six hours, and strong harmonic tremor was recorded on all the near-summit seismometers for more than 24 hours. It then diminished rapidly under the caldera but remained strong under the upper east rift until there also it died out rapidly during the early hours of 25 August.

"It is of especial interest that there has been no migration of small earthquakes and harmonic tremor to eastward along the rift while opening of cracks and appearance of lava has extended eastward. This absence of small local earthquakes and harmonic tremor has been checked by observations with the portable seismograph and constant observation of the seismometer installed near Pahoa."

Information Contacts: Howard Powers, HVO.


October 1968 (CSLP 48-68)

Lava fountaining from fissure eruption floods Napau Crater

Card 0109 (08 October 1968) Fissure eruption emits lava that covers the floor of Napau Crater

The following report was received from Dallas Peck, U.S. Geological Survey, Washington, DC. Kīlauea volcano erupted at 1435 HDT on 7 October after 3.5 hours of harmonic tremors and abundant earthquakes. The eruption is from a fissure between two and three miles in length crossing Napau Crater on the east rift zone, nine miles southeast of the summit. Quite a bit of lava has come out of the fissure and covered the floor of Napau Crater. Another small lava flow from the same fissure has blocked the trail into the crater. Ground crews are proceeding to investigate.

Card 0111 (08 October 1968) Lava fountaining continues along 3.5-mile fissure; longest lava flows has advanced 5.5 miles

"There was lava fountaining throughout the night all along the three-and-a-half mile fissure that opened up yesterday afternoon. The fountaining continued until 0400 this morning. At 0700, the lava fountaining is still continuing in the northeasterly section of the fissure. The fissure is located approximately four-and-a-half miles northeast of the Makaopuhi Road and the lava is disappearing in another fissure which is located approximately one mile to the northeast of the fountaining activity. The greatest advance of the lava is ~5.5 miles NE of the road and within two miles of the Puaialua Crater. Collapsed tilting has definitely slackened off and the total tilt is slightly more than we had in the August eruption. The earthquake pattern seems to have stabilized. The tremors are not moving down the rift. At the present time there is no indication of further opening down toward the east coast.

Card 0117 (10 October 1968) Activity decreasing; fumes and smog covering the entire island

"Napau Crater lava extrusion extending three miles from crater but activity decreasing. Fountains on 8 October 200 feet high, on 9 October 50-100 feet high. There are indications Napau activity may cease within few days but this is uncertain. Some flow activity but lava penetrating crevices and flow therefore not extensive. Fumes and smog covering entire island up to 7,000 feet above sea level.

Card 0119 (14 October 1968) Flooding of Napau Crater stopped midday on 10 October

"Kīlauea status as of 10/0200Z. Napau Crater flooded with lava. Flooding stopped midday 10 October. Fountain activity limited to 200 yard stretches approximately one to two miles from Napau Crater rim."

Card 0127 (14 October 1968) Fountaining decreases to slight bubbling by 14 October

"As of 12 October 0200Z one area still fountaining approximately one mile from Napau Crater rim. Almost no lava flowing. Tremors weak. Eruption appears to be dying out slowly. As of 13 October 0200Z yesterday's fountaining has stopped but fuming continues. Earth tremors very weak. As of 14 October 0200Z slight bubbling in previous fountaining area one mile from Napau Crater rim.

Card 0140 (15 October 1968) Fountaining has dwindled; weak tremors

"Kīlauea status as of 15 October 0200Z. Fountaining of 14 October has dwindled. Weak tremors."

Card 0151 (21 October 1968) Minor fuming and steaming; inflation resumes

"Kīlauea status 20/0200Z. No activity other than minor port-eruptive fuming and steaming. No seismic activity. Instruments indicate mountain has resumed rising. The rising which had preceded the eruptions was interrupted briefly by a short period of deflation coinciding with the period of maximum flow activity. Visibility pattern clear with intermittent clouds."

Information Contacts:
Card 0109 (08 October 1968) Howard Powers, HVO.
Card 0111 (08 October 1968) Howard Powers, HVO.
Card 0117 (10 October 1968) Smithsonian Astrophysical Observing Station, Maui, HI.
Card 0119 (14 October 1968) Smithsonian Astrophysical Observing Station, Maui, HI.
Card 0127 (14 October 1968) Smithsonian Astrophysical Observing Station, Maui, HI.
Card 0140 (15 October 1968) Smithsonian Astrophysical Observing Station, Maui, HI.
Card 0151 (21 October 1968) Smithsonian Astrophysical Observing Station, Maui, HI.


November 1968 (CSLP 48-68)

Minor fountaining resumes east of Napau Crater

Card 0252 (25 November 1968) Minor fountaining resumes east of Napau Crater

"On the afternoon of 21 October, it was found that minor fountaining activity, perhaps 15 feet high, had resumed, undetected, in a small area of the rift east of Napau Crater. Though fountaining activity can normally be detected immediately by the Hawaiian Volcano Observatory's seismic net, in this instance, the harmonic tremor characteristic of fountaining was masked by several days of strong, wind-generated microseism activity. Though it is uncertain when the activity started, it seems likely that it began in the early morning hours of 21 October. Had it begun earlier, it would have been detected by means of glow in its smoke. By 22 October, the activity ceased."

Information Contacts: Matthew Salisbury, HVO.


February 1969 (CSLP 16-69)

Fissure eruption begins on 22 February on the upper east rift

Card 0422 (24 February 1969) Fissure eruption begins on 22 February on the upper east rift

Kīlauea erupted three miles of fissure in the upper east rift, 1000 HST on 22 February 1969. The swarm of short tremors burst and small earthquakes started at 0627. By 0900 tremors were constant. Earthquakes had diminished and lava appeared about 0950. The first crack extended to the base of Kane Nui O Hamo and produced two flows that rapidly moved south across the chain of crater roads.

Within the next two hours the erupting fissure extended eastward across the north flank of Kane Nui O Hamo, westward across the mezzanine ofAlae across the chain of crater roads and to a point south of west edge of Alae. Fountains from Alae Mezzanine are forming a new lava lake in Alae that is more than 150 feet deep as of the afternoon of 23 February. A sluggish aa-flow from the eastern fissure is moving down the highway and reached more than one and a half miles by the afternoon of 23 February. Action continues at Alae as of 2100 HST 23 February.

Information Contacts: Howard Powers, HVO.


March 1969 (CSLP 16-69)

Fountaining resumed on 25 February; lava cascades into Alae Crater

Card 0447 (05 March 1969) Fountaining resumed on 25 February; lava cascades into Alae Crater

Late afternoon of 25 February, fountaining resumed on a quarter mile fissure half way between Alae Crater and Kane Nui O Hamo. This fissure is either the same or very close to the original fissure that started the activity on the morning of 22 February. Fountaining was not too strong during 24 hours, and was localized in three main fountains. The effluent lava pooled and built a confining levee that reproduced a miniature Halemaumau lake. This localized activity built up on [the night of 26 February] and the vigor of tremor increased. On [the morning of 27 February] the three fountains in the "lake" had become one vigorous fountain, playing up to 200 feet, and the levee had burst permitting a strong lava flow to cascade into Alae Crater. A small fountain had resumed at the base of the northwest slope of Kane Nui O Hamo and sent a sluggish small flow northward into the forest. A third small fountain had resumed in Alae.

During the increase in activity starting about 2100 on 26 February, the summit tiltmeters showed a modest collapse, though they had been showing inflation during the early part of the resumed fountaining. There has been no renewal of activity on the fissure crossing Chain of Craters road between Alae and Aloi that was active for about a half mile westward south of Aloi. Puʻu Huluhulu is a good vantage point, and the large fountain is visible from the Aloi overlook area. Access to Alae is blocked by new lava, and new lava has covered the new highway for a mile and a half south from Makaopuhi.

Information Contacts: Howard Powers, HVO.


May 1969 (CSLP 16-69)

Eruption sends lava flows into Aloi and Alae craters

Card 0559 (26 May 1969) Eruption sends lava flows into Aloi and Alae craters

The following report was received by cable on 25 May 1969. "Kīlauea erupted along one mile on east rift morning of 24 May local. Location of activity approximately one mile nearer to Kīlauea Summit than 22 February eruption. Lava flows moved south into Aloi Crater and back into Alae Crater. Activity almost ceased as of 25/0800Z."

The following was received by cable on 26 May. "Kīlauea activity ceased."

Information Contacts: Smithsonian Astrophysical Observing Station, Maui, HI.


June 1969 (CSLP 16-69)

Lava fountaining in mid-June

Card 0637 (30 June 1969) Lava fountaining in mid-June

"We had about eight hours of activity last week. The fountain area that had been active on 12 and 13 June revived its activity. Exactly the same fountain trough opened up again and we had very strong fountaining starting about 2100 GMT on 24 June and it stopped at 1755 GMT the next morning (25 June). It went for a little over nine hours. The fountaining was quite strong and steady. Lots of lava was produced and the flow from the fountaining followed practically the same path that the flow had taken down toward the beach, on 12 and 13 June and this flow reached within 75 yards of the beach while the fountain was still active. Then, when the fountain ceased activity, there was still lava in the system along the channel that was still hot enough to be mobile, so there was some extension of the flow at the end. . . the lava did reach the beach and a little bit of it flowed into the water at about 0835 (more than 1.5 hours after the fountain stopped). Since then, the activity ceased abruptly and there has been no resumption since then. The tilting at the summit indicated recharging - a swelling of the summit immediately after the fountain stopped."

Information Contacts: Howard Powers, HVO.


July 1969 (CSLP 16-69)

Eruption on 15 July

Card 0672 (16 July 1969) Eruption on 15 July

"Volcano eruption on the island of Hawaii (same area as 24-25 April 1969 eruption) at 0400 on 15 July 1969 and ceased 1228 same date."

Information Contacts: Howard Powers, HVO.


August 1969 (CSLP 16-69)

Alae Crater fills, then drains; lava fountaining

Card 0702 (04 August 1969) Eruption on 3 August almost fills Alae Crater

The following report was called in by D. Peck who had received a cable from H. Powers in Hawaii. "Eruption from same vent started [at 1715 on 3 August]. Stopped 0008 [on] 4 August. Flow nearly filled Alae [pit crater]. Nothing flowed toward ocean."

Card 0711 (07 August 1969) Down-dropping graben allows almost complete draining of Alae Crater

"Another phase of the current Kīlauean eruption started at 2200 on 5 August when lava started pouring into Alae Crater from a nearby fountain. The last eruptive phase which took place 3 August at the same site was followed 4 August by the down dropping of a graben extending from Alae Crater to Kane Nui O Hamo and the almost complete draining of lava from Alae Crater. Alae had been almost completely filled by lava several hundred feet deep that erupted during previous phases in February, May, June, July and August. Concurrently with the draining of Alae, lava oozed from a mile long fissure on the rift zone below Napau Crater. The concurrent eruptive phase ended at 6pm 6 August, and left a new lake of lava more than a hundred feet deep in Alae Crater."

Card 0730 (22 August 1969) Lava fountaining to 1,500 feet in height

"The volcano went into a very active phase last night about midnight Hawaiian Time. In the last few weeks the volcano has been continuously active in between violent stages; the fountaining being very low, only 25-50 feet high, and the lava flowing only a short distance until flowing down a fissure.

Starting at midnight Hawaiian Time (1000 GMT 22 August) the fountaining rapidly increased and a volcanic tremor recorded on the seismograph, increased. When Dr. Powers called, the fountaining had reached 1500 feet in height. Over the last several months in a number of eruptions, there have been two fountains, one of which feeds a stream of lava flowing down due south to the shoreline and the other feeding a flow that poured into Alae Crater. During this current phase, only the eastern fountain, feeding the flow into Alae, is active."

Information Contacts:
Card 0702 (04 August 1969) Howard Powers, HVO.
Card 0711 (07 August 1969) Dallas Peck, U.S. Geological Survey, HI.
Card 0730 (22 August 1969) Howard Powers, HVO.


September 1969 (CSLP 16-69)

Strong eruption from vent between Aloi and Alae craters

Card 0747 (11 September 1969) Strong eruption from vent between Aloi and Alae craters

"Kīlauea staged a strong eruption again from the new vent between Aloi and Alae on the upper east rift zone. This vent had been in strong eruption between midnight and 0440 on 22 August. It then relaxed into a state of steady fuming and low grade tremor very local to the vent. On 6 September, at noon, the tremor and fuming stopped and a periodic rise and fall of the lava surface in the vent began. The surface rose nearly to the lip of the fissure and then dropped 100 feet deep in surges lasting short of an hour. This continued until sustained and strong eruption began about 2000. Fountains attained heights of 1,800 feet maximum and held steady at over 1,000 feet for several hours. Alae pit crater filled, two small flows extended southward to within a couple of miles of the coast, and the pumice and spatter cones was increased to a height of more than a hundred feet. Activity suddenly stopped at 0430, 7 September. Summit swelling resumed immediately and the strong fuming started up right after the last fountain died."

Information Contacts: E.H. Roseboom, US Geological Survey, HI.


October 1969 (CSLP 16-69)

Lava fountains low but continuous

Card 0795 (16 October 1969) Lava fountains low but continuous

The following information is taken from a telephone conversation with Dallas Peck. "This information was relayed to me by Donald Swanson, acting scientist-in-charge of the Hawaiian Observatory, by a note dated 11 October which reads as follows: 'Phase end, or a very vigorous episode of interphase activity, began 10 October at 0900 and is continuing as of 1930, 11 October. Fountains have been very low (50-125 feet) but they have been continuous so they have put out a fair amount of lava. Nearly all the lava has gone into Alae Crater which was refilled by 1400, 10 October, and is now overflowing along its SE side. Flows apparently fed through tubes beneath the stable crust from Alae Lake are covering a fairly extensive area south of Alae and east of the area covered previously since 24 May.'"

Information Contacts: Donald Swanson, HVO.


November 1969 (CSLP 16-69)

Summary of east rift zone activity since August 1968

Card 0814 (03 November 1969) Summary of east rift zone activity since August 1968

The central and western part of the east rift zone of Kīlauea volcano has been the site of four eruptions, one of which is still continuing, in the past 15 months. Small eruptions in August and October, 1968, added about 7 x 106m3 of tholeiitic basalt to the surface, and an eruption from 22 to 28 February, 1969, which produced about 17 x 106m3 of lava, much of it in a lake in Alae pit crater.

A fourth flank eruption began along a fissure between Alae and Aloi craters on 24 May, 1969, and since then 11 phases (the last on 20 October) of high fountaining and significant lava output have taken place from the same vent area. The phases are spaced from two days to four weeks apart. Ten phases have each erupted about 4 x 106m3 of lava; one phase erupted about 12 x 106m3, and one, about 2 x 106m3. Fountains are 30-540 m high and issue from a 100-m-long segment of the fissure, on the downwind side of which a cone of welded spatter several tens of meters high has been built. Most eruptive phases last less than ten hours, with fountain activity building gradually but ending very abruptly (within a few minutes). The bulk of the lava of each phase is poor in olivine, but the last lava emitted is generally picritic or nearly so. Flows from the 11 phases have completely filled Alae Crater and partly filled Aloi Crater; one flow from phase four (25 June) reached the ocean, about 12 km from the vent. A thick accumulation of pumice and spatter blankets several square kilometers downwind from the vent area. Both pahoehoe and aa flows have been produced, and many rootless aa flows, fed by welded spatter gliding from the oversteepened flanks of the new cone, extend short distances downslope.

During interphase periods, the lava column can generally be seen at a depth of several tens of meters in the fissure. The column commonly rises slowly within the fissure without much gas emission. Suddenly, bubbling begins, and the column drops rapidly with violent spattering. This cyclic rise and fall, which probably operates 25 percent or more of the duration of each interphase period, normally has a period of ten to fifteen minutes, with the fall taking only two to four minutes of this time. It is safe to watch this activity from the edge of the fissure, but it can also be monitored from a distance of several hundred meters to a few kilometers on the Kīlauea seismometer network, which records strong harmonic tremor during falls and only slight tremor during rises. Occasionally the rising lava column reaches a the surface where it produces a small flow, which is generally confined within the vent area. When the column is high, fountaining may take place, but at a much reduced level from that of phase activity. All lava erupted during the interphase periods has been poor in olivine.

Significant ground deformation accompanies the phase and interphase periods. The summit of Kīlauea (eight km from the vent area) swells upward and outward between phases and contracts rapidly during the brief eruptive phases, whereas the east rift zone near the eruptive site generally expands during phases and contracts during interphases. Since the eruption began on May 24, there has been no significant overall change in altitude or cumulative horizontal strain at Kīlauea's summit because contraction during phases equals expansion during interphase periods. It seems that the magmatic system at Kīlauea has reached a state of dynamic equilibrium.

Information Contacts: Donald Swanson, HVO.


February 1970 (CSLP 14-70)

Summit deflation followed by moderate lava emission

Card 0867 (13 February 1970) Summit deflation followed by moderate lava emission

"At about 2100 29 January the summit recording tiltmeter showed the start of slow, steady deflation and sometime thereafter the vent between Aloi and Alae began a moderate welling of lava with very little fountaining. This mild activity continued until about 1530 to 1600 on 30 January when overflow ceased and drainback took place. The summit tiltmeter showed the resumption of inflation about 1530 that continued at least until 1000 31 January. The lava has risen again in the vent but is not overflowing at this time."

Information Contacts: Howard Powers, HVO.


April 1970 (CSLP 14-70)

Lava fills Aloi Crater and overflows S toward the coast

Card 0908 (10 April 1970) Lava fills Aloi Crater and overflows S toward the coast

The following was telephoned to the Center by Dallas Peck, USGS, Washington, DC on 10 April. "Kīlauea volcano erupted from its east rift zone shortly before 0800, 9 April 1970, when lava began welling out of a fissure crossing the bottom of Aloi Crater. Within a few hours, the crater was filled and lava began pouring southward toward the coast. By 0500, 10 April, deflation of the summit (10-15 µrad during the eruption) had ceased and the eruption was presumed to be over. Aloi Crater is on the SW side of a new lava dome built by repeated phases of the continuing eruption that started 24 May 1969. Surprisingly, the summit crater of the dome, which has been continuously active during both quiet and violent phases of the eruption, did no more than fume during this latest activity."

Information Contacts: Howard Powers, HVO.


December 1970 (CSLP 14-70)

Summary of activity since May 1969 that has formed broad shield named Mauna Ulu

Card 1075 (22 December 1970) Summary of activity since May 1969 that has formed broad shield named Mauna Ulu

The eruption that began on 24 May 1969 between Aloi And Alae Craters on the upper rift zone of Kīlauea is still continuing. The eruption is now the longest and probably the most voluminous of all historic Kīlauea flank eruptions. Much more than 108m3 of lava have been erupted. A broad shield, more than one km in diameter and 100 km high, has been constructed over the largest and most persistent vent fissure. This fissure extends discontinuously down the northeast flank of the shield, recently named Mauna Ulu ("Growing Mountain" in Hawaii), and lava flows and spatter are commonly erupted from several vents along this extension. Two pit craters, Aloi and Alae, have been totally filled by new lava, and many flows have advanced as far as 11 km S, cascading over fault scarps of the Hilini fault system and pooling near and even entering the sea.

The main fissure atop Mauna Ulu is about 140 m long. It was largely roofed over until July, but vents in the roof were sources of many small flows that built the bulk of the shield. The roof collapsed in early July, nearly coincident with resumption of vigorous activity of Mauna Ulu's east flank. Since July, the summit fissure has been widening by the caving of its walls until it is now nearly circular in plan view. Lava can always be seen in a pool 8-30 m below the rim, and lava in the pool nearly always has a circulation pattern from west to east. The level of lava in the pool rises and falls periodically but not as regularly as described by card 814, 3 November 1969. Moderately violent spattering and degassing take place nearly constantly from one or more locations in the fissure. No overflows have spilled from the summit fissure since July, and no episodes of high fountains have occurred since 30 December 1969.

A fissure cut the SW flank of Mauna Ulu on 9 April, and it spread westward across Aloi Crater and for 800 m beyond. Lava erupted from this fissure filled the crater, but activity died out by 1 May. The fissure on the NE flank of Mauna Ulu was active periodically in the fall and winter of 1969, but it remained quiet in 1970 until 6 July, when low fountains burst from it. Since then, eruptive activity from this fissure has been more or less constant, although most erupted lava has been fed away from the fissure by underground lava tubes. Several small pit craters have developed along this fissure. These pit craters are collapse features several tens of meters in diameter which have formed over sections of the fissure that had shown rather persistent activity before becoming roofed over by spatter and small flows. The craters are elongate along the fissure when they first form, but they become more nearly circular in plan view as the sheer walls collapse. A pool of gently circulating (W to E) lava normally fills each crater to within 2-20 m of the rim. The lava in the pool commonly rises slowly upward as gases within the lava expand. Suddenly gases begin to escape with vigorous low fountaining, and the level drops several meters. Sometimes the rising lava reaches the crater rim and spills out; overflows generated by such activity last from a few minutes to several hours before ending with an episode of degassing and fountaining.

Since early August 1970, lava has almost constantly been erupting from the fissure northwest of Alae Crater at an average rate of more than 105m3 per day. This lava flows through a large tube which enters Alae beneath the solidified crust of the lava lake that fills the crater. The lava then leaves the crater in another tube and continues its subsurface flow for several kilometers toward the sea. The lava finally emerges from the tube as fluid but relatively degassed pahoehoe, not aa, doubtless because the insulation of the tube allows the lava to remain hot despite the long distance of travel and small volume of lava. Much of the lava changes to aa after flowing on the surface for some distance, however.

We have recognized no simple connection between activity at the summit of Mauna Ulu and activity on its flank. Flank activity, however, can often be correlated from one vent to the next, with the activity generally progressing from east to west. This pattern has many deviations, however, and it is clear that the entire plumbing system has unknown complications.

Lava produced throughout the eruption is olivine-poor tholeiitic basalt whose close-range optical pyrometer temperatures are normally 1160 to 1165°C. The lava has apparently undergone no significant change in chemical composition beyond that related to the amount of olivine present.

The summit of Kīlauea expanded greatly from December 1969 to June 1970, a period when eruptive activity at Mauna Ulu was at a comparatively low ebb, but there has been little summit deformation since June. Very small episodes of summit subsidence can generally be correlated with increased vigor of activity at Mauna Ulu, reaffirming the ultimate connection between the summit and east rift zone of Kīlauea.

Information Contacts: Donald Swanson and D.W. Peterson, HVO.


April 1971 (CSLP 14-70)

Divers observe underwater lava flow

Card 1179 (23 April 1971) Divers observe underwater lava flow

"A team of five divers from the US Geological Survey, the University of Hawaii, and the Lockheed Aircraft Company dived on the lava flow from Kīlauea Volcano on the south coast of the Island of Hawaii on 19 April. This is the lava flow that has been going on for six weeks and is presently flowing into the sea. The flow is advancing under water as a wall of rubble which is some 300 to 500 feet seaward of the new sea cliff. The front of the rubble wall is at the angle of repose of about 45°, and the base of it is covering over the old ocean floor to a depth of about 100 feet. Tongues of lava, circular in cross section, extend down the front of the rubble of this rubble slope. Some of these are as long as 200 feet and they are three to four feet in diameter, generally. Budding off of them are typical pillows. We could approach one of these elongate lava tongues, in which lava was actually flowing inside and whose surface was too hot to touch on the outside. Generally, the surface was dark, but periodically it would crack and bright incandescence could be seen inside for a few seconds until the crack solidified and then it would crack in some other place. There was a continuous loud mixture of noises: hissing, cracking, small explosions, and rumbling noise as the lava went down through these tubes. General water temperature was slightly elevationated around the flowing lava tongue from a normal of 76°F to about 80°F, but in cracks and around behind thses lava tubes the water was boiling, and many bubbles were coming up out of cracks in the tubes. One surprising feature was the concentration of marine life including fish, lobsters, and eels which were crowded ahead of the advancing rubble flow at the base of the rubble, apparently having been displaced from their normal habitats along the coast. Underwater visibility was better than expected."

Information Contacts: James Moore, USGS; Don Peterson, HVO.


August 1971 (CSLP 81-71)

Summit eruption from four fissures with lava fountaining

Card 1281 (16 August 1971) Summit eruption from four fissures with lava fountaining

"A summit eruption... on 14 August 1971 lasted from 0855 to about 1900 Hawaiian Standard Time. Basaltic lava erupted from four en echelon fissures that trended from N60°E to N75°E and had a combined length of about 1.9 km. Lava fountains reached a maximum height of about 65 m. The two fissures on the floor of Kīlauea caldera extended East-northeast from a point a few hundred meters east of the south rim of Halemaumau for about 1.2 km to a point NW of Keanakakoi Crater and were roughly parallel to the caldera rim. Two other fissures about 0.7 km in length extended along the upper rim of the caldera on the N side of Keanakakoi. Fountains from the upper fissure lasted for about two hours; the lava descended the caldera walls in spectacular cascades. Fountains from the lower fissure continued for about ten hours. Lava flowed E from the fissures along the S edge of the caldera floor in a counterclockwise direction, and it ultimately reached the NE part of the caldera.

"Preliminary determinations indicate that new lava has covered about 2.1 million square meters, which is about one-fifth the area of the caldera floor, and that the total volume erupted was approximately 13 million cubic meters. During the summit eruption volcanic activity continued at a low level at Mauna Ulu about 12 km distant on Kīlauea's east rift zone. A measurement of ground deformation showed that the Kīlauea's summit region was gradually inflating for several weeks and that the rate of inflation increased rapidly for about three days just preceding the eruption. Strong seismic harmonic tremor began about an hour before the eruption started."

Information Contacts: Donald Peterson, HVO.


October 1971 (CSLP 81-71)

Summary of 25-29 September eruption

Card 1302 (18 October 1971) Summary of 25-29 September eruption

"An eruption... took place from 24 to 29 September. Fountains of basaltic lava began at 1920 HST, 24 September, on the caldera floor between Halemaumau and the SW caldera wall, and reached about 80 m high. Fountains spread into Halemaumau crater, and about a quarter of its floor was covered by new lava. At the SW side of the caldera, a tongue of lava breached the low point in the rim and flowed SE for 2.5 km. At 2059 fountains began on the upper SW caldera rim, and then progressively advanced down the southwest rift zone for about 1 km. This advancing line of fountains was about 100 m long, and averaged 15-30 m high. The fountains on the rift zone and caldera floor began to decline about 2300 and ended by 2400, but light activity continued in Halemaumau until late 25 September.

"By the morning of 25 September, the floor of Halemaumau had dropped like a piston a distance of 45 m, so its depth is now about 100 m. At 0945 on 25 September new fountains broke out on southwest rift about 5 km from Halemaumau. This was the beginning of sporadic fountaining on this rift that persisted through 29 September. Fountains were active at many places along a line spanning about 8 km; they migrated both up and down the rift. As many as five localities at a time had activity, but most of the time only one or two places were fountaining. Rows of spatter cones were built, and lava flows covered many thousands of square meters. Activity ended the evening of 29 September."

Information Contacts: Donald Peterson, HVO.


February 1972 (CSLP 09-72)

Mauna Ulu erupts in early February; new lava lake and fountains

Card 1354 (14 February 1972) Mauna Ulu erupts in early February; new lava lake and fountains

"The Mauna Ulu vent on Kīlauea's east rift is erupting again after more than three months of inactivity. A new lava lake was discovered in Mauna Ulu's summit crater about 0900, 5 February. It may be that the eruption began sometime between 2 and 4 February, as shown by a slight increase in tremor on a nearby seismograph, but a severe storm and lack of visibility prevented earlier inspection of the area. The level of the lava lake progressively rose from the bottom of the crater, formerly about 150 m deep, and when discovered it was 80 m below the crater rim. It continued to rise, and on 7 February, at a level 25 m below the rim, lava spilled over a notch at the east end of the crater and flowed into a collapsed trench about 450 m long that extends down Mauna Ulu's east flank. At the east end of the trench, lava drains into a tube, travels SSE about 250 m, and emerges at the north edge of the subsidence bowl that marks the site of old Alae crater. Thin flows have spread across about a quarter of the floor of the depression. The surface of the lava lake in Mauna Ulu crater is presently characterized by vigorous fountains that reach as much as 25 m in height. The entire surface is continually agitated by fountains and bursts of escaping gas. A prolonged period of tumescence of Kīlauea's summit preceded this eruption, which is 11 km ESE of the summit. The outbreak is mild, and only slight deflation has occurred to the present. Harmonic tremor is weak, and only a few small earthquakes, none strong enough to be felt, have accompanied the eruption."

Information Contacts: Donald Peterson, HVO.


May 1973 (CSLP 59-73)

Eruption on 5 May opens 600-foot-long fissure; high lava fountains

Card 1628 (08 May 1973) Eruption on 5 May opens 600-foot-long fissure; high lava fountains

The Kīlauea volcano erupted spectacularly on 5 May 1973, with lava fountains reaching a height of 100 feet. The eruption ripped open a fissure 600 feet wide, and caused several forest fires to sudden;y break out. The eruption occurred amidst hundreds of volcanic tremors, ten days after a 6.2 Richter magnitude earthquake shook the island. By 6 May the volcano was in a deflated condition. The Chain of Craters Highway and the Hilina Pali Road were damaged by the lava flow. The eruption on 5 May was only the second time in 60 years that an eruption went up a rift zone instead of down. As of 7 May the volcano had reverted to a more normal state of activity.

Information Contacts: Donald Peterson, HVO.


November 1973 (CSLP 59-73)

Mauna Ulu crater overflows; fountaining from fissures around Pauahi Crater

Card 1747 (19 November 1973) Mauna Ulu crater overflows; fountaining from fissures around Pauahi Crater

After sporadic sluggish activity in Mauna Ulu for several weeks, accompanied by sustained inflationof Kīlauea Volcano's summit region, the lava lake in Mauna Ulu's crater filled to the brim and overflowed on 4 November. Fountains with heights of 40 m and overflows continued for four days. Activity declined on 8 November. Flows had traveled as far as 4 km S of Mauna Ulu. At 1730 HST on 10 November, strong harmonic tremor began to be recorded by Hawaiian Volcano Observatory seismographs, the lava lake in Mauna Ulu began to drain rapidly, and at 1745, deflation of Kīlauea summit region began. These events suggested that a volcanic outbreak was imminent. At 2417, lava fountains began as a fissure opened in Pauahi Crater, 6 km SE of Kīlauea caldera and 2 km W of Mauna Ulu. Additional fissures opened both east and west of Pauahi, trending from N65°E to N70°E, and lying en-echelon along a belt 2 km long. Lava fountains reached heights of 75 m. At about 0400, 11 November, eruptive intensity began to decline, and by 0600 all fountains outside Pauahi had stopped. Fountains 10-30 m high continued in Pauahi through 12 November, after which activity has gradually declined. Sluggish outflow continues on 16 November, and summit inflation has resumed. Approximately 100 hectares of land was covered by new lava during the Pauahi episode, and approximately three million cubic meters of lava was erupted during the eight hours of strongest activity.

Information Contacts: Donald Peterson, HVO.


January 1975 (CSLP 04-75)

Lava fountains from a fissure eruption send flows 12 km

Card 2065 (31 January 1975) Lava fountains from a fissure eruption send flows 12 km

Kīlauea volcano erupted for six hours on 31 December 1974, after a four-month period of continuous inflation monitored by ground deformation measurements. The eruption began at 0255 HST (1255 GMT) from a fissure 2.5 km S of Halemaumau. Fissures opened progressively both to the NE and SW, and ultimately the total span of erupting fountains reached about 3 km in length. Maximum height of fountains was about 100 m. The individual eruptive fissures trend N80°E, but separate segments are en-echelon and form a zone that trends N60°E. The eruption began to decline in vigor about 0530 and stopped about 0850. Tholeiitic basaltic lava flows covered an area of ~7.5 km2, and their volume is estimated at 15 x 106m3. The flows traveled chiefly southwestward and southward, and have a total length of ~12 km. The eruption was accompanied and followed by an unusually large deflation of Kīlauea's summit region and extensive ground cracking and deformation along the southwest rift zone. An intense seismic swarm along the southwest rift zone lasted from 31 December to 4 January that included about 120 earthquakes stronger than M 3 and five earthquakes exceeding M 5.

Information Contacts: Donald Peterson, HVO.


November 1975 (SEAN 01:02) Citation IconCite this Report

Lava fountains following a severe earthquake

At 0532 on 29 November, 44 minutes after a severe earthquake beneath Hawaii's SE coast (table 1), lava erupted from a N85°E-trending fissure on the floor of Kīlauea caldera. Lava fountains were 50 m high for the first 15 minutes but decreased to 5-10 m heights for the next 75 minutes before stopping. Eruptive activity resumed at about 0830 in Halemaumau pit crater and continued intermittently before ceasing around 2200, after 16 hours of activity. Lava drained into the SW rift zone for days after the end of visible activity. Maximum horizontal displacement on the order of 3.5 m was involved in the seaward movement of Kīlauea's S flank.

Table 1. Seismic parameters of the Kalapana earthquake that occurred at 0448 on 29 November 1975. The epicenter was 30 km ESE of Kīlauea Caldera. Additional data on the important earthquake may be found in Crosson and Endo (1981).

Date Magnitude Latitude Longitude Depth Reference
29 Nov 1975 7.2 Ms 19.335°N 155.024°W 5 km As originally reported by HVO (SEAN 01:02)
29 Nov 1975 7.2 Ms 19.35°N 155.02°W 8 km HVO Annual Summary for 1975

The earthquake was the strongest in Hawaii since at least 1868, and extensive damage was reported. On the SE shore, at Punaluu, a 6-m tsunami was observed. At Halape, two people died when a wave in excess of 7 m high [swept inland] and reached 16 m up a fault scarp perpendicular to the coast. The coastal area at Halape, the area of maximum subsidence, was permanently lowered 3 m. The tide gauge at Hilo recorded a 2.5 m wave.

Further References. Crosson, R.S., Endo, E.T., 1981, Focal Mechanisms of Earthquakes Related to the 29 November 1975 Kalapana Hawaii Earthquake: The Effect of Structural Models, Bull. Seismol. Soc. Am., v. 71, p. 713-729.

Lipman, P.W., Lockwood, J.P., Okamura, R.T., et al., 1985, Ground Deformation Associated with the 1975 Magnitude 7.2 Earthquake and Resulting Changes in Activity of Kīlauea Volcano, Hawaii; USGS Professional Paper 1276, 45 pp.

Information Contacts: R. Tilling, HVO.


January 1976 (NSEB 01:04) Citation IconCite this Report

Slow inflation and two earthquakes

The volcano has been inflating slowly since the 29 November eruption. Two earthquakes, one of magnitude 4.0, shook Kīlauea on 11 January, the largest events associated with the volcano in several months.

Information Contacts: R. Tilling, HVO.


November 1976 (NSEB 01:14) Citation IconCite this Report

Summit deflation

A [gradual] 40 µrad deflation of the summit occurred [aseismically] during late August and September. In late October, a 15 cm dilation and a several-acre area of steam-killed trees were noted N of Kalapana on the E rift zone, about 25 km from the summit of Kīlauea. It is assumed that the magma that left the summit area migrated into the E rift zone, causing the effects observed near Kalapana.

[Intrusive episodes on 21 June and 14 July 1976, not reported in the original Bulletin, are described in the comprehensive summary of Dzurisin and others, 1984.]

Information Contacts: G. Eaton, HVO; D. Shackelford, CA.


April 1977 (NSEB 02:04) Citation IconCite this Report

Monitoring data from 8-9 February magma intrusion event

A fascinating magma intrusion event at Kīlauea on 8-9 February was unusually well documented. Continuously recording tiltmeters monitored a sharp summit deflation beginning 8 February at 1902, 5 hours after the start of an earthquake swarm (M 3-4) on the upper E rift zone. A local magnetic anomaly (approximately l0 gamma) also occurred in the upper E rift zone, and seismicity reached 200 events/hour with 3-7 km focal depths, but no eruption took place. Geodimeter surveys 1 day after the event showed extensions of up to 0.25 m across the upper E rift and electrical self-potential traverses add more documentation of magma migration. Similar events took place in June and July 1976, and HVO scientists suggest that magma is draining from beneath the summit area along subsurface paths created by the major earthquake of 29 November 1975. These drainage paths readily allow periodic intrusion into the E rift and are perhaps preventing major inflation of the summit reservoir.

Information Contacts: Hawaiian Volcano Observatory, USGS.


September 1977 (NSEB 02:09) Citation IconCite this Report

Fissure eruption begins on the East Rift near Kalalua Crater

A substantial eruption on the E rift began from fissures near Kalalua Crater (figure 1) on 13 September, after about 24 hours of premonitory activity.

Figure (see Caption) Figure 1. Sketch map outlining the September lava flows (stipple pattern) and various features of Kīlauea. Open circles are craters. Courtesy of Robert Tilling.

Field observations suggest interesting changes in lava composition during the course of the eruption. Lava erupted during the first three phases and about the first 1.5 days of the fourth phase apparently consisted of differentiated material containing plagioclase and pyroxene phenocrysts. This was succeeded on the 27th by more typical Hawaiian tholeiite basalt containing olivine phenocrysts.

Information Contacts: R. Tilling, USGS, Reston, VA; G. Eaton, HVO; R. Fiske, SI.


October 1977 (NSEB 02:10) Citation IconCite this Report

Eruption near the Kalalua cone ends on 1 October

The following is from Gordon Eaton. "At approximately 1930 on 13 September an eruption broke out on the central E rift, near Kalalua, a prehistoric cinder cone (see table 2 for detailed chronology). It followed a swarm of earthquakes that began on the previous day at 2130 on the upper E rift, near the young satellite shield, Mauna Ulu, and Makaopuhi crater. These earthquakes were accompanied by harmonic tremor and rapid summit deflation, indicating that magma was moving into the E rift in the subsurface. The deflation continued strongly for about a week and then tapered off gradually. A total of 90 µrad of tilt change was measured on the tiltmeters at Uwekahuna vault. Levelling later showed maximum summit subsidence of 44 cm."

Table 2. Chronology of the September-October 1977 eruption at Kīlauea.

Date Time Activity
12 Sep 1977 2130 Earthquake swarm began in the upper E rift.
12 Sep 1977 2200 Summit deflation began.
13 Sep 1977 mid-morning Earthquake hypocenters began to migrate E along the E rift.
13 Sep 1977 1930 Fountaining began at newly opened fissures extending 3 km E from Kalalua Crater, accompanied by heavy harmonic tremor. Total summit deflation (as measured at Uwekahuna) had reached about 42 µrad.
14 Sep 1977 0800 Fountaining was confined to the E one-third of the new fissures, feeding a lava flow moving S. Summit deflation, 3.5 µrad/hour.
15 Sep 1977 0200 Two areas of fountains, about 60 m high. Activity along remainder of the fissure was confined to low spattering. The deflation rate had declined to about 1 µrad/hour; total subsidence was about 75 µrad.
15 Sep 1977 late afternoon First phase of the eruption ended, after the lava flow had advanced about 2.5 km. Earthquakes and harmonic tremor had declined. Total summit deflation was about 85 µrad.
15 Sep 1977 2400 Harmonic tremor ended.
16 Sep 1977 0400 Renewed fountaining (phase 2), feeding a small flow [but see 02:10] parallel to the first flow. Fountains were discontinuous, rising to about 50 m from a vent area about 200 m long, slightly W of the earlier vents.
18 Sep 1977 1530 The eruption had declined to weak, intermittent spattering, and the new flow had stopped less than 0.5 km from the vent. Harmonic tremor was still being recorded from the vent area, but not from the summit, where deflation had ended. Earthquakes had declined.
20 Sep 1977 evening Phase 2 activity ended [but see 02:10].
23 Sep 1977 early afternoon Minor fountaining (to 15 m) fed small flows, and ended by nightfall (Phase 3).
25 Sep 1977 2350 Phase 4 began from a vent W of the earlier ones. During the next 24 hours, fountains rose 100 m, and discharge rates briefly reached an estimated 5-7 x 105 m3/hour. Lava advanced SE at up to 300 m/hour.
29 Sep 1977 -- Kalapana, a coastal village with population about 250, [but see 02:10] was evacuated. The flow front, several thousand meters from the village, was advancing toward it about 150 m/hour down a steep slope. A transition from pahoehoe to aa flow types occurred at the edge of the steep slope.
30 Sep 1977 0300 The fountains feeding the flow declined to 20-30 m and the flow had slowed to 60-90 m/hour after reaching a gentler slope. Summit tilt remained irregular, varying 2 µrad throughout phase 4.
01 Oct 1977 1000 Flow advance had stopped 400 m from the nearest house in Kalapana. The pahoehoe to aa transition had retreated to the vent area. The flow front had thickened from 4.5 to 12 m and had widened from 300 to 900 m.
01 Oct 1977 1530 Harmonic tremor near the vent declined markedly.
01 Oct 1977 1625 Fountaining stopped, after building an irregular 100 m [but see 02:10] spatter cone.

"The initial active section of rift was approximately 5.5 km long, but fountaining at all times and locations was restricted to a few hundred meters of this length. The remainder of the rifted zone opened as a series of en echelon fractures and were sites of profuse steaming. Maximum fountain heights reached during the early phases of the eruption did not exceed 70-80 m. Flows at that time consisted chiefly of aa, with a maximum rate of advance of about 170 m/hour. By dawn on 15 September these flows had slowed to 65 m/hour. They came to rest about 2.5 km from their source fountains, close to a papaya field and ranch.

"On 18 September new fountaining began uprift, immediately NW of Kalalua cone, several kilometers from the initial fountains. By late afternoon on 19 September this activity had decayed and flow movement was scarcely perceptible, but by midnight fountaining resumed. By 0900 hours on 20 September this phase of the eruption had ended.

"The next phase consisted of Strombolian activity at a small, new cone downrift in the afternoon of 23 September. The lava was highly viscous and was ejected sporadically in a series of taffy-like, irregular sheets and long clots. All lava to this point in the eruption was tholeiite rich in plagioclase microphenocrysts, presumably old and highly differentiated lava.

"The period 24-25 September was free of activity at the rift. Harmonic tremor decayed to very low levels. Just before midnight on 25 September, however, tremor resumed and strong glow was visible over the rift. Heat from the eruption domed a blanket of stratus clouds over the volcano into a huge cumulus cloud. Harmonic tremor amplitude rose at the two seismometers closest to the fountaining. Except for a 2-hour lull in the early afternoon of 26 September this fountaining continued until mid-afternoon on 1 October. Fountains played from heights of 20 m to as much as 300 m, lava production was copious at all times, and the new flows ran NE, ENE, and SE, but only the ENE flow eventually threatened populated areas. In the early hours of 28 September it turned away from the rift down which it had flowed for 1.5 km and started toward the village of Kalapana. Evacuation of Kalapana began at dawn 30 September and was completed by evening.

"On 1 October at 1530 tremor levels along the central E rift dropped dramatically. Fountaining had ceased by 1615. It did not resume again, although measurable tremor continued through 12 October.

"Evacuees returned 3 October, 38 hours after cessation of fountaining. The source cone, named Pu'u Kia'i (Hill of the Guardian) is 250 m long, 140 m wide, and 35 m high."

Further Reference. Moore, R.B., Helz, R.T., et al., 1980, The 1977 Eruption of Kīlauea Volcano, Hawaii; JVGR, v. 7, p. 189-210.

Information Contacts: G. Eaton, HVO.


November 1979 (SEAN 04:11) Citation IconCite this Report

Brief eruption from upper east rift zone

"Kīlauea erupted on its upper E rift zone for 22 hours on 16-17 November. Seismicity since the 1977 eruption was sustained at moderate to high levels at the summit and the E rift zone until the onset of the swarm of shallow earthquakes that preceded the eruption (figure 2).

Figure (see Caption) Figure 2. Plot of shallow earthquakes (1-5 km depth) associated with the 16-17 November 1979 eruption.

"The swarm began at 2100 hours on 15 November near Pauahi Crater, 7-8 km SE of the central caldera region, and within a half an hour the summit tiltmeter indicated the onset of deflation (figure 3). Simultaneously, two borehole tiltmeters detected inflation in the upper part of the E rift zone (see table 3 a for detailed chronology). Shallow volcanic tremor very local to Pauahi Crater (figures 3 and 4) became strong at about 0700 the next morning (16 November) as the number of earthquakes gradually decreased. At 0821, low fountaining (less than 10 m high) started in Pauahi Crater. Fifteen minutes later, observers arrived on the E side of the crater and found a curtain of fire 5-10 m high and 100 m long. These E vents ceased eruption less than 1 hour later. At 1130, two more vents opened in Pauahi Crater, W of the first Pauahi vent. Shortly thereafter, brief fountaining was observed N of the earlier E vents, followed by cessation of activity of the initial (eastern) Pauahi Crater vent. Over the next 1.5 hours, six more vents opened progressively to the W, one more in the crater and five W of the crater. Slightly before 1600, activity at the W vents began to wane and over the next hour fountaining ceased progressively eastward at the five W vents. Lava production in the three remaining vents in Pauahi Crater stayed relatively constant until 0100 on 17 November, gradually waned, then ceased activity at 0630, 22 hours after the eruption began.

Table 3. Chronology of the November 1979 eruption at Kīlauea.

Date Time Activity
15 Nov 1979 2100 Seismic swarm began local to Pauahi station.
15 Nov 1979 2130 Deflation at the summit and inflation at the eruption site.
16 Nov 1979 0005 Peak earthquake rate.
16 Nov 1979 0700 Strong tremor began local to Pauahi station.
16 Nov 1979 0805 Copious steam and fume emission began E of Pauahi Crater. The fissures occupied an old spatter rampart and never emitted lava, but the emitted gases were hot enough to ignite adjacent vegetation.
16 Nov 1979 0821 A sharp cracking sound accompanied the opening of a vent (P1, figure 4) on the NE wall of the NW lobe of Pauahi Crater; initial fountain heights were less than 1 m.
16 Nov 1979 0836 Observers arriving at Road's End parking lot found fissures already erupting a low (5-10 m) curtain of fire (E1, figure 4) about 100 m long, 230 m E of the copiously fuming area noted at 0805. Fissuring migrated E, eventually producing a separate lava pad (E2). New fissures east of the E2 vent occupied the center of an old spatter rampart.
16 Nov 1979 0925 Eruptive activity on E1 and E2 fissures ceased.
16 Nov 1979 1130 A fissure opened about 70 m W of the still active P1 vent in Pauahi Crater, and almost immediately began to fountain to heights of 2-10 m on its W end. A few seconds later, three smaller vents began activity between the new fountain (P2) and P1. These vents collectively are labeled P3.
16 Nov 1979 1135 Brief eruption (time uncertain) from a fissure (EN) N of the main E vents.
16 Nov 1979 1140 An eruptive fissure (P4) opened 20 m W of P2.
16 Nov 1979 1149 Activity at P1 vent abruptly decreased with concurrent increase of activity at P2, P3, P4.
16 Nov 1979 1150 P1 vent ceased activity.
16 Nov 1979 1155-1200 Flows produced by the now-inactive P1 began to cascade down the mezzanine into the SE crater of Pauahi, followed by flows from P2-4.
16 Nov 1979 1203 Fissures migrating W of Pauahi Crater cut the overlook parking lot and the Chain of Craters Road.
16 Nov 1979 1214 Eruption began from E to W on three fissures (W1, W2, and W3) beginning just W of the Chain of Craters Road; concurrently there was a temporary decrease in activity of vents P2-4 in Pauahi. Curtains of fire to 10 m high with spatter ejected to 30-40 m were soon established on two of the new vents (W2 and W3); weak spattering occurred at W1 vent.
16 Nov 1979 1239 Eruption began at W4 vent. Activity at W1, W2, and W3 vents decreased abruptly at the onset of this activity.
16 Nov 1979 1255 Eruption began from W5 vent, followed by roughly constant rates of effusion (about 50,000 m3/hour) from all the W vents over the next 3.5 hours.
16 Nov 1979 1445 Tremor amplitude at seismic stations 6 km from the eruption site reached a peak. The earthquake rate dropped by an order of magnitude from its peak values at 0005.
16 Nov 1979 1542 Abrupt brief decrease in fountain height of all W vents followed by cessation of activity at W5 vent and slight decrease in activity of vents P2-4.
16 Nov 1979 1543-1631 Decrease and cessation of activity of W4 vent. Decrease in activity of W2 and W3 vents; nature of activity at W1 vent unknown, but total emission from W1 was less than 15 m3.
16 Nov 1979 1547-1555 Chain of Craters road cut by small flow lobes.
16 Nov 1979 1631-1648 Activity of W2 and W3 vents declined to sporadic spatter emission.
16 Nov 1979 1651 Cessation of activity at all W vents.
16 Nov 1979 1716 Increase in activity of P2, P3, and P4 vents; approximately constant combined effusion rate of P2-4 of 15,000-20,000 m3/hour for the next 6 hours.
16 Nov 1979 1845 Activity of P4 vent decreased.
16 Nov 1979 2030 Activity of P4 vent essentially ceased.
17 Nov 1979 0100-0409 Activity at P2 and P3 continually waned.
17 Nov 1979 0413 Continued decrease in activity of P2 and P3 vents; tilt at summit reversed; seismic tremor subsided.
17 Nov 1979 0630 All but gas activity ceased in Pauahi crater vents.
17 Nov 1979 0809 Surface movement of red lava in channels in Pauahi ceased, followed over the next 2 hours by collapse of crust and levees and formation of slab pahoehoe.
Figure (see Caption) Figure 3. Daily record of summit inflation of Kīlauea, 1977-78.
Figure (see Caption) Figure 4. Preliminary sketch map of the 16-17 November 1979 eruption site.

"During the eruption, tremor amplitude fluctuated with the extrusion rate, and earthquakes continued to decline to a frequency only slightly higher than a normal background rate. Earthquakes immediately preceding and accompanying the eruption occurred within a roughly triangular zone bounded by the E rift, Koae fault zone, and a N-S line 1 km W of Pauahi (figure 2).

"Unlike previous events, which presumably defined a downrift propagation of magma from the summit reservoir, epicenters during this eruption showed no downrift migration and tremor did not occur near stations uprift of the eruption. Furthermore, earthquakes migrated upward from 3 to 1 km in depth during the first 2 hours of the swarm. It therefore seems probable that the eruption was fed by magma already stored beneath the rift zone and that magma drained from the summit reservoir to replace the magma mobilized in the E rift zone near the eruption site.

"Figure 3, summarizing the pattern of inflation at the summit of Kīlauea between the 1977 and 1979 eruptions, shows that throughout the month of November 1978, there was a slow deflation of the summit. Concurrently, an area approximately centered on the 1977 eruption site started to inflate. Except for the minor deflation centers along the upper E rift zone, the upper and lower parts of the E rift zone remained relatively undeformed during the period between eruptions.

"Summit SO2 emission averaged 100-200 t/d over the 13 months preceding the eruption and peaked occasionally at 350 t/d. Ten days prior to the eruption a spike of 500 t/d was recorded, followed by a return to approximately normal daily emission throughout and following the eruption. Anomalous abundances of S were observed in condensates at two sites and of CO2 at one site. The data base is too short to determine whether the observed variations of S and CO2 are indicators of magmatic activity preceding the November eruption, or were coincident fluctuations unrelated to magma movement.

"The eruption was characterized by less than 700,000 m3 erupted volume, low fountains, generally low amounts of fume, viscous lava and spatter, and low temperatures (generally 1,040-1,080°C with an infrared pyrometer). The overall pattern of the fissure system suggests that a left lateral shear couple was present during the eruption. The only obvious phenocryst observed by preliminary megascopic observation is olivine, 0.5-2 mm in diameter. The earliest samples, especially those from the easternmost vents, appear to be poor in olivine (1-3%), whereas those from the later stages contain 3-8% olivine phenocrysts. Interpretations of this variation include: 1) eruption of a single fractionated magma body; 2) eruption of several discrete, compositionally variable, possibly fractionated magma bodies, and 3) an influx, during the later stages of the eruption, of more primitive (olivine-rich) magma that drained from the summit reservoirs.

"The seismology, petrology, and surface deformation suggest that the eruption was likely the result of a disturbance of a shallow local storage chamber where the magma had resided for several months or years. The immediate area had been the site of the August 1968, May 1973, and November 1973 eruptions and lies along the geologically and seismically defined shallow conduit system leading from the summit magma chamber.

"Summit deflation suggests that the volume of magma withdrawn from the summit reservoirs was 4-6 times that erupted. Presumably this excess magma is stored in conduits and reservoirs in the upper E rift zone. Figure 3 indicates that the November eruption involved a trivial amount of the magma that has been supplied to the summit since the September 1977 eruption, and at present, the level of summit inflation is approximately that prior to the eruption."

Information Contacts: N. Banks and F. Klein, HVO.


March 1980 (SEAN 05:03) Citation IconCite this Report

Two intrusions into the upper east rift

Magma was intruded into the upper E rift zone on two occasions in March. On 2 March, a microearthquake swarm began near Pauahi Crater, 6 km downrift from the summit and site of a brief eruption in November 1979. Summit deflation, indicating draining of the magma chamber below, started within 7 minutes and a tiltmeter began to record deformation as magma was intruded downrift. About 2,000 earthquakes, including several felt events, were recorded before the swarm ended 8 hours later. Summit deflation, totaling only 8 mm, continued for another hour. Just over a week later, a second intrusion took place a few kilometers farther down the E rift beneath Mauna Ulu, active 1969-1974. Earthquakes began on 10 March at 2157, summit deflation at 2206, and volcanic tremor at 2310. Eight centimeters of deflation, representing the draining of 8 x 106 m3 of magma from the summit chamber, occurred before the end of summit deformation on 12 March at 1630. Volcanic tremor around Mauna Ulu waned slowly and had almost ceased by 13 March.

Inflation has resumed since the second intrusion. As of 2 April, the level of the summit was slightly higher than immediately prior to the November eruption.

Information Contacts: Hawaiian Volcano Observatory, USGS.


August 1980 (SEAN 05:08) Citation IconCite this Report

Intrusion into the upper east rift zone

Magma was intruded into the upper E rift zone on 27 August, the first intrusive activity there since March. As in the two March intrusions, no eruption took place. An earthquake swarm began near Puhimau Crater (about 1.5 km SE of the caldera rim) at 1425 on 27 August. Within 6 minutes, the number of microearthquakes had increased to several per minute. Summit deflation started 30 minutes after the swarm, at 1455.

The earthquakes migrated generally downrift at about 1 km/hour. Several were felt nearby, with the three highest magnitudes ranging from 3.6 to 4.0. Hundreds of magnitude 1-3 events occurred at depths of 1-4 km. The seismographs closest to the swarm apparently registered some shallow volcanic tremor, but microearthquakes occurred so rapidly that tremor was obscured on the records. The number of microearthquakes per minute started to decrease at about 1830 and the swarm ended early the next morning. Summit deflation had stopped at about 1930 on 27 August, after 7.5 µrad of tilt had been recorded.

The USGS interpreted the activity as the formation of a dike estimated to be about 3 km long, 1-2 km high, and l m wide, located 1-3 km beneath the surface. About 4 x 106 m3 of magma were calculated to have been injected into the dike between 1500 and 1930 on 27 August.

SO2 emission was detected in the Puhimau thermal area (where the earthquake swarm began) on 28 August. The CO2/SO2 ratios of gases emitted by the summit fumaroles before and after the intrusion remained about the same as the previous week.

Information Contacts: Hawaiian Volcano Observatory, USGS.


October 1980 (SEAN 05:10) Citation IconCite this Report

Two intrusions into the upper east rift

A minor intrusion of magma into the upper E rift zone was recorded on 22 October. At 1840, an earthquake swarm began near Pauahi Crater (6 km downrift from the summit), and summit deflation started 8 minutes later. Seismic activity declined about 2000, and deflation leveled off at about 2200, after 1.9 µrad of movement had been recorded. In the 24 hours before the intrusion, seven earthquakes with magnitudes of 3.1-4.2 had occurred at less than 5 km depth along the middle and lower E rift.

At press time, a second intrusion was recorded. An earthquake swarm began on 2 November at about 1415 and summit deflation started less than 30 minutes later. Between 1,000 and 1,500 earthquakes occurred at depths from 4 km to less than 1 km, migrating from just above Kokoolau Crater (about halfway between the caldera rim and Pauahi Crater) 2-3 km downrift to the Heake Crater area. About 4.5 µrad of deflation took place in the summit area before seismicity ended around 1700, and another 0.5 µrad of deflation were recorded in the succeeding 24 hours. In contrast to the aftermath of the smaller 22 October intrusion, inflation did not resume immediately after deflation ended, tilt remaining essentially stable. During and just after the intrusion, no changes in amount or composition of gas emission were observed at various standard sites.

Information Contacts: Hawaiian Volcano Observatory, USGS.


May 1981 (SEAN 06:05) Citation IconCite this Report

Intrusion into the southwest rift

HVO has documented an intrusion into the SW rift in early 1981. This rift intrusion is the 13th since the major earthquake of November 1975, but the first since that date in the SW rift. On 20 January at about 0300 an intense earthquake swarm began just S of the caldera (figure 5). A few earthquakes migrated northward into the caldera during the next 60 hours, but most of the activity remained in the area where the swarm began, at depths of 2.5-3.5 km. Reoccupation of dry tilt stations 21 January revealed that significant inflation had taken place in the swarm area since the last tilt measurements 13 days earlier.

Figure (see Caption) Figure 5. Locations of shallow (< 7 km) SW rift earthquakes during four time periods from 20 January to 18 March 1980.

During the next few days, some epicenters advanced about 3 km down the SE side of the upper SW rift, while earthquakes continued in the initial swarm area. Migration of the seismicity was initially measured in hundreds of meters per day, more than an order of magnitude slower than the 500-1,500 m/hour during previous intrusions into the E rift zone. Additional dry tilt measurements 28 January confirmed that the center of inflation had also moved SW, but to a point distinctly NW of the seismically active zone. Until early February, earthquakes remained within 3 km of the initial swarm area. Seismicity had been concentrated in the same region during the last intrusion and eruption episode in the SW rift, in December 1974.

On 6 February, seismic activity suddenly shifted to an zone about 17 km downrift from the caldera center and the rate of deflation increased sharply in the N caldera area, which had shown only minor tilt changes earlier in the episode. Intense seismicity was confined to less than 1 km of the rift for the next two days. Earthquakes propagated downrift 8-17 February, forming a narrow, tubular zone that rose (at an angle of about 40°) from depths of 7 to 2 km over about 3 km horizontal distance. These earthquakes eventually reached depths of only 1.5 km. Two clusters of less intense activity occurred uprift between this zone and the area of late January-early February activity.

Seismicity subsided considerab1y 17 February as inflation resumed in the N caldera area. By the end of the month much of the 15 µrad of deflation recorded on borehole tiltmeters since early February had been regained. The most active seismic zone continued to grow slowly (less than 100 m/day) downrift, reaching a length of 5 km by mid-March, but the number of events per day declined from a peak of 1800 in mid-February to 110-350 by late March. SW rift seismicity decreased gradually through April, reaching near-normal levels by the end of the month.

Information Contacts: Hawaiian Volcano Observatory, USGS.


June 1981 (SEAN 06:06) Citation IconCite this Report

Small shallow intrusion under SE part of caldera

On 25 June, HVO recorded a small but rapid summit-area inflation episode accompanied by shallow microearthquakes and harmonic tremor. As rapid summit inflation started about 1500, a single seismic station in the SE part of the caldera began to record weak harmonic tremor. Six minutes later, tremor amplitude increased and scattered small individual earthquakes started to appear, still at only one seismic station. Tremor strengthened again and earthquakes became larger and more frequent at 1510, as instruments to a radius of 5 km began to register the individual events.

A magnitude 2.5 earthquake at 1517 was followed by relatively intense localized shallow activity, including tremor and more than 6 microearthquakes per minute between 1518 and 1530. Inflation ended about 1530, as harmonic tremor weakened and the number of microearthquakes started to decline. Between 1500 and 1530, 6 µrad of inflation had been registered by the E-W component of a continuously-recording tiltmeter on the W rim of the caldera. No tremor was detected after 1600, but microearthquake activity remained high, gradually decreasing over the next 2 days. After inflation had ended, reoccupation of dry tilt stations near the caldera showed a maximum net tilt for the episode of 20 µrad (toward the NW) at a station near the SW rim.

The USGS's preliminary interpretation of this episode is that a small shallow intrusion [took place] beneath the S or SE part of the caldera. None of the hypocenters was shallower than 2 km, indicating that magma came no closer than that to the surface.

Information Contacts: R. Koyanagi and R. Decker, HVO.


July 1981 (SEAN 06:07) Citation IconCite this Report

Intrusion under S summit area and SW rift zone

"On 10-11 August seismographs and tiltmeters at HVO recorded a moderate intrusion at Kīlauea. The event was characterized by an earthquake swarm and harmonic tremor, accompanied by summit deflation and ground cracking. As of 0800 on 11 August, an estimated 30-50 x 106 m3 of magma had intruded into the S summit and SW rift zones. The activity started with an increase of microearthquakes in the S summit area at 0330 on 10 August. Shortly before 0430 tiltmeters recorded the onset of the sharp summit deflation. By 0500 the seismic intensity increased and maintained a continuous state of activity. Micro-earthquakes and harmonic tremor less than 5 km in depth indicated that magma was migrating from the summit to the SW rift zone in the vicinity of the Kamakaia Hills nearly 20 km away. At mid-morning 11 August several thousand earthquakes of <= 4.5 Ms were detected, and monitoring instruments continued to record a diminishing pattern of seismicity and ground tilt."

Information Contacts: R. Okamura, HVO.


August 1981 (SEAN 06:08) Citation IconCite this Report

More information on SW Rift intrusion

An estimated 35 x 106 m3 of magma were intruded into Kīlauea's S summit region and SW rift 10-12 August, accompanied by seismicity, substantial summit deflation, and ground cracking in the SW summit area. Microearthquake activity in the S summit region began to increase about 0330 on 10 August, followed by the onset of rapid deflation about 1 hour later (figure 6). Earthquakes began to migrate away from the summit into the SW rift (figure 7) and by evening were concentrated about 17 km downrift, in approximately the same zone that had been seismically active during the later stages of the January-February intrusion. Seismic activity peaked during the evening of 10 August and gradually declined the next day. During the intrusion, seismic instruments detected thousands of small earthquakes, most shallower than 5 km, plus several magnitude 3.5-4.5 events that were felt near the volcano. Summit deflation continued, but at a slowly decreasing rate, until the late evening of 12 August, when inflation resumed. Weak harmonic tremor accompanied the slow summit reinflation. SW rift seismicity remained slightly above average in late August, but was continuing to decline.

Figure (see Caption) Figure 6. Summit tilt measured by HVO July 1978-June 1982. Tilt is recalculated to N60°W from E-W and N-S components. Each unit mark on the x axis represent 10 µrad of tilt (up = inflation).
Figure (see Caption) Figure 7. Locations of shallow (less than 7 km deep) summit and SW rift earthquakes recorded by HVO during various time intervals between 0330 on 10 August and 0800 on 11 August. Hypocenters less than 5 km deep are indicated by + signs; those deeper than 5 km by boxes.

Information Contacts: Hawaiian Volcano Observatory, USGS.


March 1982 (SEAN 07:03) Citation IconCite this Report

Small intrusions into E and SW rifts

Summit seismicity had increased to nearly normal daily counts by late December 1981. Since January, several very small intrusions (occasionally seismic but generally aseismic) have been detected by changes in tilt, gas emission, and fumarole temperatures in the E and SW rifts. By late March, tiltmeters showed that the summit area had recovered most of the roughly 100 µrad of deflation recorded during the intrusion of magma into the S summit region and SW rift 10-12 August. The inflation center was in the S caldera-upper SW rift area. A 45-minute swarm of 400-500 earthquakes that started about 1430 on 23 March indicated that magma was forcing open a new channel (or reopening an old one). The seismic swarm was not accompanied by any detectable ground deformation. Overall seismicity in the SW rift remained high in early April but seismicity in the E rift was still relatively unchanged.

Information Contacts: N. Banks, HVO.


April 1982 (SEAN 07:04) Citation IconCite this Report

Small fissure eruption in summit caldera

"A summit eruption began at 1137 on 30 April and lasted about 19 hours, preceded by a microearthquake swarm about 3 hours long. Earthquakes at 1-3 km depth and magnitudes of less than 3 occurred in the S part of the caldera (figure 8). Rapid inflation of 5.5 µrad was recorded at the Uwekahuna tiltmeter, on the NW rim of the caldera, during the earthquake swarm (figure 9).

Figure (see Caption) Figure 8. Sketch map of Kīlauea Caldera, showing locations of the 30 April-1 May eruption fissures (hachured lines), the area covered by the new lava flows (stippled), and the earthquakes that preceded the eruption (solid squares).
Figure (see Caption) Figure 9. Tilt measured 30 April - 1 May at Uwekahuna, on the NW rim of the caldera. Increasing tilt readings correspond to summit inflation (up to E). The eruption began at 1137, just after maximum tilt.

"Lava was erupted from an ENE-trending fissure approximately 1 km long. The fissure, on the S flank of the 1954 spatter ramparts, first opened near its E end about 2 minutes before spatter appeared. Steam emission closely followed opening of the crack as it extended in length both to the E and W. Preliminary data indicate that the line of vents propagated both E and W from the initial vent. Eastward propagation occurred at about 1-2 m/second. The entire line of vents, including its westernmost part (in Halemaumau pit crater), was active within 25 minutes of the eruption's start, forming a nearly continuous and steady curtain of spatter on the order of 5-10 m high with bursts to 25-50 m. Lava flows to the N, E, and S, which eventually formed prominent lobes, were under way within minutes of the beginning of the eruption.

"A decrease in eruption rates near the ends of the line of vents was first recognized at approximately 1630, about 5 hours from the beginning of the eruption. About an hour later (at 1740) the westernmost vents, except for those in Halemaumau, had shut off, and drainback was occurring in the area of the central vents, from which the relatively extensive flows to the N and S were fed. By 2100, only the central 150-200 m of the fissure system was active. At this group of vents, activity continued steadily until about midnight, after which the rate of fountaining decreased and the length of the active fissure system gradually diminished.

"A preliminary estimate suggests that the volume of new lava is about 0.5 x 106 m3, primarily pahoehoe flows. A quick hand-lens inspection suggests that it is aphyric, or has at most rare olivine microphenocrysts. Relatively high temperatures, about 1,135-1,150°C, were measured by thermocouple and two-wavelength infrared pyrometer. Minimal fume production, relatively high density of spatter, and low fountain heights suggest that the gas content of the lava was low. However, gas bursting increased in the last hours of the eruption as the rate of fountain activity waned at the remaining centrally located vents. Frothy pumiceous lapilli were ejected during this phase."

Information Contacts: Hawaiian Volcano Observatory, USGS.


June 1982 (SEAN 07:06) Citation IconCite this Report

Intrusion into the SW rift

Summit deflation and an earthquake swarm in the SW rift marked Kīlauea's 16th intrusive event since the magnitude 7.2 earthquake of November 1975. A continuously recording tiltmeter high on the NW flank began to show deflation during the night of 21-22 June, and seismographs detected the gradual onset of earthquakes in the middle SW rift early 22 June. Low-level harmonic tremor began about 1800. Deflation reached its maximum rate of 1.05 µrad/hour (E-W component) between 2100 and 2200 on 23 June, then gradually decreased. By 0900 on the 24th, tremor had generally ceased. Deflation had nearly stopped by 2200 and the number of microearthquakes had dropped from a maximum of a few hundred per hour to about 1 every 2 minutes.

Early in the swarm, earthquakes were concentrated at 7-8 km depth about 10 km SW of the summit caldera (in the Koae fault system about 3 km S of Pu'u Koae). No significant downrift migration of the epicenters occurred. About 50 µrad of summit deflation (E-W and N-S tilt recalculated to N60°W) were recorded during the intrusion (figure 6). Roughly 20 x 106 m3 of magma were injected into the SW rift, about half the volume of the last SW rift intrusion in August 1981. During Kīlauea's 30 April-1 May 1982 eruption, about 0.5 x 106 m3 of lava flowed onto the caldera floor.

Information Contacts: Hawaiian Volcano Observatory, USGS.


September 1982 (SEAN 07:09) Citation IconCite this Report

Fissure eruption in summit caldera

"An eruption in the S part of the caldera began at 1844:40 on 25 September, following nearly 2 hours of a premonitory seismic swarm and an abrupt increase in summit tilt. The eruption continued for 15 hours. Lava erupted from a kilometer-long set of left-stepping enechelon fissures in the the southernmost part of the caldera (figure 10). The E and central parts of the vent system were oriented in the usual ENE direction, nearly parallel to the nearby caldera wall. In the W part, however, the fissure turned NW, as if to follow the arcuate circumcaldera fault system. At the NW end of this dogleg, the fissure intersected a circumcaldera fault, and a small isolated vent erupted weakly at the top of the fault scarp.

Figure (see Caption) Figure 10. Preliminary map of Kīlauea caldera, showing the April and September lavas (stippled areas) and eruption fissures (cross-hatched lines). An isolated vent W of the September fissures is represented by a filled circle.

"The ENE-trending vents were fully active within about 3 minutes of the onset of the eruption and fountained vigorously and steadily through the night. General fountain height was estimated at 20-40 m, with Strombolian bursts that occasionally went as high as 50-70 m. Lava, fed primarily by these vents, rapidly filled a broad graben. At about 1930 the lava spilled southward through a gap in the caldera wall and fed an actively flowing channel that eventually extended more than 1.5 km to the S. Between 2100 and 2200, NE-flowing lava spilled into the interior of the caldera.

"The NW-trending vent segment was first recognized at about 1900. It extended NW to the caldera wall, which it reached at about 1945. The northwesternmost vent, on a segment of the caldera rim, opened at about 2100, and a small graben about 7 m wide and 20-40 cm deep extended E and W from the vent. The NW part of this line of vents had largely ceased erupting by 2300, but all other vents erupted with unchanged vigor until about 0500 on 26 September. At that time, the color changed from the normal yellow to an orange cast, and by 0600 most of the vents had shut down. Diminution of fountaining closely followed a marked decrease in tremor amplitude and a change in summit tilt from slow decrease to slow increase (see below). For the remainder of the eruption the only active vent was one in the central or S part of the NW-trending vent alignment. By 0830, eruption of new lava was about over, but loud explosive gas bursts continued until 0940.p>

"After the eruption was over, lava from the interior of the extensive pond surrounding the main vents drained back into the vents until 1800 on 27 September. The resulting collapse of the pond surface left a bathtub `ring' on the order of 2-4 m high on the enclosing escarpments. An early estimate suggests that perhaps as much as 3-4 x 106 m3 of pahoehoe lava was erupted. Of this, possibly as much as 1-2 x 106 m3 drained back into the vent system.

"Temperatures measured during the eruption were approximately 1,140-1,145°C for flows (pahoehoe toes and lava channels), 1,130-1,160°C for the NW-trending line of vents (cooler to the NW), and 1,170°C for the main, ENE-trending, vents. The latter vents fountained more vigorously, almost certainly erupted much more lava, were hotter, and emitted far more gas than the vents on the NW alignment.

"Gases from the erupting vents had atomic C/S ratios of 0.08-0.11 indicating considerable degassing of the magma prior to eruption. The gases were different from those of the 30 April 1982 eruption, which had a higher C/S ratio and were more oxidized. Hand lens inspection shows the new basalt to be almost aphyric. Olivine microphenocrysts are rare."

Kīlauea's small eruption of 30 April-1 May, also within the caldera, was from fissures roughly 1.5 km N of the September vents.

Seismic activity. "Earthquakes related to the eruption were centered in the S summit area (figure 11), initially forming a NE-trending epicentral zone 3.5 km long. Hypocenters were concentrated in a zone ranging from about 0.5 to 4.0 km in depth (figure 12). Located earthquakes ranged from 0.5 to 3.6 in magnitude. Several dozen were felt in the summit region. Nearly 100 earthquakes were located from the pre-eruption swarm, which started at 1650 when small earthquakes and weak harmonic tremor began to record on the summit seismographs. The seismic activity intensified rapidly so that within a few minutes stations 50 km away registered the signals and the number of recorded earthquakes reached 2-5/minute. For the first 3/4 hr, the onset of earthquake activity migrated from SW to NE at a rate of about 4 km/hour (figure 13). Moderate-sized earthquakes continued repeatedly along the entire epicentral zone until the eruption began, when earthquake activity in the S caldera region virtually ceased and strong harmonic tremor started. During the eruption, detectable earthquakes were smaller and less numerous than during the pre-eruption swarm. By midnight, locatable earthquakes had decreased to about 10/hour and were mainly confined to the NE part of the seismic zone.

Figure (see Caption) Figure 11. Map of Kīlauea caldera, with epicenters of earthquakes recorded 25-26 September. September eruption fissures are shown as cross-hatched lines and an isolated vent just to the W is represented by a filled circle.
Figure (see Caption) Figure 12. Depths of 25-26 September earthquakes projected into line A-A' from figure 11. The position of the eruption fissures along A-A' is represented by a cross-hatched line above the horizontal scale.
Figure (see Caption) Figure 13. Space-time diagram of earthquakes projected along line A-A' from figure 12, showing migration of epicenters from SW to NE at about 4 km/hour early in the pre-eruption swarm.

"Tremor intensity remained fairly steady through most of the eruption, but declined sharply between 0400 and 0500 on 26 September. By 0500, the tremor amplitude had declined almost to threshold level. As the eruptive activity waned during the morning of 26 September, earthquake activity renewed in the NE part of the seismic zone. Intermittent swarms accompanied minor surges of inflation indicated by summit tiltmeters. Post-eruption earthquakes occurred vigorously for much of 26 September and activity decreased slowly over the next 2 days. As of the end of September, the number of microearthquakes beneath the summit and upper E rift remained higher than average.

Deformation. "As in the April eruption, a rapid increase in summit tilt, probably related at least in part to emplacement of the feeding dike, coincided closely with the pre-eruption earthquake swarm. Uplift had reactivated old cracks by the time (1715) the first observer arrived near the site of the eventual outbreak. The recorded change in tilt on the upper NW flank was about 30 µrad, down to the NNW (figure 14). Termination of the rapid increase in tilt coincided approximately with the onset of strong harmonic tremor and the first appearance of lava. Most of the vigorous phase of the eruption was marked by gradual summit deflation. However, the tilt reversed at about 0450 on 26 September and the waning phase of the eruption was accompanied by gradual to moderate inflation that has continued intermittently since the eruption.

Figure (see Caption) Figure 14. E-W, top, and N-S, bottom, water tube tiltmeter records at Uwekahuna Vault, on the NW caldera rim. Large summit deflation in late June (at left) accompanied an intrusion into the SW Rift. The prominent inflation at right occurred mainly during the pre-eruption earthquake swarm 25 September 1982.

"A distance survey line across the zone where the new eruptive fissure formed was measured on 9 September, and repeated measurements were made during and after the eruption. Widening caused by the new dike was at least 705 mm and was accomodated in large part by contraction distributed across a broad zone on the flanks of the dike."

Information Contacts: E. Wolfe, HVO.


November 1982 (SEAN 07:11) Citation IconCite this Report

Intrusion into upper E rift

A shallow earthquake swarm began in the summit region at about 1730 on 9 December. Epicenters soon migrated into the upper E rift, to the vicinity of Lua Manu and Kokoolau Craters (1.4-3.2 km from the caldera rim). Preliminary locations indicate depths from 0.5 to less than 4 km beneath the surface. The largest earthquake had a magnitude of 3.5. No harmonic tremor was recorded.

Tiltmeter records from the NW caldera rim (Uwekahuna Vault) showed slow deflation starting about 1730 and accelerating about 1830. Just before 2000, the deflation rate decreased, and by 2030 slow inflation had resumed. Total deflation was about 5 µrad, suggesting that 2 x 106 m3 of magma from the summit chamber was intruded into the E Rift.

As of early 10 December, earthquake counts were slightly elevationated in the swarm area and slow summit inflation was continuing. This event marked Kīlauea's 17th intrusive event since the magnitude 7.2 earthquake of November 1975. Four eruptions have occurred since the 1975 earthquake.

Information Contacts: E. Wolfe, HVO.


January 1983 (SEAN 08:01) Citation IconCite this Report

Major eruption in middle E Rift Zone

[Much of the information in 07:12 was repeated or updated in 08:01. We have therefore combined the reports.] "An eruption in the E rift zone began at 0031 on 3 January. The outbreak began at Napau Crater (figure 15), 14 km SE of the caldera rim, and extended progressively NE. By 0740, the line of eruptive fissures was 6 km long and its E end was about 0.7 km SE of Pu'u Kahaualea. Fountaining and production of SE-moving lava flows of local extent continued until 1002. After a 4.5 hour pause, the eruption resumed at 1425 along a 100-m fissure at the NE (downrift) end of the vent system (about 600 m S of Pu'u Kahaualea). This eruption lasted until 1535. During this first day's activity, fountains up to 80 m high produced an estimated 2-3 x 106 m3 of lava.

Figure (see Caption) Figure 15. Index map of the summit region and E rift (top) and map of earthquake locations, lava flows, and eruptive fissures on the middle E rift zone, January 1983 (bottom).

"The volcano remained quiet for nearly 2 days. Eruptive activity resumed at 1123 on 5 January and continued with only brief interruptions until 2049 on 6 January. The eruptive activity jumped from one segment to another of a kilometer-long section of the vent system S of Pu'u Kahaualea (including, at its E end, the easternmost vent of 3 January). A large amount of the lava poured into an open crack, parallel to the eruptive vents and about 0.1 km SE of their E ends. The crack was along a bounding fault at the NW edge of a prominent older graben. Minor aditional fountaining and flow production also occurred at, and within 1.5 km SW of, Pu'u Kamoamoa, along vents established on 3 January.

"On the morning of 7 January the main eruptive center shifted temporarily still farther NE to a 1 km-long line of vents approximately 1.4 km ESE of Pu'u Kahaualea. After a brief introductory emission from 0957-0959, these vents erupted strongly from 1030-1557 on 7 January. During this period, they produced the highest fountains of the eruption; maximum sustained fountain heights of 80-100 m were estimated, with bursts sending fragmented spatter higher. This episode also fed a lava flow nearly 6 km long that extended E toward Kalalua then turned SE toward the coast. The flow, with an estimated volume of about 4 x 106 m3, converted to aa as its front passed near Kalalua and stopped nearly 5 km from the coast. A second eruption from the same vents, from 1625 on 7 January to 0430 on 8 January, produced a smaller lava flow that overrode the near end of the first flow from the vents E of Pu'u Kahaualea.

"Seven episodes of lava production ranging in duration from 8 minutes to 11 hours occurred 8-15 January from a group of vents S and SW of Pu'u Kahaualea that were active 5-6 January. The first and briefest of these (from 1446-1454 on 8 January) was from the E end of this group of vents. The remainder erupted from the W half of the kilometer-long line. Six of the seven extrusive episodes occurred 8-11 January, the latest on 15 January. One additional extrusion occurred 8 days later, during the evening of 23 January, when approximately 7000-8000 m3 of lava were erupted about 0.25 km E of Pu'u Kamoamoa following a magnitude 4.2 earthquake on the S flank.

"New lava covered an area of approximately 4.4 x 106 m3. The erupted volume is estimated to be on the order of 10 x 106 m3. Repeated measurements indicate an eruption temperature of about 1,135°C. The basalt is slightly porphyritic with scattered small plagioclase and olivine phenocrysts.

"Strong emission of sulfur-rich gases has continued since the beginning of the eruption; widespread dispersal of the gases had caused vegetation damage over large areas of E Hawaii. Between extrusive events (and continuing at the time of this report) some vents S of Pu'u Kahaualea remained at temperatures of about 1,070°C and burning gases were visible at night. These vents periodically emit spatter composed, at least in part, of incandescent and partly melted fragments eroded from the vent walls.

Seismicity. "In the weeks prior to the eruption seismographs recorded increasing rates of microearthquakes in the E rift zone. At 0030 on 2 January the seismicity developed into a swarm of small shallow (depth < 5 km) earthquakes (figure 16) and weak harmonic tremor. The swarm started in the upper E rift near Mauna Ulu, increased in the early hours and migrated downrift about 9 km to Napau Crater. Tiny earthquakes were recorded at a rate of 3-5/minute; seismic intensity peaked between 0040 and 0110, when several earthquakes, magnitude 2.5 to 3.0, were felt in the Hawaii Volcanoes National Park area. From 0300 to 1300 2 January, the seismic zone spread farther downrift to beyond Pu'u Kamoamoa (figure 17). From then until the eruptive outbreak, small earthquakes accompanied by harmonic tremor occurred at a nearly constant rate, mainly along a zone between Napau Crater and Pu'u Kamoamoa. When the eruption was sighted at Napau Crater by a ground crew at 0031 on 3 January, [instruments] started to record increasing harmonic tremor amplitudes and constant summit deflation.

Figure (see Caption) Figure 16. N-S and E-W components of summit tilt measured at Uwekahuna Vault, NW caldera rim, January 1983. Periods of lava production are also shown.
Figure (see Caption) Figure 17. Map of 1983 lava flows and eruptive fissures on the middle E rift zone for the periods 3-15 January (horizontal lines), 10 February-4 March (vertical lines), and 28 March-5 April (dotted pattern).

From 3 through 6 January the shallow earthquakes were broadly distributed from near Napau to beyond Pu'u Kahaualea. Harmonic tremor, although continuous, waxed and waned in consonance with the production of lava. In the early morning hours of 7 January, however, the shallow earthquake activity precursory to the opening of the vents E of Pu'u Kahaualea was concentrated in a zone that extended approximately from Pu'u Kahaualea to about 2 km downrift from Kalalua. Since then earthquake activity in the eruptive zone has been relatively low (figure 18). At the end of January, seismographs were still registering a moderate level of harmonic tremor originating from a source in the vicinity of the eruptive vents extending 2 or 3 km E of Pu'u Kamoamoa to near Pu'u Kahaualea.

Figure (see Caption) Figure 18. N-S and E-W components of summit tilt measured at Uwekahuna Vault, NW caldera rim, January-April 1983. Periods of lava production are also shown.

"Throughout the month thousands of shallow earthquakes were generated in the eruption zone. Of these, nearly 500, most from depths of less than 4 km and magnitude 0.5-4.0, were processed for size and location. The vast majority of the earthquakes probably record emplacement and establishment of the feeder dike system, a process that was completed on the morning of 7 January.

"Deeper earthquakes (5 to 13 km) that occurred throughout the month beneath the S flank were more or less representative of adjustment of the S flank that continues over the long term. However, a somewhat elevationated frequency of occurrence of S flank earthquakes in the early part of the month was probably a direct response to increased stress from the magmatic activity in the rift zone.

Deformation. "Tiltmeters in the Uwekahuna Vault recorded a summit collapase of about 125 µrad (figure 16), which represents an estimated volume loss of 50 x 106 m3 from the summit region. Broken only by temporary inflation during the non-eruptive interval between 3 and 5 January, almost all of the summit deflation occurred at a high rate from early on 2 January to early on 8 January. The summit subsidence and the period of intense shallow seismic activity were coincident. Approximately 3/4 of the volume of extruded lava was erupted during the same period. Minor, very slow deflation of the summit continued until about 18 January. Gradual recovery of about 4 µrad of tilt occurred during the remainder of the month.

"Geo-electric and recorded tilt changes in the E rift zone on 3 January strongly suggest that magma was intruding the rift as far down as Kalalua at that time. However, observations of ground cracking, tilt measurements, and electronic distance measurements show that major extension (> 2 m) perpendicular to the rift zone occurred N and NE of Kalalua late on 6 January and during 7 January. An electronically measured line across the eruptive fissures S of Pu'u Kahaualea, initiated on 19 January, has shown a steady extension averaging 7 mm/day during the last part of January.

Summary. "Although no major lava production has occurred since 15 January (a minor extrusion occurred on 23 January), the continuing steady harmonic tremor, voluminous gas emission, occurrence of incandescent and flaming vents, and extension across the recently active eruptive fissure S of Pu'u Kahaualea indicate that the magmatic activity related to the January 1983 eruption has not yet ended."

Information Contacts: E. Wolfe, A. Okamura, R. Koyanagi, HVO.


February 1983 (SEAN 08:02) Citation IconCite this Report

Renewed fountaining and lava flow production on E Rift

"The E rift zone eruption of Kīlauea that began on 3 January resumed on 10 February, and lava production continued until 4 March along eruptive fissures established during the initial outbreak on 3 January (figure 17). The renewed eruption followed nearly a month in which vent activity was limited largely to incandescence and emission of burning gases along parts of a 2-km segment of the vent system that extended E from about 0.75 km NE of Pu'u Kamoamoa to the area S of Pu'u Kahaualea. During the quiet period, a little incandescant spatter was ejected sporadically from the E vents; at least some of the ejecta consisted of wallrock remelted and eroded from the vents by vigorous emission of burning gas. There was no measurable production of new lava.

"Increased spatter production was first recognized on 10 February; a small (6 m-high) spatter cone had formed at the E vents (0.7 km S of Pu'u Kahaulea). By 12 February, a second small spatter cone had formed, and a glowing crack extended tens of meters NE of the 2 cones. Subsequent intermittent production of low fountains and small lava flows through 24 February led to growth of a flat-topped shield estimated to be about 200 m long, 100 m wide, and 10 m thick. The shield was capped by a 170 m-long line of juxtaposed spatter cones ranging up to about 15 m high. Lava production during the 2-week shield-building period is estimated at 0.5 x 106 m3. In addition, a short (probably 10-minute) episode of spatter production occurred at a vent just E of Pu'u Kamoamoa at about 2220 on 19 February. Gas emission during this period was low and was characterized by extremely low atomic C/S ratios (approximately 0.05) suggesting that the near-surface magma had largely degassed during the non-eruptive interval.

"Beginning at 0145 on 25 February, fountaining and lava flow production increased in the W and central parts of the shield and a flow about a kilometer long extended NE. Gas composition also changed at this time, becoming more C-rich (C/S approximately 0.15) and generally reverting to a composition indistinguishable from that of the early January gases. Thirteen hours later, at about 1440 on 25 February, the main eruptive locus shifted about 100 m uprift and eruption from the shield vents soon terminated, at 1518. Fountains played continuously at this new locus until the end of the eruptive episode on 4 March. During this period, sporadic lava production also occurred from local vents as far uprift as 0.75 km NE of Pu'u Kamoamoa.

"During its week of sustained activity, the main fountain, about 0.75 km SSW of Pu'u Kahaualea, was commonly 40-80 m high. Estimated to be about 30 m wide at its base, the fountain arose from a lava pond about 60 m in diameter. By the evening of 25 February, the S rim of the levee containing the lava pond had developed a spillway through which 2 major flows were supplied during the ensuing week. One of these moved NE 25-26 February within the same graben that contained the upper part of the 7 January flow. Following the path of that earlier flow, the new flow turned SE about 0.5 km W of Kalalua and stopped about 3 km from its source.

"By the morning of 27 February, the active lava river leading from the pond had been diverted SE, producing a flow that eventually extended more than 7 km from the vent to its terminus, about 3.8 km from the coast. This latest flow, parallel to and a kilometer SW of the 7 January flow, advanced slowly through the rain forest until 4 March, when lava production stopped. In the half nearest the vent, where the feeding channel was largely pahoehoe, the average velocity of the advancing flow front was about 90 m/hour. In the lower half, where the flow was dominantly aa, the front advanced episodically, but at an average rate of about 30 m/hour, even on the steepest (about 7°) slopes.

"In the early evening of 2 March, the advancing aa front, locally up to 10 m thick, entered the NE part of a sparsely populated subdivision on the S flank, just E of Hawaii Volcanoes National Park. Two dwellings were destroyed before lava production at the vent stopped at about 1500 on 4 March. Subsequent movement in the distal part of the flow was limited to minor adjustments that led to only a few meters of additional lava advance.

"Preliminary estimates, as yet without benefit of careful mapping or methodical thickness measurements, indicate that about 10 x 106 m3 of lava were extruded 10 February-4 March. Thermocouple measurements in pahoehoe toes gave lava temperatures of about 1112°-1120°C, slightly cooler than in January. The basalt is sparsely porphyritic with scattered small phenocrysts of olivine and plagioclase.

Seismicity and deformation. "Apparently because the feeder dike system had become fully established in early January and was maintained until eruptive activity resumed in February, the renewed lava emission was not accompanied by increased numbers of shallow earthquakes in either the summit or E rift zone. Harmonic tremor had declined by 30 January to about 10% of its high amplitude in early January; originating from a source beneath February's eruptive vents, the tremor slowly doubled in amplitude 30 January-25 February. From 25 February-4 March, average tremor amplitude was about 30% of the early January level. On 4 March, when lava production terminated, the tremor amplitude dropped abruptly to a low, but constant, level that was continuing as of 10 March.

"By 25 February, the E-W component tiltmeter in Uwekahuna Vault near the summit had recorded approximately 9 µrad of gradual summit re-inflation following the major subsidence of early January. The vigorous eruptive activity 25 February-4 March in the middle E rift zone coincided with an 11 µrad E-W deflation at Uwekahuna. Rapid summit re-inflation averaging about a µrad per day has occurred 4-10 March.

"No significant extension across the E rift has occurred in the vicinity of Kalalua since the major eruption of 7 January. However, a survey line across the eruptive fissure near Pu'u Kahaualea showed extension 29 January-12 February of at least 13 mm/day. By 14 February, new lava had obstructed the line."

Information Contacts: E. Wolfe, A. Okamura, R. Koyanagi, HVO.


March 1983 (SEAN 08:03) Citation IconCite this Report

Eruption continues in middle east rift zone

[With the following report, HVO scientists recognized that they were dealing with episodic eruptive behavior, which continued for the next three years. We have added numbered headers to help organize the reports. Originally referred to as "phases," the HVO staff later decided that the term "episode" was more appropiate (see SEAN 10:06). We have replaced the word "phase" throughout the text of earlier reports. Where the word "episode" was used in reports 8:3 to 10:6, we have substituted "period" to avoid confusion with the revised usage of "episode."]

EPISODE 3

"The 1983 eruption entered its third major episode of lava production in the early morning of 28 March. A 3.5-week quiescent period 4-28 March was interrupted only briefly by minor emission of spatter and pahoehoe lava on 21 March at vents S of Pu'u Kahaualea.

"Initially, on 28 March, the major eruptive activity occurred at a vent 700 m NE of Pu'u Kamoamoa, just inside the Hawaii Volcanoes National Park boundary. Vigorous extrusive activity at this vent produced a flow that extended nearly 5 km SE along the National Park boundary (figure 17). Eruption of this vent stopped at 2019 on 30 March.

"A vent S of Pu'u Kahaualea that was the source of the major flows of late February and early March resumed erupting 28 March, sporadically at first. Its eruptive activity became steady at approximately 1800 on 29 March. From then through 5 April, when this report was prepared, it supplied a flow that slowly extended 4 km [revised to 3 km in 8:4] NE along the rift zone to the vicinity of Kalalua. Another flow from this vent moved about 3 km SE on 4 and 5 April. The vent continued as the single locus of lava production. Its vigorous fountain, commonly 100 m high and at times estimated as high as 300 m, was visible from a number of vantage points along the highway from the Hawaii Volcanoes National Park to Hilo. Frothy scoria fragments, bombs of spatter, and thin spatter-fed flows built a prominent cone 60 m high [note growth to 80 m in 8:4], and a thin airfall pyroclastic blanket extended more than 1 km from the cone. Pele's hair fell as far as 17 km from the vent.

"The volume of basalt extruded since the eruption began on 3 January was on the order of 30 x 106 m3 [to at least 50 x 106 m3 by end of episode 3]. Flows of the present episode were dominantly aa. Lava temperatures ranging from 1112° to 1129°C were measured by thermocouple. Like the earlier 1983 lavas, those of late March-early April are slightly porphyritic, with scattered small plagioclase and olivine phenocrysts. The gas composition remained unchanged throughout the eruption, indicating that stored E rift magma remained the predominant source of the erupted lava."

Deformation and seismicity. "The water tube tiltmeter at Uwekahuna Vault in the summit region showed the correspondence of summit subsidence with major extrusion episodes in the E rift zone (figure 18). Moderate summit re-inflation followed the extrusive episodes of early January and early March. The tiltmeter data in combination with levelling results indicated a cumulative volume of at least 70 x 106 m3 [to 80 x 106 m3 by the end of episode 3; 8:4] for magma withdrawn from the shallow summit region since the beginning of the eruptive/intrusive activity in early January.

"Since cessation of the initial earthquake swarm in early January, seismicity in the eruptive zone was characterized by unceasing harmonic tremor that waxed and waned in amplitude in concert with the eruptive activity. As determined from a seismic station near Pu'u Kamoamoa and from portable seismometer traverses, the tremor originated from a source within a few kilometers of the surface in a zone between Pu'u Kamoamoa and the vents S of Pu'u Kahaualea.

"Following the major outbreak of 25 February-4 March, tremor continued at a decreased level. On 21 March, the amplitude gradually increased from 0430 to 0630, remained moderately high for most of the day, and decreased to its previous low level on the following day.

"A gradual increase in amplitude occurred again beginning in the early morning of 27 March. By 0100 on 28 March the tremor amplitude increased by about 5 times at the Pu'u Kamoamoa station. Glow from active fountains was reported shortly thereafter. Tremor remained strong as of 5 April, at times reaching an amplitude greater than 10 times background for periods of a few minutes to several hours."

Addendum: Steven Brantley reported that lava fountaining from the vent S of Pu'u Kahaualea stopped at 0257 [but revised to 0247 in 8:4] on 9 April. By 0430, harmonic tremor had decreased to low levels, and the rate of summit deflation had decreased to less than 0.05 µrad/hour. The SE flow from this vent entered the Royal Gardens subdivision on 8 April. Approximately seven [six confirmed in 8:4] structures were destroyed before the flow stopped late in the afternoon of 9 April.

Information Contacts: E. Wolfe, A. Okamura, R. Koyanagi, and S. Brantley, HVO; UPI.


April 1983 (SEAN 08:04) Citation IconCite this Report

Lava effusion stops; low level harmonic tremor, local incandescence, and extension continue

"The third major episode of the E rift eruption ended at 0247 on 9 April. The initial activity was at a vent that erupted 28-30 March, producing an aa flow that extended nearly 5 km SE along the Hawaii Volcanoes National Park boundary. A vent about 2 km to the ENE in the same location as the source of the lava flow that entered the Royal Gardens subdivision during episode 2 erupted steadily from 29 March-9 April. Marked by two fountains that were the sources of flows that exited N and S, the vent was the locus of all April lava production. These fountains, and in particular the steadily active and more prominent N fountain that was commonly 100 m high and at times estimated to be 300 m high, were the source of tephra for construction of an 80-m-high cinder cone.

"From 29 March to the end of the eruption, a flow composed of aa locally more that 12 m thick advanced slowly about 3 km NE to the vicinity of Kalalua. Another flow moved SE between earlier flows of 7 January and 27 February-4 March. Lava production at the S fountain changed from sporadic to steady on 4 April and at least 3 lava flows were fed in succession during the remainder of episode 3. These flows were approximately 3.0, 1.5, and 7.2 km long. The advance of each of the first two apparently stopped when the lava stream feeding it was diverted to form the next. The fronts of these aa flows advanced at average rates of approximately 100 m/hour and at times faster than 200 m/hour through gently sloping rain forests. The last and longest of the 3 flows began its advance on 6 April. It entered Royal Gardens subdivision on 8 April and destroyed 6 structures before the eruption stopped early on 9 April. Near the end of the eruption the flow front reached a velocity of 6 m/minute as the narrow and elongate terminus, centered on a subdivision street, advanced down a steep slope. Decemberelerating advance of the flow front continued through at least 11 April.

"January-April lava covered about 15 km2, approximately double the 7 km2 that had been covered by the end of episode 2 on 4 March (figure 17). As a preliminary estimate, a minimum of 50 x 106 m3 of lava had been extruded since eruptive activity began on 3 January. The most recent basalt is megascopically identical to the earlier lava. It is slightly porphyritic with scattered small phenocrysts of plagioclase and olivine. This, as well as continued relatively low lava temperatures (1,112-1,129°C) and unchanged composition of eruptive gases, implied that stored E rift magma had remained as the source for all January-April 1983 lava.

"The summit (Uwekahuna) water tube tiltmeter recorded nearly 30 µrad of decreasing tilt related to subsidence during the third episode of the eruption (figure 18). Since the beginning of intrusive/eruptive activity on 2 January, the cumulative tilt decrease was nearly 200 µrad, suggesting a net volume loss in the summit area of at least 80 x 106 m3. Harmonic tremor decreased significantly when lava fountaining stopped. As of 10 May, tremor continued at a very low level in the general area of the recently active vents.

"Although hot gases of magmatic origin were becoming progressively less concentrated and more oxidized, they continued to be emitted from the recently active part of the fissure system. Local but decreasing incandescence also continued. These observations combined with the observations of persistent low tremor and minor extension across the fissure system (10 mm of extension had occurred by 29 April on a survey line established 8 days earlier) suggested that the feeder system was still active and renewal of eruptive activity was possible."

Information Contacts: E. Wolfe, A. Okamura, R. Koyanagi, and S. Brantley, HVO; UPI.


May 1983 (SEAN 08:05) Citation IconCite this Report

Incandescent vents, harmonic tremor, and dilation across fissure system continue, then lava extrusion resumes

"Although Kīlauea did not erupt during May, the fissure system for the 1983 E rift zone eruption was still active. Incandescent fissures with temperatures around 800°C were present at both vents that erupted from 28 March to 9 April (08:3-4). Steady slow dilation, averaging slightly less than 1 mm/day, was measured across the fissure system from Pu'u Kahaualea (near active vents about 17 km E of the summit caldera rim). Weak harmonic tremor continued throughout the month. These data suggest that slow intrusion was sustaining the feeder, and resumption of eruptive activity is possible."

Addendum: Eruptive activity accompanied by gradually increasing harmonic tremor resumed at about 0800 on 13 June, from the 28-30 March vent (near Pu'u Kamoamoa) about 15 km ESE of the summit caldera rim. Lava fountains 20-30 m high fed a flow that moved SE over the 28-30 March lava, along the Hawaii Volcanoes National Park boundary. The summit tiltmeter showed a deflation rate of 1 µrad per 6 hours. Moderately high and very steady harmonic tremor was recorded in the vicinity of the vent as the eruption continued 14 June.

Information Contacts: R. Decker, E. Wolfe, A. Okamura, R. Koyanagi, and J. Nakata, HVO.


June 1983 (SEAN 08:06) Citation IconCite this Report

Lava flows and spatter cones produced by two new phases of E rift zone eruption

EPISODE 4

"The fourth and fifth major episodes of Kīlauea's E rift zone eruption occurred during June and early July. The two eruptive events, each about 4 days long, produced three new major lava flows that extended SE down the S flank.

"The eruptive vent for both episodes was located just within the Hawaii Volcanoes National Park about 750 m NE of Pu'u Kamoamoa (figure 19). The same vent had been active intermittently since early January; in late March it produced a 5-km-long lava flow that extended SE along the National Park boundary.

Figure (see Caption) Figure 19. Distribution of Kīlauea lavas and vent deposits for phases 1-7, January-August 1983.

"Episode 4 lava fountains were first reported from a passing aircraft at 1025 on 13 June. When the first ground observers arrived at midday, a line of low fountains about 100 m long was feeding flows to both the NW and SE. The NE end of the vent quickly became the major locus of lava production, and an aa flow fed by a vigorous river of pahoehoe began extending SE, on top of and adjacent to the late March (episode 3) flow. A steep-sided spatter cone 30-40 m high was built at the source of the flow, which cascaded over a spillway one-half to two-thirds of the way up the S side of the cone. A low fountain, up to about 20 m high, played from the surface of the lava pond that filled the interior of the cone to the level of the spillway.

"Lava discharge was estimated at about 100,000 m3/hour. The main flow extended about 7.5 km SE from the vent and covered approximately 1.5 x 106 m2. Its front advanced at about 30-200 m/hour. Following the National Park boundary, the flow entered Royal Gardens subdivision only locally, and no homes were destroyed. Episode 4 ended abruptly at 1413 on 17 June, a little more than 4 days after it began.

"Like previous 1983 lavas, episode 4 basalt is slightly porphyritic, with scattered small phenocrysts of plagioclase and olivine. Lava temperatures, measured by thermocouple, ranged from 1,115 to 1,132°C.

EPISODE 5

"Episode 5 began on 29 June. At 1000, a pool of lava was seen slowly rising inside the main episode 4 vent. At about 1300 lava production became vigorous, and episode 5 lava cascaded over the earlier spillway and began flowing SE within the previously evacuated episode 4 channel. Lava production quickly reached and was maintained at a rate similar to that of episode 4, approximately 100,000 m3/hour, and an aa flow began advancing SE over episode 3 and 4 basalts. The flow was fed by a vigorous pahoehoe channel that was generally bank-full and frequently overflowing. Advancing at average rates ranging from 80-165 m/hour, the flow front entered the NW part of Royal Gardens subdivision at 1919 on 1 July. It finally stopped 8 km from the vent at about 1030 on 3 July, more than 3 hours after the vent had stopped erupting. Traversing the subdivision, it burned and crushed 7 dwellings and cut off 4 others from road access. The average velocity of the flow moving down the 4-8° slopes of the subdivision was 56 m/hour, but the actual velocity ranged from 0-30 m/min. Periods of stagnation up to a few hours long alternated with rapid surges that advanced the flow front by 100-300 m in 30 minutes.

"At about 1600 on 29 June a satellite vent on the W flank of the main vent began erupting. For the next 24 hours it supplied local pahoehoe flows that extended about a kilometer N and NE of the vent. Then, in mid to late afternoon of 30 June, the satellite vent stopped feeding flows to the north and began to feed an aa flow that extended 5 km SE along the SW edge of the episode 3 and 4 flows. It, too, was fed by a pahoehoe channel; the front of this flow advanced at average rates of 70-110 m/hour.

"Fountain activity at the episode 5 vents constructed a pair of juxtaposed spatter cones about 40 m high. Lava pond surfaces within the 2 vents were 20-30 m above the bases of the cones. Fountains played from the ponds, and spatter was ejected to maximum heights of about 50 m above the pond surfaces. Fountaining was more vigorous than in episode 4, which suggested that the episode 5 magma may have been less depleted in gas. Lava production at the vents stopped at 0717 on 3 July, nearly 4 days after the eruption began.

"Thermocouple measurements gave lava temperatures of 1,127-1,129°C. Basalt collected near the end of episode 5 may be compositionally different from lavas erupted in previous episodes. Millimeter-size olivine phenocrysts are abundant, and plagioclase phenocrysts are rare. Unfortunately, no temperature measurements are specifically correlated with these samples.

Deformation and seismicity. "Water-tube tilt measurements in the summit region (at Uwekahuna) showed small but distinct periods of summit deflation that correlated with episodes 4 and 5. Minimum volume loss at the summit was estimated to be about 14 x 106 m3 for episodes 4 and 5 combined. Cumulative deflation since early January was approximately 235 µrad; a minimum volume loss at the summit of about 95 x 106 m3 is suggested.

"Very low-level harmonic tremor has characterized the periods between eruptive episodes. On 13 June, approximately coincident with the onset of episode 4, tremor increased from 0500 to about 1100. It remained constantly high until 17 June, when it declined rapidly from 1400-1600. Again, coincident with episode 5, tremor amplitude increased beginning at about 0900 on 29 June. It stayed high through the eruption, and, in concert with the end of lava production, the tremor dropped dramatically from 0713-0720 on 3 July."

Robert Symonds measured a rate of SO2 emission from Kīlauea of 8000 t/d from the ground on 30 June and the same flux from the air on 1 July.

Information Contacts: E. Wolfe, A. Okamura, and R. Koyanagi, USGS HVO, HI; R. Symonds and T. Casadevall, USGS CVO, Vancouver WA.


July 1983 (SEAN 08:07) Citation IconCite this Report

Lava flows move ENE along east rift for 4 days

EPISODE 6

"Kīlauea's E rift zone eruption was in its sixth episode from 21 to 25 July. The episode 6 eruptive vent was the same spatter cone, approximately 750 m NE of Pu'u Kamoamoa, that was the major source of episode 4 and 5 lavas (figure 19). Between eruptive episodes the vent contained incandescent cracks and continued to emit magmatic gases.

"The first episode 6 eruptive activity was seen from a passing aircraft at about 0600 on 21 July. From then until midafternoon the next day, extrusive activity consisted of cyclic filling and draining of the funnel-shaped interior of the spatter cone. Fountain activity at this stage ranged from intermittent bursts of spatter to the more steady play of a 3-4-m-high dome fountain.

"At approximately 1530 on 22 July, the pond filled to a depth of about 20 m, and lava spilled over low places on the rim of the spatter cone to begin feeding flows to the N, NE, and SE. Lava production rapidly increased, and a major aa flow advanced NE, fed by a vigorous pahoehoe river issuing from the pond at spillways on the N and NE flanks of the cone. Blocked from advancing SE by flows and vent deposits of earlier episodes, this flow moved ENE through the rain forest on the N side of Pu'u Kahaualea. During the period of greatest lava discharge, estimated on 24 July at about 0.25 x 106 m3/hour, the flow advanced at more than 200 m/hour. Ultimately it extended 6 km from the vent, covering an area of about 2 x 106 m2 with a volume on the order of 10 x 106 m3.

"During the period of active lava flow production, a fountain played continuously from the surface of the pond within the vent. The fountain was at its most vigorous on 23 July, when it often reached heights ranging from 50 to 150 m. It produced flows of spatter-fed pahoehoe and a local tephra blanket that extended SW from the vent. Subsequently the fountain was less vigorous and 30-60 m high, approximately 1.5 times its height at the end of episode 5.

"Lava temperatures measured by thermocouple ranged from 1128°C on 22 and 23 July to 1138°C (a new high temperature for the 1983 eruption) on 24 July. Hand-lens inspection indicated that episode 6 basalt contains scattered small phenocrysts of plagioclase and olivine. Thus, it generally resembles, except for the more olivine-phyric basalt of episode 5, the earlier 1983 lavas.

"Harmonic tremor, which had persisted at a low level after the end of episode 5 eruptive activity on 3 July, began to fluctuate slightly and increase gradually during the period of cyclic filling and draining of the lava pond on 21 and 22 July. Shortly before 1600 on 22 July, tremor intensity increased rapidly in concert with increasing eruptive vigor. Tremor reached a high level at about 1800 and maintained it through the 3-day period of strong effusion. At about 1620 on 25 July, tremor decreased rapidly as the eruption came to an end. Low-level tremor, like that characteristic of other inter-eruptive periods, has continued in the vent area since 25 July.

"The Uwekahuna water-tube tiltmeter recorded about 17 µrad of summit deflation during episode 6. Following gradual inflation that had been underway since the end of episode 5, the summit of Kīlauea began to deflate at about 1600 on 22 July, approximately coincident with the increases in tremor amplitude and lava emission. Summit deflation increased to a maximum rate of 3-4 µrad/hour on 23 and 24 July. The rate decreased thereafter until about 1800 on 25 July. Since then the summit has been gradually reinflating."

Addendum: Eruptive activity resumed at the episode 6 vent on 15 August. Harmonic tremor increased at approximately 0700; lava fountains 20-30 m high and a 1 km-long lava flow to the NE were reported by field crews that arrived at the vent at 0845. At press time on 17 August, Tina Neal reported that lava fountains had decreased to 5-10 m high, the lava flow extended about 6 km NE with lobes both N and S of the episode 6 flow, and summit deflation continued.

Information Contacts: E. Wolfe, A. Okamura, R. Koyanagi, and T. Neal, HVO.


August 1983 (SEAN 08:08) Citation IconCite this Report

7th, 8th, and 9th major episodes produce lava flows extending NE and S from spatter cone

EPISODE 7

"The seventh major episode of extrusive activity in Kīlauea's continuing middle E rift zone eruption occurred during the 3rd week of August. Lava flows extended NE and SE from the eruptive vent, but did not threaten any developed areas (figure 19).

"After slightly more than 2 weeks of summit inflation, low-level extrusive activity was first observed on 10 August on the floor of the spatter cone (750 km NE of Pu'u Kamoamoa) that marks the vent for episodes 4-6. Sporadic production of very small lava flows through 14 August, accompanied by weak spattering, produced enough new basalt to cover the 30-m-diameter floor of the crater with thin pahoehoe. During this period, the summit continued to inflate, and harmonic tremor, which had been low but steady in the eruptive zone since the end of episode 6, was marked by intermittent bursts of higher amplitude.

"Starting at about 0709 on 15 August, tremor intensity increased rapidly. Within an hour, the seismograph at Pu'u Kamoamoa registered a 10-fold increase in tremor amplitude. By the time the first observers reached the eruptive zone at 0850, fountains 50 m high were playing from the surface of a 20-m-deep pond within the crater. A rapidly moving lava flow had advanced 1 km NE on top of the voluminous episode 6 flow, and a smaller flow was moving slowly S. Steady lava production continued for about 57 hours, ending abruptly at about 1600 on 17 August. An aa flow that had been fed by a vigorous pahoehoe river extended 6.4 km NE and buried a large portion of the episode 6 flow. A second aa flow that advanced less rapidly extended 2.9 km SE. Basalt samples contain scattered small olivine phenocrysts. Lava temperatures measured by thermocouple ranged from 1,132 to 1,141°C.

"Strong harmonic tremor persisted throughout the period of vigorous effusion. At about 1602 on 17 August, tremor decayed rapidly and within an hour assumed a fluctuating low level. Tremor amplitude slowly decreased even further over the next few days, then remained constant and low for the rest of the month.

"Summit deflation recorded by the Uwekahuna tiltmeter began at 1000 on 15 August, several hours after the onset of intense lava production. Nearly 20 µrad of summit collapse, which ended at 1900 on 17 August, suggests that a volume decrease of at least 8 x 106 m3 occurred at the summit during the eruption. For the remainder of the month, the summit reinflated at an average rate of about 1 µrad/day. At least 110 x 106 m3 of magma is estimated to have been lost from the summit reservoir since the E rift eruptive activity began in January 1983.

"On 2 September, field observations of the vent area indicated that small amounts of lava had been intermittently erupted within the main vent crater since the last field check on 29 August. There was some increase in the amplitude of low-level tremor during the night of 1-2 September, probably associated with the new lava emission.

"On the morning of 6 September the eighth major episode of the eruption began. At 0503, an increase in volcanic tremor was recorded on seismographs at HVO. By 0514 the tremor had increased to about 20 times its background level of the previous day. At 0530 a major fume cloud was visible from HVO and the roar of fountains was audible. At 0730 a field crew reported a large single fountain reaching approximately 50 m above the top of the spatter cone built in earlier episodes. A major flow was advancing NE on top of flows from the last 2 major eruptive episodes.

"The eruption was steady and vigorous throughout 6 September. Fountains reached heights of 140 m above the cone. Abruptly at 0525 on 7 September, fountaining ceased and tremor amplitude dropped to slightly above inter-eruptive background levels. Significant lava production during episode 8 lasted for approximately 24 hours. Ten µrad of summit collapse were recorded."

Addendum: On 9 September at 0631 a magnitude 5.5 earthquake occurred at 9 km depth in the S flank, between the eruption vent and the sea coast. Low-level activity resumed at the episode 6-8 vent around midday on 15 September [episode 9]. Vigorous fountaining to approximately 100 m above the spatter cone began between 1700 and 1730 on 15 September, and produced a lava flow that extended 5 km NE on the N and W sides of the episode 6-8 flows. Fountaining ceased between 1900 and 1930 on 17 September.

Information Contacts: E. Wolfe, A. Okamura, R. Koyanagi, and T. Neal, HVO.


September 1983 (SEAN 08:09) Citation IconCite this Report

8th-10th major phases of E Rift Zone eruption

EPISODES 8 and 9

"Episodes 8 and 9 of Kīlauea's long-lived middle E rift zone eruption occurred during September. All lava issued from the same vent, 750 m NE of Pu'u Kamoamoa, that has been the dominant locus of eruptive activity starting with episode 4 in mid-June. The major episode 8 and 9 flows extended NE along the NW edge of the episode 6 and 7 flows.

Low-level activity, 2-5 September. "In the pre-dawn hours of 2 September, following about 2 weeks of low but constant harmonic tremor in the eruptive zone and steady inflation of the shallow summit reservoir, approximately 4 days of low-level, intra-crater eruptive activity began at the vent. Harmonic tremor during this 4-day period, although still low, was characterized by intermittent episodes of slightly higher intensity. Prior to the renewal of activity, the crater floor was dominated by a steep-walled deep hole; an incandescent crack issued fume at the W base of the interior crater wall. By 0900 on 2 September, the deep central depression had been filled, and a 4 m-high mound of spatter surrounded a fuming and sporadically spattering conduit near the center of what had become a nearly flat, 30 m-diameter crater floor. At the W edge of the floor, several very small lava flows had been extruded from the area of the incandescent crack. Intermittent extrusion from this area continued through 4 September, producing about 300 m3 of small solidified flows. On 5 September, a lava pond 5 m deep covered the crater floor, and a lava stream carrying an estimated 1,000-2,000 m3/hour issued from the vent at the pond's W edge, disappearing downward near the pond's center. Although a 'bathtub ring' showed that the pond had earlier been as deep as 15 m, no significant change in the pond's volume was seen during 6 hours of observation on 5 September. Minimal spatter production implied that the lava of this intra-crater activity was relatively degassed.

EPISODE 8, 6-7 September 1983

"Beginning at 0503 on 6 September, harmonic tremor rapidly increased. Within 15 minutes, tremor amplitude was an order of magnitude higher, and remained intense throughout the eruption. By about 0530 the roar from the fountaining vent could be heard and the eruption plume seen from the summit region.

"Although brief, the eruption was vigorous. Fountains rose 100-200 m from the surface of the pond within the crater. As in episodes 6 and 7, lava issued from a breach in the NE rim of the crater, producing an aa flow that extended NE for more than 4 km. A subordinate aa flow extended about 2 km SE.

"Harmonic tremor decreased rapidly from about 0520 on 7 September, and fountaining stopped at about 0525, approximately 24 hours after it had begun. Steady low tremor continued until 14 September. Two open conduits were left extending steeply downward from the W edge and the center of the crater floor.

EPISODE 9, 14-17 September 1983

"After a week of quiescence, sporadic spattering began in the crater shortly after midnight on 14 September, and harmonic tremor gradually increased to mark the onset of episode 9. Lava began to cover the crater floor at about 1030 on 15 September. After an hour, when the pond was about 5 m deep, a few hundred m3 of lava spilled through the deep breach in the NE crater rim. The remainder, about 3,000 m3, drained back into the central conduit and disappeared at about 1300, 2.5 hours after the pond began to form. Two hours later, a second pond, not deep enough to overflow the breach, formed and drained within 30 minutes. Refilling of the pond began again about 5 minutes later, and within 15 minutes (by about 1540) lava had overtopped the spillway from the crater. A flow supplied at a rate of about 10,000 m3/hour began advancing NE along the evacuated episode-8 channel. A small dome fountain 3-8 m high played on the pond surface above the central conduit, and there was almost no spatter. Beginning about 1700, harmonic tremor increased gradually. At about 1711, the first spatter was visible above the approximately 50 m-high W rim of the crater, and by 1730 the tremor had increased to the large amplitude typical of vigorous lava production. By 2130 the fountain was visible from the Wahaula Visitor Center near the coast (approximately 11 km SE of the active vent), which suggests a fountain height on the order of 300 m.

"Vigorous eruption continued for just over 2 days, ending at about 1915 on 17 September. The major flow of this episode, aa supplied during vigorous eruption at about 1-2 x105 m3/hour, advanced more than 5 km NE through the rain forest along the NW edge of the episode-8 flow. Fountains were initially very high, but became erratic in height and direction, ranging up to about 200 m high. Rapidly changing in inclination and azimuth of trajectory, they heavily armored the growing spatter cone (about 60 m high) with spatter-fed flows.

"At the eruption's end, 2 apparent conduits much like those seen before the eruption were visible in the crater floor. Near the center of the floor was a nearly cylindrical, vertical, fuming hole approximately 4 m in diameter. At the W edge of the floor was a fuming, glowing, elongated hole 1 m wide and 2-3 m long.

"Harmonic tremor in the eruption zone diminished rapidly at the end of the eruption. By 1930 on 17 September it had dropped to the low level characteristic of repose periods. Since then tremor has remained continuous and low.

"The volume of new basalt, mostly aa, produced during episodes 8 and 9 is approximately 16 x 106 m3, and the total volume of basalt produced since the beginning of episode 1 on 3 January is about 106 x 106 m3. The episode 8 and 9 basalts are slightly porphyritic, with scattered small olivine phenocrysts.

"Summit reservoir deflation and inflation associated with episodes 8 and 9 extended the strongly cyclic pattern that has been established in recent months. Deflation approximately coincident with the eruptions was recorded at Uwekahuna vault by rapid inward tilt changes of 14.8 µrad for episode 8 and 16.2 µrad for episode 9. These correspond approximately to summit volume losses of 6 and 6.5 x 106 m3, respectively. The total deflationary volume loss at Kīlauea's summit since the beginning of January is about 122 x 106 m3."

Addendum: The 10th major episode of eruptive activity began early 5 October following 3 days of minor and intermittent lava emission and drainback in the episode 4-9 vent. Tremor amplitude increased at 0327, and lava fountaining started by about 0430. Fountains rose to maximum heights of about 300 m, producing a substantial volume of airfall pumice, and fed two lava flows that extended 4 km NE and SE of the vent. Fountaining ceased at about 1700 on 7 October, and inflation of the summit region resumed. Extremely low-level harmonic tremor continued as of 11 October.

Information Contacts: E. Wolfe, A. Okamura, R. Koyanagi, and T. Neal, HVO.


October 1983 (SEAN 08:10) Citation IconCite this Report

10th and 11th major phases of E Rift Zone eruption

EPISODE 10

"The 10th major episode of Kīlauea's prolonged E rift zone eruption occurred in early October. As in episodes 4-9, the active vent was at the growing spatter cone, now tentatively named Pu'u O [later Pu`u `O`o, see 10:4], approximately 750 m NE of Pu'u Kamoamoa (figure 20).

Figure (see Caption) Figure 20. Distribution of Kīlauea lavas and vent deposits of episodes 8, 9, and 10. Courtesy of HVO.

"Low-level eruptive activity marking the onset of episode 10 began at about 0800 on 2 October when a small lava flow, about 300-500 m3 in volume, was extruded onto the floor of the crater within Pu'u O. Some of the lava drained back into the open, glowing, 4-m-diameter conduit, which had been preserved near the center of the crater floor at the end of episode 9. No further activity was observed until 4 October when small bursts of spatter were intermittently emitted, most of which fell back into the conduit.

"Beginning at about 0100 on 5 October, harmonic tremor increased above the low repose-period background level, and lava began to spill through a deep breach in the NE wall of the spatter cone. Intensity of both harmonic tremor and eruptive activity increased over the next several hours. By 0330, tremor amplitude had increased by an order of magnitude, and by 0400 the glow was visible and the roar of the vent was audible 20 km away at HVO. Near dawn, the 300-m-high fountain was visible from the coast at the Wahaula Visitor Center (approximately 11 km S of the active vent). Late on 5 October, tremor amplitude increased to a maximum exceeding that of the previous eruptive episode, consistent with a trend of progressively increasing tremor that began with episode 4. High tremor occurred throughout vigorous episode 10 lava emission.

"After initially high activity, the fountains became erratic, changing rapidly in height from a few tens of meters to a maximum of about 250 m. At times, 3-4 distinct fountains were observed within the crater; sometimes high jetting fountains and a relatively low dome fountain played simultaneously from different parts of the lava pond surface.

"On 5-6 October, a thick slow-moving aa flow advanced 3.7 km ESE from Pu'u O, and rapidly moving pahoehoe formed superimposed sheets over an elongated area that extended about 2 km from the vent. By 7 October, the aa flow had stagnated, and the pahoehoe issuing to the NE had become confined to a channel in which a vigorously flowing lava river supplied a flow of pahoehoe and aa that eventually extended 4 km NE (figure 21).

Figure (see Caption) Figure 21. Lava flows and vent deposits of Kīlauea episodes 11 and 12. Courtesy of HVO.

"Eruptive activity waned between about 1630 and 1700 on 7 October; harmonic tremor amplitude decreased rapidly at about 1650, and, after 1700, assumed the low level typical of repose-period activity. Such low-level tremor continued in the E rift zone for the remainder of October.

"As in the previous several episodes, episodes 10 basalt is characterized by the occurrence of scattered small olivine phenocrysts. Lava temperatures measured by thermocouple ranged from 1134° to 1142°C; the latter is the highest lava temperature measured since the beginning of eruptive activity on 3 January.

"Episode 10 produced nearly 14 x 106 m3 of lava for a total erupted volume since 3 January of approximately 120 x 106 m3 distributed over about 23 x 106 m2 of the rift zone. At the end of episode 10, Pu'u O was approximately 600 m in diameter and 80 m high. A chaotic jumble of disrupted blocks of agglutinated spatter covered the crater floor and the spillway through which the NE flow exited. The blocks, which were apparently transported as the last lava drained back into the eruptive conduit, choked the central conduit, which had stood open after episode 9. Oxidized fume issued from the margins of the crater floor and from the nearby parts of the interior walls of the crater but not from the rubble-covered floor.

"During episode 10, summit subsidence was recorded by nearly 19 µrad of ESE tilt change at the Uwekahuna vault on the NW rim of the caldera. This corresponds to a summit volume decrease of about 7.5 x 106 m3, bringing the total deflationary volume loss since January to about 130 x 106 m3. Summit inflation from the end of episode 10 to the end of October was sufficient for the Uwekahuna tiltmeter to more than recover the deflationary tilt change of episode 10."

Addendum: Episode 11 began with an increase in harmonic tremor amplitude at 2314 on 5 November and the onset of eruptive activity around midnight. Summit deflation began at about 0200 on 6 November. An overflight at 0730 revealed a discontinuous line of fountains up to 40 m high extending approximately 200 m up and down rift from the spatter cone (Pu'u O) active in previous eruptive episodes. Vents high on the W flank of the spatter cone fed 2 lava flows which that 4 and 1.5 km S before activity ceased there late on 6 November. The main vent, on the E summit and flank of the spatter cone, produced lava fountains 10-40 m high and fed the main lava flow that extended 8 km NE [it reached 9.5 km length; 8:11]. At 1840 on 7 November, the amplitude of harmonic tremor decreased sharply; lava fountaining from the main vent ceased later on 7 November, and inflation of the summit region resumed.

Information Contacts: E. Wolfe, A. Okamura, and R. Koyanagi, HVO.


November 1983 (SEAN 08:11) Citation IconCite this Report

11th and 12 major phases of East Rift Zone eruption

"The 11th and 12th eruptive episodes occurred on 6-7 November and 29 November-1 December. As in episodes 4-10, the growing spatter cone, Pu'u O, located just within Hawaii Volcanoes National Park, was the major eruptive locus.

EPISODE 11

"Unlike most of the previous eruptive episodes at Pu'u O, when vigorous lava production was preceded by several hours to several days of low-level activity within the crater, episode 11 began quickly. Harmonic tremor in the eruptive zone began to increase above normal repose-period background levels at 2314 on 5 November and reached a maximum amplitude at 0025 on 6 November. An electric trip wire, installed within the crater of Pu'u O to monitor the first appearance of lava, was broken between 2350 on 5 November, and 0000 on 6 November. By 0010, glow from the eruption was visible 20 km away at HVO. Between midnight and dawn on 6 November, low fountains were seen from Mountain View, 18 km to the N and from Kalapana, on the coast 14 km to the SE.

"When the first observers arrived at 0730, discontinuous low fountains played along a 700-m line approximately centered on Pu'u O. All of the fountains were relatively low. Those NE and SW of Pu'u O were about 10-20 m high. The most voluminous fountains rose about 40 m from the surface of a pond within the crater at Pu'u O; throughout the eruption they were barely visible above the 80 m-high crater rim.

"Pu'u O was the major locus of lava production. As in episodes 6-10, its lava pond overflowed through a breach in the NE crater wall, forming a vigorous lava river that eventually extended about 6 km before turning from pahoehoe to aa. By the end of episode 11, the river had fed a 9.5 km-long aa flow, the longest in the 1983 eruption, that advanced NE on top of earlier flows from Pu'u O, then extended an additional 4 km through dense rain forest. Vents 100-200 m SW of Pu'u O, in combination with a vent high on the W flank of the cone, produced pahoehoe flows that spread an estimated 1.2 x 106 m3 of new basalt W and S of Pu'u O until the early morning of 7 November, when the W vents stopped erupting.

"During the 43 hours of eruption, approximately 12.1 x 106 m3 of lava was extruded, 85% in the long flow to the NE. In hand-lens view, the basalt is sparsely porphyritic with scattered olivine phenocrysts up to about 2 mm in diameter. Lava temperatures, measured by thermocouple in pahoehoe toes in flows from the W vents and in sustained overflows from the lava river, ranged from 1,141 to 1,144°C. Lower temperatures, 1,133-1,135°C, were measured at the river's edge.

"Harmonic tremor amplitude, sustained during the eruption at a level comparable to that of recent previous episodes, dropped rapidly between 1840 and 1850 on 7 November, at the end of the eruption.

"Summit subsidence began at about 0200 on 6 November, approximately 2 hours after the onset of eruption, and continued until about half an hour after the eruption's end on 7 November. The deflationary tilt change of about 19 µrad at Uwekahuna corresponds with a summit volume loss of about 8 x 106 m3.

16 November earthquake - repose period activity. "At 061301 on 16 November, a magnitude 6.7 earthquake occurred in the Kaoiki region (figure 22) between Mauna Loa and Kīlauea, an area of persistently high seismicity. Several tens of earthquakes are commonly recorded daily by nearby seismic stations of HVO's 48-station island-wide network. Over the past 3 decades, about 35 earthquakes of magnitude >= 4 have occurred in the Kaoiki region, two of the largest on 27 June 1962 (M 6.1), and on 30 November 1974 (M 5.5). The 16 November 1983 earthquake was highest in magnitude, ground breakage, and structural damage. Ground breakage related to shaking and gravitational adjustments on 16 November occurred along Kaoiki fault scarps and along Kīlauea caldera faults. Landslides and rockfalls occurred on the steep caldera and crater walls, and on the (Hilina) escarpments on Kīlauea's S flank. A 4.7 km-long zone of E-W-trending tension fissures has been identified as the possible main surface rupture. A N50°E line from the epicenter of the main shock intersects the fissure zone 5 km to the N. The fissure zone, approximately 50-100 m wide, is recognized as a series of en echelon offsets to the left. Thus far, 15-20 cm of southward extension has been measured on some E-W-trending extension cracks.

Figure (see Caption) Figure 22. Location of the M 6.7 Kaoiki earthquake and the initial 10 hours of aftershocks. Local seismic data indicate strike-slip faulting with an E-W orientation of the pressure axis, and a N-S orientation of the tension axis. Darkened circles represent seismic stations that continuously telemeter signals to HVO.

"The earthquake was 12 km deep, and a preliminary first motion analysis from local seismic data indicates a strike-slip mechanism. The faulting was a probable result of compressional stresses within the crust induced by magmatic activity generating lateral tensions from Mauna Loa and Kīlauea. The NE-trending nodal plane with a right lateral strike-slip motion is preferred on the basis of aftershock distribution of past events.

"In 8 days following the main shock, more than 9,000 earthquakes have been detected on stations a few kilometers from the aftershock zone. Over 800 of these, ranging in magnitude from about 1.0-4.3, were selected for processing by computer for location and magnitude. About 50 aftershocks were greater than magnitude 3.0, and 3 were over magnitude 4.0. Preliminary determinations of hypocenters during the initial 10 hours of aftershock activity indicate an epicentral zone about 20 km in diameter centered between the summit areas of Mauna Loa and Kīlauea. Focal depths are concentrated at about 10 km.

"Between episodes 11 and 12, low-level harmonic tremor typical of repose periods persisted in the eruption zone. Copious hot oxidized fume issued continuously from Pu'u O, maintaining incandescence in numerous openings. Neither the tremor nor the fume production changed recognizably in response to the 16 November earthquake. The earthquake, however, produced a major perturbation in the record of Kīlauea summit tilt (figure 23).

Figure (see Caption) Figure 23. Kīlauea summit tilt, periods of lava production, and amplitude of harmonic tremor for phases 1-12.

EPISODE 12

"Episode 12 began in earnest at 0447 on 30 November, and continued until 1545 on 1 December. Lava flows to the N, NE, and E originated from Pu'u O, where low fountains played on the S and N rims of the cone and within the breach on its NE flank. The main flow issued through the NE breach, which has been the principal spillway since late July. Advancing 8 km during the eruption, the front covered 1977 lavas S of the main episode 11 flow. Less voluminous flows issued from the S part of the vent and advanced about half the distance to the Royal Gardens subdivision.

"Lava apparently first reached the surface within the crater of Pu'u O at 1600 on 29 November, when an electric trip wire within the crater was cut. Faint glow in the eruptive zone was first reported at 2300. Intermittent low-level tremor near Pu'u O started to increase gradually at about that time (2300). The increase accelerated in the next few hours, and at 0447 on 30 November, a sharp increase was recorded, apparently marking the start of major lava emission. Visible fountains and audible roar from the vent were first reported at about 0450. Tremor peaked between 0530 and 0730 on 30 November with an amplitude more than an order of magnitude above background level. Tremor started to decrease rapidly at about 1545 on 1 December, marking the end of the eruptive episode. As of 5 December, the level of harmonic tremor in the E rift zone was very low but frequent microearthquakes were associated with near-surface activity at the vent."

Information Contacts: E. Wolfe, A. Okamura, and R. Koyanagi, HVO.


December 1983 (SEAN 08:12) Citation IconCite this Report

Episode 12 described; tremor and inflation continue; new ground cracks

The 12th major episode ended on 1 December after 35 hours of sustained lava production. Approximately 8.1 x 106 m3 of lava was erupted, making episode 12 the second smallest of 1983, and bringing the total volume of lava erupted to about 140 x 106 m3.

"Residents of Hilo (about 35 km NNE of the vent) first sighted visible fountains at about 0450 on 30 November, suggesting that fountains may have been higher during the early morning hours of 30 November than during the remainder of the eruption. When an HVO crew reached the vent at 0830, multiple low (10-60 m-high) fountains were playing within the crater of Pu`u O as well as on its N and S rims and in the breach in its NE rim. These changed little throughout the rest of episode 12. However, beginning shortly after midnight on 1 December, a vent just inside the N rim of Pu'u O produced a 50-m-high steam jet that distributed tephra about 1 km W and SW. The steam jet persisted until the end of episode 12 and was the first of its kind observed on Kīlauea in 1983.

"A vigorous flow was fed by a lava river that issued steadily through the eruption from a major breach of the cone's NE flank, the dominant exit from the crater since the beginning of episode 6. Like the major flows of episodes 6-11, the main episode-12 flow advanced 2.5 km NE, then turned ENE along the S edge of episode 6-11 lavas, veered directly E, and eventually halted on top of 1977 lava 8.2 km from the vent. Smaller flows comprising about 1/3 of the erupted volume extended N, S, and ESE of the cone (figure 22).

"As the eruption stopped abruptly at 1545 on 1 December, harmonic tremor amplitude decreased (figure 23). For the remainder of December, low harmonic tremor and shallow microearthquake activity persisted in the vicinity of Pu'u O. In early January, the interior of Pu'u O was a complex of craters separated by low septa. The cone was gradually cooling; incandescence that was conspicuous in numerous cracks and holes immediately after episode 12 had almost completely disappeared. A small amount of oxidized fume issued from the cone.

"As in previous recent episodes, hand samples of episode 12 are slightly porphyritic with scattered small olivine phenocrysts. Temperatures measured in actively advancing pahoehoe sheets near the vent ranged from 1,135° to at least 1,141°C.

"Minor summit subsidence as recorded by the Uwekahuna tiltmeter (figure 23) began at 0200 on 30 November; vigorous subsidence began at about 0700, approximately 2 hours after the onset of vigorous effusion at the vent. Summit deflation continued until about 1900 on 1 December. Total subsidence, measured E-W, was 13.9 µrad, suggesting a summit volume loss of about 6 x 106 m3. By the end of December the E-W tiltmeter at Uwekahuna showed a net recovery of approximately 12 µrad, including a small deflationary episode, late in the month.

"A 2-km-long zone of new steaming cracks parallel to the axis of the E rift was first observed on 17 December in the rain forest 7 km NE of Pu'u O. Ground observation suggested that at least 1 m of very recent extension perpendicular to the rift had occurred in the zone. The new cracks disappeared at their uprift end under episode 12 lava 1 km NE of Pu'u Kiai, and the evidence suggests that the lava flow may have been broken locally by propagation of the cracks. However, the lava was also emplaced against fresh fault scarps that apparently had not moved subsequently. The cracks were within a narrow (approximately 25-m-wide) graben that has apparently been the locus of such extensional movements since prehistoric time. The zone of cracking was approximately on strike with the January 1983 eruptive fissure, but it was entirely downrift of the shallow earthquake swarm that recorded emplacement of the January 1983 eruptive dike."

Tom Casadevall and Barry Stokes made airborne measurements of SO2 and CO2 with a COSPEC and a Moran Infrared Spectrometer. On 2 December, about 16 hours after the end of episode 12 lava production, SO2 was being emitted at about 260 t/d from Pu`u O. On 9 December, the rate of SO2 emission had dropped to 20 t/d. On both days, CO2 production was below the 800-1,000 t/d detection limit. Successive traverses through the plume in the south half of the summit crater yielded values of 3,600 t/d of CO2 and 300 ± 30 t/d SO2 on 9 December.

Information Contacts: E. Wolfe, A. Okamura, R. Koyanagi, T. Neal, and B. Stokes, HVO; T. Casadevall, USGS CVO, Vancouver WA.


January 1984 (SEAN 09:01) Citation IconCite this Report

13th-15th major episodes of East Rift Zone eruption include lava fountains to 300 m and temperatures to 1,147°C

"Kīlauea's episodic E rift zone eruption resumed in late January after 7 weeks of repose characterized by a desultory pattern of summit inflation, vanishingly weak harmonic tremor, and the virtual disappearance of magmatic gas at the vent. Episode 13 occurred 20-22 January, and episode 14 on 30-31 January. As in episodes 4-12, the eruptive vent for episodes 13 and 14 was at Pu'u O (figure 24).

Figure (see Caption) Figure 24. Kīlauea lava flows from episodes 13, 14, and 15. Courtesy of HVO.

EPISODE 13

"Episode 12, which ended on 1 December 1983, left a complex of craters separated by low septa in the interior of Pu'u O. The largest and most central of the craters narrowed downward into a nearly vertical pipe about 20 m in diameter and at least 90 m long.

"On 20 January, harmonic tremor in the eruption zone increased gradually beginning at about 1030, and at 1117 HVO personnel first sighted moving lava about 50 m down in the pipe; by mid-afternoon the lava column could be seen slowly rising within the pipe. At 1724, the lava, which had by then filled the pipe and spread across the 30-40 m-wide floor of the crater, began to flow through the deep breach in the crater's NE rim. Supplied at a rate of approximately 10,000 m3/hour (an order of magnitude less than normal minimum rates for vigorous eruption at Pu'u O), the lava began advancing NE in the channel evacuated at the end of episode 12. By this time, tremor amplitude had increased tenfold.

"As the lava rising within Pu'u O approached and overflowed the spillway, the lava surface, from which a low dome fountain repeatedly rose and fell, was agitated, resembling a rolling boil in a saucepan. Over the next few hours, the vigor of lava emission and fountain activity gradually increased, accompanied by increasingly intense harmonic tremor.

"Unlike some of the recent previous episodes, in which a complex of fountains formed within Pu'u O as well as on its rim and flanks, episode 13 developed a single fountain over the large central conduit. The production of lava, normally steady in previous episodes, pulsed strongly. At intervals on the order of 0.5-1 minute the flux of lava in the channel and the height of the fountain waxed and waned. Hence, the fountain alternated rapidly from about the height of the crater rim (30-40 m above the pond surface within the crater) to as much as 40 or 50 m above the crater rim. The repeated increases in discharge of lava caused surges that advanced at about 10 m/s down the first 100 m or so of the lava channel.

"Episode 13 effusion stopped temporarily on 22 January at about 0030. During this first 31-hour period the lava river debouching from Pu'u O fed a 7 km-long flow that advanced NE. It split into 2 lobes (at Pu'u Kahauale'a) that rejoined farther NE. Continuous eruptive activity resumed at about 0530; it was preceded by an hour of intermittent, low fountain activity. The fountain was visible above the rim of Pu'u O by 0550, and effusion accompanied by renewed intense harmonic tremor continued until the eruptive activity waned sporadically from 1115 to its termination at 1123. This 6-hour period produced a second flow that advanced directly on top of the first; it followed the fork N of Pu'u Kahauale'a and stopped about 3 km NE of Pu'u O. The two effusive periods each terminated with [discontinuous] lava emission such that the fountain disappeared and reappeared repeatedly for a period of several minutes. Simultaneously, harmonic tremor decayed with marked alternations in amplitude.

Repose-period activity. "After episode 13, the interior of Pu'u O was a single bowl-like crater with a narrowing conduit, about 25 m wide at its mouth, extending downward from the crater floor. Throughout the entire repose period between episodes 13 and 14, the surface of a lava column was visible at depths of 0-25 m in the conduit. Sometimes fresh to barely crusted lava was exposed at the pond surface; at other times the pond surface was a solid frozen crust through which a small (0.5-3 m) orifice accommodated intermittent venting of magmatic gas, spatter, and small flows. At times, emission of spatter and gas through the small vent in the crust or alternating rise and fall of the fluid pond surface through a vertical interval of 10-15 m became strongly rhythmic with cycles about 4-6 minutes long. The activity closely resembled the gas-piston activity noted in Mauna Ulu lava ponds (1969-1974). In a typical cycle at Pu'u O, the pond surface appeared deep in the conduit and slowly rose for about 4 minutes. It remained poised momentarily, became agitated, and the lava then drained rapidly out of sight in about 1/2 minute. Draining was accompanied by emission of a plume of magmatic gas and a brief increase in tremor amplitude. After 1.5 minutes, lava would reappear deep in the conduit. When last visited in the early afternoon of 30 January, the lava pond had filled the steep-walled conduit and had begun to spread across the more gently sloping floor of the crater. About 30 m in diameter, the pond surface was about 5 m below the low point in the breach of the crater's NE rim. The surface was solid, and gas under pressure along with minor spatter issued intermittently with a deafening roar from a 0.5 m-diameter vent in the crust. Gas samples from this vent showed that there had been no change in gas composition during more than a year of eruptive activity.

EPISODE 14

"At about 1030 on 30 January, the amplitude of harmonic tremor began a gradual and persistent increase that reached a high level by about 1830, when glow and visible fountains of episode 14 were first reported. Observations from a vantage point in the upper E rift zone as well as from the S coast of Kīlauea indicate that in the evening hours the sustained height of the fountain at Pu'u O was 150-200 m above the rim of the cone, and bursts of spatter were rising as high as 300 m. By morning, when observers arrived at the vent, the single fountain, again centered over the large central conduit, was lower; through the remainder of episode 14 the fountain height fluctuated at intervals of 10-20 seconds from low (commonly 10-20 m above the rim of the cone) to high levels (up to about 80-100 m above the rim of the cone). The high bursts produced tephra plumes and short-lived spatter-fed flows on the flanks of Pu'u O.

"Flows to the N and E (figure 24) were fed by distributary channels branching from the lava river that poured through the breached NE crater rim. The longest flow extended about 4 km from the vent. It turned SE and extended about halfway to Royal Gardens subdivision. A thick aa flow, fed entirely by spatter that cascaded over the S rim of the cone, advanced about 1.5 km S.

"Between 1315 and 1318 on 31 January lava emission declined, once again in spasmodic fits and starts. Harmonic tremor also decreased rapidly beginning at 1315, marking the eruption's end. In early February, the level of tremor, like that between episodes 13 and 14, was considerably higher than the background level during many of the previous repose periods.

"Following episode 14, the crater of Pu'u O was again a broad, steep-walled bowl from which a 20 m-diameter conduit extended nearly vertically downward. A 30-40 m-deep cleft in the NE crater rim marked the breach through which lava exited the crater.

Petrology. "Basalt of episodes 13 and 14 is sparsely porphyritic with scattered small olivine phenocrysts visible in hand-lens view. Lava temperatures measured by thermocouple were 1,129-1,131°C in the first few hours of episode 13. Subsequent episode 13 temperatures were 1,140-1,147°C, and include the highest temperature measured so far in this series of eruptions. During episode 14, temperatures, measured only at the edges of the widespread pahoehoe flow N of Pu'u O, were 1,136-1,137°C.

Deformation. Rapid summit subsidence, as recorded by the Uwekahuna tiltmeter, began at 2100 on 20 January and again at 1930 on 30 January-in each case a short time after vigorous eruption was under way. Resumption of inflationary tilt followed the end of each eruption by several hours. E-W deflationary changes measured at Uwekahuna were 11 µrad for episode 13 and 10 µrad for episode 14. This suggests that a minimum of 8 x 106 m3 of magma was withdrawn from the summit reservoir system during episodes 13 and 14."

Addendum: Episode 15 began at about 1945 on 14 February with a sharp increase in harmonic tremor. Summit deflation began about 2 hours later. During the evening, lava fountains rose as high as 300 m from the previously active vent at Pu'u O. Vigorous lava fountaining continued the next morning and lava flowed E and NE from Pu'u O. Eruptive activity ceased at about 1500 on 15 February.

Information Contacts: E. Wolfe, A. Okamura, R. Koyanagi, T. Duggan, R. Okamura, HVO.


February 1984 (SEAN 09:02) Citation IconCite this Report

15th and 16th major episodes; lava fountains to 320 m; large tephra fall

The following report was received before the start of the 16th episode (see addendum).

EPISODE 15

"The 15th major episode of Kīlauea's protracted series of middle E rift zone eruptions occurred on 14-15 February. As in recent previous eruptive episodes, the vent was at Pu'u O (figure 24).

"Following episode 14, the more gently sloping floor of Pu'u O steepened downward near the crater's center to a nearly vertical 20-m-diameter conduit. Lava was not visible in the conduit on 1 February but was seen during aerial reconnaissance on 3 and 5 February. On 7 February, the partly crusted surface of a magma column in the conduit was 45 m below the crest of the spillway through the crater's breached NE rim. The column rose steadily at a rate of 4-5 m/day. On the morning of 13 February its upper surface was an actively roiled lava pond 18 m below the spillway. By the next morning, the lava column had risen enough for a 100-m flow to have spilled through the breach, after which it subsided to a level about 10-20 m below the spillway. A vigorous 19-hour eruption began during the evening of 14 February.

"Time-lapse film shows that steady low fountain activity within the crater began at about 1940 on 14 February. By 2000, the fountain height began to increase dramatically, and a vigorous lava flow issued NE through the breach. The fountain reached a maximum height of about 320 m at approximately 2100. It remained high for about 6 more hours and was easily visible from the coast S of Royal Gardens. The high fountain produced a thick tephra blanket on the SW side of the vent, and heavy tephra fall was reported by campers on the uprift side of Napau, about 5 km from the vent. The fountain height declined abruptly (by approximately 50%) at about 0330 on 15 February.

"When HVO observers arrived at about 0700 on 15 February, the fountain typically rose about 100 m above the rim of the cone. However, pulsations in its height ranged 20-200 m above the rim. The major lava flow, debouching through the long-lived breach in the crater's NE rim, extended 2 km to the NE. A stagnating aa flow, which had apparently been fed during the night by spatter falling over the S rim of Pu'u O during the more vigorous fountain activity, extended E about 3 km.

"By the end of episode 15 at 1501 on 15 February, the main flow had extended about 5 km NE along the NW edge of flows erupted July-December 1983. Approximately 8 x 106 m3 of new basalt was extruded; the total volume emplaced at the surface since the beginning of January 1983 is about 165 x 106 m3. As in recent previous episodes, the basalt is slightly porphyritic with scattered olivine phenocrysts of about 1 mm size. Lava temperatures measured by thermocouple (in thin pahoehoe overflows from the lava river that supplied the NE flow) were 1,136-1,140°C.

"Steady, low harmonic tremor originating in the vent area was continuous after the end of episode 14. A slight increase in tremor amplitude related to the onset of episode 15 occurred from about 1939 to 1945 on 14 February. After a 1-minute decrease, increase in tremor amplitude resumed at 1946. The amplitude increased rapidly to the maxima reached in previous eruptive episodes, and high tremor continued until the end of eruptive activity. After episode 15, low harmonic tremor continued steadily through the remainder of the month.

"Approximately 7 µrad of inflationary E-W tilt change was recorded in the NW part of Kīlauea's summit region between the end of episode 14 and the onset of episode 15. Deflationary tilt change of 11 µrad, related to the extrusive activity, was recorded from 2030 on 14 February to 2100 on 15 February. Summit reinflation (of nearly 10 µrad) continued from 15 February through the end of the month.

"The morphology of Pu'u O's crater and vertical conduit was essentially unchanged by episode 15 eruptive activity. A partly crusted lava surface deep within the conduit was sighted from the air on 22 February. It was not visible again until 28 February, when it had risen to about 30 m below the surface of the spillway.

"Unlike many of the earlier repose periods, during which magmatic gases at the vent were highly oxidized or so dilute as to be practically undetectable, the repose periods preceding and following episode 15 have been characterized by the continuous emission of fresh, reduced, SO2-rich magmatic gas. This may reflect the uninterrupted exposure of the active top of the magma column within the conduit (no plug of rubble or solidified lava above the column). Repose-period flux rates of such reduced gas are less than 1% of eruption-related flux rates."

Addendum: Episode 16 began at approximately 1500 on 3 March and ended at about 2230 on 4 March. Lava fountains rose as high as 200 m above the top of Pu'u O and produced a large amount of tephra. The main lava flow, fed by a vigorous pahoehoe river, extended 8 km ESE, reaching the NE corner of Royal Gardens subdivision atop episode 2 lava. Spatter-fed lava flows extended W and N of the vent.

Information Contacts: E. Wolfe, A. Okamura, and R. Koyanagi, HVO.


March 1984 (SEAN 09:03) Citation IconCite this Report

Episodes 16 and 17 include strong fountaining, tephra, and the longest flow of the 1983-84 eruption

"The 16th and 17th major episodes of the eruption occurred 3-4 and 30-31 March. Pu'u O was the eruptive locus for both episodes. Simultaneous eruptions on 30 March at Mauna Loa, Mt. St. Helens, Veniaminof, and Kīlauea make this the first date known on which four U.S. volcanoes were erupting at the same time.

"Beginning on 28 February, lava was visible continuously within the upper 30 m of the vertical 20 m-diameter pipe that extended downward from the bowl-like crater within Pu'u O. Sometimes completely open and sometimes partly crusted, the surface of the magma column rose slowly over the next 4 days to the level of the spillway in the deep breach in the NE rim of Pu'u O. Minor amounts of spatter and small volumes of SO2-rich gas issued from the lava surface.

EPISODE 16

"Time-lapse camera data indicate that the lava ponded within Pu'u O first overflowed the spillway on 3 March at about 1450. The vigor of fountain activity increased from that time, and the fountain became visible above the rim of Pu'u O at about 1520. By 1700, when HVO personnel arrived, the fountain rose 200-250 m above the lava pond (the crater rim was about 40 m above the pond). Glowing tephra was at times wafted to twice the height of the fountain by convective air currents rising over the cone. Erratic winds distributed tephra on all sides of the vent and at times during the night, intense tephra falls, including incandescent bombs up to 20 cm in diameter, rained on observers 750 m uprift of the vent. At about 0400 on 4 March, fountain activity diminished greatly and became sporadic. During the remainder of the eruption the fountain played to heights ranging from about 20-150 m above the pond.

"The intense fountain activity produced a thick spatter-fed aa flow that advanced about 1 km N; smaller spatter-fed flows extended E, SE, and W. The major flow, dominantly aa, was fed by a vigorous lava river debouching through the breach in the NE rim of Pu'u O at an average of about 0.25 x 106 m3/hour. It advanced E and ESE, mostly on top of flows from earlier episodes. Approximately 6.4 km from the vent, it split into 2 lobes, the longer of which extended another 1.6 km SE across the NE corner of Royal Gardens subdivision. This lobe, however, was contained within the evacuated channel of the episode 2 flow that invaded the subdivision in March 1983, and caused no new damage. After a momentary pause at 2228, the eruption stopped abruptly at 2231 on 4 March. Occasional small bursts of spatter issued from the vent over the next 10 or 15 minutes.

"Basalt produced during episode 16, as in previous episodes, is sparsely porphyritic. In hand specimen, scattered, small (millimeter-size) olivine phenocrysts are visible. Lava temperatures, measured by thermocouple, were 1,139-1,142°C in pahoehoe within 1.5 km of the vent and 1,135-1,138°C at the advancing distal end of the main flow in aa and local breakouts of viscous pahoehoe.

"The volume of lava erupted during episode 16 was approximately 12 x 106 m3. The corresponding summit collapse caused almost 15 µrad of deflationary tilt change at Uwekahuna. As in previous episodes, the beginning and end of measurable summit deflation lagged slightly behind the onset and termination of lava production at the vent.

"Harmonic tremor associated with episode 16 began to increase gradually in amplitude on 3 March at 1435, and rapid increase began at 1504. Sustained, high-level tremor continued in the eruption area until 4 March at 2229 when the intensity began to pulsate and gradually decrease. Rapid decrease in tremor amplitude began at 2231, coincident with the end of lava production.

Repose-period activity. "The repose period between episodes 16 and 17 was marked by an unusually gradual reinflation of the summit, slightly over 9 µrad of inflationary tilt change in 3½ weeks. The upper surface of the gradually rising magma column was first seen at the vent on 20 March, when it was approximately 50 m deep inside the pipe that extends downward from the crater floor, and 60 m below the spillway through the NE crater rim. Intermittent observations showed that the column rose slowly until the onset of vigorous lava production on 30 March.

EPISODE 17

"Harmonic tremor related to episode 17 began to increase 30 March at 0510, and glow from the eruptive area was visible from Kīlauea's summit at 0515. A photographer camped near the vent reported seeing a low dome fountain in the crater and a short NE-moving lava flow at about 0520-0530. He estimated that the flow was about 0.5 km long by 0545, and that by about 0610 the fountain top was at the level of the rim of Pu'u O (about 40 m above the surface of the overflowing lava pond).

"HVO personnel arrived at about 1000. From then on, they observed the fountain playing in a rapidly pulsating fashion (up to 20 pulses per minute); the fountain height ranged about 40-160 m above the surface of the lava pond. A narrow lava flow, fed by a voluminous lava river discharging through the breach in the NE crater rim, was more than 1.5 km long at 1000. It extended ENE (to the spatter/cinder cone south of Pu'u Kahaualea) then, following the episode 16 flow, turned ESE. During the day the flow continued advancing ESE on top of the episode 16 flow at 0.5 km/hour. During the night it followed the northern episode 16 lobe N of Royal Gardens. Near the terminus of that episode 16 lobe, the episode 17 flow turned SE and followed a gully parallel to and 1 km NE of the subdivision's E boundary. When seen the next morning, 3.5 hours after the eruption's end, the still-advancing aa flow front was about 3 km from the ocean. A preliminary estimate suggests that this flow is more than 10 km long, the longest of the 1983-84 eruptive series. Episode 17 stopped on 31 March at 0324. The sustained high-amplitude tremor characteristic of Pu'u O eruptions began to diminish in intensity at 0316 and by 0324, when lava production stopped, the tremor amplitude had nearly reached the repose-period background level.

"The episode 17 basalt, like the episode 16 basalt, is slightly porphyritic with scattered millimeter-size olivine phenocrysts. However, thermocouple temperatures measured in overflows at the edge of the lava river range from 1,131 to 1,137°C, distinctly lower than the episode 16 temperatures.

"Measurable summit deflation began about 2.5 hours after the onset of lava production and ended nearly 4 hours after the termination of lava production. Deflationary tilt change at Uwekahuna was about 10 µrad. A preliminary guess is that the volume of episode 17 lava is significantly 1ess than the episode 16 volume."

Information Contacts: E. Wolfe, A. Okamura, R. Koyanagi, HVO.


April 1984 (SEAN 09:04) Citation IconCite this Report

18th episode; four lava flows, longest flow of 1983-84 eruption

"After 19 days of repose, the eruption resumed at Pu'u O at approximately 1800 on 18 April. Following nearly 60 hours of continuous lava emission, vigorous lava production stopped at 0533 on 21 April. Episode 18 was the longest eruptive episode of 1984 on Kīlauea, and undoubtedly was one of the more voluminous of the 1983-84 series. About 200 x 106 m3 of basalt has been produced since the eruption began on 3 January 1983.

EPISODE 18

Eruption narrative. "After episode 17 ended on 31 March, the crater of Pu'u O was again a steep-walled, nearly flat-floored bowl about 50 m deep and 120 m across at the crater rim. As before, a nearly vertical 20-m-diameter pipe descended from near the center of the crater floor. Visibility down the pipe was obscured by fume in the days immediately following episode 17; exposed lava was first seen tens of meters down the pipe on 5 April. The lava surface, largely crusted much of the time, rose higher in the pipe over the following days; on 17 April, when last observed prior to episode 18, the crusted lava surface was less than 10 m below the top of the pipe.

"A time-lapse camera set at a 1-minute interval recorded the first low fountain activity within Pu'u O at 1751 on 18 April. At about 1800, lava was first recorded passing through the deep breach in the crater's NE rim. Intensity of activity increased, and by approximately 1900 the fountain crest was about 40 m above the surface of the lava pond within Pu'u O. Bad weather obscured visibility through much of the night, but frames exposed during brief clear periods suggest that the fountain was variable and at times was at least 200 m high. During the night, 10-20 cm of lapilli were deposited near Pu'u Kamoamoa (less than 1 km W of the vent), and Pele's hair fell at HVO, 20 km W of the vent. In the early morning the fountain height decreased, and for the rest of the eruption it was about 40-80 m above the pond. Major fountain activity and lava production stopped at 0533 on 21 April; emission of minor spatter continued for another hour.

"Episode 18 produced four major aa flows (figure 25), all fed by distributaries of the lava river that debouched vigorously and steadily through the breach in the NE crater wall. Three flows were active when the first observers arrived at 0700 on 19 April. Flows A and B were receiving the bulk of the lava, and their active fronts were 3 and 4 km from the vent. A small flow (C), extending SE along the Hawaii Volcanoes National Park boundary, was about 1.5 km long.

Figure (see Caption) Figure 25. Kīlauea lava flow from episodes 17 and 18. Courtesy of HVO.

"By 1800 on 19 April, flow A, 5 km long, had stopped, its supply cut off. Most of the lava was being channeled into flow B, which had become the main flow. It was about 8 km long and had advanced at an average rate of more than 300 m/hour to a point N of Royal Gardens subdivision. Flow C, along the park boundary, was about 3 km long and advancing slowly.

"During the night of 19-20 April, the rate of advance of the main flow (B) decreased, although the supply from the vent was apparently steady. By 0730 on 20 April, the flow front was advancing through the rain forest at the E edge of the episode 17 flow; the terminus was about 10 km from the vent. Flow C had advanced to about 4.5 km from the vent, and its distal end had stagnated. The relatively small volume of lava supplied to this flow over the next several hours ponded and spread laterally about 1.5 km SE of the vent.

"At 1730 on 20 April, when the day's last aerial reconnaissance was made, the main flow had extended nearly 14 km from the vent and was threatening three houses at the end of a road E of Royal Gardens. Supply to the flow along the park boundary had been completely cut off. However, just to the NE, a pahoehoe overflow from the main channel was about 1 km long and was extending SE. This was to become the 4th major flow (D) of episode 18.

"During the night of 20-21 April, the main flow slowly advanced more than 300 m and overran two of the three threatened houses before the eruption stopped at 0533. Creeping slowly after the eruption ended, the flow overran the 3rd house the following afternoon. This is the longest flow of the 18 eruptive episodes, extending more than 14 km to within just over a kilometer from the ocean.

"The 4th flow (D), which had originated as a pahoehoe overflow in the late afternoon of 20 April, apparently captured a greater part of the supply during the night. Advancing at an average rate of between 400 and 500 m/hour, it extended more than 7 km and entered the N part of the Royal Gardens subdivision. Observed in Royal Gardens in the early morning hours, it was thin and fluid, moving more like pahoehoe than like aa.

"The episode 18 basalt is similar to that of other recent episodes in hand-lens view and in lava temperature. Scattered small olivine phenocrysts comprise less than 1% of the rock, which is otherwise aphyric. The maximum temperature measured by thermocouple in pahoehoe was 1,144°C.

"At the eruption's end, debris from the crater walls plugged the opening of the pipe. However, by 23 April the pipe was once again open and vertical, and lava was seen deep (tens of meters) within it. Intermittent sightings of lava deep within the pipe have continued. Exact determinations of the depth to the lava are prevented by fume and by excessively hazardous access to the crater floor.

Seismicity and deformation. "Harmonic tremor, centered near Pu'u O, remained at a low level from 1-18 April. During this time, periods (up to several days long) of constant low amplitude alternated with periods of variable amplitude that fluctuated on a time scale of a few minutes to several hours. Starting from about 0245 on 18 April, 1-2-minute bursts of stronger tremor occurred at intervals of 15-30 minutes. By 1200, these bursts were longer, and eventually the activity became constant. Tremor amplitude increased sharply from 1810. At 1848 the seismic alarm was triggered, and shortly thereafter the tremor had increased to levels comparable to earlier major episodes of the eruption. High tremor was sustained throughout the period of vigorous eruption. At 0535 on 21 April, tremor decreased abruptly, following about 15 minutes of spasmodic decay in amplitude. The seismicity resumed its typical low interphase level characterized by fluctuating weak tremor and tiny shocks, associated with near surface events at Pu'u O. From 0520 to 0545 on 22 April, a flurry of seismic events resembling rockfall signatures, and increased tremor were recorded at Pu'u Kamoamoa seismograph. The episode may record collapse of the rubble that plugged the pipe inside Pu'u O. This burst of activity occurred about 3 hours after 2 S flank earthquakes centered about 10 km SW of Pu'u O: at 0223, magnitude 3.8, depth 10 km; and at 0226, magnitude 3.9, depth 8 km. Harmonic tremor continued at low level near Pu'u O through the remainder of the month.

"Summit subsidence during episode 18, measured in the E-W direction by the Uwekahuna tiltmeter, was between 19 and 20 µrad. This is the largest subsidence since episode 3, 28 March-9 April 1983. Again, onset of summit deflation and resumption of inflation as recorded by the tiltmeter followed slightly behind the beginning and end of lava emission."

Information Contacts: E. Wolfe, A. Okamura, and R. Koyanagi, HVO.


May 1984 (SEAN 09:05) Citation IconCite this Report

19th and 20th episodes; gas-piston activity

"A small, relatively low-level eruption at Pu'u O on 16-17 May comprised an effusive episode in the eruption that began on 3 January 1983. Unlike the preceding eruptive episodes, which have been characterized by generally steady, voluminous lava emission and continuous vigorous fountaining, episode 19 was characterized by intermittent low-volume overflows from a lava pond in the crater of Pu'u O and a few brief periods of increased lava emission and high fountaining.

"After episode 18, and continuing through late April and the first half of May, the top of a magma column, partly crusted much of the time, remained tens of meters deep in the 20-m-diameter pipe that descends from the floor of the Pu'u O crater. At times, low-level spattering could be seen within the pipe from passing aircraft.

Episode 19

Eruption narrative. An observer on the ground in the eruption area saw intermittent spatter at Pu'u O beginning shortly after 0200 on 16 May. At about 0500, the first of many small pahoehoe flows of episode 19 (figure 26) spilled through the deep breach in the NE part of the crater rim. The flows typically lasted about 3-30 minutes and carried lava at about 103-105 m3/hour. Intervals ranging from 4 minutes to several hours separated these small effusive events.

Figure (see Caption) Figure 26. Lava flows erupted from Kīlauea between 3 January 1983 and 8 June 1984 on the E rift zone. Flows from phases 18-20 are shown separately. Courtesy of HVO.

"During episode 19 an active lava lake was maintained within Pu'u O. At times the lake was confined to the upper part of the pipe; at other times it rose and spread across the crater floor. Flows issued quietly from the crater whenever the pond rose high enough to overflow the breach. A dome fountain played intermittently on the pond surface above the pipe, particularly during times of more rapid lava supply.

"In addition to the numerous, relatively quiet overflows of the pond, there were 4 periods, 1-3 hours long, of high fountaining with more vigorous lava production estimated at 1-2 x 105 m3/hour. A fountain 30-100 m high played on the pond surface during these episodes on 16 May at about 0940-1226, 1510-1608, 1840-2020, and 2355-0125 on 17 May. The first high fountain event was marked by rapid 2- to 3-fold changes, about a minute apart, in fountain height. These were followed within seconds by similar changes in lava discharge through the breach. In addition, this nearly 3-hour episode stopped and restarted 14 times. The pauses ranged in duration from a few seconds to 4 minutes. Vigorous lava emission and high fountaining would stop and start almost instantaneously at those times.

"During the evening of 17 May, the overflows from Pu'u O were smaller and more uniform in duration and spacing than previously. Several observations suggested that regular gas-piston activity had become established. During 3 hours of careful timing, the overflows averaged about 5 minutes in duration and occurred in cycles with an average length of 12 minutes. In each a [brief gas] burst was recognized immediately before the overflow stopped. Vigorous drainback into the pipe at the termination of overflow was seen within the crater in the late afternoon; presumably such drainback events, initiated by gas bursts, terminated each of the evening overflows. In addition, the distinctive bursts of tremor that we have come to associate with the drainback episode of gas-piston events were occurring with the same regularity as the overflows. At about 0030 on 18 May, the tremor bursts diminished in amplitude and became exceedingly regular, suggesting that the overflows probably stopped at that time.

"The repeated overflows from the crater built a relatively smooth apron of dense pahoehoe within a kilometer of the E base of Pu'u O. The higher lava emission associated with the periods of strong fountaining produced narrow, thin flows of pahoehoe and some aa that extended 2-3 km E and SE of the vent. Total estimated volume of new basalt is about 106 m3.

"The lithology and lava temperature resembled those of previous episodes. The basalt is nearly aphyric with scattered small olivine phenocrysts. Temperatures measured by thermocouple in overflows were 1,138-1,141°C.

"Measurements of SO2 flux during episode 19 gave surprising results. Even during the periods of high fountaining, it was comparable to that measured during repose periods when the magma column was visible within the pipe. That value was about two orders of magnitude less than the SO2 flux measured during previous eruptive episodes.

Seismicity and deformation. "After episode 18, harmonic tremor centered at Pu'u O remained low and continuous. Intermittent high tremor was associated with renewed fountaining during episode 19. On 16 May at 0640, background tremor began to increase rapidly, initiating a series of alternating [periods of] high- and low-amplitude tremor episodes at intervals of several minutes to several hours. Periods of relatively high and sustained tremor (0940-1255, 1423-1625, and 1857-2025 on 16 May; and 2351-0135 on 16-17 May) coincided closely with the intermittent high-fountain events seen at Pu'u O. After the high-fountain events, tremor of intermediate amplitude continued at irregular intervals, coincident with overflows at Pu'u O, until 1600 on 17 May.

"Tremor amplitude shown in figure 27 is misleadingly low. Amplitudes during the high-fountain events were comparable to those of previous episodes. However, the events were intermittent and of short duration, and they occurred between the programmed sampling intervals on which the tremor-amplitude plot was based.

Figure (see Caption) Figure 27. Kīlauea summit tilt (measured at Uwekahuna), amplitude of harmonic tremor, and periods of lava production for episodes 1-23. Tall bars represent periods of high fountaining and vigorous flow production; short bars represent periods of low-level activity including the visible presence of magma in the conduit. During episode 19, the brief periods of high tremor did not coincide with the programmed sampling intervals.

"The Uwekahuna E-W tiltmeter, above the NW flank of Kīlauea's summit reservoir, showed that slow deflation of the summit began at about 1100 on 15 May, 18 hours before the first lava overflowed from the crater. Following a gradual 1.5-µrad deflationary tilt change, the rate of summit deflation increased, after high fountain activity had begun. By 0600 on 17 May, when deflation stopped, an additional 4 µrad of deflationary tilt change had been recorded. Gradual reinflation began at about 1100 on May 17, half a day before the overflows at the vent stopped.

Post-Episode 19 activity. "From 17 May until the end of the month, the tremor pattern was dominated by cyclic low-level tremor. Half-minute bursts of higher amplitude alternated with 8-12-minute intervals at lower amplitude. Repeated observation at the vent showed that the short bursts of higher tremor occurred during the gas burst and the accompanying vigorous drainback in gas-piston events.

"The pattern of periodic half-minute tremor bursts was temporarily interrupted by more continuous intermediate-level tremor from 1020 on 28 May to 2330 on 30 May. Observation at the vent on 29 and 30 May showed that the top of the magma column was open and smoothly boiling at the top of the pipe. Slowly rising and falling over a 2-m range, it occasionally spilled a minor flow onto the flat crater floor. There was no gas-piston activity.

"By 31 May, the top of the magma column was several meters down the pipe, and gas-pistoning had been re-established. Occasionally, the rise of the gas volume through the magma column caused a small pahoehoe flow to well out of the pipe and spread over the nearby part of the nearly flat 100 m-diameter crater floor. When the gas accumulation broke through the magma column surface, a flare of burning hydrogen could be seen during the drainback.

"Just under 2 µrad of deflation were associated with the period of increased harmonic tremor on 28-30 May. As in episode 19, the onset and termination of deflation preceded by several hours the onset and termination of increased tremor."

Addendum: Episode 20 began at approximately 2115 on 7 June and ended at about 0625 on 8 June. Very vigorous lava fountains, visible for a short time from HVO, fed 2 lava flows that extended about 4 km NE of Pu'u O.

Information Contacts: E. Wolfe, A. Okamura, and R. Koyanagi, HVO.


June 1984 (SEAN 09:06) Citation IconCite this Report

Episodes 20-22; highest lava fountains of 1983-84 eruption

"Two eruptive episodes occurred on the E rift zone in June [and one in early July]. Both produced relatively small volumes of lava (less than 6 x 106 m3 each) and unusually high fountains (in excess of 300 m) seen from HVO for the first time since the eruption began in January 1983. Episode 20 (7-8 June) and episode 21 (30 June) produced lava flows as long as 4.5 km, all on or NW of the E rift zone. Following episode 21, Pu'u O, the steep-sided spatter cone that has been the locus of eruptions for more than a year, stood about 140 m above the pre-1983 surface and was mantled by an extensive blanket of tephra. Between episodes, an active column of magma was visible in an open conduit several tens of meters below the floor of Pu'u O's summit crater. It periodically emitted gas and small particles of spatter in bursts of less than a minute, separated by intervals of 5-12 minutes. This gas-pistoning was reflected in the tremor record from the seismic station near the eruption site.

EPISODE 20

"Low-level repose-period activity preceded Episode 20. The time-lapse film shows that intermittent spatter was visible above the spillway as early as 6 June at 2328 but was confined to the crater; it continued until 0448 on 7 June. For the next 11.5 hours only heavy fume was recorded.

"Episode 20 occurred largely at night, so the record consists primarily of time-lapse photography and the tiltmeter and seismic data described below. At 1911 on 7 June continuous low-level spatter activity commenced and sporadic fountaining began 65 minutes later. Lava first poured over the spillway at 2104, and from 2200 until 0624 on 8 June high fountaining was continuous. Maximum fountain heights were estimated at 300 m, because they were visible above the horizon from HVO. The last fountains recorded on film were at 0627; they were followed by intense fuming that decreased over the next several hours. During the period of vigorous eruption, 4 lava flows moved N and NE of Pu'u O, the longest reaching about 4 km from the vent (figure 13-30).

EPISODE 21

"On 30 June, observers reached the eruption site at 1045, a few minutes after episode 21 lava topped the spillway and just before vigorous fountaining began. A maximum fountain height of approximately 390 m was measured by theodolite at 1115. This high level was maintained for about 4 hours after which fountaining decreased as flow apparently increased down the spillway. Early in the eruption, a fissure vent opened on the SW flank of Pu'u O, producing a line of low fountains and a pahoehoe flow that ponded on the S side of Pu'u Kamoamoa (about 0.5 km to the W). A large lava flow that divided into several tongues extended 3-4.5 km NE of the vent, generally on top of episode 20 flows. A third flow of spatter-fed aa from the N rim of the crater overran a similar episode 20 flow for about 1 km N of Pu'u O. A thin blanket of tephra, including an early deposit of reticulite, was deposited SW of the vent. The eruption ended abruptly at 1827 with a simultaneous termination of fountaining and lava flow at the spillway. Heavy fuming and sporadic burning of hydrogen gas followed the eruption for several hours.

"Approximately 3.7 x 106 m3 of new basalt was produced in episode 20 and a similar amount (mapping still in progress) was produced in episode 21.

EPISODE 22

"At the time of this writing, episode 22 has just ended, having produced 5 additional flows and another tephra blanket during activity that lasted from about 1930 on 8 July to 1017 on the 9th."

Deformation and Seismicity. "The E-W tilt measured at Uwekahuna increased irregularly after the brief episode 19 eruption of 16-17 May. On 7 June at about noon, deflation of the summit region began slowly, increasing to a rapid rate after 2100 when eruptive activity of episode 20 began. Subsidence continued through the eruption and for nearly 10 hours after fountaining activity had ceased. The post-eruptive deflation accounted for 30% of the total tilt change.

"Following episode 20, the return to summit inflation was unusually slow. For the first week, summit tilt increased by less than 2 µrad. During the next 10 days there was a 5-µrad increase in tilt followed by 5 days of little change. On 28 June, slow inflationary tilt resumed for about a day until the summit began to subside slowly. Rapid deflation commenced on 30 June at about 1100, shortly after the start of episode 21 lava production at Pu'u O. Deflation continued through the eruption and for nearly 9 hours afterwards. Post-eruption deflation accounted for nearly 40% of the total tilt change.

"Harmonic tremor at the Kamoamoa seismic station continued at low levels during the repose periods between brief eruptive stages. As in previous episodes, tremor increased to high amplitudes shortly before high fountaining began and returned to background levels when fountaining ended. High tremor of episode 20 began on 7 June at 2120 and ended on 8 June at 0627. Episode 21 tremor began on 30 June at 1028 and ended the same day at 1827. Small bursts of increased tremor during the repose periods coincided with brief intervals of gas-pistoning (09:5). This phenomenon of gas-pistoning (restricted to the vent conduit) has occurred regularly since episode 19. It became erratic several hours prior to the onset of episode 21, coincident with a slight increase in background tremor, and resumed its periodic pattern soon after episodes 20-21 ended.

Gas measurements. "COSPEC measurements of SO2 emissions during the repose period between episodes 20 and 21 averaged 1.4 metric tons per hour, rising to nearly 6 metric tons per hour during gas bursts. Measured SO2 emission during episode 21 was about 1,000 metric tons per hour."

Further Reference. Wolfe, E.W. (ed.), 1988, The Pu`u `O`o Eruption of Kīlauea Volcano, Hawaii, Episodes 1-20, January 3, 1983 Through June 8, 1984; USGS Professional Paper 1463, 8 papers.

Information Contacts: G. Ulrich, A. Okamura, and R. Koyanagi, HVO.


July 1984 (SEAN 09:07) Citation IconCite this Report

Episodes 22-23 of 1983-84 E Rift Zone eruption

"Two eruptive episodes occurred on the E rift zone in July. Episode 22 began about 1930 on 8 July, stopped abruptly at 1017 on the 9th, and produced approximately 7.7 x 106 m3 of basalt (figure 28).

Figure (see Caption) Figure 28. Lava flows erupted at Kīlauea between 3 January 1983 and 20 August 1984. Flows from episodes 22-24 are shown separately. Courtesy of HVO.

EPISODE 23

"Episode 23 began at about noon on 28 July and lasted until about 0540 on the 29th (mapping in progress). Pu'u O (Enduring Hill in Hawaiian) was again the vent for lavas that flowed about 5 km to the NE, down the NW side of the rift zone (mostly outside the National Park). Both episodes were characterized by high fountain activity, short spatter-fed aa flows, and thin tephra blankets near the cone. The crater at Pu'u O has filled with solid basalt to near the level of the spillway that, following episode 23, was located on the N side of the cone and about 50 m below the highest point on the crater rim (on its SW side). More detailed surveying since June placed the summit elevation at 145 m above the pre-1983 surface and 80-100 m above surrounding accumulations of new basalt. The average diameter of the base of the cone was about 550 m. The basalt produced continued to be nearly aphyric with widely scattered phenocrysts of small (< 1 mm) olivine.

Deformation. "During the 8-day period after episode 21 (30 June), the E-W summit tilt (at Uwekahuna) increased at a rate of less than one µrad per day. At 1200 on 8 July, the tilt started downward, indicating summit subsidence; eruptive activity at Pu'u O began 6 hours later. The maximum rate of summit subsidence (1 µrad per hour) occurred 1.5 hours after the onset of episode 22. Summit subsidence continued until 1600 on 9 July, 6 hours after lava production had ceased. The total E-W tilt change recorded was 13 µrad. Rapid inflationary tilt change during the two days following episode 22 totaled 5 µrad.

"Between 13 and 28 July, a slower rate of summit uplift was reflected in the net upward tilt change of 7 µrad. The amount of summit subsidence that occurred during episode 23 (28-29 July) corresponded to a downward tilt change of 13 µrad. At the end of July, Kīlauea's summit was reinflating.

"The summit has undergone a net vertical subsidence of 50 mm since January 1984. Cross-rift deformation lines have been established 0.7 and 9 km uprift of Pu'u O. An additional telemetering tiltmeter has been installed about 7 km uprift of the 1983-84 eruption site.

Seismicity. "Harmonic tremor at the Kamoamoa seismic station was continuous and centered near Pu'u O. Tremor amplitudes were characteristically high during periods of vigorous lava output and low between the eruptive episodes. High tremor accompanying episode 22 started at 1859 on 8 July and ended at 1017 the next day.

"Tremor began to increase for episode 23 at 1158 on 28 July and declined at 0543 the next day. Associated with the accelerated summit deflation and toward the end of the eruptive episodes, a secondary source of intermediate-amplitude tremor in the shallow summit region was detected. Low interphase tremor near Pu'u O varied from cyclic bursts at about 10-minute intervals to signals of uniform amplitude lasting up to several days."

Information Contacts: G. Ulrich, A. Okamura, and R. Koyanagi, HVO.


August 1984 (SEAN 09:08) Citation IconCite this Report

Episode 24; high fountains; thin tephra blanket

EPISODE 24

"The 24th eruptive episode of the 1983-84 eruption occurred on 19-20 August. Lava was first seen flowing through the vent's NE spillway at 2127 on 19 August. Vigorous fountaining began at 2210, reached a maximum height of 315 m above the spillway at about 0100 on 20 August, and ended at 1721. One major flow moved through the N spillway (the dominant path from the vent) and advanced N and NE, overriding much of the lava from episodes 22 and 23. The volume of lava produced was approximately 11.6 x 106 m3. A thin, uniform, tephra blanket was deposited over much of the area within a radius of about 2 km.

"The Pu'u O summit height increased by about 3.5 m and had much the same form as in earlier episodes (see sketched profiles, figure 29). The total volume of tholeiitic basalt (not corrected for void space) produced since January 1983 is slightly more than 0.25 km3. The recent basalt, like that of earlier episodes, is nearly aphyric with widely scattered small (< 1 mm) phenocrysts of olivine.

Figure (see Caption) Figure 29. Profiles of Pu'u O cinder/spatter cone. No vertical exaggeration. Top, view to the SW showing location of the N and NE spillways following episode 23. Bottom, view to the NE during episode 24 showing the asymmetry of cone shape and the slope of the N spillway, which has become the dominant path of lava from the vent.

Deformation. "During the 21-day repose prior to episode 24, the E-W summit tilt (measured at Uwekahuna bluff) increased by 10 µrad. Summit deflation, reflected by a downward tilt change of 14 µrad, began on 19 August at almost the same time as the onset of high fountaining and high-amplitude tremor at the eruption site. Deflation continued until 2000 on 20 August, about 2.5 hours after the end of lava production.

"Preliminary results from two horizontal deformation lines, installed across the E rift at points 0.7 and 9 km uprift from Pu'u O, show that changes since late June have been very small (< 20 mm), but systematic trends, similar on both lines, may be indicated. During the period of episodes 21-24, extension occurred on both sides of the rift axis between eruptive episodes and an almost equal contraction was measured following each episode. This cyclic extension and contraction suggests elastic behavior of the wall rock. Cumulative change in total line lengths has not occurred. The new telemetering tiltmeter installed near Makaopuhi Crater (about 6.5 km uprift from Pu'u O) has recorded no significant tilt changes since July.

Seismicity. "The Kamoamoa seismic station recorded continuous harmonic tremor through August. An increase in tremor amplitude near Pu'u O accompanied episode 24. A gradual buildup of high tremor started at 2125 on 19 August, 2 minutes before lava was first observed in the spillway; increased tremor continued throughout the episode and ended at 1721 the next day as fountaining stopped. Tremor of low to intermediate amplitude was also detected in the summit region. Low-level tremor with many sporadic bursts continued near Pu'u O for several days following the end of episode 24. The number of microearthquakes at the summit region fluctuated from low to average and was high in the E rift zone."

Information Contacts: G. Ulrich, A. Okamura, and R. Koyanagi, HVO.


September 1984 (SEAN 09:09) Citation IconCite this Report

Episode 25; highest fountains of 1983-84 eruption; tephra

EPISODE 25

"After a 30 day repose period, the 25th episode of the 1983-84 E rift zone eruption began at about 1604 on 19 September and ended at about 0532 the next day. Brief intervals of Strombolian activity and a small pahoehoe flow across the N spillway occurred over a 10-day period preceding episode 25. The largest flow exited through the N spillway and advanced on a broad front up to 3.3 km from Pu'u O (figure 30). A small, short-lived, fissure eruption occurred ENE of Pu'u O early in the episode, producing a thin pahoehoe flow about 800 m long just N of the National Park boundary. The total volume of lava produced was approximately 11.1 x 106 m3. An unusually thick tephra mantle, estimated to have a volume of about 1 x 106 m3, fell early in this episode, accompanying the highest (460 m) fountains yet observed in the 1983-84 eruption.

Figure (see Caption) Figure 30. Lava flows erupted from Kīlauea between 3 January 1983 and 20 November 1984 on the E rift zone. Flows from episodes 25-27 are shown separately. Courtesy of HVO.

"The summit of Pu'u O increased in height by 12 m during episode 25 and, within 11 days, had collapsed about 5 m, to stand 875 m above sea level and 155 m above the pre-1983 surface. The recent basalt, like that of earlier episodes, is nearly aphyric with widely scattered small (< 1 mm) phenocrysts of olivine.

Deformation. "During the 30-day repose period prior to episode 25, the E-W tilt recorded in the Uwekahuna vault increased by 17 µrad. Summit subsidence began around 1400 on 19 September. The net deflationary tilt change recorded during episode 25 was 15 µrad. Tiltmeters near the eruption site and at a site 6.5 km uprift recorded no significant tilt change during September. By the end of the month, slow reinflation of the summit was indicated by a recovery of 6 µrad.

Seismicity. "Prior to the onset of episode 25, tiny earthquakes, registered only at the Pu'u Kamoamoa station (about 500 m uprift from Pu'u O), started to increase after about 1500 on 19 September. At 1530, the level of harmonic tremor began to increase as well. Tremor increased rapidly at 1540, and was marked by a sharper increase at 1604. At 1613 the tremor alarm at HVO was triggered. At 1615, tremor amplitude peaked and remained at a high level until 0532 on 20 September. A rapid decrease in tremor was accompanied by intermittent high-amplitude bursts. For about 6 hours following the drop in tremor, there were many tiny high-frequency shocks recorded near Pu'u O.

"From about 2000 on 19 September to 0800 on 21 September, a swarm of very small long-period earthquakes combined with intermediate-amplitude harmonic tremor, apparently related to the post-deflation adjustments of the summit storage system, was recorded in the North Pit station at the summit.

"At the end of September, the level of tremor at Pu'u O was constant and very low in amplitude. The number of microearthquakes was low in the summit region and moderate in the E rift zone."

Information Contacts: G. Ulrich, A. Okamura, and R. Koyanagi, HVO.


October 1984 (SEAN 09:10) Citation IconCite this Report

Episode 26; shortest of 1983-84 eruption

"By the end of October, 41 days had passed since the last vigorous production of lava and high fountaining on the E rift zone. However, low-level activity continued during this period. Magma was visible several tens of meters below the top of the conduit. Periodic to irregular gas-piston activity, consisting of slowly rising magma followed by low-level Strombolian activity and rapid drainback coincident with heavy degassing, occurred at intervals of minutes to hours. SO2 emissions during the interphase period remained normal at about 100 t/d.

"On 25 October, lava ponded at the top of the conduit and occasionally spilled onto the floor of Pu'u O. On 27 October, a small pahoehoe flow, similar to that preceding episode 25, moved down the N spillway approximately 300 m from the conduit. During the next five days, a small pahoehoe shield, about 100 m in diameter and 10 m high, was built above the conduit and mainly within the rim of Pu'u O. A lava temperature of 1,145°C, near the maximum measured during the 1983-84 eruption, was determined by thermocouple.

"On 2 November, a period of high fountaining, continuous lava production, and rapid summit deflation, designated as episode 26, occurred from 1140 to 1636. This was the shortest episode since the eruption began in January 1983. A comparison of the lengths of eruptive episodes and repose periods is shown in figure 31.

Figure (see Caption) Figure 31. Comparison of lengths of eruptive phases (in hours) and preceding interphase periods (in days) for phases 2-26 of the E rift zone eruption.

Deformation. "Between the end of episode 25 (20 September) and 31 October, 17 µrad of E-W inflation were recorded at the summit (Uwekahuna). This increase brought the level of inflation to its highest point since episode 21 began in late June. Geodetic measurements near Pu'u O and about 9 km uprift indicated that very little net deformation was occurring across the rift zone. EDM measurements SW of Pu'u O show that the pattern of minor pre-eruption extension and post-eruption contraction reported in August appears to be continuing. However, theodolite measurements NE of Pu'u O showed no movement above detection limits.

Seismicity. "Seismic activity was relatively low during October. In the summit area, the number of microearthquakes gradually increased corresponding to the pattern of inflation. In the middle E rift zone, the frequency of tiny shocks resulting from minor structural and thermal adjustments near Pu'u O also increased. Harmonic tremor varied in amplitude from constant, to erratic, to cyclic one-minute bursts characteristic of gas-piston activity within the Pu'u O vent."

Information Contacts: G. Ulrich, A. Okamura, and R. Koyanagi, HVO.


November 1984 (SEAN 09:11) Citation IconCite this Report

Episodes 27 and 28 of 1983-84 middle E Rift Zone eruption

EPISODES 26 and 27

"Episode 26 occurred 2 November between about 1140 and 1634. This episode of high fountaining from the Pu'u O vent lasted only 5 hours, making it the shortest episode in 1983-84 eruption sequence. Lava exited through the N spillway of the cone and fanned out into broad aa flows that extended a maximum of 2.2 km NE and ESE from the vent. During the 17-day repose period following episode 26 there was little activity at the vent, unlike the period between episodes 25 and 26. Episode 27 began 20 November at 0005 and lasted 10 hours. High fountains produced aa flows extending 3.5 km SE.

"Because poor weather hampered efforts to obtain aerial photographs, an accurate map of episode 26 flows was not completed before the flows were overrun by lava of episode 27 (figure 30). The estimated volume of lava from the two episodes combined is approximately 16 x 106 m3. The summit of Pu'u O, which increased in height by 10 m in November, was 886 m above sea level and 167 m above the pre-1983 surface after episode 27.

Deformation. "Summit subsidence (recorded by the Uwekahuna tiltmeter) associated with episode 26 began at 1100 on 2 November. The net E-W tilt change related to the subsidence was 7.5 µrad; more than half of the tilt change occurred after the end of episode 26. During the next 17 days, the summit tilt regained 7.7 µrad. Subsidence accompanying episode 27 started at about 0030 on 20 November and continued until 1630, resulting in a net tilt change of 12.3 µrad. By the end of the month, the summit tilt had recovered 8 µrad.

Seismicity. "Shallow seismic events correlated with the continuing volcanic activity on the middle E rift zone. Strong harmonic tremor was recorded during major outpourings of lava, and low-level tremor and numerous tiny shocks occurred near the active vent between eruptive episodes.

"Harmonic tremor associated with episode 26 started with bursts of increasing amplitude at 1004 on 2 November and developed into sustained high-level tremor by 1140. Tremor remained strong for the duration of the eruptive episode. At 1634, after the cessation of high fountaining, tremor decreased rapidly. Low tremor and tiny microearthquakes resumed in the middle E rift zone during the period of relative quiescence following episode 26.

"At 2101 on 19 November, harmonic tremor began to increase intermittently at Pu'u O. The intensity of tremor reached about an order of magnitude above background at 0005 on 20 November, triggering the HVO tremor alarm system. For the next 10 hours, the seismic signal was sustained at the high level characteristic of periods of high fountaining and continuous lava production. Tremor decreased rapidly between 1008 and 1012, following the end of episode 27.

"Seismic activity assumed a typical interphase pattern for the remainder of the month. Low-level harmonic tremor continued in the middle E rift zone, varying from a pattern of constant amplitude to episodic short bursts indicative of gas-piston activity in the Pu'u O vent. The number of microearthquakes was generally below average in the summit region and above average in the E rift zone."

Addendum: Episode 28 began 3 December at about 1905. Vigorous fountaining fed lava flows to the N and SE during the 14-hour episode, which ended about 0941 the next morning.

Information Contacts: G. Ulrich, A. Okamura, R. Koyanagi, and C. Heliker, HVO.


December 1984 (SEAN 09:12) Citation IconCite this Report

Episodes 28 and 29 are one-day eruptions with fountains to 450 m

EPISODE 28

"Episode 28 began at 1905 on 3 December. High fountaining and continuous lava production lasted for 14.5 hours, ending at 0941 on 4 December. The lava spilled over the broad NE rim of the cone (Pu'u O) and produced a broad short aa fan to the NE and two larger aa flows to the SE. The SE flows extended 4.7 km from the vent, ending about 1.2 km short of Royal Gardens subdivision. The high fountains were accompanied by heavy tephra fallout in a broad swath downwind of the vent. Episode 28 produced 12.3 x 106 m3 of lava and approximately 0.2 x 106 m3 of tephra (lava equivalent).

"Pu'u O was in repose for the remainder of the month. On 30 December, low fountains (3-10 m) produced thin pahoehoe overflows that reached the base of the cone. Similar activity occurred intermittently for the next 4 days until high fountains and continuous lava production signaled the start of episode 29.

Deformation. "Summit subsidence began at about 1900 on 3 December, at the start of episode 28. The Uwekahuna tiltmeter recorded continuous summit deflation until 1330 the next day, resulting in a net tilt change of 15.9 µrad. During the rest of the month the summit tilt recovered 17.7 µrad.

Seismicity. "Harmonic tremor associated with episode 28 at Pu'u O started to increase gradually at 1815 on 3 December. By 1905 tremor recorded at the Kamoamoa seismic station increased to a level characteristic of high lava fountaining. High-amplitude tremor continued for nearly 15 hours. The sharp decrease in tremor following the end of the eruptive episode was recorded at 0941 on 4 December. For the rest of December, tremor was at low levels, varying from the fluctuating amplitude associated with gas-pistoning activity at Pu'u O, to continuous amplitude with no visible lava activity.

Addendum: The current Kīlauea eruption sequence celebrated its 2nd anniversary on 3 January 1985 with the start of episode 29. Fountains up to 460 m high fed aa flows to the NE and SE during the 16 hour episode.

Information Contacts: C. Heliker, R. Koyanagi, A. Okamura, G. Ulrich, HVO.


January 1985 (SEAN 10:01) Citation IconCite this Report

Episodes 29-30; fountains to 460 m; heavy tephra fall

EPISODE 29

"The E rift zone of Kīlauea entered its 3rd year of repeated eruptive activity with its 29th major display of high fountaining and vigorous lava production beginning at 1315 on 3 January, exactly 2 years after the first eruption in 1983. This episode followed 29 days when the magma column was frequently visible within the upper 40 m of the 25 m-diameter conduit of Pu'u O. It was also preceded by two small events of fountaining 3-10 m high and pahoehoe spillovers from the Pu'u O conduit on 30 December and 2 January.

"Fountains briefly reached a maximum height of 460 m about 3 hours after episode 29 began, matching the previous record set early in episode 25. Very heavy tephra fall (estimated volume [0.15] x 106 m3) occurred on the SE side of Pu'u O and the cone height increased by 14 m, but about 8 m were lost by collapse during the next 2 weeks, after which Pu'u O's summit was about 195 m above the pre-1983 surface. A broad aa flow traveled 4 km S (figure 32), burying much of the episode 28 flow and terminating about 1.7 km from Royal Gardens subdivision. Episode 29 ended abruptly at 0504 on 4 January. The total production of new lava was about 13 x 106 m3. The recent basalt, like that of earlier episodes, is nearly aphyric with widely scattered small (< 1 mm) olivine phenocrysts.

Figure (see Caption) Figure 32. Lava flows erupted from Kīlauea between 3 January 1983 and 5 February 1985 on the E rift zone. Flows from episode 29 (top) and episode 30 (bottom), are shown separately. Courtesy of HVO.

Deformation. "The summit subsided rapidly during episode 29. The Uwekahuna (W-E) tiltmeter recorded subsidence from approximately 1100 on 3 January to 0800 on 4 January. The most rapid deflation recorded was between 1600 and 1800 on the 3rd and reached a value of nearly 1.3 µrad/hour (figure 33). The net tilt change during episode 29 was 16 µrad. The summit had recovered approximately 13 µrad of inflationary tilt by the end of January.

Figure (see Caption) Figure 33. Kīlauea summit tilt, relative amplitude of harmonic tremor at the Pu'u Kamoamoa seismic station, and periods of lava production for 1984-85. In the lower plot, showing lava production, tall bars represent periods of high fountaining and vigorous flow production; short bars represent periods of low-level activity including magma frequently visible in the conduit. The gap in the tremor record following episode 30 is a result of the relocation of the Pu'u Kamoamoa seismic station. Courtesy of HVO.

Seismicity. "On 2 January between 1500 and 1950, a slight increase in tremor amplitude was recorded near Pu'u O. The seismic level decreased and remained relatively low until the following day at about 1100 (2 hours and 15 minutes before the eruption began), when the amplitude of continuous tremor began to increase gradually. A rapid increase of tremor associated with the high fountaining of episode 29 started about 1340. Tremor amplitude remained strong throughout the eruptive episode. Tremor decreased sharply at 0504 on 4 January, at the end of major lava production.

"Seismicity then decreased to the normal background activity in the Kīlauea region. Harmonic tremor in the middle E rift zone remained low, varying from relatively constant amplitude to periodic fluctuations in amplitude that were commonly correlated with gas-pistoning activity at the vent. Shallow microearthquakes were few in the summit region and varied from few to moderate in number in the E rift zone."

Addendum: At 0546 on 4 February, episode 30 began. Vigorous fountaining fed a major lava flow that extended 7 km SE from Pu'u O, before eruptive activity ended at about 0246 on the 5th.

Information Contacts: G. Ulrich, R. Koyanagi, R. Hanatani, HVO.


February 1985 (SEAN 10:02) Citation IconCite this Report

30th episode lasts about 21 hours; tephra falls in Hilo

EPISODE 30

"Episode 30 began on 4 February at 0546. High fountains and continuous lava production from the Pu'u O vent continued for 21 hours until 0246 on 5 February. Lava flows spilled over the NE rim of the cone and turned S to form one 8.3 km-long aa flow (figure 32). The flow advanced rapidly through National Park forest and passed 0.7 km W of Royal Gardens subdivision. Nearly 2 km2 of forest were destroyed by the lava flow, and grass fires at the distal end of the lava burned an additional 0.3 km2 over the next 3 days. SW winds deposited tephra and Pele's hair in Hilo, 35 km from the vent.

"Episode 30 produced about 14 x 106 m3 of lava and a minimum of 0.09 x 106 m3 of tephra (dense rock equivalent). Dense basalt specimens from the episode 30 flow appear to contain a higher concentration of olivine microphenocrysts than those of previous episodes.

"Because of the unusual wind direction during episode 30, the elevation of Pu'u O's summit increased by only a meter to 913 m above sea level. The growth of the cone since episode 24, as seen from a photo station on vent 1123, is illustrated in figure 34.

Figure (see Caption) Figure 34. Profiles of Pu'u O as seen froma photo station on vent 1123, 1,500 m to the NE, after episodes 24, 26, 28, and 30. Courtesy of HVO.

"Pu'u O was in repose for the remainder of February, although the magma column was intermittently visible at an estimated depth of 40-50 m in the 20 m-wide conduit.

Deformation. "Rapid summit subsidence associated with episode 30 began on 4 February at 0600, about ¼ hour after the onset of lava fountaining. The Uwekahuna (W-E) tiltmeter recorded continuous summit deflation until 0400 on 5 February, about 75 minutes after vigorous lava production ended. The maximum deflation rate was 1.75 µrad/hour, the highest rate recorded since the initial episode of intrusion and eruption in January 1983. The net tilt change was -22 µrad. Reinflation began very slowly, but by the end of February, the summit tilt had recovered 10.4 µrad.

Seismicity. "Harmonic tremor recorded at the Kamoamoa seismic station near Pu'u O began to increase 4 February at 0552, a few minutes after lava emission began. After 0600, tremor increased rapidly to a high amplitude that was sustained until the early morning hours of 5 February, when the tremor level began to fluctuate. Tremor amplitude dropped to the characteristic inter-episode signal at 0247 as episode 30 ended. For the remainder of the month, harmonic tremor continued at variable low amplitudes in the middle E rift zone.

"Seismic activity was highlighted by a magnitude 4.9 earthquake 9 km beneath the S flank on 21 February at 1948. The event was widely felt on the island and was followed by a series of aftershocks, but the earthquake had no immediate effect on the pattern of summit tilt or inter-episode activity at Pu'u O.

"Preliminary geodetic measurements near the epicenter of the 21 February earthquake showed that surface deformation was relatively local and did not extend beyond 4 km from the epicenter. Similarly, measurements made across the E rift zone at Pu'u O and near Mauna Ulu 4 days after the earthquake showed no significant deformation.

Addendum: On 13 March at 0720, episode 31 began. Lava fountaining fed flows that extended about 6 km SE from Pu'u O; lava flows entered Royal Gardens subdivision, but no structures were damaged. The 21-hour episode ended about 0455 on the 14th.

Information Contacts: C. Heliker, R. Hanatani, R. Koyanagi, HVO.


March 1985 (SEAN 10:03) Citation IconCite this Report

Episode 31; lava flows into subdivision; tephra builds Pu`u `O`o

EPISODE 31

"The 1983-85 eruption produced the 31st episode of vigorous fountaining and continuous lava production on 13-14 March. Sustained high-level activity began on 13 March at 0720 and continued for almost 21.5 hours. Fountain heights reached a maximum of 340 m above the Pu'u O conduit 5 hours after the eruptive episode began. A single broad aa flow advanced 4 km SE before splitting into two lobes. The E lobe entered Royal Gardens subdivision on 14 March at 0100; no buildings were damaged, although the lava passed within 200 m of one house and eventually stagnated within 150 m of another. The W lobe extended 7.8 km from the vent, to about 90 m elevation (within the National Park).

"Heavy tephra fall occurred on the SW side of Pu'u O, adding 11 m to its height. At the end of episode 31, the summit elevation was 924 m above sea level and 205 m above the pre-1983 surface. The volume of lava produced during episode 31 was approximately 19 x 106 m3, with an estimated tephra volume of 0.2 x 106 m3 (dense rock equivalent). The basalt of episode 31, like that of recent episodes, is microporphyritic, with about 2.6 modal % olivine microphenocrysts (< 1 mm).

"Following episode 31, dense fume obscured the view into the conduit of Pu'u O, and the magma column was not seen for the remainder of March.

Deformation. "Rapid summit subsidence associated with episode 31 began at approximately 0700 on 13 March, about as high-level eruptive activity began. The Uwekahuna (W-E) tiltmeter recorded continuous summit subsidence until 0600 the next day. The net tilt loss was 20.4 µrad. The maximum rate of deflation, 2.3 µrad per hour recorded between 1200 and 1300 on the 13th, was the highest recorded since the episode 1 intrusion. As at the end of episode 30, reinflation of the summit began slowly, and by the end of March the summit tilt had recovered 4.7 µrad.

Seismicity. "The intensity of harmonic tremor recorded at the Kamoamoa seismic station near Pu'u O increased rapidly starting on 13 March at 0600. By the start of vigorous eruptive activity at 0720, tremor had reached a high amplitude that was sustained until the end of the episode at 0458 the next day. Following episode 31, tremor amplitude dropped to the low level characteristic of inter-episode periods. Fluctuating low-level tremor continued in the middle E rift zone for the rest of March, with variation in amplitudes occurring at intervals of a few minutes to several days."

Information Contacts: C. Heliker, R. Hanatani, R. Koyanagi, HVO.


April 1985 (SEAN 10:04) Citation IconCite this Report

Episode 32 of 1983-85 middle E Rift Zone eruption

EPISODE 32

"The 32nd episode of the 1983-1985 eruption occurred on 21-22 April, following 38 days of repose. Intermittent dome fountaining began at 1516 on the 21st and lasted for about 4 hours. Continuous fountaining and lava production commenced at 1804. By 1910, tremor amplitude had increased and vigorous lava fountaining had begun. A broad aa flow advanced SE and split into 3 lobes about 3-4 km from the vent. The central lobe advanced the farthest, passing W of Royal Gardens subdivision, and stagnated 6 km from the vent (figure 35). Lava fountaining ceased at 0906 on the 22nd.

Figure (see Caption) Figure 35. Lava flows erupted from Kīlauea between January 1983 and 22 April 1985. The episode 32 flow is shown by diagonal lines. Courtesy of HVO.

"Heavy tephra fallout added 9 m to the elevation of Pu`u `O`o (a name recently suggested by local elders to replace the previously used Pu'u O') and blanketed the area SW of the vent. The summit collapsed 5 m during the following week.

"At the end of April, the cone was 928 m above sea level and 209 m above the pre-1983 surface. The total volume of lava produced through episode 31 was 354 x 106 m3, slightly exceeding the total reported for the Mauna Ulu eruption of 1969-74.

"Kīlauea remained quiet through the end of April. Heavy fume obscured the view into the vent, and the magma column was not observed.

Deformation. "The summit of Kīlauea subsided rapidly during the 32nd episode of the eruption. The Uwekahuna (W-E) tiltmeter recorded continuous summit subsidence from 1700 on the 21st until 1100 the next day, about 2 hours after fountaining stopped. The maximum rate of subsidence occurred between 2200 and 2300 on 21 April and measured nearly 2.1 µrad per hour. The net tilt change was 17.0 µrad. Reinflation of the summit had reached 6 µrad by the end of April.

Seismicity. "Harmonic tremor in the middle E rift zone near Pu`u `O`o increased gradually from about 1516 on 21 April, when intermittent dome fountaining began. Starting at 1843, tremor increased rapidly to an order of magnitude above background and remained high for the duration of the eruptive episode. At 0903 on the 22nd, about the time that lava fountaining ceased, the tremor level decreased rapidly, and by 1240 the intensity was down to nearly background levels.

"Following episode 32, harmonic tremor continued near Pu`u `O`o in the characteristic pattern observed during previous interphase periods. The number of microearthquakes decreased to a low level in the summit region and E rift zone."

Information Contacts: Episode 32 of 1983-85 middle E Rift Zone eruption


May 1985 (SEAN 10:05) Citation IconCite this Report

Summit inflation and low-level harmonic tremor continue; episode 33 of 1983-85 eruption

"For the first time since October 1984, Kīlauea did not erupt during a calendar month. Mapping of episode 32 (21-22 April) eruptive products was completed in May and showed that 16.1 x 106 m3 of lava and 0.25 x 106 m3 of tephra (dense rock equivalent) were produced. Lava from the 1983-85 eruption covered 40 km2 of the middle E rift zone.

"Following episode 32, magma was first visible in the conduit on 9 May, at approximately 50 m depth. By the end of May, the magma column had risen to within 30 m of the Pu`u `O`o crater floor and remained mostly crusted over.

Deformation. "The summit of Kīlauea continued to inflate during May. However, a period of significant summit subsidence occurred from 22 May at 1800 to 27 May at 0900. During this interval, the Uwekahuna tiltmeter recorded 2.8 µrad of summit deflation. The net inflation during May was 5.7 µrad.

Seismicity. "Harmonic tremor continued at a fluctuating low level in the middle E rift zone near Pu`u `O`o following episode 32. The number of shallow microearthquakes in the E rift zone and summit region varied from several tens to a few hundreds per day. Short-period summit earthquakes increased gradually in response to the slow rate of inflation. Frequent bursts of long-period events and harmonic tremor were recorded from intermediate to deep sources beneath Kīlauea."

Addendum: Episode 33 of the middle E rift zone eruption occurred on 1213 June. Discontinuous low level fountaining and spillover from the Pu`u `O`o vent began at 0430 on the 12th. By 2306, fountaining had become vigorous and continuous. Lava flowed about 3.5 km to the SE over older lavas from Pu`u `O`o before the episode ended at [0453] on the 13th.

Information Contacts: C. Heliker, G. Ulrich, R. Hanatani, R. Koyanagi, and R. Okamura, HVO.


June 1985 (SEAN 10:06) Citation IconCite this Report

Episodes 33 and 34; aa lava flows SE

EPISODE 33

"Two more episodes of the 2.5-year-old middle E rift zone eruption occurred 12-13 June and 6-7 July. Episode 33 was both preceded and followed by continuous low-level activity at the vent. Spattering was first observed on 1 June and continued intermittently until 12 June at 0430, when a low dome fountain produced a thin pahoehoe flow that extended 0.25 km from the vent. Fountaining ended after 20 minutes, but was followed by 20 more periods of low fountaining over the next 19 hours. At 2306 on the 12th, continuous high fountaining began. The high fountains persisted for almost 6 hours and produced a single aa flow that extended 4.5 km SE from the vent, overriding an earlier (episode 32) flow.

"Following episode 33, magma was continuously visible in the conduit, and by 20 June spatter was again reaching the conduit rim. Episode 34 began on 6 July at [1903] and ended 14 hours later, producing an aa flow that terminated 3 km SE of the vent.

Deformation. "The Uwekahuna tiltmeter began recording subsidence on 12 June at 2200, approximately 1 hour before continuous high fountaining began. Summit subsidence continued for 17 hours, resulting in a net loss of 7.0 µrad. Reinflation of the summit began slowly then increased rapidly after 22 June; by the end of the month, the summit tilt had regained 6.7 µrad. Deformation data for episode 34 had not been reduced at the time of this report.

Seismicity. "Harmonic tremor began with a minor increase in amplitude on 12 June at 0430, recorded by the Kamoamoa seismic station 1 km W of Pu`u `O`o. Tremor amplitude increased rapidly at 2230 and remained high until 0452 on 13 June. The intensity of eruption tremor subsided rapidly thereafter, marking the end of vigorous lava fountaining. Moderate-amplitude tremor was recorded in the summit region until about 1600 on the 13th.

"The number of short-period caldera, or summit, earthquakes increased gradually in May then decreased from 1 June until the onset of the eruptive episode on 12 June. Intermediate-depth (5-13 km), long-period events were persistent throughout the month. Shallow long-period events at the summit accompanied the deflation event and eruptive episode on 12-13 June."

Accident. "On 12 June, George Ulrich, staff geologist at HVO, and Dario Tedesco, a volcanologist from the Osservatorio Vesuviano, were collecting lava samples and making temperature measurements at Pu`u `O`o vent. A low dome fountain from Pu`u `O`o was feeding a short flow to the SE. George was standing on the edge of the lava channel on solid but recently formed crust. At 1430, after completing a temperature measurement (1,137°C), he walked onto the older lava to return the thermocouple and gather a sampling pick. When he returned to the lava channel to obtain a sample, the pahoehoe river had stopped moving, and he inadvertently went past the stable recent crust onto even more recent crust, which then gave way. He went in over his field boots, and was unable to pull himself out. In the attempt to reach for safety, his knees made further contact with the molten lava. Within an estimated 5 seconds, Dario pulled him to safety. His outer clothing (NOMEX suit) was then burning, but quickly extinguished itself. At the time of the accident, a helicopter piloted by Bill Lacey was landing to deliver an extra time-lapse camera. George got into the helicopter under his own power and Bill Lacey flew him directly to Hilo hospital. George was subsequently transferred to the Straub Clinic in Honolulu, where the following evaluation was made one week after the accident: first degree burns over parts of arms, hands, and face, healing normally; second degree burns from ankles to uppermost thighs on both legs; third degree burns on left kneecap, extending to upper thigh, and possible third degree burns on right kneecap. The long-term prognosis is for full recovery with no permanent disabilities, as none of the burns affected the musculature of the legs."

[George Ulrich returned to work part-time after a 2-month hospital recovery. After a few weeks, he resumed full-time responsibilities. Within 5 months, after achieving more than 90% recovery, he returned to full-time field work.]

Information Contacts: C. Heliker, R. Hanatani, R. Koyanagi, HVO.


July 1985 (SEAN 10:07) Citation IconCite this Report

Continuing lava production from new fissures uprift of active vent

EPISODES 34 AND 35

"Kīlauea's E rift eruption continued with two episodes of high fountaining at the Pu`u `O`o vent in July. Episode 34 began on 6 July at 1903 with a low dome fountain that gradually increased to 300-400 m in height over the next 4 hours. The activity ended after 14 hours and produced an aa flow that extended 3 km SW (figure 36). The estimated volume of the flow is 10.6 x 106 m3 (including approximately 0.4 x 106 m3 of tephra reduced to lava equivalent).

Figure (see Caption) Figure 36. Lava flows produced on Kīlauea's E rift zone since January 1983. Episode 34 flow is shown in a diagonal pattern (top). The fissure-fed pahoehoe flows of episode 35 and the predominantly aa flows of episodes 35 and 36 are shown separately (bottom). Courtesy of HVO.

"Episode 35 departed from the established pattern of Pu`u `O`o eruptions. Fissure vents opened on the W flank of Pu`u `O`o either shortly before or simultaneously with the start of fountaining at the O'o vent, which began on 26 July at 0252 (observers were not in the area because of a hurricane warning). By 0700, the fissure vent was inactive after producing a pahoehoe flow that extended 1.5 km SE. High fountains continued at the Pu`u `O`o vent until 0952 and produced short aa flows to the NW and a 2.2 km-long aa flow to the SW. Two hours later, a 50-m stretch of the fissures nearest Pu`u `O`o reopened and a small volume of pahoehoe oozed to the surface. This activity ceased after an hour and a half but was followed late in the afternoon by extensive ground cracking that extended the fissure system 2.5 km up the rift (NW) from the base of Pu`u `O`o.

"At 0414 the next morning, the eruption resumed along the 1 km of fissures nearest Pu`u `O`o. By 28 July activity was localized in the eastern 400 m of the fissure system. Lava production in the first week of August was nearly continuous and characterized by low fountains that generated lava flows N and S, within 1 km of the 26 July fissure system. The fissure eruption was continuing 9 August with activity localized at two vents at the base of Pu`u `O`o. When geologists returned to the vent on 12 August, no lava outpouring or spattering was observed. Late July-early August pahoehoe flows cover an area of approximately 400,000 m2 with an estimated maximum depth near the vent of 15 m.

Deformation. "The summit rapidly subsided starting on 6 July at approximately 2000, as one of the events marking the beginning of the 34th episode of the eruption (figure 36). The subsidence continued until approximately 1400 the next day. The Uwekahuna tiltmeter (at the summit of Kīlauea) recorded a net loss of 12.0 µrad. The maximum rate of subsidence was 1.3 µrad/hour.

"Reinflation of the summit following episode 34 occurred at a fairly steady rate until 26 July at 0200, when rapid subsidence marked the beginning of episode 35. This second major subsidence of July continued for about 12 hours and resulted in the loss of 12.1 µrad of tilt. The maximum rate of summit subsidence associated with the 35th episode was 1.6 µrad/hour and occurred between 0400 and 0500. The summit briefly reinflated until 27 July when a fissure eruption began SW of Pu`u `O`o. The Uwekahuna tiltmeter recorded little change from then until the end of July.

Seismicity. "Harmonic tremor associated with eruptive episode 34 started gradually on 6 July at 1903. The amplitude of tremor near Pu`u `O`o increased several orders of magnitude above background after 1915. High tremor continued with minor fluctuations in amplitude until 0912 on 7 July.

"Episode 35 was preceded on 26 July at 0230 by an increase in the number of tiny earthquakes near Pu`u `O`o. At about 0252, harmonic tremor increased in amplitude by nearly an order of magnitude and continued until 0952, when tremor decreased to moderate to low levels. At 0414 on 27 July, tremor increased to a moderate level, marking the start of renewed activity on the 26 July fissure system, and assumed a pattern of slightly fluctuating amplitudes until the end of the month. The number of micrcoearthquakes had decreased to a low level above the E rift zone and summit region at the month's end. In early August harmonic tremor continued with moderate amplitude near the eruption site."

Information Contacts: C. Heliker, R. Hanatani, R. Koyanagi, HVO.


August 1985 (SEAN 10:08) Citation IconCite this Report

Fissure activity ends; new episode three weeks later

A decrease in harmonic tremor on 12 August at 0430 indicated the end of episode 35 lava production from fissures uprift of Pu`u `O`o vent. The fissure activity formed a small lava shield at the W base of Pu`u `O`o. The total volume of lava erupted during episode 35 was estimated to be 11.7 x 106 m3. Kīlauea's summit began to reinflate on 8 August, four days before the end of the fissure activity. By the onset of the next eruptive episode, on 2 September, the summit had recovered 12.9 µrad, compared with the 12.1 µrad of deflation that accompanied episode 35 (figure 36).

EPISODE 36

After only 21 days of repose, episode 36 began on 2 September at 1400. Fountaining at the Pu`u `O`o vent increased slowly during the first 3 hours from 100 m to over 300 m high. The fountains fed a broad aa flow that extended 2.5 km SE on top of previous flows, and a small 1.8-km flow to the NE. Harmonic tremor was first recorded about 1 hour prior to the start of the episode. The seismic station at nearby Pu'u Kamoamoa was moved uprift during episode 35, so the tremor signal from episode 36 was not as sensitive as in the past.

Summit deflation started on 2 September at 1300, one hour before fountaining began. Fountains stopped abruptly at 2335, after 9.5 hours of activity, but subsidence continued until 0300 on 3 September, totalling 11.7 µrad before inflation resumed (figure 37). The episode 35 fissure system remained inactive during episode 36. The September activity extended the duration of the ongoing eruption, beginning in January 1983, to 33 months.

Figure (see Caption) Figure 37. Summary of Kīlauea activity for 1985 showing summit tilt, caldera short- and long-period earthquakes, carbon/sulfur ratios of summit (Halemaumau) gases, MgO content of lava collected during and between eruptive episodes, and lava volumes.

Information Contacts: G. Ulrich, C. Heliker, R. Hanatani, and R. Koyanagi, HVO.


September 1985 (SEAN 10:09) Citation IconCite this Report

Episode 37 of the 1983-85 East Rift Zone eruption

"Two episodes of high fountaining and lava production at the Pu`u `O`o vent occurred in September. Episode 36 occurred on 2 September. The distribution of episode 36 lava flows and the partly covered flows of episode 35 (July-August) are shown in figure 36. Episode 37 flows are unmapped as of this report. The total volume of lava produced by episode 35 was 11.7 x 106 m3. Episode 36 produced a lava volume of 11.5 x 106 m3.

EPISODE 37

"After a 22-day repose period, when the magma column in the Pu`u `O`o conduit was visible at depths of 50-80 m, the 37th episode occurred. Preceded by several small pahoehoe spillovers from intermittent fountains, the fountaining became continuous on 24 September at 1808. The level of eruption increased slowly to a peak between midnight and 0200 when fountain heights of approximately 250 m were estimated. Episode 37 ended as the fountaining died at 0619, having lasted 12 hours. The basalt, as in recent episodes, is microporphyritic with abundant olivine crystals (< 0.5 mm in diameter). The composition has remained unchanged since episode 32 in April.

"Summit deflation during episode 37, as recorded by the Uwekahuna tiltmeter (W-E), commenced on 24 September at 1900 (about an hour after lava fountaining became continuous) and ended at 0900 the next day, resulting in a net loss of 13.2 µrad.

"Tremor amplitude at the newly located seismometer near Pu`u `O`o increased on 24 September at about 2050 (2.5 hours after the onset of continuous lava fountaining), activating the tremor alarm at HVO at 2214. Tremor level decreased rapidly at 0619, coinciding with the end of fountaining. The decreased tremor following episode 37 assumed a pulsating pattern characterized by one-minute bursts of moderate amplitude alternating with several minutes of lower amplitude. This gas-piston pattern continued for about a day then changed to a more continuous background of low-amplitude harmonic tremor for the remainder of the month.

Information Contacts: G. Ulrich, C. Heliker, R. Hanatani, and R. Koyanagi, HVO.


October 1985 (SEAN 10:10) Citation IconCite this Report

Episodes 37, 38, and 39 of 1983-85 eruption

"Episode 37 produced a lava volume of 14.7 x 106 m3. During the 26-day repose period that followed episode 37, the summit tiltmeter recorded 13.0 µrad of inflation. Summit subsidence associated with episode 38 began on 20 October at 1900, nearly simultaneously with the onset of low-level, discontinuous activity at the Pu`u `O`o vent. Intermittent dome fountaining produced thin pahoehoe spillovers for the next 8 hours.

EPISODE 38

"Beginning at 0230 on 21 October, a gradual increase in tremor amplitude was recorded by the seismometer near Pu`u `O`o. Continuous lava production began at 0301, signalling the official beginning of episode 38. Fountain heights reached approximately 300 m by 0607. Broad aa flows advanced SE, closely following the path of the episode 37 flows (figure 38) and eventually stagnating 4.2 km from the vent.

Figure (see Caption) Figure 38. Lava flows produced on Kīlauea's E rift zone since January 1983. Episodes 37 (top) and 38 (bottom) are shown separately. Courtesy of HVO.

"Harmonic tremor amplitude began to decrease rapidly at 1118, and the fountain died at 1120. By 1145 the tremor was at a non-eruptive level. Gas-piston activity followed the end of the eruptive episode for about 24 hours, before continuous low-amplitude background tremor resumed. Summit subsidence continued until about 1500 on 21 October, resulting in a net deflation of 13.0 µrad (figure 37). Following the eruption, the familiar pattern of summit reinflation resumed, and by the end of October, the summit tiltmeter had recorded a net gain of 9.5 µrad."

Addendum: On 13 November at 0530, low-level activity at Pu`u `O`o signaled the onset of episode 39. At 1534 continuous lava production began with fountain heights reaching an estimated 260 m, producing lava flows that extended about 6 km E. Vigorous activity lasted nearly 10 hours, stopping at 0124 on 14 November.

Information Contacts: C. Heliker, G. Ulrich, R. Hanatani, and J. Nakata, HVO.


November 1985 (SEAN 10:11) Citation IconCite this Report

Episode 39 includes S-flank vent activity

EPISODE 39

"Kīlauea's eruption continued in November with the 39th eruptive episode. From 12-13 November, the magma column was within a few meters of the conduit rim and spattering nearly continuously. At about 0530 on 13 November, three small vents opened on the S flank of Pu`u `O`o. Two of these vents remained active through the day and produced a pahoehoe flow that extended approximately 600 m beyond the base of Pu`u `O`o.

"The summit of Kīlauea began to deflate on 13 November at 1430. An hour later, activity at the main Pu`u `O`o vent increased, and a low fountain began to feed a thin pahoehoe flow. The fountains gradually increased in height, reaching 415 m by 1925. The vents on the S side of the cone probably died at about the same time. The high fountains continued until 0124 the next morning and produced an aa flow that extended 6 km ESE of Pu`u `O`o (figure 39).

Figure (see Caption) Figure 39. Lava flows produced by the E rift zone eruption since January 1983. Episode 39 flows are marked by diagonal lines.

"Summit subsidence continued until 14 November at 0330, with a total loss of 13.9 µrad recorded by the summit tiltmeter. By the end of November, the summit had regained 9.6 µrad.

"Harmonic tremor associated with episode 39 increased gradually from 13 November at 1610, peaked in amplitude between 1725 and 0100, and decreased at 0126 on 14 November. Following episode 39, harmonic tremor persisted at background levels in the E rift zone near Pu`u `O`o."

Information Contacts: C. Heliker, R. Hanatani, R. Koyanagi, HVO.


December 1985 (SEAN 10:12) Citation IconCite this Report

40th episode marks end of 3rd year of East Rift eruption

"December ended the third year of Kīlauea's ongoing E rift zone eruption. The month was uneventful, with Pu`u `O`o maintaining an unusually long repose period after episode 39 on 13-14 November correlating with the low rate of inflation measured at the summit during most of the month.

"Harmonic tremor continued at a low level near Pu`u `O`o. On 21 December a short burst of moderate-amplitude tremor that lasted about 30 minutes originated from a mantle source about 40 km deep, SW of Kīlauea. The number of earthquakes of magnitude 2.5-3.5 on Kīlauea's S flank increased during the last two weeks of December.

EPISODE 40

Addendum: Episode 40 arrived with the New Year, beginning at 1309 on 1 January and lasting 13.5 hours. A narrow aa flow passed through the NE corner of Royal Gardens subdivision, but remained on top of older lava flows. The flow eventually stagnated about 9 km from the vent.

Summary of 1985 activity. "Eleven eruptive episodes occurred during 1985, each characterized by high fountains from the Pu`u `O`o vent and broad aa flows extending 3-7 km from the cone. Departures from the normal pattern were observed during the early stages of episodes 29, 35, and 39, when short-lived vents erupted at the base of the cone. During episode 35, fissure activity resumed after fountaining at the main Pu`u `O`o vent had ceased and continued for 17 days, producing a pahoehoe shield 26 m high at the base of Pu`u `O`o.

"Lava has covered 39 km2 since January 1983, and the total volume of lava exceeds 0.46 km3, surpassing all historic eruptions of Kīlauea. The Pu`u `O`o cone reached a height of 250 m in 1985 and is now the most prominent landmark on the E rift zone (figure 40). The single conduit is 20 m in diameter, with its top 110 m below the summit of the asymmetric cone.

Figure (see Caption) Figure 40. Profiles showing the growth of Pu`u `O`o since 5 February 1985, drawn from photographs taken from the 1123 cone, 1.5 km to the E.

"Pu`u `O`o lava compositions showed marked intra-episode variation during episodes 30 and 31, with more mafic lava erupted late in the episode. These variations suggest that during these episodes the eruption drew down a compositionally zoned magma chamber. Over the long term, the lava compositions appear to have stabilized at nearly constant values, suggesting that less mixing with differentiated melts stored in the rift zone is taking place compared to early episodes.

Information Contacts: C. Heliker, G. Ulrich, R. Koyanagi, and R. Hanatani, USGS.


January 1986 (SEAN 11:01) Citation IconCite this Report

Episodes 40 and 41 of East Rift Zone eruption

EPISODE 40

Episode 40 began 1 January at 1309 and lasted 13.5 hours. It produced a lava flow ~9 km long that overlies earlier flows and reached the NE corner of Royal Gardens Subdivision (figure 41). The volume of this flow was 11.6 x 106 m3. [A volcanic plume from the east rift crater could be seen from the Space Shuttle on 15 January (figure 42).]

Figure (see Caption) Figure 41. Lava flows produced by Kīlauea's East rift zone eruption since January 1983. Episode 40 flows are shown by a separate pattern.
Figure (see Caption) Figure 42. Space Shuttle photograph (no. 61C-41-050), taken 15 January 1986, showing most of the island of Hawaii. Mauna Loa is at center. On its S flank is the much smaller Kīlauea, partially obscured by clouds. A large plume extends from the active east rift crater, Pu`u `O`o, following episode 40 of the eruption that began in January 1983. Courtesy of C. Wood.

EPISODE 41

When episode 41 began on 27 January, after only 25 days of repose, only 9.5 µrad of the deflation that occurred during E-40 had been recovered (figure 43). Because of inclement weather, it was not possible to establish a precise start time from time-lapse film but the first lava spillover from the crater into the flow channel was reported by a helicopter pilot on 26 January at 1240. A field crew that was at Pu`u `O`o on 27 January from 1230 to 1600 observed almost continuous small spillovers. Deflation began on 27 January at 1900 and totaled 16.5 µrad by the end of E-41. Harmonic tremor started at 2030, increased at 2035 and continued at high amplitude until 0737 the next morning when lava production stopped. Lava flows extended 6.7 km to SE, to within 400 m of the NE corner of Royal Gardens Subdivision. By the end of January tilt had recovered 8.4 µrad.

Figure (see Caption) Figure 43. Six-month summary of Kīlauea's activity, January-June 1986, showing tilt, short- and long-period caldera earthquakes, carbon/sulfur ratio of summit gases, lava volumes, and the MgO content of lavas produced prior to and during major eruptive episodes. The main summit tiltmeter is still under repair, as indicated by the break in the tilt curve, but a substitute tiltmeter has been installed to record summit deformation.

Information Contacts: C. Heliker, G. Ulrich, R. Koyanagi, and R. Hanatani, HVO.


February 1986 (SEAN 11:02) Citation IconCite this Report

42nd episode of East Rift Zone eruption

EPISODE 42

Eruptive activity . . . resumed in February . . . . After 25 days of repose, the summit began to deflate on 22 February at 1000 and 10 minutes later lava fountaining began at the Pu`u `O`o vent. Low-level fountaining and pahoehoe spillovers occurred intermittently until 1515 when continuous lava production began. High-amplitude harmonic tremor started 25 minutes later.

Fountain heights increased steadily over the next 7 hours until they reached ~300 m above the vent at 2230 and were sustained at that level for several hours. Four pulses of fountain jetting 360-450 m high, each lasting several minutes, occurred between 0233 and 0416 on the 23rd. After the fourth pulse at 0416, fountaining declined quickly and lava production stopped at 0420. Strong harmonic tremor ended at 0419, but was followed by moderate-amplitude, pulsating tremor for a day. Summit deflation, totalling 14.8 µrad, ended at 0700 on the 23rd; by the end of February, the summit had reinflated by 4.3 µrad (figure 43). Episode 42 lava flows extended ~3.5 km SE from Pu`u `O`o on a broad front. A small flow advanced ~1 km to the N.

Information Contacts: C. Heliker, G. Ulrich, R. Koyanagi, and R. Hanatani, HVO; E. Nielsen, SI.


March 1986 (SEAN 11:03) Citation IconCite this Report

Two brief episodes of high lava fountains feed short flows

EPISODE 43

Episode 42 was followed by 26 days of repose, before intermittent lava spillovers from Pu`u `O`o vent began on 21 March at 1330. Summit deflation began at midnight, and continuous lava production of E-43 began at 0450 the next day. Fountains reached their maximum height of ~310 m at 1110. The episode ended at 1556 on 22 March after forming two lava flows, one extending 5 km E of the vent, the second 2.3 km NE toward the older Kahaualea cone. The summit grew 5 m . . . to 255 m above the pre-January 1983 surface.

After E-42 the summit had inflated 12.9 µrad before the onset of E-43 deflation. Deflation, totaling 12.8 µrad, continued until ~2 hours after the end of lava production. Inflation following E-43 amounted to 6.3 µrad by the end of March (figure 43).

The strong tremor associated with E-43 began at 0635 on the 22nd, peaked at 1200, and ended at 1554. Fluctuating low-amplitude tremor continued through the rest of the month near Pu`u `O`o.

Addendum: By 9 April, the summit had recovered all of the deflation associated with the previous episode. Episode 44's vigorous lava production began 13 April at about 2100, after a few hours of lava spillovers into the main channel. Lava fountains reached heights of 250 m [but see 11:04] by 0200 then stopped at 0756, feeding a few short lava flows to the NE and a longer aa flow that extended > 4 km to the ESE.

Information Contacts: C. Heliker, M. Sako, and J. Nakata, HVO.


April 1986 (SEAN 11:04) Citation IconCite this Report

Episode 44 included lava production from new vent

Episode 44 (E-44). After 22 days of repose, E-44 . . . began 11 hours of continuous lava production on 13 April at 2054. Several hours of intermittent low-level lava spillovers from Pu`u `O`o vent had preceded vigorous fountaining, which continued until 14 April at 0756. A small satellite vent that opened 1.2 km N of Pu`u `O`o was first observed on 13 April at 1310. Fountains 5-10 m high fed a pahoehoe lava flow ~1 km long. "

Lava fountains from Pu`u `O`o vent with maximum sustained heights of 280 m were directed to the E, eroding the main channel to form two spillways, one to the NE and another to the SE. Lava flows surrounded HVO's primary observation post on a cinder cone built earlier in the eruption (the "1123 vent"), [1.5] km E of Pu`u `O`o. Lava advanced a maximum of 4.1 km (to the ESE).

By 12 April . . . the summit had recovered all of the deflation recorded during the previous episode. Slow deflation began that day at 1000, and rapid subsidence started on 13 April at 2000, less than an hour before the onset of vigorous fountaining. The summit lost 13.7 µrad of inflation before subsidence ended at 1000 on 14 April, 2 hours after fountaining stopped. Only 2.6 µrad had been regained when the tiltmeter was removed for repairs (figure 43). Strong tremor began 13 April at 2104, remained high until 0754 on the 14th, and then dropped to background level for the rest of the month.

Information Contacts: C. Heliker, R. Koyanagi, and M. Sako, HVO.


May 1986 (SEAN 11:05) Citation IconCite this Report

Episodes 45 and 46 of East Rift eruption

Episode 45 (E-45). Episode 45 . . . began 7 May at 1645 with typical intermittent lava spillovers. Continuous high fountaining started at 2240, and lava flows exited from both spillways formed during the previous phase. The NE flows extended a maximum of 2 km and those to the SE ~4.5 km, mostly on top of previous flows. Some short flows advanced to the N and NW, forming a broad fan at the base of the cone. The "1123 cone" observation post was again surrounded by flows.

High-amplitude tremor began on 7 May at 2242, almost simultaneously with the loss of 10.8 µrad. By the end of the month, the summit had regained 12.4 µrad of inflation (figure 43).

Episode 46 (E-46). During the afternoon of 1 June intermittent lava fountains were reported at Pu`u `O`o. Continuous fountaining began 2 June at 0230 and ended at 1327. High-amplitude harmonic tremor began at 0240 and declined to background levels at 1309. Summit deflation totaling 11 µrad began on 1 June at 1200 and stopped the next day at 1700, 3.5 hours after lava production ended. Lava flowed through both the NE and SE spillways, extending a maximum of 5 km SE.

A series of very high fountain jets started at 1041, 2¼ hours before the end of the episode. Jetting lasted from several seconds to about a minute, then died back briefly before fountaining resumed. Similar fountain jets were observed during E-42 on 23 February.

After E-46, the summit of Pu`u `O`o was 255 m above the pre-1983 surface, a growth of only 5 m since the end of 1985. The cone was steep and the many short flows on the flanks were widening the base.

Since E-40 on 1 January, the eruption recurrence interval has been very regular, ranging from 22 to 26 days.

Information Contacts: C. Heliker, R. Koyanagi, and R. Hanatani, HVO.


June 1986 (SEAN 11:06) Citation IconCite this Report

Intermittent activity precedes episode 47

Episode 47 (E-47). After 21 days of quiet, intermittent activity resumed at Pu`u `O`o at 1600 on 23 June. For nearly 2 days, spatter and lava spillovers remained within the flat area around the conduit, or moved just over the edge of the spillway. Intermittent fountaining began 25 June at 1400, giving way to sustained fountaining of E-47 at 0419 the next morning. Fountaining ended the same afternoon, and reached maximum heights of 225 m.

During the last 2 hours of activity there were three high fountain jets, ~50 minutes apart, that lasted several seconds . . . . Theodolite measurements of these jets, obtained for the first time, gave maximum heights of 550 m. Intermittent fountaining occurred the last 20 minutes of the episode, ending at 1635.

Three main flows were generated, two extending 2.4 km S and 3.6 km SE mostly over previous lava flows, and one 2.5 km to the N that burned some trees. During E-47, the cone increased 2 m in height, to 257 m above the pre-l983 surface.

Gradual subsidence of the summit commenced at 1000 on 25 June and changed to rapid decline about 0400 the next morning, just before the onset of sustained fountaining. Summit subsidence ended at 1900 with a total loss of 11.1 µrad. By 30 June the summit had regained 5 µrad (figure 43). Sustained high-amplitude tremor started at 0257 on 26 June and ceased at 1614.

Further Reference. Wilson, L., and Head, J., 1988, Nature of local magma storage zones and geometry of conduit systems below basaltic eruption sites: Pu`u `O`o, Kīlauea East Rift, Hawaii, example: JGR, v. 93, p. 14785-14792.

Information Contacts: C. Heliker, R. Koyanagi, and R. Hanatani, HVO.


July 1986 (SEAN 11:07) Citation IconCite this Report

Episode 48 from three new fissures

Episode 48 (E-48). "After 22 days of repose, E-48 . . . began on 18 July with a local earthquake swarm and eruptions from new fissures on both the uprift and downrift sides of the Pu`u `O`o cone. At the time of the swarm, the magma column had reached the top of the conduit and was emitting spatter from a 15-m-high cone within Pu`u `O`o, but as fissures opened, the column subsided, the top of the spatter cone collapsed, and only burning gas issued from the small opening for the duration of the activity. After nearly 23 hours, activity ended temporarily on 19 July at around 0930. Mostly pahoehoe flows were produced. The longest flow moved rapidly SE for 7.5 km through a forested part of the Hawaii Volcanoes National Park to within 2.5 km of the sea. The Chain of Craters road was closed briefly until the flow stagnated, and ~4 km2 of forest were burned.

"On 20 July at about 0830, following 23 hours of inactivity, low fountains on the downrift fissure ("B" on figure 44) were first observed by a National Park Service overflight while the "A" fissure and the main Pu`u `O`o conduit remained quiet. By 0950, the "B" fissure had shut down and a new fissure ("C" on figure 44) had begun to erupt along a line parallel to, and ~150 m N of, the original January 1983 fissure. Low fountains, a few meters high, played intermittently along the 1100-m-long fissure, which eventually shortened to a pair of vents, < 50 m apart, that have continuously produced lava at a low rate. A pahoehoe shield, ~1.2 km2 in area and > 25 m high, has been built around the vents and a branching tube-fed pahoehoe and aa flow has moved ~4.5 km SE toward the sea. By the end of July, it had stagnated and remained ~6 km upslope from the nearest developed area. As of 8 August, lava was still welling out of one main vent without fountaining and was spreading over the summit of the growing shield. The new basalt flows have sparse small (<1 mm) olivine phenocrysts, similar to those of recent eruptions.

Figure (see Caption) Figure 44. Sketch map of eruptive fissures A-C and lava flows on Kīlauea's East rift zone, July 1986. Courtesy of HVO.

"The earthquake swarm . . . began on 18 July at 1046 and progressed downrift. It was recorded by seismometers just uprift of Pu`u `O`o and N of Kalalua. High tremor amplitudes on the uprift seismometer characterized the early phase of activity. From 20 July on, the tremor on the uprift instrument decreased to background levels, while very low-amplitude tremor has continued on the downrift instrument nearest the eruption vent. Above-normal levels of long-period seismicity occurred following the early activity of E-48 (figure 45).

Figure (see Caption) Figure 45. Six-month summary of Kīlauea's activity, July-December 1986, showing tilt, short- and long-period earthquakes, carbon/sulfur ratio of summit gases, lava volume, and the MgO content of lava. The intermediate depth swarm of 17-20 November are "C" type long-period (deeper) earthquakes and the caldera long-period earthquakes are "A" type (shallow) events, so the swarm is not shown on this summary.

"Deflationary summit tilt began on 18 July at about 1145, an hour after the onset of seismicity, and reached a record rate of nearly 3.1 µrad/hour between 1200 and 1300 (figure 45). The deflationary pattern reversed temporarily into an inflationary trend from about 0500 on 19 July, in concert with the short repose period. Since 20 July, tilt changes have been very small and no particular trend has been defined."

Information Contacts: G. Ulrich, HVO.


August 1986 (SEAN 11:08) Citation IconCite this Report

Lava shield continues to grow

Episode 48 (E-48). Activity continued through August into mid-September, building a large shield ~3 km NE of Pu`u `O`o. By mid-September, the shield had grown to 1.5 km in diameter and 41 m high. Overflows filled low areas, and lava tubes fed short pahoehoe flows to its margin, with the longest flows extending only 2 km SE from the vent. Most of the shield was composed of pahoehoe flows but there was some aa lava at the margin. Upwelling was almost continuous from one or both of the two active vents, and low spattering has been occasionally observed. A lava pond had developed on the flat top of the shield by late August, and had grown to 100 m in diameter by 1 September (figure 46).

Figure (see Caption) Figure 46. Sketch map of new eruptive vents, lava shield and flows on Kīlauea's East rift zone.

Low-level tremor centered in the middle East rift zone continued with only slight changes in amplitude. Summit tilt remained unchanged through August (figure 45).

Pu`u `O`o vent remained inactive, although the conduit was incandescent and there was a slight gas plume. The magma column that had been present in the conduit during past interphase periods was no longer visible.

Information Contacts: C. Heliker, HVO.


September 1986 (SEAN 11:09) Citation IconCite this Report

Lava tubes feed flow complex; continued lava shield growth

The eruptive episode . . . continued into October, building a new pahoehoe lava shield ~3 km NE (downrift) of Pu`u `O`o, the vent active in most of the 47 previous episodes. The estimated lava output rate since 20 July is ~0.5 x 106 m3/day. The new shield grew 10 m in height during September, to 44 m high and 1,600 m across by the end of the month. Activity from the shield's W vent stopped by mid-September, but lava production was continuous through a 150-m lava pond in the shield's E vent. Depth of the pond varied by no more than 3 meters. Through most of September, the activity fed a series of small pahoehoe flows that did not extend much beyond the margin of the shield. A lava tube system formed in late September, feeding lava flows that advanced SE at irregular rates of as much as 0.5 km/day. At the end of September, a thin broad flow front was 4 km from the vent, and by 8 October a complex network of tube-fed flows occupied a broad area between the westernmost 1977 lava and the longest April 1984 flow. The conduit at Pu`u `O`o remained open and incandescent, with flaming gases visible at night.

Low-level harmonic tremor was continuous, with minor fluctuations in amplitude. No well-defined trends were detected by the summit tiltmeter, and some of the measured variation may have been instrument response to heavy rains (figure 45).

Information Contacts: C. Heliker, HVO.


October 1986 (SEAN 11:10) Citation IconCite this Report

Continued lava production builds shield; flows burn forest

The eruptive episode . . . was continuing in mid-November. The lava shield around the vent grew 2 m in height in October, to 46 m, but had not changed significantly in diameter despite occasional spillovers from the active lava pond. The level of the pond varied from 5 m below the rim to overflowing. Most flows were tube-fed to the SE. As of 3 November the longest was 6.8 km from the vent and had reached 290 m elevation, ~3.8 km from Chain of Craters Road (figure 47). The lava production was ~500,000 m3/day.

Figure (see Caption) Figure 47. Map showing flows 20 July-3 February (diagonal lines), the new cracks and flow of 2 February, and the 1984 aa flow.

The flows have not threatened inhabited areas, but large areas of forest have burned in the Kapaahu and Kaunaloa districts. Some residents with respiratory problems have left the Royal Gardens subdivision, especially at night when the wind direction commonly changes, bringing heavy smoke from burning vegetation upslope of the houses.

Summit tilt showed minor fluctuations (figure 45) but no significant trend of inflation or deflation. Harmonic tremor in the middle East rift zone continued at low levels with sporadic variations in amplitude

Information Contacts: C. Heliker, HVO.


November 1986 (SEAN 11:11) Citation IconCite this Report

12-km-long lava flow destroys 11 houses, enters ocean

The lava production . . . at Kīlauea's new shield vent has continued at about the same rate as the previous four months. The height of the new pahoehoe shield remained at ~46 m, while lava spillovers have increased its diameter to > 1.6 km. An active lava pond remained on top, producing overflows beyond the shield margins, mostly to the E and SE, during early November. The lava pond was ~200 x100 m, elongated toward the SE, with a narrow neck that roofed over to form the main tube of the complex flow system. The level of the lava pond fluctuated between periodic overflows to as much as 10 m below the rim. Magma output was estimated to be [500,000] m3/day.

Flows extended E, surrounding Kalalua (a prehistoric cinder cone), to Puʻu Kiai, formed by the September-October 1977 eruption and SE against the margin of the 1977 flows. By 20 November, a narrow flow had moved SSE to ~270 m elevation, advancing at 200-300 m/hour on the steeper slope. By a process of extending the tube network and widening, lava moved to ~60 m elevation late 23 November, threatening several houses at Kapa'ahu (figure 47). On 25 November at 2350, the 20-30-m-wide flow reached the coast highway. A second lobe of the flow was further W, near the April 1984 flow, and a third lobe later bypassed a popular fresh water natural pool (Queens Bath) used for swimming. The lava flowed W along the highway, slowing and spreading laterally for a few hours, then crossed it and destroyed nine houses the next morning. Several more were threatened. All residents of the community had been evacuated. Lava moved slowly over the gradual slope S of the highway and entered the ocean, 12 km from the vent, on 28 November (figure 47). By the next day, lava had covered ~200 m of shoreline and extended 30 m into the sea. Several small lobes broke away from the main flow on 30 November, threatening four more houses.

On 3 December most of the lava produced at the vent was entering the ocean, but in the next 2 days decreasing amounts of lava reached the ocean because of blockages within the tube system. The lava pond was filled and overflowing on 5-6 December, then blockage cleared or was bypassed by lava breaking out and overriding earlier flows. New lobes consumed two more houses on 7-8 December. Pond spillovers caused short flows to the NE and SE. A total exceeding 0.08 km2 of new land had been added to the island as of 19 December.

Low-level harmonic tremor persisted near the eruptive area . . . . Microearthquakes in the summit region continued to gradually increase. At mid-month a moderate burst of intermediate-depth low-frequency (long-period) earthquakes occurred ~5-15 km below the summit. More than 700 events of M 0.1-2.0 were associated with harmonic tremor and magma movement. Activity peaked 17-20 November, then declined.

Summit tilt, measured by EDM instruments and other tiltmeters around the caldera, was unchanged. Electronic tiltmeters were affected by heavy rains throughout the month and no new data were available.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


December 1986 (SEAN 11:12) Citation IconCite this Report

Lava destroys more homes

Lava production . . . has continued since July. Flows from this vent moved down the S flank of the volcano and destroyed 17 more homes in mid-December. Lava output remained at ~500,000 m3/day. The active lava pond level fluctuated from overflowing to ~12 m below the rim. The shield surrounding the vent has reached about 48 m height.

A lobe that consumed two houses on 7-8 December stagnated on 9 December because of collapses and breakouts within the tube system feeding it (figure 47). On 12 December a flow started down the flank farther to the E (figure 47), reaching the break in slope on the 14th.

On 17 December this flow destroyed another house, then crossed the coast highway the next day at 0918. At 0330 on the 19th the first house in the Kalapana Gardens subdivision was overrun by lava and in the next few hours 15 more homes were destroyed. By 21 December that flow was stagnant, with no lava movement observed in skylights in the lava tubes above 300 m elevation. About 100 homes had been evacuated during the emergency; people were allowed to return to their homes on 22 December. Aerial photographs of the lava that destroyed 11 houses and entered the ocean on 28 November showed that 0.07 km2 of new land was added to the island.

During the following week, lava flows were confined to within 1-2 km of the vent, mostly to the E and NE. On 31 December, a breakout from a reoccupied tube system at ~495 m elevation fed a new slow-moving flow, which generally remained on top of previous flows but burned some vegetation along its eastern edge. This flow stopped at ~395 m elevation, ~5 km from the coast highway.

Low-level harmonic tremor continued in the eruption zone, with intermittent bursts of tremor beneath Kīlauea's summit originating at depths from 10 to nearly 60 km. Microearthquakes persisted at a moderate rate beneath the summit and the East rift zone. Earthquakes were most numerous beneath the S flank of Kīlauea with foci at depths of 5-10 km. Summit tilt showed no change (figure 45).

Information Contacts: C. Heliker and R. Koyanagi, HVO.


January 1987 (SEAN 12:01) Citation IconCite this Report

Activity confined to shield area, new tube system

During the first part of January, lava reoccupied the tube system extending SE from the shield that has been growing since 20 July. Lava outbreaks from the tube system occurred to 365 m elevation, intermittently producing short tube-fed flows for two weeks. During the last half of the month, a new tube system developed on the W side of the lava field, on the E side of the 1984 aa flow. Many breakouts in the area between 485 and 515 m elevation caused flows only a few hundred meters long. All tube-fed flows were of small volume. Most activity was in the shield vent area, adding bulk to the shield through tube-fed breakouts on the E side, not pond overflows as in previous weeks. Periodic overflows did occur, but the shield remained ~46 m high.

On 1 February, a flow poured into a NE-trending fissure 3.8 km NE of the pond and reappeared in a parallel fissure 800-1,100 m downrift, overflowing an area of ~75 x 103 m2 before stagnating on the night of 3 February. New cracks up to 2 m wide opened for a distance of ~1 km.

Weak harmonic tremor continued near the eruption site. The number of microearthquakes remained at average levels in shallow summit region and East rift zone. Deep crustal earthquakes continued at moderate levels beneath the S flank adjacent to the eruptive area. Summit tilt remained unchanged with minor fluctuations.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


February 1987 (SEAN 12:02) Citation IconCite this Report

New outbreaks along lava tube system stagnate

Most February activity occurred along a tube system SE of the vent that has fed a lava pond and built a small shield . . . since July. The elevation of the pond was ~656 m asl. There was no further flow activity into the NE-trending fissure after 3 February (figure 47). Beginning at ~520 m elevation the first part of the month, breakouts along the tube system gradually migrated downslope. By mid-month, most activity was within a 60 m elevationn range near the 335 m contour, 6 km SE of the lava pond. From the 15th on, there were two concurrent flows, one traveling along the E margin of the 1984 aa flow and the second on top of the 1984 aa, both emanating from the same tube system at ~450 m elevation. The first flow was intermittently active. A new surge of lava advanced on 25-27 February, then stagnated on the 28th at 130 m elevation, < 3 km from the coast.

The 2nd flow had reached 260 m elevation by the 22nd, then ran off the W side of the 1984 aa and traveled down to 130 m through forest and grassland, stagnating on the 24th. Both flows were narrow, low-volume, channeled aa, too small to show on the scale of figure 47. Lava did not directly threaten residents of nearby Royal Gardens subdivision, but started smoky brush fires 23-26 February. Residents along the E edge of the subdivision were evacuated for one day and the County Fire Dept set backfires to protect the homes in the area.

Since 28 February, activity has been limited to pond overflows on the shield, indicating blockage within the tube system. The height of the shield remained ~46 m above the pre-1983 surface and the daily output of lava was estimated to be 500,000 m3/day. There has been no significant change in summit tilt.

Harmonic tremor persisted at low levels . . . near the vent area. The number of microearthquakes remained at a relatively low level in the summit and East rift zone. Earthquake activity was centered mainly along the S flank of Kīlauea and the vicinity of the Kaoiki fault (between Kīlauea and Mauna Loa). A burst of deep seismicity 60 km N of Keahole Point on the W side of the island started with a M 4.8 event at 1622 on 3 February, followed by 24 aftershocks ranging from M 2.5 to 4.0 over the next three weeks.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


March 1987 (SEAN 12:03) Citation IconCite this Report

Lava flow enters ocean; more coastal destruction

The continuing production of pahoehoe flows . . . during March was primarily through the 12-km-long tube system that has been forming since July 1986. This system extends SE to the Kapa'ahu community that was largely overrun by lava in November 1986 (figure 48). Activity through the first half of March was confined mainly to the shield as spillover flows from the pond; a few sluggish breakouts occurred, generally above 450 m elevation. One flow reached 90 m altitude on 9 March.

Figure (see Caption) Figure 48. Sketch map showing the active lava flow on the Kalapana coast as of early May. The March-May 1987 flow is shown by a dashed line.

On 24 March a new flow, fed from a tube opening at the 245 m level, overrode the Kapa'ahu flow, started a brush fire that burned an abandoned house W of the flow, and reached Highway 130 on 31 March. Queens Bath (a spring-fed fissure that was a popular swimming hole), and a nearby heiau (ancient Hawaiian temple) were also overrun on the same day. On 6 April, a small lobe stagnated within 5 m of an abandoned house within the kipuka N of Kapa'ahu, but it remained unharmed as of 9 April.

On 7 April, the first tongue of a broad westward-moving flow penetrated the E boundary of the national park (figure 48). By 0700 on 8 April, lava had blocked the entrance to Royal Gardens, closing the subdivision to all vehicle traffic. More than a kilometer of Hwy 130, which had reopened in February following late 1986 closing by the Kalapana Gardens and Kapa'ahu flows, was largly overrun by new flows. On 9 April at about 0200, lava entered the sea for the second time since . . . January 1983.

The height of the shield at the vent area reached 48 m above the pre-1983 surface. There has been no significant change in the summit tilt record since July.

Harmonic tremor continued at a low level in the East rift zone. Minor variations in amplitude occurred, generally at intervals of a few hours. Shorter tremor bursts and shallow microshocks from crustal adjustments and degassing associated with the lava activity were commonly recorded by seismometers within a few kilometers of the vent. The number of earthquakes was low in the summit region and moderate along the S flank.

Information Contacts: G. Ulrich, C. Heliker, and R. Koyanagi, HVO.


April 1987 (SEAN 12:04) Citation IconCite this Report

Lava advance continues, three more houses destroyed

The flow that entered the ocean on 9 April continued intermittently until 1400 on 21 April. Advance into the ocean has been sporadic and relatively minor in overall volume. Lava flows continued to advance, covering the November Kapa'ahu flow and spreading W over new ground. The main flow front continued to advance W into Hawaii Volcanoes National Park, overrunning more of . . . Hwy 130 and the entrance road to Royal Gardens subdivision. About 1.6 km of Highway 130 had been covered by late April. The small untouched area (kipuka) surrounded by the November lava flow has been slowly invaded and three more homes were destroyed by early May. A broad flow on the W side of the 1984 lava slowly advanced S and reached 43 m elevation (figure 48). Brush fires set by this flow generated heavy smoke, but have not threatened the Royal Gardens subdivision.

The level of the lava pond over the vent (figure 49) fluctuated from overflowing on 16-17 April to as much as 5 m below the rim. The pond was ~150 x 250 m, including the neck that leads to the main tube system. Tumescence occurring on the flanks of the ~52-m-high shield preceded lava breakouts and formation of fissures that emitted short aa flows. However, most movement of lava was through the underground tube system to the SE, visible through windows or skylights from ~660-40 m elevation.

Figure (see Caption) Figure 49. Photograph showing the active lava pond on the shield formed on Kīlauea's East rift zone since July 1986. The lava level is 3-4 m below the rim. Courtesy of J.D. Griggs, USGS.

There was no significant change in summit tilt. Harmonic tremor persisted in the East rift zone with some minor changes in amplitude at intervals of a few hours. Short tremor bursts 1-3 minutes in duration occurred intermittently. The number of microearthquakes in the summit area and East rift zone was slightly above average. Earthquakes of M 1.5-3.0 occurred beneath the SE flank of Mauna Loa (Kaoiki fault) and the S flank of Kīlauea.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


May 1987 (SEAN 12:05) Citation IconCite this Report

Lava enters ocean from underwater tubes and surface flows

The primary activity . . . in May and early June was a slow advance of dense pahoehoe continually overriding older flows. By mid-May the lava . . . was completely within tubes, with some minor breakouts . . . at 150-20 m elevation late in the month. Low-volume lava flows entered the ocean 11-18 May. On 17 May, divers reported lava issuing from tube openings ~10 m underwater. Occasional lava extrusions along the tube system fed flows that overran > 30 m of Hwy 130 on 29 May and 2 June, buried more of Pacific Paradise Ocean Front Estates (partially overrun in November 1986) and again entered the ocean on 4 June. More than 1.8 km of the Chain of Craters Road has been covered with lava.

The level of the lava pond over the vent at 670 m elevation varied from as much as 9 m below the rim to vigorous overflows on 30 May. Tumescence followed by intermittent breakouts of pahoehoe and aa occurred in the shield's N flank, forming short flows.

The summit tiltmeter showed minor fluctuations but indicated no long-term trend of inflation or deflation. Harmonic tremor persisted . . . near the eruptive vent. Bursts of relatively high-amplitude tremor lasting 5-20 minutes occurred at irregular intervals of less than an hour to many hours during the week of 6-13 May and again in early June. The number of microearthquakes was slightly above average in the summit and East rift zone. Earthquakes of M 2.5-3.5 were concentrated on the S flank of Kīlauea and the Kaoiki fault region at 5-10 km depth.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


June 1987 (SEAN 12:06) Citation IconCite this Report

Lava flow builds coast, destroys house; inflation resumes

Lava continued to emerge along the S coast from the tube system . . . . On 4 June lava again entered the ocean, and continued to flow into the sea until late in the month. It was more active 10-24 June than at any time since it entered the ocean, flowing at an increased rate, generating steam clouds and black sand, and forming pillow lavas. The flow front was ~700 m wide as it entered the ocean and extended at least 50 m from the old shore. The flow into the ocean declined 25-26 June and stopped between the 27th and the 30th.

Although no aerial photos have been taken, and no estimate made of the amount of new land added to the island, figure 50 shows the ~1.5 km of new shoreline.

Figure (see Caption) Figure 50. Sketch map of the S coast of Hawaii showing Kīlauea's March-June lava flows and the approximate position of the new shoreline.

From 1 to 6 June, lava threatened the two remaining houses in the kipuka formed in November, and on the 6th, one was destroyed. From 8 June, lava threatened to bury the remains of an historic church established by Father Damien, a famous Hawaiian cleric, and a beach house off the edge of the November 1986 flow margin. By the end of the month, the old church was surrounded by 3-4 m of lava. On the 29th, a lobe of the lava flow covered another 200 m of highway reconstructed after the November-December blockage. It flowed across the highway and moved E, funneling into a small graben behind the beach house. Inland, at the shield surrounding the vent, activity remained about the same. The level of the lava pond fluctuated between overflowing and 5 m below the rim. Tumescence on the N flank of the shield has continued but at a reduced rate.

On 25 June at 2146 a moderate seismic event occurred, associated with partial collapse of the conduit at Pu`u `O`o, the sole source of lava production from 13 June 1983 to 19 July 1986. When part of the conduit wall collapsed, the conduit was enlarged from 10 to 30-40 m in diameter. Bright red magma was sighted ~100 m down in the inactive vent, before it crusted over. There was a high rate of microshocks caused by rockfalls from the conduit walls and resulting structural readjustments within the cone.

Harmonic tremor continued at low level . . . near the eruption site. The number of shallow short-period earthquakes remained nearly constant at average levels. There was a swarm of intermediate-depth long-period events during the second week of June (figure 51).

Figure (see Caption) Figure 51. Kīlauea's activity, January-June 1987, showing summit tilt, short- and long-period earthquakes, carbon/sulfur ratio of summit gases, MgO content of lavas, and estimated lava volume.

The E-W tiltmeter at Kīlauea's summit indicated an inflationary trend following almost a month of gradual deflation. The level of tilt remained low relative to the peak of inflation prior to E-48 (19 July 1986).

Information Contacts: C. Heliker and R. Koyanagi, HVO.


July 1987 (SEAN 12:07) Citation IconCite this Report

Tube system blockage changes shield, lava flows

Considerable change occurred during July at the East-rift shield surrounding the active vent. At the beginning of the month, lava continued to flow toward the S coast, slowly entering the ocean along the E edge of the lava field. The tube system feeding the March-June flows became blocked close to the lava pond and by 4 July all of the flows at the coastal area were stagnant. Most of the activity was confined to the vent area. Lava continued flowing from the neck of the lava pond on the 48-m-high shield, but piled up on the SE flank, forming a lava mound. That activity ceased as lava emerged from the base, W of the previous tube outlet and flowed along the W side of the lava field. The level of the lava pond fluctuated from overflowing or nearly full to as much as 10 m below its rim.

By 14 July the longest flows extended to 530 m elevation, 3.5 km SE of the vent, and moved slowly downslope to 350 m, 4 km from the vent by the 22nd. There the slope steepens and the main lava flow advanced rapidly to ~90 m elevation before stopping on 26 July. The terminus of the flow was 8 km from the vent and consisted of small, multiple aa lobes. Several of the small aa flows came within 0.3 km of Royal Gardens Subdividion, causing concern for some of the remaining residents, but it stagnated before any property was damaged.

The main tube-fed pahoehoe flow was advancing slowly over the aa and had reached 45 m elevation by 29 July, ~9 km from the vent and < 2 km from the coastline. No dwellings were threatened. Lava supply to the flow front had significantly diminished 21-28 July and the lava pond was overflowing. On 30 July, the tube system became completely blocked near the vent and all lava supply to the current flow ceased. Activity resumed near the vent and by early August channel-fed pahoehoe emanating from the base of the shield had covered the upper 2 km of the previous flow.

Harmonic tremor continued at low levels . . . near Pu`u `O`o and the current eruptive vent. Shallow microearthquakes associated with structural adjustments to Pu`u `O`o occurred at a gradually decreasing rate following the moderate collapse event of 26 June. The number of microearthquakes was about average in the summit region. Most of the July earthquakes occurred at <10 km depth on the SE flanks of Kīlauea and Mauna Loa with magnitudes ranging from 0.5 to 4.3.

The summit tiltmeter indicated some minor short-term inflation, but no long-term trend has been established . . . .

Information Contacts: C. Heliker and R. Koyanagi, HVO.


August 1987 (SEAN 12:08) Citation IconCite this Report

Lava production continues; deep tremor

The low-level eruptive activity . . . continued through August. Lava advanced SE from the vent area through well-developed tubes over the steep slope of a major fault scarp ("pali") threatening only the E end of Royal Gardens Subdivision and covering a small portion of an unused access road. At ~150 m elevation, lava moved slightly W of earlier flows, and by the end of the month the flow front had advanced to ~25 m elevation, 1 km from the ocean. During the first week of September, lava overrode earlier flows that covered Hwy 130, and the most active part of the 200-m-wide flow, along its W margin, had moved to within 100 m of the Chain of Craters Road inside the national park (figure 52). A small lobe was approaching the ocean E of the park, but advance was only sporadic. The level of the lava pond over the vent continued to vary, with a few small, brief overflows onto the shield during the month. Most of the lava emptied from the neck at the SE end of the pond into the tube system.

Figure (see Caption) Figure 52. Kīlauea's recent lava flows near the S coast. The hachured area is a preliminary sketch of the August-September flows; outlines of other flows are based on airphoto data. Filled squares represent houses destroyed in September.

Harmonic tremor continued at a low level below the shield vent and Pu`u `O`o. Tremor occasionally varied at intervals of a few hours, but generally remained constant for periods of a few days. Bursts of 40-60-km-deep tremor SW of Kīlauea became increasingly frequent during the last half of the month after three weeks of relative quiet. By mid-August, the number of seismic events beneath Pu`u `O`o (structural adjustments after the 26 June conduit collapse event) had declined considerably, from ~200 shallow microshocks/day in July to ~50/day in late August. There were no unusually significant earthquakes in August; eight had magnitudes of 2.5-4.2. Most occurred in persistent seismic source areas 5-10 km deep in the S flanks of Kīlauea and Mauna Loa.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


September 1987 (SEAN 12:09) Citation IconCite this Report

Lava destroys seven more houses

The August lava flows continued to advance through 20 September, mostly on top of older flows on the coastal plain. A small amount of national park land was newly covered with lava (on the coast side of Chain of Craters Road) but no more of the coastal highway was overrun. Lobes of the lava flow approached the Royal Gardens Subdivision access road and another small lobe reached the high tide zone but stopped before it entered the ocean.

On 20 September the tube system became blocked on the upper slopes and flows stopped. The next day, a new flow broke out above the top of the fault scarp (pali) at ~365 m elevation, moved W, and by the 25th had destroyed one house along the E edge of Royal Gardens at ~50 m elevation. The flow continued to advance through the SE corner of the subdivision, and by 1 October had destroyed seven houses, raising the total destroyed to 55 since . . . January 1983. The temporary access road to the housing area was overrun by lava on 5 October, and lobes continued to cover older lava flows and the flat coastal plain (figure 52).

The estimated output of lava . . . remained steady at 500,000 m3/day. Some brief overflows occurred at the lava pond, mostly in conjunction with blockages in the tube system.

Harmonic tremor persisted . . . at the active vent and near Pu`u `O`o. Microshocks associated with structural adjustments at Pu`u `O`o occurred intermittently during the month. Short bursts of deep tremor lasting less than several hours occurred along the magma conduit system in the eastern part of Kīlauea. Most earthquake activity was distributed broadly along the S flank as well as the summit region, and in the Kaoiki area along the SE flank of Mauna Loa.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


October 1987 (SEAN 12:10) Citation IconCite this Report

Lava flows into ocean

Activity . . . continued through October with three flows moving toward the coast. The westernmost lobe, up to 5 m thick in places, broadened but mostly stayed on top of September flows. The flow intermittently entered Royal Gardens subdivision, and the footpath from the road into the housing area was covered in late October, leaving the few remaining residents with no way of reaching their homes. The middle lobe was entering the ocean inside the national park. The new ocean front was ~700 m wide W of Kupapau point, moving W along the seacliffs toward the national park visitor center (at Wahaula; figure 53). The E lobe has completely buried the 1984 aa flow, and was intermittently entering the ocean 600 m E of Kupapau point along a front ~50 m wide. The level of the lava pond . . . was fairly constant, from nearly full to 6 m below the rim. There have been no overflows from the pond and all lava production has been carried away in the tube system.

Figure (see Caption) Figure 53. Sketch map of part of the SE coast of Hawaii with flows from the new eruptive vent in the lava shield, November 1986-January 1988. The dotted line shows the location of the new shoreline.

Harmonic tremor continued at low and constant amplitude . . . . The number of shallow microearthquakes was about average in the summit region and East rift zone. Most of the earthquakes . . . in October were centered along the S flank of Kīlauea and SE flank of Mauna Loa at intermediate depths of 5-10 km. Twelve events with preliminary magnitudes of 2.5-4.1 were the strongest during the month.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


November 1987 (SEAN 12:11) Citation IconCite this Report

Lava flows into ocean, destroys house

Lava production continued into early December. . .. Lava flowed into the sea 1-25 November, the W lobe continuously (in the national park, W of Kupapau Point), and the eastern intermittently (E of Kupapau Point), as in October. Activity at the coast declined to a trickle on 26 November. The next day lava broke out at several points between 240 and 170 m elevation, indicating blockage within the tube system. Several flows advanced over the prominent south flank fault scarp, reaching 60 m elevation. By 2 December, the middle lobe had reached the previously covered coast highway and by 7 December lava was again flowing into the ocean near Kupapau Point, on top of previous flows. In Royal Gardens subdivision, lava movement was intermittent through November, primarily slow ooze-outs on top of older flows. However, lava re-entered Royal Gardens in early December, and one lobe destroyed the last remaining house in the SE part of the subdivision before stagnating on 4 December.

Shallow tremor continued at a low level . . . near the active vent and Pu`u `O`o. Accompanying microshocks caused by rockfalls, degassing, or thermal compensation in recent lava flows occurred several to 100 times a day. Intermediate and deep tremor activity in summit region was intermittent. Minor bursts of short-period events beneath the summit were recorded for a week in mid-November, and were followed a week later by a 2-day swarm of long-period events. Many of the month's earthquakes occurred at intermediate depths . . . under the summit and S flanks of Kīlauea.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


December 1987 (SEAN 12:12) Citation IconCite this Report

Lava flows into sea, destroys more houses

The . . . eruption continued through December . . . . After the brief hiatus at the end of November, flows re-entered the ocean W of Kupapau Point on 7 December and E of the point the next day. Throughout the month, flows entered the SE part of Royal Gardens, mostly on top of older lava. On 3 December, heat from a finger of lava ignited the last remaining house in the SE part of the subdivision. Another lobe moved slowly along the E margin of the 1986-87 lava field S of the coast highway, entered the ocean on 20 December, and continued intermittently for the rest of the month. The flow overran a beach house on the 28th, and burned another on 12 January.

Glow was seen above the inactive Pu`u `O`o vent on 3 December, but heavy fuming obscured the crater floor until the 9th, when lava was seen ~125-150 m down in the conduit. The crater is ~150 m wide at the top.

Harmonic tremor continued . . . at low to moderate levels . . . near Pu`u `O`o. Sporadic rockfall events recorded at Pu`u `O`o during the month peaked on 18 December between 1413 and 1416, with a series of four moderate-sized collapse events. Typical inflation-related shallow microearthquakes in the summit region averaged ~100/day with a peak of ~300 daily for several days during the middle of the month. A swarm of very small, shallow, long-period events accompanied by weak tremor persisted beneath the summit caldera 3-20 December. Most of the month's strong earthquakes occurred . . . beneath the S flanks of Kīlauea and Mauna Loa. Ten were of M 3.0-4.2.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


January 1988 (SEAN 13:01) Citation IconCite this Report

Increased lava production; activity resumes at Pu`u `O`o

Vigorous eruptive activity continued . . . through early February. Lava flowed into the ocean from two main tube systems. One entered the water on the E margin of the lava field (S of the partially covered ruins of the Damien church), the other in four places E and W of Kupapau Point, forming two deltas that have added 0.273 km2 of new land to the island. An unoccupied house on the E edge of the lava field S of the coast highway was overrun by lava on 12 January. Three more buildings were destroyed in Royal Gardens subdivision during the night of 11-12 February, bringing the total to 62 since . . . January 1983.

From 30 January to 3 February, the lava pond overflowed intermittently, but vigorous activity at the coast, geoelectric data from lava tube monitoring, and stronger seismicity all suggested an increase in the magma supply rate. Renewed fountaining within Pu`u `O`o crater was first observed on 30 January. Several 10-15-m-high fountains were seen 180 m down the conduit in a small lava pond, rising, then falling back into holes in the crater floor. Some tephra and spatter reached the crater rim via Strombolian bursts and rising gases.

Harmonic tremor persisted at low to moderate levels near the lava lake and Pu`u `O`o through 20 January. Between 20 and 29 January, irregular variations in tremor were recorded at intervals ranging from a few minutes to many hours. As fountaining began on 30 January, seismicity beneath Pu`u `O`o gradually changed to a pattern associated with gas piston activity, typically with 10-30-minute bursts of higher amplitude. The daily number of shallow microearthquakes at the summit have increased to above average since 30 January. Coupled with several strong bursts of deep tremor during the month, the seismicity seemed to indicate accelerated magmatic activity during the latter part of January.

There was no significant change in the pattern of tectonic earthquakes beneath the island of Hawaii. The two strong events in January were a M 4.1 earthquake off the SE coast on 22 January and a M 4.3 shock beneath Kīlauea's S flank on the 26th.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


February 1988 (SEAN 13:02) Citation IconCite this Report

Lava continues to enter ocean; littoral cones and tephra

Lava . . . continued . . . building deltas near Kupapau Point and farther E near the old Damien church site (figure 53). The W lobe had several active fronts and more volume than the E lobe. Near the end of February, the volume of lava feeding the E lobe began to decrease slowly, and by 1 March growth of the eastern delta had ceased. During the same period, the W lobe began to increase in volume along all the fronts that were entering the ocean, causing explosions and forming small littoral cones. A small spatter rampart was formed by one flow. Sand-sized tephra was produced by some of the explosions, and flakes of basaltic glass > 5 cm long, formed by steam bubbles rising through lava and exploding at the water's surface, were found as far as 1-2 km downwind of the steam columns.

The flow that . . . destroyed three more houses on the 11th reached the bottom of the steep slope and stopped on 14 February. The lava pond . . . overflowed intermittently 31 January-2 February, raising the N rim of the lava shield 6-8 m. The lava level dropped to 5-10 m below the rim for the rest of the month, at times exposing the top 2-3 m of the outlet to the tube system (figure 54). Lava fountaining and gas piston activity . . . at Pu`u `O`o continued. Strombolian activity and fountaining deposited spatter and reticulite pumice on the rim.

Figure (see Caption) Figure 54. Aerial view showing Kīlauea's East-rift lava pond in the foreground, ocean in the far background. The line of fume traces the main lava tube feeding flows into the ocean. The pond is about 125 m in diameter. USGS photograph by Jim Griggs, taken 18 February 1988.

Harmonic tremor continued at a low level . . . beneath Pu`u `O`o and the shield vent. The generally constant tremor amplitude was occasionally interrupted by many hours of gas piston activity, characterized by 1-minute tremor bursts repeating at intervals of ~3-15 minutes. In the summit region, the number of shallow microearthquakes peaked at nearly 400/day then gradually decreased to < 100/day by the end of February. However, there were intermittent swarms of long-period events and weak tremor at shallow and intermediate depths beneath the summit region. Of the thousands of recorded earthquakes during February, 16 of the strongest had magnitudes ranging from 2.5 to 4.6. The M 4.6 event, at 1847 on 19 February, was centered on the S flank of Kīlauea at 9 km depth. It was widely felt on the E half of the island, but no structural damage was reported.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


March 1988 (SEAN 13:03) Citation IconCite this Report

Lava flows into ocean; littoral explosions

The . . . eruption continued through March . . . . As of 1 March, lava stopped entering the ocean from the E part of the tube system. For the rest of the month, all activity was from the W tube system, which fed flows into the ocean along 2-4 fronts straddling Kupapau Point. Littoral explosions continued from at least two of the flow termini. At the main terminus, the explosions were continuous, producing a half cone or littoral rampart. This feature showed little vertical growth during the month, because flows continued to extend the shoreline, and the combination of wave erosion and settling caused parts of the cone/rampart to collapse.

A new black sand beach, 1.5 km long by 25-30 m wide, has formed from the pulverized volcanic glass produced by the explosions. Ocean currents carried the sand ~4.5 km from the tube system and have deposited it where there had formerly been low cliffs. A few very minor lava breakouts from the tube system occurred within a few hundred meters of the shore and upslope on the prominent S-flank fault scarp, but only lasted a few hours. The level of the lava pond over the active vent remained 9-15 m below the rim through March. The large surface overflows of late January-early February built up the walls of the pond by ~4-5 m, mostly on the lower N edge, but did not significantly change the height of the surrounding lava shield.

Harmonic tremor continued . . . near the eruptive vent site and Pu`u `O`o. Tremor amplitude varied between scattered gas piston activity with short interval changes, banded tremor with regularly spaced changes ½ hour to several hours apart, or a steady state sustained for many hours. Long-period events and tremor occurred intermittently beneath Kīlauea's summit in bursts that were sustained for a few hours to several days. The number of shallow earthquakes was generally below average beneath the summit and East rift zone. Some intermediate depth earthquakes occurred along the S flank of Kīlauea. A series of moderate-sized earthquakes occurred offshore 40-50 km NW of Keahole Point. Activity was initiated by M 5-5.5 shocks on 24 and 27 March that were widely felt on the islands of Maui, Oahu, and Hawaii. During the rest of the month, several dozen events in the same area had magnitudes of 2.5-4.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


April 1988 (SEAN 13:04) Citation IconCite this Report

Lava production resumes after a one-week hiatus

Activity . . . continued at a low level during the first 24 days of April. The level of the lava pond on the newly named Kupaianaha shield remained 20-25 m below the rim. Lava entered the ocean along 3 or 4 fronts straddling Kupapau Point. A few minor surface flows occurred near the shoreline. Harmonic tremor generally continued at a low level . . . near Pu`u `O`o and Kupaianaha shield. Minor changes in tremor amplitude occurred at varying intervals ranging from a few minutes to many days. At the summit, the number of shallow microearthquakes persisted at a low level of ~100/day during the first three weeks of April, coinciding with summit deflation. Shallow and intermediate-depth tremor occurred sporadically in the summit region. Moderate-sized earthquakes of M 2-4 continued to be most frequent in the S of the island.

On 24 April the lava level in the pond began to drop and by the end of the day was 30 m below the rim. By the next morning lava was down another 5-10 m and there was little surface overturn activity. Large sections of the pond rim had become unstable and collapsed into the pond. The lava had drained to below the level of the outlet tube but did not retreat into the conduit. Slowly solidifying lava remained in the bottom of the pond with remnants of the pahoehoe skin that had covered the surface . . . . A few sluggish flows continued to enter the ocean from residual drainage of the tube system. One small aa outbreak occurred at the 450-m level, probably a result of tube collape. Three kilometers uprift, lava had been visible in the bottom of the Pu`u `O`o conduit on 24 April. On the 25th, heavy fume prevented observation, but no orange glow was evident over Pu`u `O`o at night during the decreased activity of the next several days. There was no seismic evidence indicating where blockage may have occurred in the feeder dike between the summit and the eruptive areas in the middle East rift zone. East-rift tremor decreased to a low and constant level between 25 and 28 April. Tremor remained relatively steady but gradually increased in amplitude from the 28th to the end of the month. Microearthquakes increased during the last week of the month from 100/day to a peak level of > 500/day as the summit re-inflated. This slight inflation at the summit during the hiatus in lava production did not exceed fluctuations often measured during previous months.

Shortly after 0500 on 1 May, after nearly a week of quiescence, lava re-entered Pu`u `O`o crater and the pond at Kupaianaha shield. Episodic tremor resumed . . . following the onset of summit deflation. At 1100 lava was observed streaming from the W side of Pu`u `O`o crater and draining into its central vent. The lava pond at Kupaianaha had refilled to ~8 m below the N rim. By 1400 lava was within 5-6 meters of the rim. On the morning of 2 May lava had re-entered the December-April tube system and broke out . . . at six places between the base of the shield and 470 m elevation. Only the four lowest breakouts were active late in the day. Lava also overflowed from the pond onto the NE sector of the shield and into the neck area. These flows were <150 m long. On 12 and 13 May, lava overran the two remaining inhabited houses near the E edge of the lava field.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


May 1988 (SEAN 13:05) Citation IconCite this Report

Lava destroys houses, re-enters ocean

After the short hiatus at the end of April , lava quickly reoccupied the tube system to 480-500 m elevation, where outbreaks fed new surface flows. The new flows branched into two primary lobes and covered a broad area down to 360 m elevation. New tube systems were formed and lava moved rapidly down the steep scarp (pali) on 6 May. The W lobe followed earlier flows along the W edge of the lava field.

The E lobe advanced along the E edge of the lava field on top of pre-1983 flows, following the course of November 1986 lava. When 1,100 m from the coast on 11 May, the E lobe divided (figure 55). On the following day, the last house in the Kapaahu subdivision was destroyed . . . . By the 13th, the flow reached Hwy 130, covered another 200 m of the road, and destroyed another house on the ocean side of the road before reaching the sea the next day. Both houses had been occupied until just prior to the renewed activity. The other sublobe moved E into the forest, turned SE and filled an abandoned gravel quarry 500 m E of the previous flows, before crossing the highway on the 14th. The two eastern sublobes remained intermittently active for the rest of the month, one entering the ocean at times, and the other pooling near an old quarry. On 13 May the W lobe entered the ocean E of Kupapau point. During the second half of May, new lava was much more voluminous along the W front, probably accounting for > 2/3 of the total output.

Figure (see Caption) Figure 55. Sketch map of the S coast of Hawaii showing 1983-8 lava flows from Kīlauea (white), May 1988 flows (cross-ruled), and locations of destroyed houses.

At Pu`u `O`o, heavy fume obscured the conduit for part of the month, but lava was observed moving W to E in a narrow channel at the bottom of the crater (roughly 160 m below the rim) the first week in May, and a helicopter pilot sighted active fountaining at the bottom of the crater on another occasion. Rockfalls from the crater walls covered the bottom of the crater with debris. Activity at the lava pond on Kupaianaha shield fluctuated from minor overflows at the beginning and end of the month to 10-20 m below the rim 10-23 May.

Harmonic tremor continued . . . near Pu`u `O`o and Kupaianaha. After several days of relatively steady tremor that gradually increased in amplitude during the late-April hiatus in lava production, the signature changed into a variable-amplitude pattern characteristic of vigorous lava movement within Pu`u `O`o vent at 0510 on 1 May. For most of the month the East-rift tremor varied from moderate to low amplitude at intervals ranging from minutes to days. Short tremor bursts alternating with long intervals of low-amplitude tremor characterized gas piston activity at Pu`u `O`o on some days. The number of shallow microearthquakes was generally low in the summit region and East rift zone. Several bursts of shallow and intermediate-depth long-period events and tremor occurred beneath the summit region. Earthquakes of M 1.5-3.0 persisted in the S flank of Kīlauea at depths of 5-10 km.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


June 1988 (SEAN 13:06) Citation IconCite this Report

Tube system feeds lava into ocean

Lava flows . . . continued to enter the ocean along two fronts E of Kupapau Point. The W flow front had two active areas ~200 m apart. At the W end of a 100-m-wide front, minor littoral explosions built a small ephemeral cone that sometimes grew to 1-2 m high by 4 m in diameter, and added pyroclastic material to a growing black sand beach 100 m to the W. Divers observed development of underwater tube systems that extended as much as a few hundred meters from the coast. Flows from the other front sporadically entered the ocean nearly a kilometer to the E. Surface activity upslope along the two lava tube systems was minimal. The lava pond level remained several meters below the rim all month.

Low-level tremor continued . . . near Kupaianaha and Pu`u `O`o. Amplitude varied according to the pattern of lava movement and ranged from frequent tremor variations, minutes apart during gas-piston activity, to relatively steady tremor sustained for hours to days. Some collapse events at Pu`u `O`o were also recorded. The number of microearthquakes was about average in the summit region and East rift zone. Of more than 1,000 earthquakes located . . . in June, 23 registered at M 2.5-5.1. The largest (M 5.1) was centered above the S flank of Kīlauea at a depth of 10 km on 7 June.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


July 1988 (SEAN 13:07) Citation IconCite this Report

Lava bench collapse at seacoast

Through July, two lobes of lava continued to enter the ocean ~1 km E of Kupapau Point. Lava flowed intermittently into the ocean from a tube at the E edge of the lava field. The E lobe was active along a 200-300-m-wide front. As lava entered the ocean during the past few months, it formed wide lava benches extending the shoreline. Three nested littoral cones had formed behind the most active entry point and another was forming at the terminus of a different tube system ~50-100 m farther E. At 1212 on 9 July, the entire active lava bench at this entry point collapsed into the water. On 12 July at 0842 another area of ~100 x 25 m collapsed within 20-30 seconds, producing two large explosions as water rushed into the tube systems. Both events were evidently triggered by massive slumping of the underlying submarine fan. Thomas Wright (HVO) and two visitors reported that the normally white steam column turned black and spatter was thrown skyward and deposited within 30 m of the cliff edge. The 12 July collapse and explosions registered as a relatively large seismic event on the Waha'ula seismometer (> 1 km away) and the disturbance continued for the next hour.

Sometime during the night of 21 July approximately 1/2 of the active lava bench collapsed into the ocean. Seismic records from the Waha'ula station show a series of strong explosions during the night, but no single collapse event was evident. The collapse/explosion sequence lasted over an hour. A littoral cone began building the following day, and unusually large explosions sent spatter 25-30 m into the air.

By 22 July, the flow along the E edge of the lava field had ceased advancing. Backup of lava in the E tube system 20-29 July caused surface outbreaks between ~70 m elevation and the coast, at the junction of the two tube systems at 470 m elevation, and from the W system at ~365 m elevation. Some small spiny pahoehoe flows < 200 m long were produced.

The W lobe became inactive on 27 July. However, visible effusion at the eastern lobe entry point seemed less than the total output of the Kupaianaha lava pond, suggesting that another tube may have formed deeper in the subaerial part of the flow carrying lava directly to submarine extrusive vents. The lava pond level remained 10-20 m below the rim for the month.

Shallow tremor continued at low levels through July . . . near Pu`u `O`o and Kupaianaha. Amplitude variation reflected a pattern of lava movement and degassing in the vent region. Oscillating tremor related to fountaining in the bottom of Pu`u `O`o crater also continued the first week. A secondary source of tremor was . . . attributed to explosions caused by lava entering the sea. In addition to the background tremor, strong bursts were associated with collapse of the shoreline deposits. Both the 9 and 12 July slumping events were recorded as ~1 minute of strong tremor . . . and were followed by 45 minutes of suppressed background tremor. The signature was apparently triggered by the primary event. Except for a significant M 4.4 earthquake and some aftershocks deep beneath the offshore component of the Hilina fault, Kīlauea S-flank events were mostly local at crustal depths along the outlying seismic zone of the Southeast rift zone. Kīlauea summit earthquakes were mostly shallow at < 5 km but there were some scattered long-period events at ~5-13 km depth.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


August 1988 (SEAN 13:08) Citation IconCite this Report

Coastal lava benches build and collapse

During August, lava continued to enter the ocean ~600 m E of Kupapau Point (figure 56). The collapse of lava benches into the sea . . . continued during August. Several lava benches collapsed during the month, the largest a 250 x 50 m bench that collapsed at 0614 on 15 August. On 17 August, "fountaining" was seen from two openings on the bench, ~10-15 m from the coast. This steam jetting and spattering was apparently caused by water entering a partially congealed submarine tube. Another bench collapse occurred on 27 August at 1000. The E tube system had no activity since the last week in July.

Figure (see Caption) Figure 56. Map showing the lava flows from the Kupaianaha vent on Kīlauea's East rift zone. The dashed lines show the active tube system in August 1988. The arrow indicates the area where lava enters the ocean.

Although new shoreline is being formed, the total area of new land is changing very little because lava is being added to previous collapse sites. Cones formed by small littoral explosions are washed away when collapses occur. Early shoreline extension was more rapid as lava flows covered tide pools and shallow shoreline, but flows have advanced onto a much steeper submarine slope and thus are unstable, causing frequent collapses.

Minor surface breakouts from the tube system occurred 1-11 August at ~72 m elevation on the E edge of the flow field, advancing ~150 m into forest. The lava pond level at the active (Kupaianaha) vent was 16-23 m below the rim through August. There was one sighting of activity at Pu`u `O`o on 2 August and incandescence was observed a few times when the vent was not obscured by fume. Rockfall debris covered most of Pu`u `O`o's crater floor.

Volcanic tremor continued at low level . . . near the eruptive site. Rockfall signals from Pu`u `O`o were frequent during the month. A second source of tremor related to flows entering the ocean was detected at Wahaula, 3 km away. Explosive collapses of oceanfront deposits were also recorded. Notable collapses occurred at 0615-0640 on 15 August, 0100-0130 on the 21st, 1000-1040 on the 27th and 0010-0030 on 31 August. The number of shallow microearthquakes was about average. A swarm of intermediate-depth long-period earthquakes occurred beneath the summit area in mid-August. Most of the earthquakes located during the month were concentrated in Kīlauea's S flank and in the Kaoiki region at intermediate depths of 5-15 km. There were scattered occurrences of earthquakes ~50 km W of Upolo Point on the N tip of the island. Intermittent earthquakes have occurred in this area since March.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


September 1988 (SEAN 13:09) Citation IconCite this Report

Littoral explosions and lava bench collapse

The . . . eruption continued to feed lava into the ocean near Kupapau Point. Fluctuating tremor associated with explosive lava entry into the sea was recorded 3 km away at Wahaula seismic station. Tube system surface outbreaks occurred on 19 and 20 September above the fault scarp at ~350 m elevation. The 19 September outbreak fed 1-km-long aa flows that stagnated the same day. The lava pond level at Kupaianaha remained 20 m below the N crater rim and lava was occasionally seen in Pu`u `O`o crater's main vent. Additional lava bench collapses occurred, with major episodes on 6, 15, and 26 September. Lava bench collapse was detected seismically as a series of high-amplitude bursts followed by smaller rockfall and explosion signals and a temporary decrease in tremor. At 2038 on the 26th, 1/3 to 1/2 of the 200-m-long and 50-70-m-wide bench collapsed. Strong explosions built a pair of littoral cones (4-5 m high) on the resulting collapse scarp. A new bench grew rapidly, and by 10 October, two small new cones (2-3 m) had built 20-30 m seaward. Small spits grew in front of the cones. Increased pyroclastic activity in early October covered 1/3 of the bench's western area with several centimeters of tephra and added to a pre-existing 250-m-long tephra blanket that covered the nearby beach.

Low-level tremor continued . . . near Pu`u `O`o and Kupaianaha. At Kīlauea's summit, the number of short period microearthquakes was relatively steady at ~100/day. Two moderate swarms of intermediate-depth (6-15 km), long-period earthquakes occurred 4-6 and 26-27 September and consisted of several hundred events (M>0.1). The month's largest event (M 4.4) at 1952 on 12 September was centered 11 km beneath Kīlauea's S flank and was widely felt in the S part of the island. No structural damage was reported.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


October 1988 (SEAN 13:10) Citation IconCite this Report

Repeated collapse of new coastal lava benches

. . . lava continued to flow into the ocean from the tube system near Kupapau Point through October. Some minor surface activity occurred 2-4 October when lava broke out from the tube system between 300 and 180 m elevation.

The coastal lava bench growth and collapse sequences continued. A major collapse on the 13th removed ~2/3 of the 220 x 30-40 m bench, and there were minor collapses on 20 and 29 October and 5 November. Benches collapsed suddenly, without warning, making viewing the coastal area very hazardous. Small littoral cones formed periodically, the largest 10 m high. They were soon stranded behind the growing shoreline, then destroyed as the benches collapsed. Pyroclastic material consisting of fine shards and Pele's hair was ejected by littoral explosions, forming a tephra blanket several centimeters thick > 250 m downwind.

The lava pond at Kupaianaha remained 15-28 m below the rim. A 5-m-diameter "island" was visible 15-24 October ~20 m from the pond's edge, probably a piece that had collapsed from the rim. Activity increased in Pu`u `O`o crater on 26-27 October, with lava covering ~25% of the crater floor. Lava appeared to well up through one of the two active vents on the crater floor, and drain back down the other.

Low-level tremor continued . . . near Pu`u `O`o, Kupaianaha, and the Wahaula station near the coastal lava flows. East-rift tremor showed steady amplitude until the 27th, then changed to a pattern of varying amplitude that produced a banded pattern on the revolving drum seismic recorders. High-amplitude tremor lasting < 1 hour typically alternated with several hours of low-amplitude tremor. The fluctuating tremor continued until 4 November, then resumed its typical steady pattern. Bursts of deep tremor . . . increased from last month. The number of microearthquakes was about average in the summit region and East rift zone. There were 12 earthquakes of M 2.6-4.1, mostly centered beneath Kīlauea and Mauna Loa.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


November 1988 (SEAN 13:11) Citation IconCite this Report

Lava benches form and collapse at coast

On 5 November at 1130, ~1/3 of the 400-450 x 60 m lava bench collapsed, and numerous smaller bench collapses were detected seismically throughout November. A large littoral cone that formed on 28 November produced 1-5-cm flakes of volcanic glass.

On 10 November, a series of surface outbreaks near the top of the fault scarp at ~350 m elevation fed lava that flowed into the Royal Gardens subdivision but caused no threat to remaining structures. By 14 November, the flow was barely moving. Two weeks later, an outbreak occurred at 180 m elevation, flowed E of the subdivision, and stagnated days later at ~100 m elevation. The Kupaianaha lava pond level remained stable at 25-30 m below the rim through November. During overflights on the 3rd and the 28th, low fountaining (~5-10 m high) was observed in Pu`u `O`o crater, covering as much as ½ of its floor with lava. Irregular tremor . . . near Pu`u `O`o had ended 4 November and typical low-level tremor resumed. Most upper East rift zone events were deeper than 5 km except along the rift axis where events were generally more shallow. Seismicity was steady beneath Kiluaea's S flank, but episodic swarms of intermediate-depth (5-13 km), long-period earthquakes were measured beneath the summit.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


December 1988 (SEAN 13:12) Citation IconCite this Report

Continued lava flow into sea; tube breakouts upslope

Kīlauea continued to erupt in December. Lava traveled through the tube system to the coast, continuing to build an active lava bench at sea level. Seismic stations > 10 km away detected minor bench collapses at 1804-1825 on 2 December and 2129-2150 on the 14th. These destroyed 10% and 20% of the total bench area. A series of lava breakouts from the main tube system at 440 and 330 m elevation began on the 10th and continued throughout the month. Lava (mostly low volumes of pahoehoe) repeatedly broke from the tube system, branched into several flows, and stagnated after the flow fronts reached ~100 m elevation. The lava flowed over and E of the main 1986-88 field, posing no threat to property. The Kupaianaha lava pond level averaged 20 m below the rim during the month.

Low-level tremor continued . . . near Pu`u `O`o and Kupaianaha. The signal pattern varied from steady amplitude sustained for many days to recurring bursts at intervals of a few minutes or hours. Rockfalls were detected at Pu`u `O`o throughout the month. Shallow microearthquakes continued at an average rate in the summit region and along the rift zone. Most of the 17 largest earthquakes (M 2.5-4.3) were located along the S flank of Kīlauea and the SE flank of Mauna Loa at intermediate depths of ~5-15 km.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


January 1989 (SEAN 14:01) Citation IconCite this Report

Lava flow remains active at seacoast and upslope

During January, an estimated 70% of the lava that emerged from the Kupaianaha lava pond entered the ocean via the W tube system . . . . The pond level averaged 20-25 m below the rim all month. Two flows that branched from the main tube system at 440-425 m completely roofed over during the month but fed surface breakouts at low elevations. The terminus of the first flow was near the N edge of the 1986 Kapa'ahu kipuka at 35 m elevation. The second flow followed the E edge of the 1986-89 lava field during early January. By the 23rd, the main terminus had advanced onto grassland and was 800 m upslope of Hwy 130. The 150-m-wide terminus did not advance after the 23rd, but the flow remained active upslope. Active lava was also sighted several times in the bottom of Pu`u `O`o.

Output from the tube system at the coast continued to build an active lava bench, which measured 535 x 115 m on 5 January. Lava entered the bench at one main entry point and at two smaller outlets to the E. From 5 to 9 January, 20% of the bench was destroyed by small collapses. On the 11th, a steam jetting event from the tube on the bench deposited spatter 150 m inland. On the 20th, three littoral cones (~1-2 m) were forming on the bench. A major collapse on the 23rd at 0844 removed the bench's W half, causing an explosion that threw 10-50-cm blocks 40-50 m inland. On 24 January, spatter explosions built cones 2 m high on the remaining portion of the bench, which began to rebuild on the 26th. Growth continued until the end of the month.

Low-level tremor . . . continued in the middle East rift zone and at the flow front near Kupapau Point. Tremor was generally steady except 5-9 January when amplitude fluctuated at intervals varying from minutes to several hours. A series of rockfall and acoustic signals, caused by the major bench collapse on 23 January, was recorded . . . from 0820-0948. The number of microearthquakes was about average in the summit region and East rift zone.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


February 1989 (SEAN 14:02) Citation IconCite this Report

Lava enters sea through tubes; surface breakouts upslope

The . . . eruption continued during February with the source remaining the Kupaianaha lava pond (filled with lava to 20-25 m below its rim). About 80% of the lava that entered the ocean traveled through the W branch of the tube system. Frequent surface breakouts at ~300 m elevation produced small pahoehoe flows that moved over older lava. One reached 200 m elevation on the 22nd before stagnating. Flows produced by surface activity from the smaller central tube during the first week in February had stopped by the 8th. The terminus of the E tube remained stagnant above Highway 130, but outbreaks upslope from 350 to 400 m elevation fed sluggish flows until the 10th. The seacoast lava bench continued to grow after the large 23 January collapse. On 12 February, a 160-m-long edge of the older portion of the bench collapsed. The collapse was [seismically] registered . . . as a series of rockfalls and acoustic signals. On 15 February, the bench measured ~315 x 30 m and it continued to grow through the month.

Tremor . . . was generally steady in amplitude except during occasional rockfalls at Pu`u `O`o. An average number of shallow microearthquakes were detected in the summit area and East rift zone. Intermediate-depth, long-period events beneath the summit increased to ~100 or more/day during the last week of February. Intermittent bursts of deep tremor originated from 40-50 km beneath the summit. Most of the hundreds of earthquakes (M>0.5) processed for location were centered 15 km beneath Kīlauea and Mauna Loa. Eleven large events had magnitudes of 2.5-3.8.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


March 1989 (SEAN 14:03) Citation IconCite this Report

Breakouts upslope slow lava bench growth at coast

The level of the lava pond in Kupaianaha vent . . . varied from 21 to 25 m below the rim during March (figure 57). Lava breakouts from the tube system were relatively frequent near the major fault scarp at ~270-360 m elevation. Lava that emerged from the W tube system advanced to 150 m elevation, flowed ~120 m into forest, and passed near the Royal Gardens subdivision, causing no damage. Sporadic breakouts from the E tube produced sluggish pahoehoe flows. Lava advanced to the point where a December 1986 flow had . . . entered the Kalapana Gardens subdivision. Breakouts from the central tube had advanced down the E side of the flow field to 45 m elevation by the end of the month, but remained on top of older flows.

Figure (see Caption) Figure 57. The lava pond at Kupaianaha vent on Kīlauea's East rift zone. In this photograph by J. Griggs (USGS), the lava is mostly covered with crust and is about 15 m below the rim of the pond. The pond is ~100 m across at its widest point. The entrance to the main lava tube (below the surface) is located in the upper left (SE) wall of the pond.

Lava continued to enter the ocean, building a lava bench (figures 58 and 59), although at a diminished rate during strong surface activity. The active portion of the bench was 200 x 80 m in March, and older inactive portions remained susceptible to collapse. Minor collapses occurred 3 and 17 March, then a major collapse on the 23rd at 0335 destroyed 65% of the bench, including almost all of the active section. By the end of the month, the bench was rebuilding and the new active portion measured ~170 x 20 m. Explosivity during the collapses was minor.

Figure (see Caption) Figure 58. View by J. Griggs (USGS) from the E side of Kīlauea's 1986-89 flow field, looking W. The steam plume marks the point where lava has been continuously entering the ocean since May 1988.
Figure (see Caption) Figure 59. Close-up aerial view by J. Griggs (USGS) of Kīlauea's actively growing lava bench, 1-3 m below the older sea cliff. As the bench grows, it spreads laterally (parallel to the sea cliff) as well as seaward. In the photograph, the bench is 30-40 m wide. A smooth tephra deposit, extending onshore from the edge of the sea cliff, is visible to the right of the plume.

Low-level tremor continued near vents on the middle East rift zone and where lava entered the ocean. Bench collapse was registered as a series of rockfall and acoustic signals at the Wahaula seismic station, 3 km away. Intermediate-depth, long-period events and tremor were intermittent beneath the summit. Bursts of deep tremor were centered 40-60 km beneath the S part of Hawaii.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


April 1989 (SEAN 14:04) Citation IconCite this Report

Lava flows threaten houses

Kīlauea's . . . eruption continued to feed lava through tubes into the ocean near Kupapau Point during April. Surface lava breakouts along the W tube were active 1-12 April and extended from ~300 m (top of the fault scarp) to 70 m altitude. Lava traveled along the W side of the flow field, entering the E margin of the Royal Gardens subdivision (figure 60). A major breakout on the 13th at ~500 m elevation remained active throughout the month. Large surface flows burned forest to the W and on 25 April passed within 50 m of an occupied home . . . . Access to the upper subdivision, as well as several houses, were threatened. By the end of the month, the flow had reached 60 m elevation and slowed, but was still active. Surface activity from the E tube at the top of the fault scarp was sporadic in early April but ceased after the 10th. The terminus of a breakout from the central tube was active just above the Kapaahu kipuka but stagnated after the 12th. The lava breakouts from the W tube on the 13th apparently lowered the magma supply to the E and central tubes, causing their flows to stagnate. The active portion of the seacoast bench that had formed since the 23 March collapse measured 160 x 60 m at the beginning of the month. Following two large collapses on 13 April (at 2024) and 22 April (at 2307), the bench continued to rebuild.

Figure (see Caption) Figure 60. Sketch map showing lava flows produced from Kupaianaha, July 1986-April 1989, and the current lava tube system. The April surface flows were mostly confined to the 1986-89 flow field. Courtesy of HVO.

The lava pond at Kupaianaha was 20-25 m below the rim during April. Lava was observed in the crater bottom of Pu`u `O`o . . . for most of the month, ranging from spatter to a sizeable lava pond that covered much of the crater floor. Gas pistoning events were witnessed at mid-month. By the 25th, only glowing holes in the rubble at the crater bottom could be seen.

Most of April's 18 strongly recorded seismic events . . . were tightly clustered beneath Kīlauea's summit and S flank. Shallow events (0-5 km depth) continued to be recorded. The number of intermediate-depth long-period events beneath the summit decreased and developed a fluctuating pattern after a persistent high rate in March. Increasingly longer bursts of deep tremor (40-60 km depth), at near-regular time intervals during the first half of the month decreased thereafter. Low-level tremor continued beneath Pu`u `O`o and Kupaianaha. Relatively steady tremor amplitude beneath Pu`u `O`o was interrupted 13-17 April by short gas piston bursts and long intervals of banded tremor, correlated with increased activity in the crater. Tremor returned to a relatively steady state in the latter part of the month. Low-amplitude signals from lava entering the sea near Kupapau Point continued to be recorded.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


May 1989 (SEAN 14:05) Citation IconCite this Report

Surface activity destroys four houses

Lava continued to flow into the ocean E of Kupapau Point, and [13] May marked a full year of lava entry into the ocean through the W tube system. Surface lava breakouts were numerous from two areas (420-450 and 120-150 m elevation) of the W tube system. A surface flow that formed in April at 120 m elevation had reached the coast by 4 May and remained active until the [9th]. The flow added to the E half of the active seacoast lava bench, bringing the bench's dimensions to 500 x 50-70 m. On the 25th, the only collapse of the month destroyed 70% of the bench. The collapse was witnessed by two geologists who saw areas as large as 100 m long and 10 m wide fall into the sea up to one-half hour after the initial collapse. Small littoral explosions accompanied the collapse.

Lower-elevation breakouts also produced pahoehoe flows that moved around the SE corner of the Royal Gardens kipuka and continued onto the coastal flats, forming a broad area (~600 m wide) of activity. By 29 May, the lava front had advanced to within 30 m of the coast and stagnated, but activity continued upslope. The surface flows that formed by breakouts above the fault scarp in April remained active in the Royal Gardens subdivision, destroying four houses (on 15, 21, 23, and 27 May) and blocking normal access to remaining structures. East of the subdivision, a flow blocked a major access road in the . . . National Park on 6 June. Active flows were 600 m NE of, but did not directly threaten, the Wahaula visitor center. Some flows advanced over grassland, starting small fires. The central and E tube systems (drained in April) remained inactive in May. The surface of the Kupaianaha lava pond was 23-25 m below the crater rim during the month . . . . Spattering and small sporadic lava ponds were intermittently observed in Pu`u `O`o crater.

Low-level seismicity continued beneath Pu`u `O`o and Kupaianaha during May. Relatively steady tremor beneath Pu`u `O`o was occasionally interrupted by variable-amplitude signals associated with temporary increases in crater bottom activity. Occasional rockfall signals from Pu`u `O`o and flurries of small high-frequency shocks near Kupaianaha were also recorded. The Wahaula seismic station continued to detect a variety of low-amplitude signals generated by lava entering the sea. The number of shallow (<5 km) microearthquakes was relatively low in the summit region and East rift zone. Episodic bursts of intermediate-depth (5-13 km) events and tremor occurred beneath the summit region. Fourteen relatively large earthquakes (M 2.5-3.9) were recorded . . . during the month.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


June 1989 (SEAN 14:06) Citation IconCite this Report

Earthquake causes bench collapse; no effect on eruption

A M 6.1 S-flank earthquake on 25 June triggered collapse of the coastal lava bench, but apparently had little effect on the continuing eruption. Lava flows that emerged from the tube system on the lower flanks reached the sea at two new sites, after destroying structures near the coast.

Surface lava flows that broke from the W tube system in April and destroyed houses . . . in May advanced S towards the coast in June. Lower elevation lava breakouts from the W tube, which had moved SW around the Royal Gardens kipuka in May, also continued to advance. Lava flows moving W along the Chain of Craters road destroyed a maintenance area on 21 June. The two flow fronts merged the next day, destroying the National Park Service Wahaula Visitor Center (figure 61). By 25 June, the flow front had advanced another 100 m W along Chain of Craters road. A lava front that had moved to within 30 m of the coast in mid-May, stagnated, reactivated in mid-June, and entered the sea on 22 June in a new area at Kupapau Point. The Kupapau flow (intermittently active) had stagnated by 30 June, but resumed activity in early July. On 23 June, lava began entering the ocean at Poupou (just E of the Wahaula residential area). Lava also continued to enter the ocean E of Kupapau Point.

Figure (see Caption) Figure 61. Map of the coastal area affected by the recent activity of Kupaianaha, as of September 1989. Dashed lines indicate roads buried in June and July; filled squares represent structures destroyed during the same period (VC = Visitor Center). Lava contacts from lower Royal Gardens subdivision to the Wahaula area are preliminary. The four "entries" are places where the lava was entering the ocean in July. Lava contacts from lower Royal Gardens subdivision to the Wahaula area are preliminary. Courtesy of Christina Heliker.

The M 6.1 earthquake on 25 June at 1727 was centered on the SE coast, W of Kalapana, at 19.36°N, 155.08°W, 9 km depth (figure 62). Preliminary assessment of the data suggests that the main shock caused seaward movement of Kīlauea's S flank along a subhorizontal plane at the bottom of the volcanic pile near the ocean floor. Aftershock focal depths indicate rupture from near the surface to slightly more than 10 km depth. The motion was similar to the M 7.2 earthquake that struck the same region on 29 November 1975 and most of the strong S flank earthquakes (M>5.5) commonly occur in the mainshock area. Significant earthquakes also were located in this area in March 1954 and September 1979.

Figure (see Caption) Figure 62. Locations of the M 6.1 earthquake and associated aftershocks, 25 June-6 July, 1989. Courtesy of R. Koyanagi.

The earthquake caused almost total collapse of the seacoast lava bench, but apparently did not significantly disrupt the lava tube system. The next morning, geologists noted that the level of the Kupaianaha lava pond had dropped by ~1 m. Lava flow activity at the coast declined 27-28 June, accompanied by a slight decrease in tremor 26-28 June. On the 28th, tremor near the vent gradually rose to normal as the level of Kupaianaha lava pond rose ~1.5 m. By the next day, activity at the coast returned to the pre-earthquake level. An active lava pond in Pu`u `O`o was visible on 28 June.

During the last few days of June, tremor amplitude was relatively steady beneath the East rift zone near Pu`u `O`o and Kupaianaha. Low-amplitude tremor signals associated with ocean front activity near Kupapau Point also resumed. The 25 June earthquake saturated seismographs, masking signals from the associated lava bench collapse. The number of shallow microearthquakes was about average in the summit region and above average in the East rift zone. Intermediate-depth long-period events in the summit region continued at a moderate rate . . . .

Information Contacts: C. Heliker and R. Koyanagi, HVO.


July 1989 (SEAN 14:07) Citation IconCite this Report

High surface activity, new flow enters ocean

. . . In July 1989, Kupaianaha's lava pond remained active, and filled by lava to within 25 m of its rim, which partially collapsed on the 9th and 13th. The earlier collapse (on the E rim) formed a talus pile near the bottom of the wall that was covered by lava, forming a 40 x 15 m ledge and altering the shape of the pond.

Lava continued to travel through the W tube system toward the coast in July (figure 63). Surface lava breakouts in the Wahaula area fed lobes that flowed from the lower Royal Gardens subdivision to the ocean (figure 61). On 5 July, lava advanced 150 m along Chain of Craters road, reaching the lower end of Prince Street (the westernmost street of the Royal Gardens subdivision) by the 23rd. A surface breakout from the W tube on the 21st at 320 m elevation (top of the pali fault scarp) reached 120 m elevation by the end of the month. The Kupapau flow that had entered the ocean on 22 June and then stagnated, reactivated 5-21 July. Flows that had merged and destroyed the visitor center on 20 June moved N and W of the Heiau (a religious site, several hundred years old), entering the ocean on 5 July. This flow, named Kailiili, remained active into early August, as did the Poupou flow, which had entered the ocean E of the Wahaula residential area on 23 June. Both flows built seacoast benches that were ~700 m long and actively growing (mostly westward) by the end of the month. The bench that began to form E of Kupapau Point in May 1988 remained active. On the 27th, a surface flow advanced over the sea cliff, covering the E half of the old bench. There were no collapses, and by the end of the month, the bench measured 200 x 50 m.

Figure (see Caption) Figure 63. Flows produced by the current eruption at Kīlauea. The July 1986-July 1989 flows from the Kupaianaha vent are striped; the rest of the flows (outlined but not shaded) were erupted January 1983-July 1986, mostly from the Pu`u `O`o vent. Courtesy of Christina Heliker.

By the end of July, the number of aftershocks from the 25 June earthquake had decreased to near normal on Kīlauea's S flank. Most earthquakes were M 1.0-3.7, 5-15 km deep, and concentrated in a 45-km-long, NE-trending zone. The number of shallow earthquakes (<5 km) was above average in the East rift zone and slightly below average at Kīlauea's summit. Intermediate depth (5-15 km) long-period events continued. Low-level tremor near Pu`u `O`o and Kupaianaha had steady amplitudes, with episodic swarms of small high-frequency shocks near Kupaianaha and occasional rockfalls at Pu`u `O`o.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


August 1989 (SEAN 14:08) Citation IconCite this Report

Lava continues to enter the ocean at several sites

Kīlauea's . . . eruption continued in August, with surface activity concentrated on the flat area near the coast. The surface flow that had emerged from the W tube on 27 July and covered the E half of the lava bench E of Kupapau Point remained active until 14 August. On the 22nd, a major surface lava breakout, midway down the fault scarp at ~120 m elevation, destroyed a house in the lower Royal Gardens subdivision that had been surrounded by lava for more than a year. This breakout gradually slowed growth of the long-lived bench E of Kupapau Point, established in May 1988 (13:5) and lava stopped entering the sea there the next day. However, another entry had developed ~400 m to the E on 8 August, when the easternmost active flow reached the ocean. This flow had broken out from the tube system at ~300 m elevation on 21 July. The Kailiili and Poupou flows continued to advance into the ocean, broadening their benches westward. The entry at Kupapau Point that had stagnated 21 July remained inactive. Twice during the month, lava was observed in the bottom of Pu`u `O`o. Lava in the Kupaianaha pond averaged 24-28 m below the rim.

Low-level tremor continued . . . near Pu`u `O`o and Kupaianaha in August. Tremor amplitude was generally steady with intermittent rockfall signals at Pu`u `O`o and episodes of increased high-frequency microshocks lasting less than a day near Kupaianaha. The number of shallow (<5 km) microearthquakes was below average in the summit region and about average in the East rift zone. Intermediate-depth (5-15 km) long-period earthquakes continued at a moderate level beneath the summit region.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


September 1989 (SEAN 14:09) Citation IconCite this Report

Coastal lava entries active; breakouts from tube system

Surface lava breakouts . . . continued to feed flows into the ocean during September. Activity was concentrated in the lower Royal Gardens subdivision (below Orchid street), and in the area between the Royal Gardens kipuka and Kupapau Point (figure 61). Two houses (on Queen St., below Orchid St.) were destroyed on the 28th. Lava emerged from the W tube ~500 m above Chain of Craters Road on the 24th, and reached the road on the 26th. By the end of the month, new lava had covered ~½ km of the road and was entering the ocean near the W portion of the Kailiili bench . . . . On 18 September, lava emerged from the W tube near the remains of the National Park Service residential area, covering the E portion of the Wahaula kipuka. The Heiau . . . was not affected. Within two days, the flow had reached the ocean at the W edge of the Poupou entry . . . where small volumes of lava intermittently entered the ocean throughout the month. The Kupapau Point entry, which had been stagnant since 21 July, was reactivated by a new flow that entered the ocean there on 3 September and remained active throughout the month. The entry E of Kupapau Point remained inactive, but breakouts continued to the E, with one flow (~475 m to the E) reaching the sea on the 14th. By 21 September, all activity E of Kupapau Point had ceased.

Lava in the Kupaianaha pond averaged 25-27 m below the rim through September. No lava was observed in Pu`u `O`o crater during the month.

Low-level tremor continued . . . near Pu`u `O`o and Kupaianaha. Occasional bursts of rockfall signals accompanied the steady background tremor from Pu`u `O`o. Weak signals associated with the submarine component of the oceanfront lava flow activity were detected by the Wahaula seismometer (~2 km NW). Intermediate-depth (6-15 km) long-period events occurred episodically beneath the summit region. The number of shallow (<5 km) microearthquakes was otherwise about average in the summit region and along the East rift zone. Several hundred tectonic events (M 0.5-3.6) located during September were concentrated along the S flank of Kīlauea and the SE flank of Mauna Loa at ~5-15 km depth.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


October 1989 (SEAN 14:10) Citation IconCite this Report

Lava flows into sea at three sites; breakouts from lava tubes

Kīlauea's . . . eruption continued in October, with lava entering the sea at the Kailiili, Poupou, and Kupapau Point entries. Surface activity was concentrated between the lower Royal Gardens subdivision and the Wahaula area. During the first week of October, lava covered an additional several hundred meters of the Chain of Craters road. The flow reached the sea at the W edge of the Kailiili entry on the 6th, extending the bench a few hundred meters W. A surface lava breakout near the SE corner of the Royal Gardens kipuka entered the sea on 12 October ~250 m E of the former entry E of Kupapau Point (inactive since 23 August). This new entry remained active for only a week. Surface activity at higher elevations included an intermittently active breakout at the 580 m elevation that built a small parasitic shield on top of older flows. A surface flow that extended from 180 to 120 m elevation remained active throughout the month.

The level of Kupaianaha lava pond averaged 21-23 m below the rim during October. Activity at Pu`u `O`o was sporadically observed for the first time in more than a month on 15 October. Periods of spattering alternated with episodes in which lava ponded and flowed in channels across the crater floor.

Eruption tremor continued near Pu`u `O`o and Kupaianaha in October. Days when tremor had relatively steady amplitude were interrupted by successive minor amplitude changes lasting from <1 to several hours. Bursts of increased signals at Pu`u `O`o were associated with rockfalls on the unstable cone. Pronounced longer bursts, lasting ~10 minutes on 11 and 13 October, were apparently also produced by rockfalls. Swarms of shallow high-frequency microshocks near Kupaianaha lasted less than an hour and occurred against a background of variable-amplitude tremor, notably on 8 and 26 October. Three seismic bursts on 23 October were related to partial collapse of Kupaianaha's pond wall. Weak intermittent signals from coastal lava flows entering the sea were detected . . . . Intermediate-depth (5-10 km) long-period events and weak shallow tremor (< 5 km) occurred episodically beneath the summit region. The number of microearthquakes throughout the month was about average in the summit region and along the East rift zone.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


November 1989 (SEAN 14:11) Citation IconCite this Report

Three ocean lava entries remain active; littoral explosions

Kīlauea's . . . eruption continued in November, feeding lava into the ocean through a tube system originating at Kupaianaha lava pond (figure 64). The Kailiili, Poupou, and Kupapau Point ocean entries (figure 65) remained active during the month, while former entries E of Kupapau Point were stagnant. Most lava entered the sea at the Poupou entry, where small sporadic littoral explosions ejected spatter (to ~25 m) and limu (fine thin sheets of transparent glass), building a 2-m cone. Lava slowly entered the ocean at Kupapau Point in early November, but this entry was inactive by the 26th. Several small flows extended the Kailiili bench W throughout the month. A surface flow that crossed Chain of Craters road on the 14th (covering an additional 50 m of the road) entered the ocean W of Kailiili and merged with that bench, increasing its area by ~200 m.

Figure (see Caption) Figure 64. Lava flows produced by the Kupaianaha vent, July 1986-November 1989. The active lava tube system is shown by dashed lines. Solid arrows indicate the location of persistent breakouts from the tubes in November. Courtesy of C. Heliker.
Figure (see Caption) Figure 65. Distal portion of the Kupaianaha lava field as of November 1989. Orchid Street intersects the lava at an elevation of ~100 m. Points where lava entered the ocean in November are labeled. The arrows indicate the general location of surface lava flows. Courtesy of C. Heliker.

Surface lava breakouts continued at 560 m elevation and on the fault scarp between 180 and 60 m elevation. A small pahoehoe flow that extended from 560 to 450 m elevation stagnated on the 19th. Surface lava breakouts were sporadic along the W margin of the flow field from Lower Royal Gardens to the coast near the Kailiili bench. There were two reports of activity at Pu`u `O`o (5 and 19 November), but bad visibility during the month prevented close observation.

Eruption tremor continued . . . near Pu`u `O`o and Kupaianaha, where shallow high-frequency microshocks occurred at varying rates. Intermediate-depth (~5-10 km) long-period events associated with tremor beneath the summit decreased in late October and remained low until about 15 November. The number of events steadily increased, peaking at ~100/day during the month's third week, then decreasing during its final week. An average number of shallow (<5 km) microearthquakes was recorded in the summit region and along the rift zones. Regional earthquakes were concentrated beneath the summit region and SE flank of Kīlauea. Nineteen located events had magnitudes of 2.5-4.0, with depths between 1 and 40 km. The largest earthquake (M 4) occurred 9 km beneath Kīlauea's S flank at 2311 on 25 November.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


December 1989 (SEAN 14:12) Citation IconCite this Report

Two ocean entries remain active; littoral explosions

Throughout December, lava from Kupaianaha pond continued to flow into the ocean . . . (figure 64). Most of the lava (75-95%) entered the water at the Poupou entry, the rest at the October entry on the Kailiili delta, now designated the W Kailiili entry (figure 65). The output at W Kailiili had diminished to a trickle by the end of December.

The Poupou lava tube branched near the coastline and, during most of the month, terminated in two streams of lava, 25-50 m apart at the waterline. Intermittent littoral explosions added spatter and limu to the large 2-3-m littoral cone atop the sea cliff. Two smaller cones formed in early December ~20 m to the E. They were nearly buried at mid-month by a surface flow that emerged from the tube near the ocean and cascaded over the sea cliff to form a 30 x 10 m bench. This flow stagnated within a few days. As the surface flow emerged, an inflated area ~3 m high by 15-20 m in diameter formed behind the large cone.

Breakouts from the lava tube system at 550-480 m elevation (1,850-1,600 ft) produced small pahoehoe flows that encroached on the kipukas along the W flow margin. At the 180 m (600 ft) level, breakouts fed small flows that terminated 300-400 m upslope of the Royal Gardens kipuka through the 18th. Surface breakouts in Royal Gardens were first reported on 11 December. On 6 December, a thin flow encroached on the S half of the Wahaula Heiau (temple) grounds. One lobe of the flow stagnated ~10 m N of the ruins, but most lava flowed farther E and cascaded over the sea cliff onto the new black sand beach below. Activity of the Wahaula flow ceased after 8 December.

The level of Kupaianaha lava pond, which had dropped to ~30 m below the rim in November, remained low and stable in December. Glowing vents at the bottom of Pu`u `O`o were reported on the 3rd and 11th, but no active lava was present.

Low-level tremor continued . . . near Pu`u `O`o and Kupaianaha. Above the background of continuous tremor, high-frequency microshocks associated with minor crustal fracturing around Kupaianaha were detected by the Kalalua seismometer, ~1 km away. The number of shallow (<5 km) microearthquakes was about average in the summit region and the East rift zone. Intermediate-depth (5-15 km) long-period events continued, reaching several hundred/day. A widely felt earthquake (preliminary M 5.1) struck the S flank of Kīlauea at 2313 on 27 December at 9 km depth.

Information Contacts: C. Heliker and R. Koyanagi, HVO.


January 1990 (BGVN 15:01) Citation IconCite this Report

Lava production stops for three days but resumes with more vigor; seismicity suggests E Rift crustal adjustment

The eruption . . . continued in January. Tube-fed lava flowed into the sea at one active entry and surface breakouts occurred upslope. The pond level remained ~32 m below Kupaianaha's N rim throughout the month. Glowing vents in the talus pile on the crater floor of Pu`u `O`o . . . were reported on the 7th, the only day during the month when weather conditions allowed observations.

On 12 January, a 50-100-m inflated area formed over the lava tube at the 575 m (1,900 ft) elevation. The bulge ruptured the next morning and produced aa lava that flowed SE across Kupaianaha's lava field (figure 66). By the 14th, the flow had formed a tube and had a pahoehoe front. It entered the forest on 17 January, moving between the 1977 aa flow and the December 1986 Kupaianaha flow (which destroyed 17 homes in and near Kalapana Gardens). The new flow, ~100-150 m wide, was advancing slowly near the 230 m (750 ft) elevation by the end of the month.

Figure (see Caption) Figure 66. Lava flows produced by Kīlauea's Kupaianaha vent, July 1986-March 1990. The dotted line indicates the active lava tube system, dashed lines are flows active before the eruption's 19 March hiatus, and arrows show flow fronts active in late March. Courtesy of C. Heliker.

Minor surface breakouts at 480-360 m (1,600-1,200 ft) elevation fed small hummocky pahoehoe flows along the W margin of the flow field. A long-lived surface breakout from the main tube at the 180 m (600 ft) elevation (active since late October) sent flows W into Royal Gardens, destroying a house (just below Orchid St.). Surface flows on the coastal plain were limited to the area immediately inland of the Poupou entry . . . , where moderate littoral explosions hurled spatter 10-15 m into the air and built a 2-3-m littoral cone.

Eruption tremor continued at low levels . . . near Pu`u `O`o and Kupaianaha. Tremor of relatively steady amplitude was punctuated by intermittent high-frequency bursts of seismic energy related to crustal adjustments near both the Kalalua (KLC, ~1 km from Kupaianaha) and Steam Cracks (STC, a few kilometers from Pu'u 0'o) seismometers. The most significant of these were two strong 15-minute avalanches registered on the STC instrument at 0240 on 18 January and at 1305 on 21 January. Shallow microearthquake activity in the East rift zone and at the summit was average throughout the month. The daily number of intermediate-depth (5-15 km) long-period events was erratic, with > 100/day occurring 12-14 and 16-18 January. A gradual increase from levels of tens/day to approaching 100/day began 27 January.

Addendum: The first hiatus . . . since April 1988 occurred 7-9 February [but see 15:2]. Kupaianaha's magma supply decreased on the 6th and the flow that had formed 13 January stagnated. By the next day, tremor had generally declined, all flows had stopped, and only small pahoehoe lobes were active around margins of crusted lava in Kupaianaha. Activity resumed late on the 9th, with strong night glow from Pu`u `O`o and a slight increase in tremor. By the next day, lava had returned to Pu`u `O`o and Kupaianaha, and had reoccupied the tube system, with several surface breakouts forming vigorous pahoehoe flows.

Information Contacts: C. Heliker and P. Okubo, HVO.


February 1990 (BGVN 15:02) Citation IconCite this Report

Eruption stops, then resumes with vigorous surface activity; two new ocean entries

An eruption hiatus [see also Addendum to 15:01] began on 5 February at about 2000, when . . . tremor near Kupaianaha lava pond decreased to about half its previous level. A peak in long-period caldera seismicity of almost 200 events/day had been recorded on 4 February, but the number of these events had fallen to < 20/day by the 7th. By 6 February, the terminus of the 13 January 1990 flow (figure 66) was stagnant, with only minor activity upslope. A rockfall near the ocean entry was recorded . . . at 1319 on 6 February, and background tremor in that area has remained low since then. By the 7th, only 10-20% of the normal lava output at the Poupou ocean entry was flowing into the sea. On the 8th and 9th, only small pahoehoe lobes were active around crusted lava in Kupaianaha lava pond and the Poupou ocean entry was generally stagnant.

Renewed activity was signaled by a sharp increase in summit microearthquakes on 9 February at 0900-1000 that continued for 8 hours, with >150 events registered on the Kīlauea caldera station (NPT). From 1400 to 1500 the number of earthquakes in the upper and middle East rift zone rose significantly, remaining high until seismicity decreased to moderate levels at 2200. Strong glow from Pu`u `O`o was observed that night, and by the next morning, vigorous surface activity had resumed. Active lava had returned to Pu`u `O`o, the level of Kupaianaha had risen to 20 m below the rim, and lava had reoccupied the tube system as far as 560 m (1,850 ft) elevation. A surface lava breakout at 590 m (1,950 ft) elevation fed a flow that contained ~1/3 of the lava output from Kupaianaha pond. Lava flowed into the Royal Gardens subdivision (along Queen St.), destroying two houses and narrowly missing several others. By the end of the month, its terminus had stagnated, but small breakouts continued above the fault scarp at ~180 m (600 ft) elevation. Another major surface flow emerged from the tube at the 560 m elevation and split into three lobes. The main (Quarry) lobe flowed along the E side of of the 1988 Quarry flow (figure 66), entered the ocean on the 20th at 2340, and built a 500 x 100 m bench by the end of the month. The second (Roberts) entered the ocean on the 23rd at 0500, ~600 m SW of the main lobe's entry, building a small bench. To the E, the third, low-volume lobe (Keone) flowed through grassland, and by the end of the month was < 1 km from houses and a highway near the town of Kalapana. All lobes remained active by the end of February.

Information Contacts: C. Heliker and P. Okubo, HVO.


March 1990 (BGVN 15:03) Citation IconCite this Report

Eruption stops briefly then resumes after seismic swarm; lava destroys house

Lava flows . . . remained active during the first half of March. The main (Quarry) and low-volume (Roberts) flows continued to enter the ocean, while a third (Keone) flow advanced slowly to within 600 m of a highway at 30 m elevation (figure 66). Activity was periodically observed at Pu`u `O`o. Crusted lava in Kupaianaha pond averaged 30 m below the rim and only overturned a few times/day, in contrast to vigorous past activity. On the 19th, the eruption stopped and the lava pond roofed over. Small collapse pits were found in the lava pond's crust the next day. Only residual lava from the Quarry and Roberts lava tubes drained into the ocean on the 21st.

Activity resumed on the night of the 21st, with glow reported from the East rift zone. By the next day, active lava was visible in Pu`u `O`o, had risen to 20 m below the rim at Kupaianaha, and had reoccupied the tube system to 550 m elevation. Surface lava breakouts at 550 and 600 m elevation fed two flows. Lava followed the course of the January 1990 flow between the December 1986 and 1977 aa flows, and by the end of the month had reached 200 m elevation. Lava also followed the course of the Keone flow, to within 500 m of the intersection of highways 130 and 137. Kupaianaha pond remained active through 23 March when it again began to roof over ~30 m below the rim, and by the 26th, only small pahoehoe lobes were periodically active around the pond's margins.

Seismic signals . . . marked the eruption's changes. From early to mid-March, sporadic gas pistoning was recorded, manifested as background volcanic tremor decreasing to an essentially quiet state for several minutes, generally ending with a sharp burst of energy followed by continued background tremor. This activity subsided after 17 March, succeeded by a marked increase in tremor and, on the afternoon of 18 March, brief summit deflation.

At Kīlauea's summit, swarms of long-period tremor events occurred from late 16 March through midday 18 March and from the evening of 19 March through the early morning of the 21st (figure 67). A swarm of short-period microearthquakes began later that morning and continued until early 22 March. Five hours after the onset of the summit swarm, and several hours before eruptive activity resumed, a sudden increase in earthquakes occurred in the upper East rift zone between the summit and the active craters. The hypocenters were in two areas: near Makaopuhi (roughly midway between the summit caldera rim and Kupaianaha) and Pauahi (~5 km uprift from Makaopuhi). The swarm continued until the morning of 25 March.

Figure (see Caption) Figure 67. Preliminary locations of earthquakes in the Hawaii Island region, including Kīlauea and Lōʻihi, 1-26 March 1990. Courtesy of R. Koyanagi.

After lava returned to Kupaianaha on 22 March, variations in seismicity became less obvious. Tremor near Pu`u `O`o increased gradually and was relatively steady from the 24th until the end of the month.

Addendum: Eruptive activity declined on 5 April [see also 15:4], but had resumed by the night of the 6th. Lava entered Kalapana Gardens subdivision on 3 April, and within three weeks had destroyed a dozen houses.

Information Contacts: C. Heliker, P. Okubo, and R. Koyanagi, HVO; AP.


April 1990 (BGVN 15:04) Citation IconCite this Report

E Rift lava flows destroy dozens of homes

. . . lava production continued from Kupaianaha vent, feeding flows that overran dozens of houses in a community near the coast. Lava production halted briefly in early April and early May but promptly resumed each time, and activity remained vigorous in mid-May. Shallow tremor . . . continued at a low level.

Lava that had advanced to just above [Hwy 130] by the end of March crossed the highway on 2 April (100 m E of its intersection with Highway 137). A small N-facing fault scarp (the Hakuma horst) blocked the flow's direct path to the sea, turning it ESE toward Kalapana Gardens subdivision, in a low-lying area below the scarp (figure 68). Lava entered the subdivision's W edge on 3 April, destroying two houses the next morning, but lava production stopped late that day. Tremor amplitude near Kupaianaha decreased appreciably 4-6 April while lava production was stopped. As in previous instances, USGS geologists believe that the pause in lava production was due to blockage in the upper East rift zone. The summit responded with a sequence of deflation and shallow tremor followed by inflation and an increased number of shallow microearthquakes. Eruptive activity resumed during the night of 6-7 April. By the time of an early morning overflight, lava had reoccupied the tube system along the E side of the flow field, and numerous breakouts were occurring along much of its length, between ~600 and 120 m (1,950 and 400 ft) altitude. The lava formed three flows, the largest advancing along roughly the same path as previous flows toward Hwy 130.

Figure (see Caption) Figure 68. Kalapana Gardens and the E side of Royal Gardens subdivision on Kīlauea's S flank, April 1990.

The primary flow moved down the main flow field to ~120 m (400 ft) elevation, then turned E, following approximately the same path as the previous Kalapana Gardens flow. The lava advanced slowly, but by 13 April two separate lobes had crossed Highway 130, one on top of the early April flow along the Hakuma horst, the other farther E. The W lobe entered Kalapana Gardens on 17 April. The two lobes merged by the 20th. Two homes just outside Kalapana Gardens were destroyed on 13 and 15 April, and destruction of houses within the subdivision began on 18 April. By the end of the month, the April flows had overrun nearly 4 dozen houses, had cut off the main access road into the subdivision (Highway 137) and were moving along both Highway 137 and the fault scarp below it. By 3 May, the flows reached Kalapana village, an older settlement to the E. As of 5 May, the Hawaii County Civil Defense Agency reported that the eruption had destroyed 63 houses since 4 April.

A smaller flow, originating from the breakout at ~600 m elevation, moved diagonally toward the E side of the lava field . . . into the "woodchip area," then onto the December 1986 flow. Lava in this area advanced slowly through April, reaching 30 m (100 ft.) elevation by the end of the month. Another small flow originated from a breakout high in the tube system at slightly above 600 m (2,050 ft) elevation, cutting across lava from Kupaianaha vent and advancing W onto earlier aa lava from Pu`u `O`o . . . . This flow entered the extreme NE corner of Royal Gardens subdivision by mid-April, but moved down the E edge of the subdivision without threatening any homes, reaching ~250 m (800 ft) elevation by the end of the month.

When lava production halted briefly on 7 May [see also 15:3], two lobes had reached the water. One partially filled a spring-fed brackish water inlet behind the fault scarp, and the second (W) lobe reached the open ocean (at Harry K. Brown Park) E of Kalapana Gardens. Lava production resumed during the evening of 9 May. Onset of the renewed activity was gradual, but the eruption was again vigorous by the 11th. On 14 May, lava traveling over roughly the same route as previous flows had reached 120 m (400 ft) elevation and was again turning E toward Kalapana Gardens.

Kupaianaha vent . . . generally remained covered with frozen lava at ~18 m below the rim throughout April, having effectively become part of the tube system. After lava production resumed on 9 May, lava in the pond was at times again actively overturning. Lava also returned to the bottom of Pu`u `O`o after 9 May, but dimensions were difficult to estimate at the base of the 180-m-deep crater.

April seismicity generally conformed to the pattern of crustal earthquakes that has persisted beneath Kīlauea and the SE part of Mauna Loa. Small (M <2.0) shallow (<5 km) events were mainly centered beneath Kīlauea's summit and East rift zone. Of the hundreds of earthquakes processed in April, eight ranged from magnitude 3.0 to 4.4.

Information Contacts: C. Heliker, P. Okubo, and R. Koyanagi, HVO; AP.


May 1990 (BGVN 15:05) Citation IconCite this Report

E Rift eruption pauses briefly, then lava destroys more homes

Kīlauea's . . . eruption continued through mid-June, and lava destroyed most of the remaining buildings in a coastal subdivision. Substantial variations in seismic activity were associated with changes in eruptive behavior.

Lava flows remained active in early May, while summit instruments registered a gradual increase in volcanic tremor from the beginning of May through the 5th. About two days after tremor began to build, more rapid tremor increases were detected . . . near Pu`u `O`o and Kupaianaha vents. A sharp jump in summit tremor amplitude during the afternoon of 6 May accompanied rapid summit deflation. Lava production halted the next day, and summit tremor level remained high until the eruption resumed on 9 May. Tremor amplitude then declined rapidly accompanied by a sharp increase in summit microearthquake counts, which continued at moderate levels for the next 4 days, then decreased later in the month.

Lava from the renewed activity . . . crossed the coast highway during the night of 17-18 May, entered Kalapana Gardens, and destroyed a house there the next day. The May flow was forced E by April lava, which formed a barrier to its south (figure 69). Homes along the N side of the April flow were overrun, and by the time lava had moved beyond the April flow's E margin, most of the remaining buildings in Kalapana Gardens had been destroyed. Lava did not reach the ocean in May, instead filling a large low-lying area E of the April flow (NW of Harry K. Brown Park).

Figure (see Caption) Figure 69. The Kalapana area on Kīlauea's S flank, May 1990. April flows are outlined by a heavy line; diagonal shading marks May lava. Courtesy of Will Bussard.

On 28 May, instruments began to record sharp summit deflation, a precursor of previous pauses in the eruption, followed after a few hours by increased summit tremor (which had been building gradually since 9 May) and earthquakes. The next day, only sporadic activity was evident from coastal lava flows. Little eruptive activity was apparent during the day on the 30th, but summit earthquakes had begun to decrease by 1400, and at around 1800 lava began to emerge from the main tube at roughly 600 m (1,950 ft.) elevation. A small breakout was seen at 60 m elevation (200 ft.) at 1950, and by the next morning at 0700, additional significant breakouts were occurring below Hwy 130 in Kalapana Gardens. Lava arrived at the coast, probably on 2 June, but barely reached the open ocean, spreading along the beach in an area of shallow tide pools. Active lava ponds were observed in both Kupaianaha and Pu`u `O`o after the resumption of eruptive activity, but most of the pond in Kupaianaha remained crusted over.

Continued lava flows overran several more homes in the NW part of Kalapana Gardens. As of 10 June, only two homes were still standing in the subdivision below the highway while seven remained unscathed above the highway. All but three houses had been destroyed in the older coastal community of Kalapana. All of these homes were at risk from the continuing activity.

Information Contacts: C. Heliker and P. Okubo, HVO.


June 1990 (BGVN 15:06) Citation IconCite this Report

Vigorous East Rift lava production resumes after brief pause; lava pond recedes

. . . lava production continued through June . . ., feeding flows that overran eight homes, a store, and a church in the town of Kalapana. Lava production halted briefly in mid-June but promptly resumed, and activity remained vigorous through early July.

Activity during the first half of June was characterized by numerous large lava breakouts from the tube system. Lava reached the coast early in the month, probably on 2 June. By 18 June, lava flow activity in Kalapana had slowed and little movement was visible in skylights upslope. No surface activity was visible the next day, but the eruption resumed early 20 June. Large breakouts of pahoehoe lava were seen at ~620 m (2,050 ft) elevation at 0045, and at 560 m (1,850 ft) altitude 2 hours later. Lava progressively reoccupied the tube system along the E side of the flow field, and breakouts were soon occurring below 60 m (200 ft) elevation. Within 5 hours, > 500 m of the tube system had been reoccupied, to < 15 m (40 ft) asl, below the coast highway. By 22 June, two large flows were active in Kalapana. One covered older flows, while a second broke out of the May tube on the N edge of lower Kalapana Gardens, covering much of the remaining area between Hwy 130 and previous Kalapana flows. Other smaller flows in the Kalapana area continued to cover older flows and posed no threat to homes or property.

By early July, lava had advanced to within 600 m of the ocean in the May tube, but no breakouts had reached the ocean since activity halted in mid-June. A new beach had formed in front of the June entry, composed of old sand and blocks plus new material from the June flow. At higher elevations, a large, viscous pahoehoe flow advanced on top of earlier flows E of the main flow field (through the "Woodchip area"). By the first week in July, this flow was characterized by more fluid and sometimes slabby pahoehoe. For the first time, lava crossed the 1986 Kalapana flow and threatened homes in upper Kalapana Gardens, above Hwy 130. However, the flow bypassed all of the homes, crossed Hwy 130 on 10 July, and began to wrap around the N edge of earlier Kalapana flows. Numerous breakouts occurred along this flow and from the main Kalapana tube system. On the main flow field, breakouts between 620 m (2,050 ft) and 400 m (1,300 ft) elevation remained active, and on 2 July large channelized pahoehoe flows were seen on the E margin of the 1990 flows, near 480 m (1,600 ft) altitude.

The lava pond in Kupaianaha vent, source of the recent East-rift flows, has been receding throughout 1990. The pond has rarely been active, and has often been crusted over by frozen lava. A 2 July overflight revealed that the top of pond was ~40 m below the crater rim, occupying an inner pit only ~5 m in diameter. A series of roughly concentric ledges created a series of nested craters within Kupaianaha. During the same overflight, a lava pond with active spattering was visible in the bottom of Pu`u `O`o crater, 3 km uprift.

Information Contacts: T. Moulds, HVO.


July 1990 (BGVN 15:07) Citation IconCite this Report

Lava flow destroys two homes, re-enters ocean

Vigorous . . . lava production continued through July. During the first week of the month, a lava flow from the "Woodchip area" on the E side of the flow field began to threaten homes in Kalapana, moving from the 100 m (300 ft) elevation to Hwy 130, a distance of ~1.5 km, in 3 days. On 6 July, this flow was threatening homes in upper Kalapana Gardens, but bypassed them, covering a road intersection at 0300 the following morning. By 9 July the flow had crossed Hwy 130 and was wrapping around the N side of earlier Kalapana Gardens flows (figure 70). The "Woodchip" tube sustained numerous breakouts during the first half of July, from the 400 m (1,300 ft) elevation down to the coastal flats, with active breakouts behind the front at elevations of 250, 180, and 140 m (800, 600, and 450 ft).

Figure (see Caption) Figure 70. Kīlauea's recent flows (outlined by a heavy line) in the Kalapana area, 2 August 1990. Contour interval is 20 feet, about 7 meters. Base map is the USGS Kalapana 7.5-minute topographic sheet (1981).

During the week of 10-16 July, the "Woodchip" flow began to advance onto the 1977 aa flow, which had been an effective barrier to eastward advance of Kupaianaha lavas above 40 m (130 ft) elevation. Lava moved E, just below Highway 130, covering most of the aa flow, and by 16 July had reached the E edge of the Kalapana flow field, threatening homes by Hwy 130. The active front extended > 500 m from this area to Harry K. Brown Park.

By mid-July, upslope breakouts on the "Woodchip" tube had decreased. On the main flow field, active flows were observed between 400 and 600 m (1,300 - 2,000 ft) elevation and there were some breakouts noted on the "Woodchip" tube by 360 m (1,200 ft) elevation. Early in the week of 17-23 July, the flow continued to wrap around the E margin of the flow field in Kalapana, overran two more homes near Hwy 130, and buried Harry K. Brown Park as well as an adjacent playground. On the morning of 21 July lava re-entered the ocean. As the new entry began to establish itself, eastward advance of the "Woodchip" flow slowed and activity localized around Hwy 137. By 23 July, flows were within a kilometer of Kaimu beach.

During the week of 24-30 July the ocean entry in Kalapana spread E toward Kaimu Bay. Lava entered Kaimu Bay on 29 July, moving along its W edge. By the 30th lava was entering the ocean at several points. Flows above this active ocean entry advanced E, coming within 400 m of homes and businesses near Kaimu.

The original Kalapana tube system . . . continued to feed breakouts in Kalapana during the week of 3-9 July. Most remained on top of earlier flows. On 14 July a breakout from the May tube system reached the N-facing fault scarp between highways 130 and 137, most of which had been buried by previous flows. The new flow easily crossed over the fault, which had acted as a barrier prior to burial, and continued S. This flow was still active at the end of July but had not yet crossed Hwy 137. During its advance the "Woodchip" flow buried two lobes that broke out of the May tube system. Activity upslope decreased the week of 24-30 July with no significant breakouts noted along the "Woodchip" or Kalapana tube systems; some breakouts from the May tube showed minor activity throughout the last week in July.

During a brief pause early in the week of 31 July-6 August, all surface activity slowed to a halt, with the exception of the ocean entries by Kaimu. By the 2nd, half of Kaimu beach was covered by lava. That day, the eruption resumed normal activity. Lava reoccupied the "Woodchip" tube system down to Kalapana. Initial breakouts from the tube were sticky pahoehoe. As the day progressed, breakouts became more fluid and began to move down the tube system, toward Kaimu. By 6 August numerous small breakouts were observed in Kalapana. Ocean entries were confined to the beach in front of the Harry K. Brown Park.

Kupaianaha vent remained covered with frozen lava in July, although the level of lava in the crater may have risen slightly since June. A vigorously degassing lava pond was active throughout the month in Pu`u `O`o crater. A portion of one crater wall collapsed into Pu`u `O`o on 4 August . . . .

Seismic activity . . . continued through July in the pattern established during the preceding months. The level of activity was low, with only minor fluctuations in the level of background volcanic tremor . . . . Microearthquakes in the East rift zone and at the summit continued at moderate rates, with substantial fluctuation of their average levels. Summit activity was punctuated on two occasions, apparently correlating with changes in ground tilt at the summit. From the evening of 15 July through the morning of 16 July, a rather abrupt change in measured tilt rate was observed, to ~1 µrad/day. From 0900 to 1000 on 16 July a sharp jump in summit microearthquakes was registered after a tilt increase of ~1 µrad. This activity quickly dropped back to a lower level. On 30 July a flurry of long-period earthquakes was registered beneath the summit, subsiding after 2200, after which both a large increase in tremor amplitude and a sharp drop in ground tilt were recorded. This series of instrumentally recorded events can be generally associated with the onset of the pause in eruptive activity registered during the last week of July [see also 15:8].

Information Contacts: T. Moulds and P. Okubo, HVO.


August 1990 (BGVN 15:08) Citation IconCite this Report

Continued East Rift lava production; two houses destroyed; three brief eruptive pauses

Kīlauea's . . . eruption continued through August. Lava from Kupaianaha vent (figure 71) advanced through tubes and entered the ocean along a broad front. Lava breakouts occurred from many parts of the tube system. The resulting flows destroyed one house in Kalapana (and started brush fires that burned another) and built small shield-like features on the upper part of the main tube near the base of Kupaianaha's shield. Three brief pauses in activity were noted, bringing the year's total to nine.

Figure (see Caption) Figure 71. Lava produced by Kīlauea's East rift zone eruption, 1983-90. Arrows indicate paths of recent flows, and crosses mark inflated areas at the base of the Kupaianaha shield. The locations of seismometers STC and KLC are indicated, as is the epicenter of the 8 August earthquake.

Eruptive pause, 30 July-1 August. Most surface activity slowed to a halt on 30 July, although lava flows at the coast showed little evidence of the pause, and by 2 August half of Kaimu beach (figure 70) was covered by lava. The most direct seismic expression of previous eruptive pauses had been the very low amplitude of volcanic tremor registered on seismometers near the vents. Tremor amplitude on the station nearest Kupaianaha (KLC) remained consistently low, but dropped near Pu`u `O`o (at station STC) by about a factor of two to a very quiet background level at about 1200 on 1 August. Background noise at STC remained low for ~12 hours, allowing detection of frequent small bursts of seismicity. Seismologists believed that these might be interpreted as small landslides or other crustal adjustments around Pu`u `O`o while local flow rates were diminished. During the same period of low seismicity on the East rift zone, from about 1200 to 2300 on 1 August, summit volcanic tremor was at high amplitude.

Eruption resumes, 2-8 August. The resumption of eruptive activity on 2 August was marked by a sharp increase in microearthquake activity beneath the summit that began as tremor background suddenly decreased and summit ground tilt sharply increased. The peak of the summit microearthquake swarm was recorded between 1 August at 2300 and 2 August at 0200. Tremor amplitude recorded near Pu`u `O`o gradually increased to levels registered during earlier periods of surface activity. Lava reoccupied the "Woodchip" tube system down to Kalapana. Initial sticky pahoehoe breakouts became more fluid later in the day and began to move down the tube system toward Kaimu. Numerous small breakouts observed in the Kalapana area by 6 August began to cover more land on the perimeter of the flow field. A surface breakout on the 7th advanced W of Kaimu Bay and entered the ocean. The next day, a large breakout below the coast highway quickly began to fill the area between the highway and inflated flows below it, threatening the road.

Eruptive pause, 8-9 August. Another eruptive pause began late 8 August. At the summit, a sharp decrease in ground tilt and a sharp increase in background volcanic tremor were preceded by a vigorous burst of long-period seismicity that began on 8 August at about 2100 and stopped abruptly at about 0400 the next morning. A M 4.9 earthquake was recorded in the East rift zone on 8 August at 1606 (figure 71). Tremor amplitudes registered near Kupaianaha and Pu`u `O`o remained unchanged. By 10 August, activity behind the active ocean entries had diminished, and breakouts along flow margins were viscous and of low volume.

Eruption resumes briefly, 10-12 August. Microearth- quake activity beneath the summit was slightly elevationated during the 24 hours beginning at 0900 on 10 August and a sharp increase in summit tilt was measured the same morning, probably reflecting the resumption of magma and lava movement. The eruption resumed on the 10th, and the next day a large breakout was noted from the "Woodchip" tube at 35 m (120 ft) elevation in the upper part of Kalapana, above some houses that had been spared by earlier flows. By afternoon, lava was 100 m from the nearest home, but the flow front advanced only another 50 m before stagnating on 13 August. That day (13th) several other breakouts were noted in Kalapana along the "Woodchip" tube system.

Third eruptive pause, 12-14 August, and subsequent seismicity. On the morning of 12 August, a sharp drop in summit tilt again coincided with the onset of stronger summit tremor. However, these changes were not preceded by significantly increased long-period seismicity beneath the summit. Tremor amplitudes near Pu`u `O`o decreased during the evening of 13 August, and through much of the next day the reduction in background tremor again made it possible to observe very small discrete events. Summit tilt reversed as inflation resumed during the afternoon of 14 August and tremor amplitude dropped. At about 1500, summit microearthquake activity increased, remaining elevationated through 18 August. Tremor amplitude near Pu`u `O`o gradually increased and by the morning of the 16th had returned to levels comparable to those during obvious surface activity. For much of the rest of the month, summit and East rift zone seismicity fluctuated around low average levels, but microearthquake activity approximately doubled 25-31 August.

Renewed lava production from 15 August. A significant decrease in the volume of lava entering the ocean was noted on 15 August, perhaps a delayed response to the pause. However, lava was attempting to reoccupy the tube system upslope, and a large aa/pahoehoe flow seen at 90 m (300 ft) elevation on 15 August destroyed one of the few houses remaining in Kalapana on the 20th. A large channelized aa flow broke out of the primary Kalapana tube system in the main flow field about 15 August. By the 21st, this flow had reached 50 m (160 ft) elevation but had not turned toward Kalapana. A large surface flow broke out of the "Woodchip" tube in Kalapana on 16 August, and by the 18th had crossed Hwy 130, cutting off access to a home and ranch above the highway.

Activity in Kalapana slowed 21-27 August. Surface flows generally remained on top of earlier lava, with some small breakouts burning vegetation on the edge of the flow field near the end of Hwy 130. Lava continued to enter the ocean along a broad front (between Right Point and the Harry K. Brown Park area). By the 27th, no surface activity was visible in the Kalapana area and only the ocean entry at Right Point remained active. On 28 August, a fluid sheet flow broke out of the "Woodchip" tube (just below Hwy 130) and advanced toward the fault scarp bordering Kalapana Gardens. Five homes isolated by previous flows were between the scarp and the ocean. The flow destroyed one home on the 30th and set off brush fires that burned another; the fires came within a couple of meters of the remaining three homes before going out. Another flow that broke out on 29 August followed the E edge of the former Kalapana Gardens subdivision. By 2 September, the two flows had merged, but were only producing small ooze-outs. The volume of lava entering the ocean then appeared to increase, and by 3 September several entries were active (between Right Point and the former canoe landing).

Near-vent lava breakouts. Activity increased at higher elevations during August. Several fluid pahoehoe flows were noted at the base of Kupaianaha shield on 16 August. The flows continued along the edge of the Kupaianaha flow field, reaching 500 m (1,700 ft) elevation by the 25th. Breakouts from an inflated area at the shield's base were observed the same day. By 2 September, four large inflated areas (marked x on figure 71) had developed over the tube that transports lava from Kupaianaha to 550-580 m (1,800-1,900 ft) elevation. Numerous shelly pahoehoe flows broke out from the inflated areas until they began to resemble small shields. The lava pond at Kupaianaha remained sealed over, but lava was noted in a collapse pit 50-60 m SE of the pond.

Lava ponds in Pu`u `O`o. Three kilometers uprift, two active lava ponds were noted ~75 m below the rim of Pu`u `O`o crater on 22 August. Lava from the E pond was seen overflowing and draining into the W pond on the 28th, producing a large lava river across the crater floor. Throughout the week, observers noted similar activity in the reverse direction, with lava from the W pond overflowing and feeding the E pond. Since 26 August, frequent gas-piston signatures have been recorded by the seismometer nearest Pu`u `O`o, with quiet periods of up to 30 minutes terminated by a strong seismic burst.

Information Contacts: T. Moulds and P. Okubo, HVO.


September 1990 (BGVN 15:09) Citation IconCite this Report

Continued east rift lava production; lava extending hundreds of meters into ocean

"The . . . eruption continued through September, feeding ocean entries in the Kalapana area (figure 72). Lava entered the ocean along a 1-km-wide front, extending from the shoreline a couple of hundred meters into the ocean. The ocean entries dominated activity in Kalapana until 24 September. Surface activity in Kalapana was confined to small breakouts that started small brushfires, burning one structure on the 15th. A large breakout was noted in the middle of the Kalapana flow field on the 17th.

Figure (see Caption) Figure 72. Kīlauea's recent flows as of 31 October 1990 (outlined by a heavy line) in the Kalapana area. Contour interval is 20 feet (~7 m). Base map is the USGS Kalapana 7.5-minute topographic sheet (1981).

"On 24 September, a new breakout was noted on the 'Woodchip' tube, nearly 500 m W of Kaimu Bay. At the same time, activity at the ocean entries and other surface flows in the Kalapana area declined. The new breakout entered Kaimu Bay on 25 September. Within four days Kaimu Bay was filled, and new ocean entries were established 200 m beyond the old shoreline. The Kaimu flow continued to advance E and began to threaten homes in the Kalapana Shores subdivision. By the end of the month, lava flows had cut off access to all homes in the Kaimu area, as well as power and water to many.

"Pu`u `O`o remained active in the base of its crater; two active lava ponds were noted on the crater floor. Kupaianaha vent remained crusted over through September. The inflated areas at the base of Kupaianaha shield continued to produce active lava flows, which generally traveled no farther than 30 m from their breakout points. By the end of the month, no active lava flows were noted on these small shields."

The change in activity on 24 September coincided with a sequence of events registered beneath Kīlauea's summit, associated with earlier pauses in surface lava flow activity: 1) a flurry of intermediate-depth (5-13 km) long-period earthquakes; 2) a significant increase in the amplitude of continuous shallow volcanic tremor coincident with a sharp decrease in ground tilt; and 3) sustained higher tremor amplitude as the ground tilt remained low.

"The September sequence began with a gradual buildup of the long-period activity from the early morning of 23 September. This activity peaked after ~12 hours, and the hourly counts of long-period events dropped suddenly with the decrease in ground tilt registered at approximately 1400. Summit volcanic tremor amplitude increased and remained elevationated through the next 2½ days while earthquake counts were very low. During this time, while flow activity at lower elevations in Kalapana and Kaimu did not subside, a decrease in flow activity at higher elevations nearer the Kupaianaha vent was noted and some gas-piston event signatures were registered . . . near Pu`u `O`o. The summit suddenly began to reinflate at about 0000 on 26 September, and the background volcanic tremor amplitude decreased following a 15-minute burst of shallow tremor at about 0100 on the 26th. A small, but clearly indentifiable increase in summit microearthquakes followed and microearthquake activity recovered to higher, average levels. During this 'instrumental' eruption pause it was possible to observe more event-like tremor behavior at the summit, and count the discrete events. While the registered counts possibly reflect only a lower background tremor level allowing individual events to be distinguished, the shallow tremor activity during this most recent pause did differ from that observed during earlier pauses."

Information Contacts: T. Moulds and P. Okubo, HVO.


October 1990 (BGVN 15:10) Citation IconCite this Report

Lava continues to flow into sea; more homes destroyed

Lava . . . moved down the S flank and continued to enter the ocean during October (figure 73). At the beginning of the month, lava from a persistent tube system along the E side of the flow field formed a coastal front 750 m wide (in the Kaimu area; figure 72). The E margin of the flow advanced along the coast in front of the Kalapana Shores subdivision, which had been evacuated by the beginning of October. Lava breakouts destroyed two homes in the subdivision on 7 October. By mid-October, lava had nearly reached the W edge of the 1750 flow, > 500 m E of the former Kaimu Bay, and ocean entries were active along a front 1 km wide. A lava breakout from the flow's main ("Woodchip") tube at ~40 m elevation destroyed a home in the upper Kalapana Gardens subdivision on 15 October. A low to moderate number of intermediate-depth long-period earthquakes were evident from the beginning of the month. These peaked 6-7 October when almost 100 were counted, then subsided about 10 October.

Figure (see Caption) Figure 73. Lava produced by Kīlauea's East rift zone eruption, 1983-90. Arrows indicate paths of recent flows, with the "Woodchip" flow on the E side of the lava field, the "Royal Gardens" flow on the W side. Crosses at the coast mark new lava entries into the sea in the Wahaula area.

Flows that emerged from the inflated area at the base of Kupaianaha's shield in early October moved down the W side of the flow field, the most active as channelized aa that reached relatively level terrain near the coast on 12 October. By the 15th, the distal end of the flow was pahoehoe and had advanced to below 30 m elevation. Less-active lobes of the same flow were observed upslope in Royal Gardens subdivision, but did not destroy any of the subdivision's remaining homes. Lava reached the ocean on 20 October along the W side of the flow field (near Kupapau Point) and was moving through newly formed tubes by the 22nd. A large lava breakout on the E side of the flow field destroyed another home in Kalapana Gardens on 19 October, while activity declined at the coast to only two small entries.

On 22 October a flurry of long-period events occurred between 0500 and 0800, averaging ~30/hour. Long-period seismicity increased again at about 2100, accompanied by summit tremor. The number of intermediate-depth long-period earthquakes, which had resumed in mid-October, peaked at about 380 on the 23rd. That day, lava movement viewed through a skylight at ~350 m elevation was slower than it had been in the past several weeks, and a decline in activity at all coastal entries was evident by 24 October. However, a new lobe from the E side of the flow field reached the ocean on the 24th (at Hakuma Point), an entry that remained intermittently active through early November, and lava that had moved through Royal Gardens in mid-October entered the sea 29 October on the W side of the flow field (just E of Wahaula). By 31 October, lava was flowing into the ocean at several points in the Wahaula area along a front 700 m wide, and the flow feeding this entry was moving through tubes upslope. . . . Intermediate-depth long-period seismicity declined from its peak on 23 October to a few tens of events/day at the end of the month, and dropped further in early November.

A lava pond was seen on 31 October in the base of Pu`u `O`o Crater, where a pair of lava ponds had been active in August and September. Lava at Kupaianaha remained deep in the vent and covered by a frozen crust.

Information Contacts: T. Moulds and P. Okubo, HVO.


November 1990 (BGVN 15:11) Citation IconCite this Report

E rift lava continues to flow into sea; earthquake swarm

Lava . . . continued to flow into the ocean through November. Coastal activity was generally most vigorous on the W side of the flow field (near Wahaula) . . . . Lava feeding the W ocean entry was enclosed in tubes at the beginning of the month, but by 5 November, lava had broken out at ~50 m elevation and the flow volumes at the coast had declined. Lava re-entered the sea near Wahaula on 8 November and entries were dispersed along a 700-m front by the 11th. During the following weeks, several breakouts were active behind the flow front, but lava continued to enter the ocean, and at least three of the entries were explosive late in the month.

On the E side of the flow field (figure 74), small amounts of lava entered the ocean (at Hakuma Point), but breakouts from the tube system were frequent at low elevations (in the Kalapana area). On 10 November, lava destroyed a home (at the base of the Hakuma Horst). A second, slow-moving flow advanced to within 30 m of the four remaining houses in upper Kalapana Gardens, but did not reach them. Lava outbreaks overran new land in the Kalapana area in mid and late November, covering parts of the old coast highway and cutting off a temporary access road built over the lava in September, but did not destroy any additional houses.

Figure (see Caption) Figure 74. The extent of flows on the E side of the lava field as of 22 November 1990.

Harmonic tremor near Kupaianaha and Pu`u `O`o vents continued through November, but at low levels. An earthquake swarm centered ~5 km W of the caldera occurred between 11 and 13 November. Activity spread over a 5-km-long region at the E end of the Kaoiki fault zone. Over 200 swarm events with magnitudes of up to 3.3 were located during the 3-day period. Hypocentral depths ranged from very close to the surface to 12 km. HVO's preliminary locations suggest that the deeper earthquakes clustered at the E end of the active zone, with shallower events more concentrated to the W. Activity returned to normal regional levels of ~20-30 events/day by 15 November.

Information Contacts: T. Moulds, P. Okubo, and C. Heliker, HVO.


December 1990 (BGVN 15:12) Citation IconCite this Report

East rift lava continues to enter sea; briefly increased lava lake activity after seismic swarm

Through December 1990, lava from Kupaianaha continued to advance through tube systems on the E and W sides of its 1986-90 flow field. Flows entered the ocean throughout December in a zone ~500 m wide on the W side of the lava field (figure 75). The low-level volcanic tremor registered near Kupaianaha and Pu`u `O`o vents continued without marked variations, and tremor was vigorous near the W ocean entry. Summit seismicity increased in late December and early January and the E-W component of summit tilt showed >20 µrad of inflation since September (figure 76).

Figure (see Caption) Figure 75. Lava produced by Kīlauea's east rift eruption, 1983-90. Arrows indicate lava flow in tubes, and crosses at the coast mark areas where lava was entering the ocean. Courtesy of HVO.
Figure (see Caption) Figure 76. N-S and E-W components of tilt measured by the water-tube tiltmeter at the summit of Kīlauea, and daily number of shallow summit earthquakes, 1 January 1989-7 January 1991. Courtesy of HVO.

Summit seismicity and tilt, associated with increased activity at Pu`u `O`o, suggest that an intrusion occurred in early December. A shallow microearthquake swarm in the summit region began at about 1600 on 4 December and continued until the following midmorning. After the initial swarm events, volcanic tremor increased and was at sustained high levels between 1735 and 1810. Summit tilt data indicated a trend of rapid inflation coincident with increasing amplitude of summit earthquakes and tremor. Shallow seismicity continued, extending over a larger area from the summit roughly 8 km SE to the vicinity of Mauna Ulu. The swarm activated what is believed to be a magma conduit connecting the summit and East rift zone. In the past, this feature had consistently sustained small earthquakes, but the seismicity had been much less intense. Although no changes were apparent in the continuing tremor farther down the East rift zone at Pu`u `O`o and Kupaianaha, lava lake activity increased briefly at Pu`u `O`o. At 1700 on 4 December, lava covered ~¼ of the rubble-filled crater floor. When observed the next day, the entire floor was lava-covered, but by the 6th the lava lake had shrunk to its previous dimensions.

Most of the December lava from Kupaianaha moved through the W tube system to the sea, but small surface breakouts occurred in Royal Gardens subdivision and near the coast. No additional houses were destroyed. On the E side of the lava field, small flows covered another 50 m of Hwy 130 at the beginning of December. A small lava flow entered the sea (near the former Painted Church site) on 15 December and remained intermittently active for a few days, but was stagnant by the 20th. Another lobe of the same breakout moved slowly eastward along the forest line. By 17 December this lobe was 400 m from the nearest house in Kaimu, but stopped before reaching it. In late December, a larger breakout from the E tube system advanced to the Hakuma fault scarp and began to cover new land near the area's two remaining homes. This flow remained active at the end of December, when it was moving both E and W along the scarp on a front > 500 m wide. One of the houses was overrun by lava on 10 January.

On the morning of 25 December, many small summit events began to be recorded. Earthquake counts totaled hundreds daily, with nearly 1,000 on several days (figure 76). During the first week in January, summit microearthquake activity continued, at rates that exceeded 1,000 events/day. Many appeared to have a more harmonic character (dominant frequency ~10 Hz) than typical summit short-period earthquakes. On 2 January, a series of intermediate-depth long-period events occurred at the summit, with most intense activity between 0800 and 1000. A period of similar intense seismicity began on the morning of 7 January, tapering off the next morning.

Information Contacts: T. Moulds, P. Okubo, and C. Heliker, HVO.


January 1991 (BGVN 16:01) Citation IconCite this Report

Continued lava flow into sea; increased summit seismicity

The majority of January lava . . . moved downslope through the W tube system, flowing into the ocean at three main entries along a 300-m front (figure 77). The W entry was very explosive. Lava entering the ocean . . . often interacted explosively with sea water, ejecting substantial quantities of spatter, limu, and Pele's hair onto the old sea cliff, and building a littoral cone 2-3 m high. The lava bench at the W entry did not grow > 10-20 m outward from the shore, but the two E entries built a bench that extended ~40 m . . . . Both E entries deposited a considerable amount of tephra onto the bench, and constructed large littoral cones. The new sea cliffs (built by recent, but not currently active flows) in the area were quite unstable, and pieces of the cliff frequently broke off. Portions of the bench < 10 m wide collapsed into the ocean. Underwater tubes have been observed offshore from all of the entries.

Figure (see Caption) Figure 77. Lava produced by Kīlauea's East rift zone eruption, 1983-91. Arrows indicate lava flow in tubes, and crosses at the coast mark areas where lava was entering the ocean. Courtesy of HVO.

Numerous lava breakouts occurred from the W tube system ~1 km behind the active ocean entries. None of this lava reached the ocean but the flows covered a large part of the flat area near the coast.

On the E side of the flow field, only small lava breakouts were observed in the Kalapana area during January. Most of these occurred at the end of the coast highway, covering more of the road. The lobe that destroyed a house on 10 January then stagnated, and no additional houses have been threatened. In late January, a large flow broke out of the E tube system at higher elevation, burning vegetation on the slopes above Kalapana. It reached 200 m (700 ft) elevation by 28 January, and ~90 m (300 ft) elevation by 6 February.

The summit of Pu`u `O`o cone was 236 m above the pre-eruption surface during a January 1991 survey. Since June 1986, just before activity shifted 3 km downrift to Kupaianaha, erosion and collapse had reduced the summit elevation by 21 m and widened the crater from ~15 m to some 280 m in diameter. A lava pond was active in Pu`u `O`o through January. About half of the crater floor was covered by debris from recent crater wall collapses, while the remainder was occupied by the pond, lava overflows from the pond, and a small apparent skylight in the overflow area.

Continuous volcanic tremor persisted along the East rift zone through January, fluctuating in amplitude near Kupaianaha and Pu`u `O`o, but remaining relatively steady at the station nearest the ocean entries on the W side of the tube system. Summit seismicity was dominated by very numerous shallow harmonic tremor events at depths to 5 km. Their number increased at the end of December, and they became larger (and thus easier to identify) through January. Event counts averaged just under 600/day during 1-21 January, but a rather abrupt increase occurred 19-21 January and the daily average more than quadrupled to >2,700/day since 22 January (figure 78).

Figure (see Caption) Figure 78. Number of earthquakes/day at Kīlauea, 1 October 1990-31 January 1991, subdivided into event types. Tremor rates are shown in number of minutes/day. Note the 4-5 December intrusion earthquake swarm and the striking increase in long-period caldera events in December and January. Courtesy of P. Okubo.

Information Contacts: T. Moulds and P. Okubo, HVO.


February 1991 (BGVN 16:02) Citation IconCite this Report

Lava flows build more new land at coast

Lava . . . moved downslope through tubes and entered the ocean, adding new land on the W side of the lava field, where three main ocean entries were active in February (figure 77). The W entry continued to build a littoral cone on the 1989/90 sea cliff, but rapid erosion prevented new lava from persistently extending farther into the ocean in this area. Collapse of the W entry's small lava bench about 20 February exposed its feeder tube, and lava poured into the ocean in a high-pressure stream, building a new bench. At the central and E entries, new lava was accumulating below two earlier features, the 1989/90 sea cliff and the bench formed between fall 1990 and early 1991. Cumulative new land from these two entries extended ~30 m into the ocean along 125 m of shoreline, with the newest material covering an area ~10 m wide and half the length of the old bench. Pele's hair, spatter, and limu were abundant along the benches and the old sea cliff. Lava broke out from the tube system in several places on both the E and W sides of the flow field, but covered little new land and did not threaten additional homes. A lava pond remained active in Pu`u `O`o crater, which appeared essentially unchanged from the previous month.

Long-period tremor episodes remained frequent through early March, averaging ~2,000/day since mid-February, except for a brief decline 27-28 February to <1,000/day. A swarm of shallow, upper east rift microearthquakes occurred 15-17 February, reaching 129 events on the 17th, ~3x the average daily count, and this activity remained elevationated later in the month.

Information Contacts: T. Moulds and P. Okubo, HVO.


March 1991 (BGVN 16:03) Citation IconCite this Report

Lava continues to enter ocean; upper east rift magma intrusion

. . . lava production continued through early April, advancing through tubes and entering the ocean at three sites on the W side of the flow field (figure 77). A lava bench, built by the two eastern ocean entries since autumn 1990, was 125 m long and extended ~30 m into the sea in early March. A new bench then began to grow 2-3 m below the older bench, and was over half its length by mid-March. Significant erosion at the E end of the older bench culminated in its partial collapse late in the month, causing lava to pour into the ocean from beheaded tubes and large surface flows. The W entry remained quite explosive as its fragile lower bench collapsed frequently. A littoral cone on the old sea cliff was >3 m high by the end of March, and > 90% of its surface was covered by spatter. A long-lived surface flow on the W side of the lava field continued to advance slowly through the remnants of Royal Gardens subdivision. No surface flows or breakouts from the still-hot tube system have recently been observed on the E side of the lava field, where numerous homes had been destroyed in the Kalapana area.

Through the first half of March, many shallow long-period earthquakes or tremor events continued . . . beneath the caldera at 0-5 km depth. Since beginning in late December, the long-period activity had shown representative rates of >2,000 events/day, but in March it appeared to alternate with other summit seismicity. As shallow long-period activity started to decline 10 March, short bursts of slightly deeper long-period seismicity were recorded, also beneath the summit but at 5-13 km depth. Two days of elevationated high-frequency summit microearthquakes followed, apparently terminating on 13 March with a short burst of intermediate-depth long-period events, then a return to high levels of the shallow long-period seismicity. A similar sequence occurred 19-22 March. After 22 March, however, the number of shallow long-period summit events fluctuated more than in previous months, as the summit deflated ~7-8 µrad by 26 March.

On 26 March at about 0532, a shallow (<5 km deep) earthquake swarm and magma intrusion started in the upper east rift zone (between Pauahi and Aloi craters), 6 km SE of the caldera rim and 15 km uprift of the active Kupaianaha vent. Sharp summit deflation began 5 minutes later, and another 7-8 µrad of deflation was registered at the summit by late the next day. New tiltmeters just downrift of the swarm area (at Pu'u Huluhulu) also measured rapid deflation to the SSE, totaling ~40 µrad. Intense seismic activity continued for ~3 hours before tapering off, although upper east rift seismicity remained elevationated through the end of the month.

The seismicity was apparently associated with collapse in Pu`u `O`o crater, ~12 km downrift, where a new blanket of red dust extended 2 km SW of the cone on 26 March. Collapse episodes have been common at Pu`u `O`o in recent years, substantially increasing the diameter of the crater. A lava pond on the crater floor remained active in March. As of early April, the lava pond and its overflows covered the entire crater floor, and small intermittent lava fountains were observed in the pond.

The swarm and intrusion occurred near the intersection of the East rift zone with the ENE-WSW-trending Koae fault system, which passes S of the summit and connects the East and Southwest rifts. The resulting East rift/Koae/Southwest rift system forms the linear boundary zone between Kīlauea's mobile S flank and the rest of the volcano.

Information Contacts: T. Moulds and P. Okubo, HVO.


April 1991 (BGVN 16:04) Citation IconCite this Report

Lava breakout from tube system feeds new ocean entry

Lava . . . continued to enter the ocean . . . on the W side of the flow field through April (figure 77). The tube supplying lava to the coast divided just above the sea cliff. Its W branch fed a single entry site, where repeated collapse of the fragile lower lava bench caused nearly continuous explosive activity in early April. Bench collapse episodes left the lava tube perched in the sea cliff, and lava poured into the ocean in an arching stream. The explosive activity built a littoral cone >3 m high that was >90% covered by spatter. The two entry sites fed by the tube's E branch have built a large bench below the (pre-autumn 1990) sea cliff.

In mid-April, lava broke out of the tube system near 150 m (500 ft) elevation, generating a large pahoehoe flow that was diverted E by 1990 and 1991 flows and reached the ocean ~1.5 km E of the W entry sites. By 22 April, it had built a new bench below the sea cliff, and had an active front ~300 m wide that extended no more than 20 m offshore. Lava continued to pour into the sea until the beginning of May, when only three sluggish streams of lava were observed at the ocean front. Behind the active entry, small viscous surface flows broke out from the main flow. Despite the apparently diminished supply of lava to the E entry, large volumes of lava continued to flow into the sea at the W entry sites in early May. Surface flows, noted during April along the tube system between ~430 and 340 m (1,400-1,100 ft) elevation, covered a previously lava-free area (kipuka) on the W side of the flow field.

Skylights in the tube system at the base of Kupaianaha shield revealed lava velocities of ~1.5 m/s in late April. The uppermost skylight, at ~620 m (2,050 ft) elevation, was fuming heavily, but very little degassing was occurring from the vicinity of Kupaianaha and its former lava pond, which remained sealed through the month. Three kilometers uprift, the lava pond in the base of Pu`u `O`o crater, ~60 m below the rim, remained active through April. The pond covered less than half of the crater floor, but sometimes overflowed onto more. The walls of Pu`u `O`o remained unstable and collapse continued.

Since the intrusive swarm seismicity in late March seismic activity has returned to lower levels. Low-amplitude volcanic tremor continued along the East rift zone, with some variability at stations near Kupaianaha and Pu`u `O`o. Increases in summit-area microearthquakes were recorded 9-10, 14, and 26-27 April, but events were very small and did not appear to be associated with changes in eruptive activity.

Information Contacts: T. Moulds and P. Okubo, HVO.


May 1991 (BGVN 16:05) Citation IconCite this Report

E rift lava continues to flow through tubes into the ocean

Lava . . . continued to flow into the sea at two sites on the W side of the flow field (figure 79). More than 95% of the lava advanced through the Wahaula tube system, which divided a few hundred meters from the coast and fed the W and E entry points in the Poupou area. The W Poupou entry has been persistently explosive, continuing to throw tephra onto a large littoral cone on the old sea cliff. Growth of the littoral cone halted in May as erosional mechanisms (weather and cliff collapse) kept pace with explosive activity at the lava/sea interface. Below the old sea cliff, the W entry had built a small bench that extended <10-15 m into the ocean and was easily broken up by high surf. The E branch of the tube continued to feed the E Poupou entry points, which in previous months had built a sizeable 2-level bench below the old sea cliff. Throughout May, there were at least two major entry points off this bench. In early May, fluid lava flows broke out onto the E bench from its junction with the old sea cliff, covering the W side of the bench and entering the ocean. Successive overflows and inflation (perhaps caused by lava underplating) continued to build the lower bench, and by the end of the month it was within 1-2 m of the upper bench.

Figure (see Caption) Figure 79. Lava produced by Kīlauea's Kupaianaha vent, 1983-91. Arrows indicate flow in tubes and crosses at the coast mark sites where lava was entering the ocean in May 1991. Surface flows are shown above the tube's E and W branches. Courtesy of HVO.

Small lava flows broke out during May from the Wahaula tube between ~180 m (600 ft) elevation and the flat area near the coast. Two large flows were active. One (Waiaka) moved downslope atop the Wahaula tube in April, turning E off the tube near the coast and entering the ocean 17 April-2 May. This flow's activity declined during the first 2 weeks in May, and the flow was stagnant by the 16th. In mid-May, a new (Paradise) flow broke away from the Wahaula tube between 150 and 180 m elevation (500-600 ft) and established a new tube to the E. By the end of May, this flow was entering the ocean at the same site as the Waiaka flow.

A lava pond remained in the bottom of Pu`u `O`o crater through May. Kupaianaha's lava pond remained completely crusted over. Fume from the pond area diminished significantly, and the primary area of degassing shifted from the Kupaianaha shield area to a skylight in the tube system near 620 m (2,050 ft) elevation. In early May, all of the skylights along the Wahaula tube overflowed, closing some of those at lower elevations. The upper skylights remained open, and observations of times required for logs thrown into the upper skylight to reach the lower skylight yielded lava velocities of 1.4 m/s.

Information Contacts: T. Moulds, HVO.


June 1991 (BGVN 16:06) Citation IconCite this Report

E rift lava continues to enter the ocean

Lava . . . continued to flow into the ocean at two main entries through June. The W branch fed two active sites (at the Poupou entry). At the E Poupou site, lava continued to build the E edge of the lower bench, although its W edge had been eroded by waves. "Firehose"-like outflow of lava from truncated tubes occurred periodically at the E Poupou site, as on 7 June when the activity fed a tube in the surf zone. Frequent underwater explosions occurred along the tube, sometimes sending spatter several meters into the air. Firehose activity typically ended with the construction of a new lower lava bench. At the W Poupou site, parts of the 3-m-high littoral cone and the underlying sea cliff were eroding. A fissure developed just inland of the littoral cone in late May and additional large fissures appeared within a few meters of the sea cliff on 25 June.

Lava broke out from the main tube in mid-May and formed a new (E branch) tube, reaching the sea (at the Paradise entry) late in the month. Lava initially entered the ocean along a front 300-400 m wide, but within a few days the entry narrowed to <20 m across. The resulting bench sloped steeply and smoothly into the ocean, with none of the step-like changes in relief evident at the Poupou entry. Lava continued to pour into the ocean from the bench until the last week in June, when a large flow broke out and moved W across the beach behind the bench. The new entry was <500 m E of a 1988-89 bench where major collapses occurred after it extended no more than 45 m into the ocean. Only one significant collapse episode, which removed ~15 m of the new bench, had been noted at Paradise as of early July.

No changes were observed near the source (Kupaianaha) vent. Lava in a tube near the vent was flowing at ~0.9 m/s . . . on 20 June. A small lava lake persisted in the older Pu`u `O`o vent . . . . Overflows from the lava lake covered the crater floor, ~80 m below the rim. Some spattering was observed, concentrated in the S part of the lake.

Information Contacts: T. Moulds, HVO.


July 1991 (BGVN 16:07) Citation IconCite this Report

Continued E rift lava production; summit earthquake swarm

The . . . eruption continued through July, as lava from Kupaianaha vent flowed into the sea. The surface of Kupaianaha's lava pond remained frozen, while lava was still active at the bottom of Pu`u `O`o crater. Nearly simultaneous earthquake swarms occurred in the summit areas of Kīlauea and its larger neighbor Mauna Loa.

Eruptive activity. Lava from Kupaianaha was confined to tubes as it advanced down the upper slopes, where skylights at ~650 m (2,150-2,140 ft) elevation revealed an average velocity of ~1 m/s. Active surface flows were intermittently observed in a steeper area near 350 m (1,100 ft) elevation, and additional large surface flows emerged from the tube system between there and the coast through July. One large flow, active since June, advanced on top of the main (Wahaula) tube's E branch (figure 79). Its terminus was near 40 m (140 ft) elevation on 9 July. Although the flow front was wide with many active lobes, it did not reach the coast. Numerous small breakouts were active behind its front. Another flow emerged from a tube near 180 m (600 ft) elevation, moved downslope above the tube's W branch, and reached the coastal plain on 14 July. Two fluid pahoehoe lobes were advancing toward the coast on 16 July, moving past a kipuka at 35 m (120 ft) elevation. By the end of the month, the active flow front was > 400 m wide, and small breakouts from the flow were burning vegetation in Royal Gardens subdivision.

Despite the extensive surface activity, lava continued to pour into the sea from tubes at two main entries. The tube's W branch fed two active sites (at the Poupou entry). The littoral cone at the W Poupou site continued to erode, but erosion slowed toward the end of July as a bench growing outward below the littoral cone absorbed most of the waves' force. A cycle of bench erosion and rebuilding occurred repeatedly at the E Poupou site. Undercutting by wave action removed meter-sized blocks from the cliff face, and the resulting rapid collapse and erosion generated increased spatter activity, initiating construction of a new lower bench. At the entry fed by the E branch of the tube (Paradise), a prominent mid-bench scarp was noted on 4 July. Spatter was found draped over the scarp but none was evident on the lower portion of the bench, suggesting that the lower bench grew after the collapse episode. However, no seismic evidence of collapse was noted. The lower bench grew to within 1 m of the upper bench by 26 July. By the end of the month, the lava entry point shifted from the middle to the E side of the bench. Its W side began eroding and soon developed a cliff facing the ocean.

Seismicity. Continuous volcanic tremor persisted through July at the seismic stations nearest the eruption site and near the W ocean entry. Tremor amplitudes were generally low, although occasional brief bursts of higher amplitude tremor were recorded.

Earthquake activity beneath the summit appeared to have changed slightly since mid-late June. Shallow activity (0-5 km depth) had decreased, especially from the first 3 months of 1991. Daily visual scans of analog records since mid-June suggest that the dominant frequency content of shallow harmonic events had also changed, from 3-5 Hz to 1-3 Hz. The number of deeper (5-13 km) harmonic events fluctuated through July. Between 3 and 6 July, there were swarms of both shallow and deeper long-period events, then activity declined before a second, less intense swarm of intermediate-depth long-period events occurred on 11 July. This was followed first by an increase in shallower long-period activity, then a swarm of several hundred short-period microearthquakes on 13 July between 1400 and 2300, ~2 hours after the onset of a swarm under neighboring Mauna Loa. Almost all were too small for precise location. The 13 July seismicity was not associated with obvious eruptive changes, but geophysicists believe that it may indicate changes in magmatic activity or the state of stress beneath the summit.

Information Contacts: T. Moulds and P. Okubo, HVO.


August 1991 (BGVN 16:08) Citation IconCite this Report

Continued lava flow into sea; lava pond overflows; magma intrusion

Lava . . . continued to enter the ocean at two main sites through August (figure 79). By the end of the month, numerous breakouts from the tube system had reduced the volume of lava reaching the sea. Flows produced by major breakouts at ~180 and 340 m (600 and 1,100 ft) elevation spread over the W third of the lava field. Most remained on older lava, but a few lobes reached the field's W edge and ignited small brush fires in the remnants of the Royal Gardens subdivision. One flow from the breakout at 180 m reached 20 m elevation in early August.

Since at least January, a small lava pond has been continuously active in the bottom of Pu`u `O`o crater, covering ~20% of the crater floor on its E side. By April, the pond was circular and surrounded by levees. During the evening of 27 August, bright glow was visible over Pu`u `O`o, and a nearby seismometer recorded frequent bursts of higher amplitude tremor lasting 1-3 minutes. Overflights the next morning revealed that the pond had overflowed its levees, covering the entire crater floor with several meters of active lava that had a thin, frequently overturning, crust. Lava periodically drained back to its former level, remaining confined within the original pond until the next overflow. Similar activity continued through the end of the month. Crater depth remained roughly 80 m.

Seismicity in August included the upper East rift zone's third intrusive swarm since December 1990. More than 200 shallow summit microearthquakes were registered between 1100 and 1200 on 21 August. Earthquake counts quickly declined during the next hour, but elevationated levels of seismicity . . . continued through the next day. The largest concentration of events appeared to be centered just SE of the caldera, and very few occurred beyond Hiiaka crater, 4.5 km from the caldera rim. Most of the month's seismicity in the summit/upper east rift area occurred during the swarm.

Earthquake epicenters since December 1990 (figure 80) have been concentrated in several clusters, the largest of which were associated with the period's three intrusive episodes. The three swarms occurred in different portions of what geophysicists infer to be the same shallow (<5 km deep) structure between the summit and the East rift zone, suggesting a significant role for the summit in the current East rift eruption. During the early December swarm earthquakes were located from the summit roughly 6 km downrift (to Pauahi crater). The largest concentration of events was in the SE part of the caldera, perhaps extending a short distance into the rift zone (toward the Chain of Craters). The March activity occurred away from the summit, with the majority of located events between Pauahi and Mauna Ulu, roughly 3 km farther downrift. Following the early December seismicity and a long-period summit swarm late in the month, seismicity increased between the summit and Hiiaka crater. The same segment of the uppermost East rift zone has consistently shown low levels of shallow seismicity throughout Kupaianaha vent's post-1986 eruptive activity. After the March swarm, seismic activity along this rift segment appears to have increased further, and the August swarm was largely confined to this area.

Figure (see Caption) Figure 80. Plot of earthquake epicenters in Kīlauea's summit, upper to middle East rift zone, and south flank areas, December 1990-11 September 1991. Some of the larger craters are labeled. The eruption's two currently active vents, Pu`u `O`o and Kupaianaha, are off the map ~3 and 6 km ENE of Napau Crater. Courtesy of HVO.

Information Contacts: T. Mattox and P. Okubo, HVO.


September 1991 (BGVN 16:09) Citation IconCite this Report

Numerous surface flows break out from tubes, then lava stops entering ocean; lava lake active

Frequent breakouts . . . fed numerous surface lava flows between ~450 m (1,500 ft) altitude and the coast during September. Some lobes advanced rapidly downslope, but upon reaching the more level area near the coast they generally inflated, oozed small viscous breakouts, then stagnated. New flows covered previously untouched portions of Royal Gardens subdivision, and started a 1-day brush fire in a nearby section of Hawaii Volcanoes National Park.

The numerous breakouts and surface flows apparently reduced lava supply to the ocean entries, since all were inactive by late September. Lava had ceased to reach the sea by 3 September at the eastern of the two main ocean entries (Paradise). Two kilometers to the SW (at Poupou), lava had been flowing into the ocean at two points. A 1-2-m tumulus developed atop Poupou's E lava bench on 4 September, and extruded small, very viscous flows through cracks before all activity stopped at the E entry point 2 days later. Lava continued to pour into the ocean at the W Poupou entry point for the next 2 weeks. On 19 September, a very viscous pahoehoe flow broke out from its main feeder tube <500 m inland, in an area of inflated and fractured ground, remaining active for a few days before stagnating. Lava stopped flowing into the sea on 20 September, when small collapses of the bench front exposed hot rock to seawater, creating short-lived steam plumes. Entry of lava into the sea had not resumed as of early October, but surface flows from breakouts between 30 and 300 m elevation spread over a broad area.

Little surface activity was evident at Kupaianaha vent, source of the lava for the main tube system, although a skylight in the neck of its frozen lava pond was open on 7 September, and heavy fuming and a glowing crack were visible on the uprift edge of the pond on the 17th. Three km uprift, an 80 x 50 m lava pond covered ~15% of the floor of Pu`u `O`o crater during most of September, and frequent overflows sent lava across the crater bottom, ~36 m below the 1986 spillway. During 1.5 hours of observations from the crater rim on 17 September, vigorous upwelling of lava occurred on the downrift side of the pond while continuous spattering on the pond's N side added to its 2-3-m-high spatter rampart. Two episodes of strong degassing were characterized by vigorous upwelling and spattering followed by roughly 2-3 m of rapid drainback. Pond level was high and the entire crater floor was typically covered by overflows before drainback episodes. Seismic instruments registered tremor during the degassing episodes, which were sometimes precipitated by collapses from the crater walls. On 28 September, lava in the pond withdrew to >15 m below the crater floor. After at least 5 hours of inactivity, a small vent opened on the crater floor and a cascade of lava poured into the drained pond, filling it to within a meter of the crater floor by the next day. The vent remained open and intermittently active, sending lava across the crater floor and into the pond. The vent continued to feed periodic overflows the following week, and the crater floor was covered with lava during observations on 4 October.

Information Contacts: T. Mattox, HVO.


October 1991 (BGVN 16:10) Citation IconCite this Report

New east rift fissure vents

New fissure vents opened on 8 November between the East rift zone's two active vents (Kupaianaha and Pu`u `O`o), feeding aa flows that advanced into the remnants of Royal Gardens subdivision (figure 81). Lava from Kupaianaha vent continued to emerge from tubes on the W side of the flow field, but the lava pond in Pu`u `O`o drained rapidly and was no longer visible by 11 November.

Figure (see Caption) Figure 81. Lava produced by Kīlauea's East Rift eruption, 1983-91 (stippled). The area of October surface lava flow activity from Kupaianaha vent is indicated by a diagonal pattern. Arrows indicate flow in tubes. Crosses mark the discontinuous fissure vents that opened between Pu`u `O`o and Kupaianaha on 8 November. Lava extruded by the new fissures as of mid-November is black. Courtesy of HVO.

October activity. Lava from Kupaianaha vent moved downslope through tubes and emerged onto the W side of the flow field through October, feeding surface flows between ~400 m (1,300 ft) altitude and the coastal plain (figure 81). Lava that broke out of the main (Wahaula) tube at ~270 m (900 ft) destroyed one of the remaining houses in Royal Gardens subdivision on 27 October. Breakouts behind the flow front destroyed a nearby house 4 days later. The two destroyed houses, and two others that remained intact nearby, had been isolated by 1990 flows. Three houses in Royal Gardens remained inhabited at the end of October, one within 1 km of recent flows. In the past few months, flows in this area have extended the margin of the lava field ~700 m to the W, but have been blocked from reaching the ocean by 1989 lava.

Kupaianaha vent's lava pond remained frozen during October. During an 11 October overflight, two small skylights were seen next to the former pond: one in large cracks on the faulted, uprift side of the pond, and the other (emitting heavy fume) in the crater wall on the pond's SE side. The lava pond in Pu`u `O`o crater fluctuated between 1 and 10 m below the crater floor, 36 m below the 1986 spillway. The vigorous degassing episodes noted in previous months were not as common in October. Fieldwork on 25 October revealed a large pile of spatter in the former spillway, and tephra that included Pele's tears and reticulite were found along the downrift side of the crater rim (figure 82).

Figure (see Caption) Figure 82. Pu`u `O`o's crater floor, 25 October 1991. Tephra deposits in and around the 1986 spillway are shown. Periodic overflows of the active pond have coated much of the crater floor. Sketch by Mauro Coltelli; courtesy of HVO.

Fissure eruption beginning 8 November. Seismic activity preceding the fissure eruption began with a short burst of shallow summit tremor on 8 November at about 0200, followed by small earthquakes that became frequent beneath the summit and upper East rift zone. The summit began to deflate at about 0430 as magma moved into the upper east rift. The fissures opened from W to E starting before 0445, with the easternmost fissures opening about 0500. Glow was reported just downrift from Pu`u `O`o at 0450. A plume of dust rose roughly 400 m above Pu`u `O`o at about 0715, as the crater floor collapsed. Helicopter pilots reported that at 0745 the pond at Pu`u `O`o had drained and a fissure eruption was underway, initially from a discontinuous series of fissures ~1.5 km long. Volcanic tremor intensified beneath the summit and in the vent area that night. The next day, lava fountains were <5 m high, and by the morning of 10 November the eastern fissures were feeding lava directly into a pond nearly 15 m deep. Late that day, the pond was stagnant NE of the fissures, but to the SE, two wide channelized aa flows were moving slowly toward the coast. The pond had drained into a rapidly advancing aa flow by the morning of 11 November, and fountains had again emerged above the subsided pond.

By 1600 on 11 November, the flows had advanced 3 km to ~400 m (1,300 ft) altitude, at the top of Royal Gardens subdivision, and trees were burning along the subdivision's E side. Two days later, the flows had advanced another 200 m into Royal Gardens. As of 14 November, the flow front was stagnant, but new aa flows were advancing atop earlier lava, and were particularly active ~125 m above the multilobate terminus. Lava was issuing quietly into a channel ~30 m wide that fed the flows downslope, but fountaining had stopped. The deflation rate at the summit had slowed during 8-10 November, accelerated on 11 November, but was slowing again as of the 14th. Volcanic tremor, indicating magma migration, continued at moderate levels beneath the summit and upper East rift zone, but amplitudes decreased on 13 November.

The level of lava in the tube extending from Kupaianaha to the flat area near the coast has dropped somewhat since the onset of fissure activity. Pahoehoe flows originating at Kupaianaha remained active on the E side of Royal Gardens subdivision on 14 November, but other Kupaianaha flows had stagnated along the coastal plain. [see also 16:11]

Information Contacts: T. Mattox and P. Okubo, HVO.


November 1991 (BGVN 16:11) Citation IconCite this Report

Lava from new east rift fissure vents

Episode 49 (E-49). A line of fissures opened between the East rift zone's Pu`u `O`o and Kupaianaha vents early on 8 November, feeding lava fountains 1-3 m high [through 26 November]. The first fissure opened shortly before 0445 at the base of Pu`u `O`o cone, and others began opening progressively eastward (downrift), with the last developing around 0500 at the base of Kupaianaha shield. The first fissure had stopped erupting by 0930, after producing a small amount of pahoehoe lava. Fountain heights from the remaining en-echelon fissures progressively increased eastward. Fissures immediately uprift of 1123 cone (Pu'u Halulu, built during the first episode of the eruption in January 1983: figure 83) closely followed the line of fissures that formed during E-48 in July 1986 (11:7). That episode broke a pattern of brief, regularly recurring periods of vigorous lava production at Pu`u `O`o and culminated in the building of Kupaianaha shield.

Figure (see Caption) Figure 83. Lava flows (stippled) and eruptive fissures from episode 49 of Kīlauea's East rift zone eruption, as of 8 November at 1600. Courtesy of HVO.

By 1100 on 8 November, fountaining uprift of 1123 cone had subsided to quiet upwelling, feeding pahoehoe lava that advanced SE. Large channelized pahoehoe flows (changing to aa at their distal ends) emerged from the central fissures, near and immediately downrift of 1123 cone, abutting channelized pahoehoe flows from the E fissures. The flow from the easternmost fissure moved N and ponded against the base of Kupaianaha shield by 0950 (figure 83). Other flows from the E fissures moved SE along the edge of the Kupaianaha flow field, reaching ~640 m (2,100 ft) elevation by 1600.

Lava continued to pond near the new vents through the night. By early the next morning, lava from most of the vents had merged into a large channelized aa flow with a terminus near 630 m (2,080 ft) elevation. Only the fissures downrift of 1123 cone were active by the afternoon. Tubes had developed over lava channels near the 1123 fissures, although the frequent spatter activity occasionally ruptured tube roofs and formed small spatter cones near channel heads. Ponded lava covered the eastern fissures.

By 10 November, lava ponded N of the rift began to drain southward, adding to the volume of the flow moving SE. The channel head of the SE-moving flow was nearly 75 m wide, narrowing to ~30 m wide downslope. The flow surged between 1000 on 10 November and 1800 the next day, advancing nearly 4 km and entering the upper portion of the Royal Gardens subdivision. Eastern vent fountains reappeared with the draining of lava that had ponded next to the vents. By the 12th, all activity was confined to a single vent near the E end of the fissure system.

During the next week, the flow widened considerably and channel morphology changed frequently, but the flow front did not advance farther into Royal Gardens. On 18 November, tubes covered the immediate vent area, pahoehoe flowed in the channel to 610 m, then sluggish aa to 550 m. The channel appeared empty the next day, with small aa breakouts emerging from an apparent tube below the crusted channel floor at ~550 m elevation. Two new flows broke out near the vent area that day, but they did not advance far and stagnated within a few days. In the last reports of episode-49 activity, helicopter pilots observed ponded lava and lava moving in a vent-area skylight on 22-25 November, and a sluggish aa flow was seen in the channel on the 26th.

Effects of episode 49 on Pu`u `O`o. The lava pond in Pu`u `O`o crater was ~55 m below the rim between 1 and 4 November. Within a few hours of the onset of E-49 on 8 November, a large dust plume billowed from the crater, and by 0745, helicopter pilots reported that the lava pond had completely drained. At 1025, however, geologists observed an active lava pond ~85 m below the rim of Pu`u `O`o, while the crater floor appeared to remain at its previous level of 46 m below the rim. Rockfalls occurred regularly as the walls confining the pond collapsed. The lava pond seemed to remain active until a series of rockfalls occurred on 11 November, apparently caused by removal of lava and the resulting collapse of the crater floor, leaving a pile of rubble 72-118 m below the rim.

Continued lava production from Kupaianaha vent. Lava originating at Kupaianaha vent has built an extensive flow field since activity began there in July 1986. A well-developed tube system carries Kupaianaha's lava down Kīlauea's S flank toward the sea, with breakouts from tubes feeding surface flows. The small breakouts noted in Royal Gardens subdivision during the first week in November continued for several days after the onset of E-49 fissure activity, but were less frequent. No surface lava from the main (Wahaula) tube was observed on . . . 15-21 November. During that period, the level of lava in a persistent skylight at 655 m (2,150 ft) altitude dropped from ~11 m to ~20 m below the rim. Within the tube, the flow surface had begun to form a crust. Lava continued to move under the crust, but at a reduced rate. On 21 November, a spiny pahoehoe flow broke out of the Wahaula tube at ~550 m (1,820 ft) elevation and advanced ~200 m. Six days later, two new spiny pahoehoe flows emerged from large tumuli on the tube. Geologists speculated that the tube may have been stressed by the E-49 aa flow that passed directly over it downslope at 520 m (1,720 ft) altitude.

Information Contacts: T. Mattox, HVO.


December 1991 (BGVN 16:12) Citation IconCite this Report

Small lava flows emerge from tube system; new lava covers Pu`u `O`o Crater floor

Lava production . . . continued as of early January, but at a steadily declining rate (figure 84). December surface activity was limited to a continuation of the lava breakouts . . . from the main (Wahaula) tube at ~570 m (1,860 ft) elevation. The breakouts had initially produced viscous, spiny pahoehoe that accumulated near the tube, but a change to fluid pahoehoe at the beginning of December persisted for the rest of the month despite a continued decline in volume. The longest flows from this site reached ~500 m (1,660 ft) elevation during the first week in December, but later flows generally did not extend below 530 m (1,750 ft) asl.

Figure (see Caption) Figure 84. Lava produced by Kīlauea's Kupaianaha vent, 1986-91 (stippled) and by the episode-49 fissure vents, November 1991 (black). A star marks the site of December 1991 lava breakouts. Courtesy of HVO.

Lava production in the bottom of Pu`u `O`o crater was temporarily halted by collapse associated with the E-49 fissure eruption. Renewed activity in Pu`u `O`o was first observed on 4 December and increased through the month, although it was not as vigorous as in September and October. The former lava pond remained empty, but a former vent N of the pond and a new vent against the SW crater wall were sources of activity ranging from low-volume spattering to upwelling of crater-floor lava flows. Toward the end of December, flows from both vents were frequently observed cascading into the former lava pond. The crater floor, which had been covered with talus after dropping at least 20 m, was gradually resurfaced with fresh pahoehoe. By the end of the month, most of the rockfall rubble was covered and the crater floor was nearly flat.

Low-amplitude volcanic tremor continued in the East rift zone. After a modest swarm of long-period summit earthquakes at 5-13 km depth 7-17 December, increased shallow (<5 km deep) microearthquake activity was observed along the East rift zone ~2-5.5 km from the summit crater rim (between Puhimau and Pauahi craters). This segment of the East rift zone had persistently shown low levels of seismicity, but the number of events had greatly decreased after the onset of E-49. An increase in shallow, long-period summit events began the last week in December. Their number peaked 31 December-1 January, totaling nearly 400, then decreased later that week.

Information Contacts: C. Heliker and P. Okubo, HVO.


January 1992 (BGVN 17:01) Citation IconCite this Report

Lava from new fissure; continued lava pond activity; lava production ends from shield vent

The rate of lava production. . . decreased through January. Frequent lava breakouts occurred from the tube system at ~570 m (1,860 ft) altitude. The flows were initially fluid, covering portions of E-49 aa in early January, but as the eruption rate declined they became progressively more viscous and limited in areal extent. Fieldwork on 11 February indicated that lava production from Kupaianaha had stopped.

Lava emerged from vents in the bottom of Pu`u `O`o crater, 3 km uprift from Kupaianaha, through early February. Frequent overflows resurfaced the crater floor. The lava pond fed by the downrift vent since December showed continuous spattering and gas-pistoning through January. Early in the month, two vents on the crater's uprift side overflowed intermittently, supplying lava to the downrift pond. By 6 January, a lava pond had formed on the uprift side, with vigorous overflow and drainback episodes. Overflows fed the downrift pond, while drainback frequently emptied the uprift pond, exposing a vent 20 m wide in its floor. Refilling of the uprift pond was occasionally accompanied by dome fountains. A drainback episode on 10 January led to the collapse of a spatter rampart into the uprift pond's vent. The pond did not immediately refill and a small glowing hole was noted there on 17 January. Two days later, the uprift vent was again active, feeding lava into the downrift pond, where activity was vigorous. Tephra and spatter from this pond rose above the rim of Pu`u `O`o. The pond level fluctuated between 5 and 9 m below the crater floor during the last 10 days of the month. Overflows from one or both ponds resurfaced the crater floor between 25 and 31 January. By the end of January, the uprift pond had again stagnated, leaving a glowing hole in the crater floor.

A swarm of intermediate-depth long-period seismic events began on 20 January at about 0600. Earthquake counts peaked 21-22 January, when > 700 events were recorded, returning to low levels by 24 January. Shortly after midnight on 24 January, shallow seismicity increased in the SE part of the caldera and uppermost East rift zone, remaining high for the next several days.

Episode 50 (E-50). Lava production began on 17 February at about 1930 from a new fissure at Pu`u `O`o (figure 85). The fissure started about one-quarter of the way up the cone's W flank and extended ~100 m uprift. Low-level (3-5 m high) lava fountains fed small flows that moved N and ponded near the base of Pu`u `O`o. Discrete earthquakes did not appear to increase before the episode, but a 2-hour burst of increased tremor at the Pu`u `O`o seismic station began 1/2 hour before the fissure opened, and summit tiltmeters measured 1.5 µrad of deflation.

Figure (see Caption) Figure 85. Lava produced by Kīlauea's East rift zone eruption, January 1983-September 1992 (stippled), with episode 49 and episode 50-51 lava indicated by contrasting patterns. Crosses mark positions of episode 49-51 fissure vents. Courtesy of HVO.

Information Contacts: T. Mattox and R. Okamura, HVO.


February 1992 (BGVN 17:02) Citation IconCite this Report

Continued lava production from East rift fissure vents; magma intrusion into upper East rift

Lava production from a fissure that extended ~150 m uprift from the lower W flank of Pu`u `O`o began during the evening of 17 February (E-50; 17:1). The small lava lake in Pu`u `O`o crater dropped ~40 m as E-50 began, and the lava surface remained ~80 m below the rim until 19 February, when it rose ~15 m. Lava from the E-50 fissure flowed N and S from the axis of the East rift zone (figure 85). By 19 February, only ~30 m of the fissure was active. The next day, the S flow had stagnated, and all of the lava from the fissure was moving N, where it formed a large ponded area fed by a channel 10 m wide. Overflows from the ponded lava built levees that were 7 m high by 21 February. Lava broke out of the N side of the ponded area on 21 and 22 February, as the eruption rate declined and lava in the channel dropped to a few meters below the levees. The channel had narrowed to ~3.5 m by 23 February. A large flow began to advance southward on 25 February. It stagnated within a few days, but new flows continued to move S atop previous lava.

When observed on 28 February, a thick crust had formed over the lava in Pu`u `O`o crater, although occasional spattering was noted on its margins. Gas-piston activity resumed at the beginning of March, and two separate vents were visible when the lava level was low.

An earthquake swarm in the summit area and upper East rift zone began on 3 March at about 0000. An hour later, the summit began to deflate at a rate of ~0.5 µrad/hour as an intrusion . . . roughly 4-6 km from the caldera rim (between Devil's Throat and Pauahi Crater). Small cracks developed in Chain of Craters Road, but no eruption occurred in the area. By 0930, summit tilt had leveled off. Seismic activity declined through the day, although > 3,000 events were recorded by 5 March at 0800. Activity at the E-50 vent had stopped by 0130, and later observations revealed that the level of lava in Pu`u `O`o crater had dropped to > 100 m below the rim. The large northern aa flow continued to advance sluggishly for much of the day, but stagnated by 1600, and the episode-50 eruption site remained quiet until 7 March.

Episode 51 (E-51). Eruption tremor remained near background levels in the middle East rift zone until shortly before noon on 7 March, when a 1-hour burst of increased activity was noted on the seismic station nearest Pu`u `O`o. At 1340, a helicopter pilot saw lava pouring from a new fissure near the E-50 vents, while the level of lava in Pu`u `O`o crater had risen to ~55 m below the rim. Lava production from the E-51 fissure was intermittent through the evening, but was continuous by 9 March, at rates that appeared slightly less than during E-50 and substantially below those of episode 49. The E-51 fissure appeared to overlap the E edge of the E-50 fissure and extended ~30 m to its E, on the steep W flank of Pu`u `O`o. By 9 March, a spatter cone 6 m high had formed, and lava was ponding on the W side of the fissure. Some flows moved N from the ponded area, but most of the lava fed channelized aa and slabby pahoehoe flows that moved S. Intermittent lava production from the E-51 vent continued through mid-March.

Information Contacts: T. Mattox, HVO.


March 1992 (BGVN 17:03) Citation IconCite this Report

Continued lava production from East rift fissure vent

Episode 51 . . . began on the afternoon of 7 March, four days after an intrusion in the upper East rift marked the end of the previous episode. A new fissure vent developed on the W flank of Pu`u `O`o, directly upslope from the E-50 vent, and lava within Pu`u `O`o rose to within 55 m of the rim. Lava production apparently stopped at about 2100, but resumed by midnight. Fieldwork the next day revealed an active fissure 34 m long with a spatter rampart 6 m high. Lava ponded W of the vent, while channelized flows moved south and new lava briefly filled the E-50 aa channel.

Lava production stopped at least four times during the following weeks. Active periods that sometimes lasted little more than a day were separated by repose intervals of 16-67 hours. Summit tilt consistently showed slight inflation during repose periods. The E-51 vent built a small shield on the W flank of Pu`u `O`o. Most of the small braided lava streams that covered the shield were fed by a summit lava pond, on the uprift (W) side of the active fissure. Large flows advanced in all directions from the new vent, expanding the W and S margins of the E-50-51 lava field (figure 85). Some flows emerged from the vent without passing through the pond. These wrapped around the base of Pu`u `O`o. On 13 April, a large pahoehoe flow was moving south and was nearing a forested area.

The level of lava inside Pu`u `O`o fluctuated between 35 and 60 m below the spillway on the crater rim, sustaining frequent gas-piston events and vigorous spattering. The lava level apparently dropped during two of the repose periods, then rose with renewed activity at the E-51 vent. On 12 April, several lava overflows briefly covered the crater floor before lava again retreated deeper into the vent.

Information Contacts: T. Mattox, HVO.


April 1992 (BGVN 17:04) Citation IconCite this Report

East rift lava production from fissure vent continues, but with brief pauses

Episode 51 . . . continued through early May with two pauses, each lasting less than a week. During the first half of April, E-51 vents on the W flank of Pu`u `O`o (figure 85) fed lava N to a perched pond on the small shield built by the recent activity, and to a large channel that carried flows southward. This channel, active since the brief pause at the end of March, had roofed over to form a tube by 6 April. Flows advancing through the tube reached the edge of the lava field on 13 April and began to burn trees in Hawaii Volcanoes National Park, > 1 km from the vent. During this period, several smaller flows were active on the shield, some fed by the perched lava pond. The E-51 vents remained active, sustaining periodic low fountains, until the eruption halted on the evening of 19 April. No large flows were observed the next day, although small aa flows continued to drain lava stored in the pond area.

The eruption resumed on 23 April, as two vents along the E-51 fissure fed the pond and a channelized flow that headed S. Its aa front advanced rapidly and began burning vegetation in the national park by the next day. The lava pond and main channel also fed large shelly pahoehoe flows that moved N and W. Small, apparently tube-fed aa flows continued to break out on the shield. By 28 April, the main channel was beginning to roof over, but lava production stopped at 1130 that day, the channel drained, and lava flows stagnated.

The level of the small lava lake in Pu`u `O`o fluctuated between 36 and 53 m below the crater rim in April, sustaining numerous overflows onto the crater floor and vigorous spattering as it remained active throughout the month. After lava production stopped at the fissure vent on 28 April, the Pu`u `O`o lava lake rose until it spilled onto the crater floor on 3 May, and was still overflowing when the eruption resumed from the E-51 fissure vent the next day. Flows from the fissure vent generally remained on top of earlier lava during the following week, while the Pu`u `O`o lava lake withdrew into the conduit, to nearly 70 m below the crater rim.

Information Contacts: T. Mattox, HVO.


May 1992 (BGVN 17:05) Citation IconCite this Report

Lava production from episode-51 vent interrupted by brief pauses; lava lake in nearby crater

Lava production at the E-51 vent halted on 28 April. Shallow long-period (LPC-A type, 3-5 Hz) microearthquake counts declined for a few days, then increased to > 200 events daily between the mornings of 1-3 May. During the interval of eruptive quiet, the small lava lake in Pu`u `O`o crater rose until it spilled onto the crater floor on 3 May.

The lava lake was still overflowing when activity resumed at the E-51 vent the next day. Channelized lava flows covered much of the S flank of the E-51 shield between 4 and 22 May, many forming tubes that extended to the shield's base. Flows emerged from the tubes under enough pressure to create dome fountains at their heads. Some ponding occurred at the base of the shield before flows advanced S and E. The perched lava pond on the E-51 shield fed large overflows as well as small aa flows on the shield's NW flank. The pond level fluctuated, dropping as much as 15 m below the rim when the eruption paused again on 22 May.

Shallow long-period (LPC-B type, 1-3 Hz) microearthquake rates were nearly 100/day 8-11 May, declined for a few days, then increased again 15-21 May, peaking on the 17th when 442 were detected. As these events declined, an increase in LPC-A types was noted. The amplitude of eruption tremor remained low, then abruptly dropped to near background on 22 May at about 1300.

The eruption resumed on 27 May, for the first time re-occupying tubes formed during the previous active period. Activity paused again on 29 May, resuming on 2 June, again using the same tubes on the S flank of the shield.

The lava lake in Pu`u `O`o remained active throughout May. Its level fluctuated between 35 and 70 m below the crater rim, periodically overflowing onto the crater floor. Collapses of the crater walls and floor left the lake with a smaller diameter, against the E crater wall.

Information Contacts: T. Mattox and P. Okubo, HVO.


June 1992 (BGVN 17:06) Citation IconCite this Report

Continued east rift lava production

Lava production continued through early July from the E-51 vent . . . (figure 85), but was interrupted by several brief pauses. With each resumption in activity, lava reoccupied tubes on the S flank of the E-51 shield. Flows emerged from the tubes under some pressure, creating small, meter-high dome fountains at their heads. The lava pond at the top of the E-51 shield drained and refilled with changing lava supply, sustaining frequent overflows that did not advance far. Some lava also ponded at the base of the shield before flows advanced S and E. The small lava lake in Pu`u `O`o crater remained active, fluctuating between 38 and 55 m below the crater rim in June. The lake surface rose during pauses in activity at the episode-51 vent and dropped when lava production resumed there. By early July, it had dropped farther, to 65 m below the rim.

Activity resumed on 2 June, after a 3-day pause (17:5), while harmonic tremor began a gradual increase to about twice background levels at 0000. Large flows advanced N along the W flank of Pu`u `O`o cinder cone. These shelly pahoehoe flows formed shallow tubes and stagnated within a few days. The eruption stopped briefly on 5 June, as tremor dropped to near background at 1800, resumed the next day accompanied by a tremor increase at about 0700, and halted again ~24 hours later on the 7th, when lava drained slowly from the pond atop the shield.

Another increase in tremor began early on 9 June, reaching about twice background levels by noon on the 10th. Shallow, long-period microearthquakes (LPC-A, 3-5 Hz) were frequent on 9 June, as were upper east rift events on 9-10 June. Lava started to emerge from the E-51 vent at 1325 on 10 June, re-entering the tube system on the S flank of the E-51 shield. The lava lake in Pu`u `O`o crater had been nearly level with the crater floor when E-51 activity resumed, but had dropped ~9 m by the next day.

A small spatter cone formed 3-11 June over a weak point in the tube on the N flank of the E-51 shield. This tube had fed numerous aa ooze-outs that spread out around the shield's N flank in past months. On 13 June, an aa flow was active on the shield's N flank, appearing to originate from the new spatter cone.

Lava production stopped again on 16 June, the pond at the top of the shield drained, and flows slowed their advance. The eruption restarted during the morning of 21 June, continuing through the end of the month. Pahoehoe flows extended N and SE from the vent. Through 25 June, the shield's pond was full and intermittently overflowing, but by 1 July it had drained to ~15 m depth with a solid crust at the bottom. However, lava continued to ooze into the S-flank tube system and to break out at the base of the shield. Tremor amplitudes gradually declined to near background by 2000 on 29 June, and remained at low levels into early July.

Information Contacts: T. Mattox and P. Okubo, HVO.


July 1992 (BGVN 17:07) Citation IconCite this Report

Lava flows south from East-rift vents

Lava production . . . was continuous for most of July, pausing for a few days on the 22nd. The lava pond perched next to the E-51 spatter cones drained in early July, and a thick crust formed on its surface. The pond remained inactive for the rest of the month, as lava from the E-51 vent bypassed it through a lava tube to the S. Lava flows emerged from a tube at the base of the E-51 shield, building a sizeable secondary shield there. Flows moving SE entered the forest on 9 July just E of the 1986 flow, advanced along a front 500 m wide (figure 85), and reached the steepest portion of the S-facing fault scarp (pali) on 20 July.

The number of microearthquakes beneath the summit and East rift generally remained low, but 275 shallow, long-period (B-type, 1-3 Hz) events were recorded on 22 July. That day, observers reported a decline in activity at the vent, and the tube system slowly drained. By 23 July, the terminus of the new flow was stagnant.

A gradual increase in tremor amplitude to about twice background level began early on 27 July. Lava returned to the tube system during the day, breaking out at the base of the E-51 shield, where flows ponded before spreading in all directions. On 30 July, more flows emerged from the tube system S of the ponded area and advanced S, reaching the forest in the national park on 3 August.

The lava lake in Pu`u `O`o crater was active throughout July. Its surface fluctuated between 45 and 70 m below the crater rim. Upwelling was constant in the uprift portion of the lava lake, while degassing and spattering was most vigorous on the lake's downrift edge.

Information Contacts: T. Mattox and P. Okubo, HVO.


August 1992 (BGVN 17:08) Citation IconCite this Report

Continued East-rift lava extrusion interrupted by brief pauses

Lava production . . . continued in August with one 4-day pause around mid-month and another that began 29 August. The surface of the active lava lake in Pu`u `O`o Crater fluctuated between 36 and 75 m below the crater rim. During eruptive pauses at the E-51 vent on the outer W flank of Pu`u `O`o, the lake slowly dropped to more than 60 m below the rim, but overflowed onto the floor of the crater (36 m below the rim) at the onset of renewed activity.

Flows began to emerge from the tube system after activity resumed in late July, advancing S to the edge of the flow field and starting forest fires on 4 August. There the flows split, with one lobe staying on top of the 1986 aa flow and two others advancing downslope W of the 1986 flow (figure 85), reaching 658 m (2,160 ft) elevation before the eruption paused on 11 August. Tremor levels began to gradually decline, from 2x background at about 1600 on 11 August to background level by 13 August. Shallow, long-period (LPC-B, 1-3 Hz) counts were high 4-12 August, with a maximum of 345 events per day.

The level of the Pu`u `O`o lava lake began rising the morning of 15 August, stabilizing ~2 hours before the eruption resumed. At about 1300, slow-moving pahoehoe flows broke out ~1 km S of the episode-51 shield and headed S. Tremor levels began increasing again at about 1800, reaching 2x background. Lava advanced to ~664 m (2,180 ft) elevation by 27 August, reaching the edge of the flow field and burning trees SE of the vent. The eruption paused on 29 August as tremor amplitude again decreased to background levels between 0600 and 1100.

There have been only one or two August observations of lava on the floor of the E-51 pond, active from March until it drained in July. The pond is apparently being completely bypassed, with lava now directly feeding tubes in the S flank of the E-51 shield. Occasional glimpses of vent activity have been possible through skylights that opened at the base of some of the spatter cones.

Lava in the Pu`u `O`o lake was 51 m below the crater rim on 1 September. Eruption tremor began to build gradually at 2100 that day, reaching a steady 2x background by 0100 the next morning. Shallow, long-period (LPC-A, 3-5 Hz) and upper East rift microshock counts were high 1-2 September. The eruption resumed on 2 September with lava reoccupying the tubes to the S and breaking out S of the E-51 shield. Flows headed S and E, reaching the treeline on 6 September and 661 m (2170 feet) elevation on 8 September. The seismic station (STC) nearest Pu`u `O`o detected an increase in tremor amplitude to 3x background 3-6 September. Shallow, long-period (LPC-B, 1-3 Hz) events seismicity 7 September at > 140 events, then began gradually decreasing, dropping to just above background by 0400 on 9 September. Flows stagnated when the eruption paused 9-12 September. Shallow, long-period events and upper East rift microshocks were again frequent 11-12 September. Tremor increased to 3x background, starting at 0400 on 12 September, when lava broke out of the tube ~1 km from the vent and formed sluggish, channelized pahoehoe flows.

Information Contacts: T. Mattox and P. Okubo, HVO.


September 1992 (BGVN 17:09) Citation IconCite this Report

New vent opens after M 4.5 earthquake

The . . . E-51 vent was intermittently active during September. Flows headed S and E, reaching the edge of the lava field by 6 September and 660 m (2,170 ft) elevation on 8 September. Flows stagnated the following day when the eruption paused. The vent reactivated 12 September when lava broke out of the tube ~1 km from the vent, forming sluggish channelized pahoehoe flows that advanced S from the shield complex, reaching the SW edge of the flow field and slowly burning vegetation in the National Park (figure 85). The eruption paused 27 September and activity at the vent area declined the next day as the E-51 spatter cones stopped glowing, lava in the skylights slowed, and flows stagnated.

The Pu`u `O`o lava lake remained active all month, its surface fluctuating between 70 and 51 m below the crater rim. The level of lava in Pu`u `O`o was low before and during the pauses, rising immediately before renewed activity at the vent. There was steady circulation from the W to the SE edge of the lake.

Tremor increased to 3x background 3-6 September, began a gradual decline on 7 September, the day before the eruption paused, then increased again to 3x background as the eruption resumed on 12 September (17:8). Eruption tremor remained steady until the eruption paused again in late September. Shallow, long-period (1-3 Hz) seismicity peaked at >140 events on 7 September.

Episode 52 (E-52). A M 4.5 earthquake occurred at about 2000 on 2 October [but see 14:10] on the S flank, W of Royal Gardens subdivision, at ~6.5 km depth. An anomalous glow, reported to the Civil Defense authorities soon after the shock, marked a new eruptive fissure on the S flank of Pu`u `O`o and the beginning of E-52. Seismic tremor and summit tilt . . . did not show any significant changes until about 0300 on 3 October, when tremor amplitude recorded near Pu`u `O`o increased dramatically and the summit region began to subside as magma was withdrawn and erupted from the new fissure. By 1000, helicopter pilots reported that a new aa flow had advanced ~3 km and was burning the forest just E of the E-51 lava. The E-51 vents, which had restarted during the late afternoon of 2 October, stopped as the new E-52 vents became active. Late on 3 October, the E-51 vents slowly started up again, and by early the next afternoon the lava output from the E-52 vent had decreased slightly as emission from the E-51 vents increased. Lava from both vents was ponding just S of Pu`u `O`o as of 5 October.

Information Contacts: T. Mattox, M. Mangan, and P. Okubo, HVO.


October 1992 (BGVN 17:10) Citation IconCite this Report

Lava flows into ocean

A new fissure opened on the S flank of Pu`u `O`o soon after a M 4.3 S-flank earthquake on 2 October at 1951. Vigorous lava production from the fissure started the next morning at about 0300, as tremor amplitude increased to ~4x background level, marking the onset of E-52. . .. The fissure, 65 m long and subparallel to the axis of the East rift zone, developed four spatter cones and fed pahoehoe flows that moved southward (figure 86). Distal ends of the channelized pahoehoe flows turned into aa, advancing ~3 km from the fissure. Most of the lava was extruded from the two vents closest to Pu`u `O`o. Lava production from the E-51 vent system had paused on 27 September, but by 1530 on 3 October a sluggish lava flow was observed ~100 m from the E-51 vent.

Figure (see Caption) Figure 86. Lava produced by the first 10 years of Kīlauea's East rift zone eruption, January 1983-early January 1993, with lava from episodes 1-47, 48, 49, 50-51, and 52 indicated by contrasting patterns. Stars mark sites of active lava flows in early November 1992. Courtesy of HVO.

By the morning of 4 October, only the two easternmost E-52 vents remained active. Lava from these vents formed a single flow that ponded just S of Pu`u `O`o at ~730 m altitude. Vigorous activity had resumed from the E-51 vent, breaking out from a tube ~1 km downslope from the vent and ponding on the shield built by E-51 lava. By evening, the volume of lava emerging from the E-51 vent exceeded the volume being erupted from the E-52 vent.

The ponded area below the E-52 vent was breached on 6 October at 1550. The resulting flow advanced over earlier E-52 aa, and by evening had reached forest to the SE. Pahoehoe and aa lava emerged very sluggishly from the E-52 vent 7-16 October, advancing only a few hundred meters from a single vent. During the same period, E-51 lava flowed from several breakouts on the shield. One of these formed a channelized aa flow that entered a forested area at ~730 m altitude by 8 October, but stagnated downslope by the 12th.

Episode-51 lava continued to flow down the shield to the SE and SW. Most of these pahoehoe flows were fed into a large ponded area at ~720 m elevation. No active flows were evident below that level on 16 October, but sluggish tube-fed pahoehoe flows had reached 640 m altitude SW of the E-51 shield by the 22nd, burning the forest at times. Flows to the SE had ceased.

The flow to the SW moved over a steep scarp (Holei Pali) and reached 60 m elevation by 3 November. Lobes cascaded over a small scarp (Paliuli), ponding at its base, then headed E along the foot of the scarp. Lava crossed the Chain of Craters highway during the evening of 7 November and entered the ocean on the evening of the 8th. The lava formed a small bench on the E edge of Kamoamoa Bay, extending nearly 20 m into the ocean and spreading laterally along the coast.

The lava lake in the bottom of Pu`u `O`o crater had been rising before the onset of E-52, but once lava production began at the surface, pond depth dropped rapidly, and by 12 October, the depth to the lake surface was estimated to exceed 75 m. It remained deep (~70 m) through early November. The drop in lava level revealed two inlets to the lake on the W wall. Lava entered at ~70 m depth and descended into a plunge pool ~15 m below. Very active cycles in the lake that lasted about an hour each began on 18 October and continued through the 21st. Large rockfalls produced dust plumes on 29 and 31 October.

Information Contacts: C. Heliker and P. Okubo, HVO.


November 1992 (BGVN 17:11) Citation IconCite this Report

Lava flows extend 350 m into the ocean

The eruption . . . continued through November. Most of the surface activity was near the coast below the E end of the Holei Pali, one of a series of prominent seaward-facing scarps on Kīlauea's S flank. Lava flows were fed from E-51 vents on the W flank of Pu`u `O`o (figure 86). On 12 November, the lava-production rate was ~100,000 m3/day. Lava reached the sea on 8 November, entering the bay at Kamoamoa from several points along the new delta. Lava filled the bay and extended nearly 350 m into the ocean by late November. Violent littoral explosions were observed on 24 November at the Kamoamoa ocean entry. Explosive episodes lasting 20-45 minutes occurred at intervals of 15-90 minutes, sending tephra to nearly 90 m height during the most active periods. The last explosive activity (2015-2100) built a 7.5-m littoral cone in 10 minutes. Behind the active ocean-entry points, flows continued to cover new land, including the Kamoamoa campground, picnic area, and most of the remnants of Hawaiian archaeological sites in the area. Some small channelized aa flows were noted on Holei Pali. The Pu`u `O`o lava lake was rarely visible due to poor weather conditions, but appeared to be deep within the crater.

Eruption tremor remained at ~2x background level, with minor amplitude fluctuations in mid-November. Shallow, long-period microearthquake counts (LPC) were high on 12 November with 236 LPC-B (1-3 Hz) events, and on 19 November with 133 LPC-A (3-5 Hz) events. Swarms of LPC-C (5-13 km depth, 1-5 Hz) events were recorded at 1300 on 21 November (28 events) and between 0830 and 1300 on 22 November (39 events).

A helicopter carrying two movie cameramen crash-landed in Pu`u `O`o crater on 22 November. The pilot was rescued several hours later at the crash site, which the cameramen had left in an attempt to climb out of the crater. One man managed to climb out the next day, but the other spent 27 hours ~20 m below the rim before being rescued. He suffered from chemical pneumonia, inflammation of the lungs caused by sulfur dioxide, exposure, and dehydration. Rescue efforts were hampered by bad weather.

Information Contacts: T. Mattox and P. Okubo, HVO; AP.


December 1992 (BGVN 17:12) Citation IconCite this Report

Lava continues to flow into sea as East rift zone eruption enters 11th year

The . . . eruption continued in December, with flows entering the ocean at Kamoamoa, in Hawaii Volcanoes National Park (figure 86). By early December, lava had built a 1.1 km-wide delta extending 300 m into Kamoamoa Bay from the former shoreline (figure 87). Almost all of the lava erupted from the vent in early December reached the ocean through the lava-tube system, with some minor breakouts near the coast. Collapsing of the delta front (blocks up to car-size on 26 December) and slumping of the western bench at the delta's outer edge caused vigorous littoral explosions that have thrown tephra to 60 m height and built spatter cones. Breakouts of lava on the delta on 25 December were preceded by a rise in the lava level in a skylight ~1 km upslope (at the base of Paliuli: figure 87), and fieldwork revealed evidence of other recent overflows.

Figure (see Caption) Figure 87. Recent episode-51 lava flows into Kamoamoa Bay from the East rift zone of Kīlauea, December 1992. Courtesy of HVO.

The eruption paused for 24 hours beginning at 1600 on 3 January, after a collapse around the E-51 vent. This was the first pause since just before E-52 began on 2 October, and marked the 10th anniversary of the eruption's start. Vent activity declined, the skylights were empty, and the ocean entries were almost inactive. Tremor amplitude decreased to background levels and there was an increase in shallow, long-period microearthquakes during the eruptive pause. Eruptive activity gradually increased starting at 1500 the next day. At 1528 lava was overflowing from a skylight in the reoccupied lava tube at ~360 m elevation, and the tube was eventually reoccupied down to the delta. The lava tube fed numerous breakouts from the top of the Pulama pali (figure 87) 3.5 km down to the delta on 5 January. There was no evidence of large surface flows or recent overflows from the skylights above the pali.

The first 10 years of the eruption have produced roughly 1.4 km3 of lava. The flow field covers > 83 km2, and ~150 hectares of new land have been added at the coast. Lava flows have destroyed 181 homes in several S-flank communities.

Information Contacts: T. Mattox and P. Okubo, HVO.


January 1993 (BGVN 18:01) Citation IconCite this Report

Lava flowing through tube system continues to enter the sea

Following a 24 hour pause on 3 January, the East rift zone resumed activity. Flows were active on the Kamoamoa delta on 6 January, subsiding a few days later. For most of the month, lava was fed directly to the Kamoamoa coastline through the lava-tube system and enlarged the delta, with at least three flows breaking out of a skylight at 455 m elevation. Ocean entries were mildly explosive. On 17 January, one of these flows re-entered the tube system through a lower skylight within hours of breaking out. In addition, there was a minor breakout on the upper pali on 20 January, but activity was generally quiet on the E-51 flow field. The largest spatter cone in the episode-51 vent complex collapsed on 21 January, leaving an opening 15 m wide and 20 m deep. Pilots reported seeing lava in the base of the new crater. Pu`u `O`o crater remained active and deep below the crater rim in January.

Eruption tremors continued at 2-3x background level, with minor amplitude fluctuations in early January. Microearthquake counts were low beneath the summit and rift zones. There were two moderate earthquakes in January, one at 2214 on the 24th and at 0524 on the 26th. The 24 January earthquake of M 4.5 located near Namakani Paio campground was felt from Hilo to Volcano. No major damage was reported. The 26 January earthquake of M 5.0, located N of Pahala, was the largest in a series of earthquakes during a 48 hour swarm. Most of the 350 aftershocks were not felt and were too small to locate. The water-tube tiltmeter at Uwekahuna vault recorded ~15 µrad of deflation 5-9 January, followed by inflation of about the same magnitude. There was a slight southerly tilt 5-18 January, with no net change of the summit area through the end of the month.

Information Contacts: T. Mattox and P. Okubo, HVO.


February 1993 (BGVN 18:02) Citation IconCite this Report

Episode 53 begins; lava flows from tube breakout reach Kamoamoa delta

"An upper east rift intrusive swarm began at 2325 on 7 February. More than 5,000 microshocks were counted in the first 48 hours of the swarm; these continued, in smaller numbers, until 18 February, when counts gradually decreased to normal. Several hundred events were processed, most located near Makaopuhi Crater, ~15 km SE of the summit and 6.4 km SW of Pu'u ' O'o. High-amplitude tremor beneath the summit accompanied the swarm. The count of shallow, short-period events beneath the summit was low, while that of shallow, long-period events was slightly above average until 22 February, peaking at >100 events on 19 February. The Uwekahuna water-tube tiltmeter at the summit of Kīlauea recorded ~15 µrad of deflation during the swarm. The tilt then reversed, recovering all of the deflation associated with the swarm by 23 February. The summit then slowly deflated again, with an E tilt of ~4 µrad recorded 23 February-1 March.

"On 8 February the magma supply to the E-51 vent was interrupted. Eruption tremor amplitudes, which had been ~2x background, rapidly diminished to background by 0400. As the E-51 tube system drained at the coast, sea water entered the tube, resulting in increased explosive activity starting at 0430 that continued intermittently for 3 hours. All flows stagnated by 9 February, but skylights remained incandescent for several days.

"The floor of Pu`u `O`o crater (35 m below the rim) collapsed on 8 February. After the collapse, the bottom of the crater consisted of talus slopes, with the lowest point >85 m below the crater rim. The lava pond reappeared on 10 February, and flows began to resurface the crater floor.

Episode 53 (E-53). "Eruption tremor remained at background levels until a gradual increase in amplitude on 16 February. On the same day, the lava pond in Pu`u `O`o rose dramatically and slow-moving lava was visible through the upper skylights of the E-51 tube. Two days later, sluggish pahoehoe flows broke out of the tube at 640 m elevation. More flows broke out at lower elevations, and by 20 February, channelized flows reached the top of Pulama pali. At 1450, lava fountains up to 4 m high were observed on the S flank of Pu`u `O`o, marking the beginning of E-53. The following day, the E-53 vent was ejecting spatter 15 m into the air and had formed a 30 m wide cone, with walls as high as 14 m. Flows from the vent area fanned out, filling the old E-52 collapsed pond and heading S towards the E-51 tube system.

"On 22 February, E-53 flows entered the E-51 tube through a skylight at 715 m elevation. The increase in magma in the tube led to an increase in activity. From 0000 to 0500, the eruption tremor amplitude increased noticeably to ~3-4x background. Amplitudes were sustained at 2-3x background for the remainder of the week. Large channelized flows advanced down the pali, fed by both the E-51 and E-53 vents. These flows merged with breakouts between 150 and 120 m elevation, reaching 60 m on 26 February. By 1 March, lava flows from the two vents were within 200 m of the ocean on the Kamoamoa delta, and within 40 m of Chain of Craters Road (figure 88).

Figure (see Caption) Figure 88. Map of recent lava flows from the East rift zone of Kīlauea, April 1993. Courtesy of HVO.

"On 26 February, the crater floor in Pu`u `O`o was 59 m below the spillway rim. The last 2 weeks in February, lava in the pond fluctuated between this level and ~77 m below the rim."

Information Contacts: T. Mattox and P. Okubo, HVO.


March 1993 (BGVN 18:03) Citation IconCite this Report

Lava continues to flow into ocean; phreatic explosion kills one

The . . . eruption continued as lava from E-51 and 53 vents fed several channelized flows that descended from Pulama Pali. Flows on the Kamoamoa delta entered the ocean on 2 March while a flow near Laeapuki (~750 m W of the Kamoamoa delta) stagnated within 30 m of the Chain of Craters Road. Breakouts on 5 March began covering new land E of the delta, including nearly 200 m of the Chain of Craters Road. By 15 March, much of the Kamoamoa delta had been resurfaced by new flows and lava was entering the ocean on the E and W sides of the delta. More flows cascaded over Paliuli on 13 March and advanced towards Chain of Craters Road N of Laeapuki. On 28 March, the Laeapuki flow cascaded over Paliuli W of the Kamoamoa flows, crossed Chain of Craters Road and entered the ocean (figure 88). The Laeapuki flow inflated rapidly creating a hummocky, tumuli-covered surface. Lava continued to enter the ocean at Laeapuki and on the E and W sides of the Kamoamoa delta through 12 April. Small blocks of Laeapuki bench collapsed into the ocean on 11 April.

A new collapse pit, containing lava, formed in late February halfway up Pu`u `O`o cone from the E-51 vent (figure 89). In the first half of March the spatter cone at the E-53 vent collapsed to half its original height. On 18 March, a vigorous flow broke out of the E-51 lava tube between the 51 and 53 vents, filling most of the 52 collapse area before it stopped.

Figure (see Caption) Figure 89. Map of the active vent area on the East rift zone of Kīlauea, March 1993. Courtesy of HVO.

On 26 February the crater floor of Pu`u `O`o was 59 m below the crater rim. In late March, the floor was 4 m lower and the lava pond fluctuated 1-14 m below that. During early April the lava pond fluctuated from 73-77 m below the rim.

The summit of Kīlauea continued to deflate until 5 March, when it reached the low recorded during last February's earthquake swarm . . . . From 5 to 15 March, the summit water-tube tiltmeter recorded ~7 µrad WNW inflation. This trend continued until about 20 March. During 20-27 March, the tiltmeter recorded almost 20 µrad deflation, surpassing the low of 5 March. After some reinflation, no significant changes occurred 30 March-12 April.

Tremor amplitudes recorded by a station near Pu`u `O`o were 2-3x background. Microearthquake activity continued at low rates beneath the summit and at low-to-average rates along the East rift.

At approximately 2100 on 19 April, a group of as many as 20 people ventured into a restricted area near Laeapuki to observe lava flowing into the ocean. A lava bench on which they were standing collapsed, causing the group to flee. The collapse was followed by three distinct earthquake-like events and the sudden explosion of a lava tube that had filled with ocean water. The explosion threw 35-cm-diameter rocks as far as 170 m inland. One man did not attempt to leave the initial collapse area and was last seen falling into the ocean. This is the first known death attributable to explosive volcanic activity at Kīlauea since 1924. Others in the group sustained 3rd-degree burns and serious abrasions caused by falling incandescent rock and hot ocean water. No one was seriously hurt by the large bombs.

Information Contacts: T. Mattox and D. Clague, HVO; Hawaii Volcanoes National Park.


April 1993 (BGVN 18:04) Citation IconCite this Report

Lava continues to enter the ocean

The . . . eruption continued in April and early May as lava from E-51 and E-53 vents entered the ocean. Surface flows were rare during the second half of April, but lava continued to reach the coastline through tubes. The volume of lava entering the ocean at Lae Apuki and along the W edge of the Kamoamoa delta began to decline in the last few days of April and early May as surface flows began breaking out inland from the entry points. By 6 May only the W Kamoamoa entry remained slightly active. The same day, three large breakouts were observed on Pulama Pali and two large sheet flows appeared on the coastal plain at night. One flow emerged from a tube below Pali Uli (~1 km inland) and advanced down the W side of the Lae Apuki flow. The other flow broke out of the Kamoamoa lava tube and covered new land on the E margin of the Kamoamoa flow field. By 10 May, the flows at Lae Apuki were stagnant, but lava continued to enter the ocean on both the E and W sides of the Kamoamoa delta. The Pu`u `O`o lava pond was very active during this period, fluctuating between 75 and 79 m below the rim.

Eruption tremor along the East rift zone continued with tremor amplitude 2-3x background levels during this period. Microearthquake counts were low beneath the summit and slightly above average along the East rift zone. Seismicity associated with ocean front bench collapse/explosion was recorded at 0939 on 17 April across almost the entire network, with P-arrivals that appeared to have very long-period characteristics. Many smaller events were recorded locally by the Wahaula seismograph (~4 km NE).

A number of collapse events with slightly higher frequency characteristics, including six that were locatable, were detected between 2143 and 2158 on 19 April by the Wahaula station. Based on field evidence and tourist reports, a major bench collapse during that time period was followed by a steam explosion as sea water inundated newly exposed hot rocks (figure 90). One person disappeared into the ocean, and 22 others were treated for injuries caused by the explosion showering them with incandescent lithic blocks and from falls on older flows while fleeing the area. The collapsed bench measured 210 m parallel to the coast, 14 m wide, and 8 m maximum thickness. Ejecta from the steam explosion were directed NW. Blocks near the viewing area and trail were generally <25 cm in size; meter-sized blocks were restricted to within 20 m of the entry area. Blocks were observed up to 200 m from the coast.

Figure (see Caption) Figure 90. Map of the Lae Apuki ocean entry area following the bench collapse and steam explosion on 19 April 1993. Courtesy of HVO.

Information Contacts: T. Mattox and P. Okubo, HVO.


May 1993 (BGVN 18:05) Citation IconCite this Report

Lava continues to enter the ocean; bench collapses cause explosions

Lava entered the ocean in May and early June . . . . Activity at the W Kamoamoa entry was sluggish in early and mid-May, stopping altogether by the 24th. Most of the material erupted from the E-51 and 53 vents entered the ocean on the E side of the Kamoamoa delta. These flows built out a lower bench, ~200 m wide, that extended 40 m into the ocean. Lava entries along the bench were very explosive, probably due to material sloughing off the unstable front, allowing seawater to contact lava and hot rocks. This intermittent explosive activity built up littoral cones on the lower bench.

Very few surface flows were observed on the flow field after 11 May. However, minor breakouts occurred inland and on the E side of the Kamoamoa delta. Small surface pahoehoe flows were active above a fault scarp (Paliuli Pali) on the W edge of the old Lae Apuki flow, but had not crossed it as of 7 June. More skylights have opened up on the tube system, including some immediately inland of the ocean entries. Surface flows broke out of one skylight that was intermittently open on the bench, resurfacing the lower bench. Another skylight was seen above the lower bench at the edge of the old sea cliff.

The lava pond in Pu`u `O`o remained active, varying from 75-77 m below the crater rim in mid-May before dropping to ~84 m below the rim in early June. Eruption tremor amplitudes remained at 2x background, with occasional bands at slightly higher levels. Microearthquake counts were low beneath the summit and rift zones in mid-May, and slightly below average along the E rift zone in early June.

Information Contacts: T. Mattox and P. Okubo, HVO.


June 1993 (BGVN 18:06) Citation IconCite this Report

Ocean entries remain active; bench collapses continue

The . . . eruption continued in June with little change as lava from the active vents continued to erupt directly into the tube system. Lava traveled downslope in the tubes and was visible through many skylights formed by tube-roof collapse. The W tube system . . . continued to feed small surface flows above 60 m elevation. Breakouts on the W side of the flow field had declined by the end of June. The E tube system (Kamoamoa tube) continued transporting lava into the Kamoamoa area (figure 91) . . . . Pieces of the bench, often including newly built littoral cones, frequently sloughed into the ocean. Vigorous littoral explosions usually followed these small collapses.

Figure (see Caption) Figure 91. Recent lava flows (November 1992-June 1993) from Kīlauea in the Kamoamoa delta area, active lava tubes, and ocean entries, June 1993. Courtesy of T. Mattox.

A lava flow broke out of the Kamoamoa tube on 29 June and quickly traveled 500 m to enter the ocean on the W side of the Kamoamoa delta. This flow was apparently the culmination of a volume surge in the system, which resulted in breakouts all along the active tube. With the exception of this flow, all of the breakouts were short-lived. On 3 July, most of the bench collapsed into the ocean, leaving a small sliver of material attached to the Kamoamoa delta. A new littoral cone formed almost immediately, and lava flows began to construct a new lower bench.

The volume of material erupted fluctuated considerably in June. Flux estimates based on geoelectric measurements over the active tube system were 150,000-250,000 m3/day. The level of lava in the Pu`u `O`o pond also fluctuated. Early in the month, lava was ~84 m below the crater rim; by mid-June, lava in the pond had dropped another 10 m. By the end of the month the lava level in the pond was up to 74 m below the rim.

Eruption tremor . . . persisted at ~2x background into early July. A swarm of shallow long-period events occurred 17-18 June, followed by a flurry of intermediate-depth long-period events on 18-19 June. Counts in both categories were slightly above average. Shallow, long-period microearthquake counts were high 24-27 June, peaking on 24 June with >700 events; counts gradually declined during the following days. Short-period microshocks were low in number beneath the summit and East rift zone. A watertube tiltmeter near the summit recorded several fluctuations in summit tilt, with a slight inflation from 29 June to 5 July.

Information Contacts: T. Mattox and P. Okubo, HVO.


July 1993 (BGVN 18:07) Citation IconCite this Report

New lava breakout on the Kamoamoa delta reaches the ocean

The . . . eruption continued in July with lava entering the ocean on the E and W sides of the Kamoamoa delta. The W Kamoamoa . . . flow built small benches below the old sea cliff that were soon broken apart by the high surf. Activity at this new flow declined throughout July. Lava entered the ocean along a 160-m-wide front on the E side of the Kamoamoa delta through most of the month. New land continued to be very unstable in this area. On 3 July, most of the lower bench at the E entry collapsed (an estimated area of 20 x 150 m), leaving behind a sliver of bench still attached to the delta. Lava flows quickly built a new bench extending ~35 m into the ocean, and two new littoral cones formed on the bench surface.

Lava tubes drained on 23 July and lava stopped pouring into the ocean . . . . The eruption resumed the next day as lava reoccupied the E-51 tube. Two small flows broke out of the tube; however, most of the erupted material traveled within the tube to the coastal plain. A large pahoehoe sheet-flow broke out just below a fault scarp and spread out over older Kamoamoa flows (figure 92). One part of the flow descended the W side of the Kamoamoa flow and entered the ocean on 27 July. Another finger advanced down the E side of the Kamoamoa flow and entered the ocean on 28 July. Isolated portions of Chain of Craters Road were covered on both sides of the Kamoamoa flow. Lava entered the ocean along wide fronts and explosive activity was rare. However, one large explosion on 28 July blew lithic blocks inland of the W entry point.

Figure (see Caption) Figure 92. Recent lava flows (November 1992-July 1993) from Kīlauea in the Kamoamoa delta area, July 1993. The new lava flow broke out of the tube on 24 July; lava reached the W Kamoamoa entry on 27 July, and the E entry became active on 28 July. Courtesy of T. Mattox.

A team of French and Swiss geologists who spent the night of 10-11 July at the summit of Pu`u `O`o observed the . . . lava pond for a number of hours. Activity was intense throughout the night, with the level of lava fluctuating 1-2 m. Bubbling was localized in the S and SE parts of the pond. At one point, a large collapse of the inner SSE crater wall produced a wave surge across the lava pond. Waves were several meters high, and covered the entire surface for several seconds. Other smaller landslides occurred during the night, showing the instability of the inner crater walls. The lava pond remained active throughout the month, with the surface fluctuating between 74 and 81 m below the crater rim.

Eruption tremor along the East rift zone continued in July at a relatively steady amplitude of 2x background level. Shallow, long-period microearthquake counts were slightly above average in the first half of the month, but were low later in the month, except for 22-23 July. Counts of short-period events were low beneath the summit and about average along the East rift zone.

Information Contacts: T. Mattox and P. Okubo, HVO; H. Gaudru, SVE, Switzerland.


August 1993 (BGVN 18:08) Citation IconCite this Report

Lava enters ocean along both sides of the Kamoamoa delta

The . . . eruption continued throughout August as lava entered the ocean on the E and W sides of the Kamoamoa delta . . . . Early in the month the W lava flow had several breakouts active along its length and several littoral explosions were observed at the ocean entries. The E branch of this flow also fed lava into the ocean but at a lesser volume. On 8 August, large flows broke out of the tube system between 420 and 480 m elevation. One large flow from the lower breakout advanced down over a fault scarp and covered new land and ancient Hawaiian ruins on the E side of the flow field. By 10 August, this channelized aa and pahoehoe flow cascaded over another fault scarp and ponded at its base. The flow continued to advance along the E margin of the Kamoamoa flow and soon entered the ocean on the E side of the delta (figure 93). This new flow fed lava into the ocean through 21 August and as activity on the E side of the delta declined, most of the erupted material continued to feed directly to the ocean on the W side of the Kamoamoa delta. Vigorous littoral explosions were observed at the ocean entries.

Figure (see Caption) Figure 93. Recent lava flows from Kīlauea in the Kamoamoa delta area, August 1993. Lava entered the ocean fed by the flow that broke out of the Kamoamoa tube at the end of July. The E lava flow was active until 21 August while the W entry continued to be active as of this writing. Courtesy of T. Mattox.

On 21 August, a 277 m-long sliver of land separated from the W side of the Kamoamoa delta along a 1-2 m-wide crack. The crack exposed lava tubes, some filled with lava and others empty and glowing. The sliver of land was 2-3 m below the level of the main Kamoamoa delta. On the evening of 23 August, water entered this active tube system, generating large jets of steam, tephra, and large radial spatter explosions. A ground survey of the area revealed large fields of lithic debris and spatter behind the W Kamoamoa entry.

Eruption tremor along the East rift zone was relatively stable in August at 2x background level. Shallow, long-period microearthquake counts were high during the first half of the month, ranging from 169 to slightly over 300 per day. Return to average long-period activity levels was as abrupt as the onset of the high counts. During the last half of the month, shallow long-period events were moderate in number except during 22-26 August when > 800 long-period events originating from intermediate depths were recorded. Counts for shallow short-period events were low beneath the summit and about average along the East rift zone. On 21 August, a large explosive event registered on East rift seismic stations, coincident with coastal bench collapse.

Information Contacts: T. Mattox, HVO.


September 1993 (BGVN 18:09) Citation IconCite this Report

Lava from tubes enters ocean; lava pond remains active

There was little change . . . during the first half of September. Lava . . . traveled directly to the ocean completely confined in lava tubes. There were no breakouts from the tubes, and lava poured into the ocean at two distinct entry points on the W side of the Kamoamoa delta. New land in this area was unstable with pieces of the lower bench sloughing off into the ocean, followed by pyroclastic explosions. On 25 September, helicopter pilots noticed a decline in activity in the skylights, and by the following day, lava entries had stagnated. The pause in activity only lasted until 27 September when lava flows broke out of a tube below a fault scarp. Breakouts were confined to the portion of the Kamoamoa tube formed by the July 1993 sheet flow. The emerging lava was initially viscous but became more fluid as the day progressed. Entries into the ocean via the lava-tube system were re-established the morning of 27 September. The water vapor plumes at the ocean entries started out wispy, but were more voluminous by the end of the day.

The lava pond in Pu`u `O`o was active throughout September as the level fluctuated between 81 and 87 m below the crater rim. Upwelling and spatter activity on the W side of the pond increased towards the end of the month. There were no confirmed depth changes in the pond coincident with the pause of 25-27 September.

Eruption tremor remained low . . . during September. Tremor amplitudes peaked at ~2x background, with periods nearly down to background. The number of shallow, long-period events was high for 3-5 September, with counts >100/day. Several "gas-piston" and rockfall episodes were apparent on seismic records, and shallow, long-period events were high on 26-27 September, probably coincident with the slowdown of eruptive activity. Microearthquake activity was low beneath the summit and slightly below average along the East and Southwest rift zones during the first half of the September, but about average for during the last half of the month.

Information Contacts: T. Mattox and P. Okubo, HVO.


October 1993 (BGVN 18:10) Citation IconCite this Report

Ocean entries remain active; partial collapse at episode-53 vent

The . . . eruption continued in October as lava entered the ocean along a 30-m-wide front, mostly from two distinct entry points. The volume of lava entering the ocean declined on 5 October and no lava was visible in any of the skylights. By the following day, surface flows were active on the coastal plain, and on 7 October, lava entered the ocean on the W side of Kamoamoa delta. Surface lava flows that accumulated on parts of the bench in late September built up to the elevation of the main delta. Portions of the W Kamoamoa bench collapsed into the ocean throughout the month. By 14 October, lower benches had formed below the original bench. Both entry points appeared to have one tube entry and several surface flows building into the ocean. Explosions were noted in the surf at both entries. By 22 October, there were two prominent entry points into the ocean and two additional, more diffuse entries. For most of the month lava traveled to the ocean through lava tubes. A small surface flow broke out of the Kamoamoa tube and extended <100 m before stagnating.

Upslope of the Kamoamoa area, lava was visible through a skylight at 60 m elevation and remained active throughout the month. One skylight at 330 m elevation was covered by a small aa flow sometime between 28 September and 7 October. A new collapse area was noted E of the 700 m elevation skylight in late September. Part of the E-53 spatter cone had collapsed by early October. Cracks and holes in the cone were incandescent, suggesting that lava was still erupting at the E-53 vent.

The level of the lava pond at Pu`u `O`o was ~83 m below the N spillway rim for most of October. Strong upwelling and spattering was observed on the W side of the pond on 7 October. A powerful current in the pond circulated SW to NE. There was continual moderate spattering along the E and NE wall of the pond.

Eruption tremor continued . . . at low and steady amplitudes ~2x background levels. Intermediate, long-period microearthquake counts were high from 4-9 October, peaking on the 5th and 6th at >100 /day. Many of these events were large enough to locate, including a large bench collapse on 19 October. Low-level volcanic tremor persisted near the ocean entry point. Short-period counts were low beneath the summit and about average along the east rift.

Information Contacts: T. Mattox and P. Okubo, HVO.


November 1993 (BGVN 18:11) Citation IconCite this Report

Lava bench collapse with vigorous explosive activity

Lava . . . continued to enter the ocean via the lava tube system throughout November. In the beginning of the month, lava entered the ocean on the W side of Kamoamoa delta along a 50-m-wide front, which grew to 270 m by mid-month. There were two prominent entry points along the W side of the front as well as two diffuse entry points on the E side. For most of the month, lava flows built a bench that extended 50 m into the ocean. Intermittent explosive activity at the entries built loosely consolidated littoral cones on the bench.

On 7 November, the National Park Service reported a bench collapse resulting in vigorous explosive activity. The active bench area continued to build out toward the W after the collapse. A littoral cone was constructed as a result of explosive events at the western-most ocean entry, possibly associated with the 7 November bench collapse. As the cone grew, cracks developed on its flank parallel to the coast. On the afternoon of 26 November, vigorous littoral explosions began, followed by a collapse of 20,000 m2 of lava later that evening. The scarp formed by the collapse was over 400 m long and 80 m wide. In one location, the area of collapse extended 30 m inland of the bench. Violent littoral explosions immediately followed this event; however, only two small spatter blankets were deposited on the delta. By the end of the month, two new benches were building out beyond the 8-m-high scarp. A skylight at 60 m elevation remained open and no surface flows were reported throughout the month.

The lava pond in Pu`u `O`o was active at 83-84 m below the N spillway rim with sluggish circulation from W to E. There were two areas of spattering below the spillway area. It was observed that a meter-wide sliver of the E crater wall, between the spillways, collapsed sometime between 29 October and 16 November. Volcanic tremor persisted at low amplitude levels of ~2-3x a quiet background level. Tremor amplitudes occasionally increased slightly, but essentially steady tremor continued through November. Microearthquake counts were low, but there were 7 earthquakes M >3.0 from 26 October to 8 November.

Information Contacts: T. Mattox and P. Okubo, HVO.


December 1993 (BGVN 18:12) Citation IconCite this Report

New collapse area engulfs much of the episode-53 cone

The eruption . . . continued with little change . . . . Lava . . . traveled through the tube system and entered the ocean on the W side of Kamoamoa delta along a 350-m-wide front. The ocean entries were moderately explosive, forming small littoral cones on the bench.

On 1 December, a surface flow broke out above 610 m asl. The pahoehoe/aa flow descended ~500 m, then stagnated the following day. Breakouts from the lava tubes occurred again toward the end of the month, producing surface flows at 640 m elevation on 21 December, and a larger flow extending 400 m at 580 m elevation on 29 December. On 24 December a small breakout occurred at lower elevations on the coastal plain. Motion of each of the flows lasted <24 hours. A small skylight formed on the coastal plain on 20 December; lava upwelled in this breach several times before plugging it up.

Explosive activity at the ocean entries on 8 December deposited molten spatter onshore at the edge of the active bench. The lava benches at the W Kamoamoa entry continued to grow and extended almost 35 m into the ocean after the 26 November collapse of the old lava bench. The active bench area remains unstable and small collapses take place frequently.

The lava pond at the bottom of Pu`u `O`o crater remained active during the month, at a depth of 84 m below the crater rim. A new collapse area, 35-40 m in diameter and 15 m deep, was discovered at the E-53 vent. The pit engulfed all but the southern third of the E-53 spatter cone.

Microearthquake activity increased dramatically during the early part of the month from levels of 40-50 events/day to nearly 200 events on 9 December and >150 earthquakes the next day. Seismicity quickly dropped to prior levels in the early morning hours of 11 December. In the late evening of the following day, a swarm of long-period earthquakes began beneath the summit region. During 12-16 December, over 500 events (5 >=M 3.0) were counted and several were clear enough to be located. Another M 3.3 event preceded this swarm on 6 December, and was located 23 km beneath the NW flank of Mauna Kea.

Information Contacts: T. Mattox and P. Okubo, HVO.


January 1994 (BGVN 19:01) Citation IconCite this Report

New skylights open; W ocean entry remains active

The . . . eruption continued as lava . . . traveled through tubes to the ocean. There was no change at the vent area, with the exception of small pahoehoe overflows within the crater of the E-53 vent; collapse pits around the E-51 vent continued to widen. The level of Pu`u `O`o lava pond was 84 m below the N spillway rim. A large, new skylight was spotted above 705 m elevation.

On 6 January, an active pahoehoe flow fanned out behind its aa terminus at the base of a fault scarp (Pulama pali) and descended to 60 m elevation before stagnating. A small flow oozed out of the Kamoamoa tube, at the base of another fault scarp (Paliuli). Another flow broke out at 120 m elevation on 8 January. This channelized aa and pahoehoe flow cascaded over the Paliuli fault scarp the next day before it stagnated.

Another new skylight opened above 60 m elevation. Lava in the skylight was almost 7 m below the ground surface and an underground lava fall was visible. The volume of lava in the skylight was high on 19 January, but decreased on the 27th.

Lava flows continued to enter the ocean on the W side of the Kamoamoa delta. The E bench stopped building into the ocean and began to erode during this interval while the W bench continued to grow. Prominent littoral cones formed as pieces of the bench collapsed, exposing lava tubes. There were several small collapses along the length of the bench but no major collapses were observed. The bench area extended >50 m into the ocean.

Eruption tremor continued during the first half of the month along the east rift zone. Low amplitude tremor fluctuated from near background to ~3x background levels. Higher amplitudes ranged from a half hour to ~2 hours duration. Shallow, long-period microearthquakes were moderate in rate. The number of short-period events was low beneath the summit and moderate to high along the east flank.

Information Contacts: T. Mattox and P. Okubo, HVO.


February 1994 (BGVN 19:02) Citation IconCite this Report

Three lava bench collapses, littoral cones, and a M 5.2 earthquake

. . . At the end of January the eruption rate slowed for a 24-hour interval; lava circulated sluggishly in the Pu`u `O`o lava pond, and views through skylights into lava tubes confirmed that the level of lava traveling through them was low. Later, on 8 February, the lava pond was 84 m below the N spillway rim, the same level seen last month, indicating that the rate of lava discharge had returned to normal. Surface flows were intermittently active above and at the base of Pulama pali during this interval, but above Paliuli views through skylights showed little change.

At the W Kamoamoa bench, lava continued to plunge into the ocean. In the first half of February the bench underwent two major collapses. Each dislodged a 200 x 30 m area that slid into the sea, but after each collapse new lava reconstructed the area lost. On 22 February, a substantial collapse took place, involving an area ~25 m wide extending along 400 m of coastline. Collapses also exposed active lava tubes. Their escaping lava built littoral cones along the coastal margin. The 22 February collapse deposited spatter fallout to 80 m inland, and in addition, fine rock fragments and "Limu o Pele" (thin flakes of basaltic glass) to 200 m inland.

An earthquake struck on 1 February with a preliminary magnitude of 5.2. It was received at all stations on the HVO network, and was felt over the entire island of Hawaii as well as parts of Maui, Molakai, Oahu, and Kauai; no damage was reported. The earthquake had an epicenter 18 km S of Kīlauea's summit, just offshore, and its focal depth was 33 km. After the earthquake, seismologists counted over 300 aftershocks, ~100 large enough to locate.

From mid-January through February the number of short-period microearthquakes was low beneath the summit, but above average along the east rift zone. The number of long-period microearthquakes on the east rift zone was moderate in the first half of February and slightly above average in the last half of February.

Tremor continued along Kīlauea's east rift zone. In the last half of January the tremor fluctuated over an amplitude range up to 3x background. During this time amplitude commonly remained consistent for 1-2 hours. This behavior created a "banded" seismic record, on which the bands represent multiple seismic traces of similar amplitude. The banded seismic records in the first half of February also recorded 1-2 hours of consistent tremor amplitude. During the last half of February banded tremor persisted for 2-3 hours, as consistent tremor with amplitudes 3-4x background, was followed by 2-3 hours of lower amplitude tremor.

Information Contacts: T. Mattox and P. Okubo, HVO.


March 1994 (BGVN 19:03) Citation IconCite this Report

New lava flows, bench collapse, and postulated water entry into lava tubes

In March . . . E-51 and E-53 vents continued to erupt fluid tholeiitic lavas that traveled through tubes and plunged into the ocean (figures 94 and 95). On 2 March, half of the newly formed W Kamoamoa bench collapsed. Spectacular explosions followed (visible from the Chain of Craters road), which deposited spatter over an area extending 280 m along the coast and 35 m inland.

Figure (see Caption) Figure 94. Map of the recent lava flows from Kīlauea's east rift zone, March 1994. Contours are in meters and the contour interval is approximately 150 m. Labeled features include lava flows identified by episode, active vents, and the Pu`u `O`o lava pond. Courtesy of T. Mattox, HVO.
Figure (see Caption) Figure 95. Detail of Hawaii coastline (Kamoamoa delta) showing the March 1994 lava flows from Kīlauea. Contours are in meters. Courtesy of T. Mattox, HVO.

Lava stopped entering the ocean the next day, but by 1100 on 3 March, a flow escaped from a weak point in a tube at the base of a fault scarp (Pali Uli, figure 95); by 1153 the flow reached the coast. Explosions rapidly built a 6-m-high littoral cone on the bench. By 1200 on 5 March the rate of discharge decreased, leading to a lull in the eruptions. The rate of discharge picked up again on 8 March and continued through the next evening. These post-lull eruptions were accompanied by particularly large steam plumes, and they contained abundant spatter derived from broken bubble-walls, including some "Limu o Pele" (thin flakes of basaltic glass).

The large steam plumes in the post-lull eruptions presumably came about because seawater invaded the unoccupied tube system during the interval with low discharge. When lava reentered the tubes, contact with seawater lead to bubble-rich explosions.

Activity quieted by 10 March, and 3 days later lava again stopped entering the ocean. Activity resumed on 14 March when lava flows escaped at the 610-m and 274-m elevations. Lava continued to escape from the ~610-m elevation (the top of the cliff area called Pulama pali), but in the days that followed lava flows broke out of the tube system at progressively lower elevations. Lava escaped from the tube system just below Pali Uli on 15 March; on the following day it flowed into the ocean. The active flow front at the ocean (figure 95) wrapped around existing littoral cones, leaving their tops as prominent landmarks. By the end of the month, at least four tubes delivered lava to the active bench.

The surface of the Pu`u `O`o pond was 90-95 m below the level of the spillway rim during March. The pond's surface was not stagnant, it circulated with upwelling in the center moving outward.

During March the east rift zone continued to produce eruption tremor with fluctuating amplitude, sustained highs interrupted by nearly background levels ("banded tremor"). The last report on seismicity, 29 March, noted that after 27 March sustained tremor sometimes rose to 3x background. The number of microearthquakes was low beneath Kīlauea's summit, and it ranged from low to average along the east rift zone. Shallow, long-period earthquakes were abundant in these areas on both 15 March (200 events) and 16 March (84 events).

Information Contacts: T. Mattox, P. Okubo, and C. Heliker, HVO.


April 1994 (BGVN 19:04) Citation IconCite this Report

Lava escaping from an active tube feeds aa flows

In April . . . lava traveled through tubes and plunged into the ocean. Lava also occasionally escaped from the tubes and formed surface flows. In mid-April, flows escaped lava tubes at three locations: a) along the E side of the Kamoamoa lava delta, b) at 61 m elevation, and c) at 610 m elevation. The latter site fed aa flows that descended to 488 m elevation.

A 2-day pause . . . on 15-16 April [resulted] in stagnant surface flows. During this time the volume of lava entering the ocean backed off to a residual trickle.

For the interval 29 March to 11 April the surface of the active lava pond rose from 90 m to 84 m below the crater rim. Following the 2-day pause, the surface of the active lava pond at the bottom of Pu`u `O`o crater stood at 79 m below the crater rim.

During 1-17 April, tremor . . . often sustained amplitudes 2-3x larger than background. Beginning 18 April, tremor amplitude began to drop to near-background levels, marking the start of irregular banding patterns on the seismic record. The patterns consisted of low-level tremor alternating with 1-2 hour bursts of higher amplitude tremor.

Information Contacts: T. Mattox and P. Okubo, HVO.


May 1994 (BGVN 19:05) Citation IconCite this Report

Littoral explosions as lava continues to enter the ocean

"The . . . eruption continued this month with lava entering the ocean along a 500-m-long front between the Kamoamoa and Lae Apuki areas in Hawaii Volcanoes National Park. Explosive activity was reported on 8 May, and continued with increased vigor through the end of the month. Some littoral explosions threw incandescent lava as high as 50 m in the air, and detonations could be heard from the highway (>500 m away). Large cracks were observed running parallel to the pre-April shoreline. Surface flows were rare during May. The Pu`u `O`o lava pond was active and its surface was 79-88 m below the crater rim.

"On 3 June a large channelized aa flow broke out of the lava tube at the 125-m elevation and advanced down to the coastal plain. Within a day, all break-outs from this flow were pahoehoe. The flow spread out on the coastal flats and was within 500 m of the shoreline by 6 June. More skylights opened at 150 m elevation."

Information Contacts: T. Mattox, HVO.


June 1994 (BGVN 19:06) Citation IconCite this Report

A few lava flows break out of tubes onto the surface; banded tremor continues

The . . . eruption continued with lava entering the ocean in the Lae Apuki area . . . . This bench area (W Kamoamoa/Lae Apuki) is defined by a 60-m-wide system of large cracks that extend >300 m from one edge of the delta to the other. After a small bench collapse on 15 June, a surface flow broke out of the active tube where it intersects the crack system. The flow resurfaced much of the bench before stagnating. Small pieces of the bench that fell into the ocean during June were accompanied by littoral explosions that threw incandescent lava as high as 20 m into the air.

On 3 June, a large, channelized aa flow broke out of the tube at 125 m elevation and cascaded over the Pali Uli fault scarp that evening. However, within a day, all of the breakouts from this flow were pahoehoe lava. The flow spread out below the pali and stagnated within a few hundred meters of the shoreline. Another surface flow cascaded over Pali Uli on 9 June, but by 13 June all of the large surface flows had stopped. Except for one small breakout below Pali Uli, no other active lava flows were observed in June.

Surface flows originating earlier in the year from the base of Pulama Pali had built a low, broad shield near 135 m elevation. A number of skylights have since formed on top of the shield, allowing intermittent observations of active lava through the skylights. There was very little change in the active vent area in June, but the Pu`u `O`o lava pond remained active with the surface 77-88 m below the N spillway rim.

Irregular intervals of banded eruption tremor in late April and early May alternated between background level and up to 4x background. Throughout most of May and into early June, however, tremor amplitudes were relatively steady at 2-3x background. Shallow, long-period earthquakes were slightly above average in number, and intermediate-depth long-period events fluctuated between high and low counts. These intermediate-depth events totaled several hundred on 15-17 May, nearly 200 during 22-23 May, and >200 on 29-30 May. More than 100 shallow long-period microearthquakes were also recorded on 30 May. Short-period microearthquake activity was low beneath the summit and along the rift zones. The steady, high levels of tremor recorded in April and May persisted until 11 June, when amplitudes gradually began to decrease to background level. Low-level tremor, alternating with several minutes to several hours of high-amplitude tremor bursts, in somewhat banded patterns, continued through at least 20 June.

Information Contacts: T. Mattox and P. Okubo, HVO.


July 1994 (BGVN 19:07) Citation IconCite this Report

Bench collapses and littoral explosions occur as lava flows continue to enter the ocean

"The . . . eruption continued throughout July with more lava entering the ocean in the W Kamoamoa/Lae Apuki area. On the morning of 8 July, a piece of the Kamoamoa bench, ~4,000 m2, fell into the ocean. Littoral explosions following the collapse deposited a small amount of spatter on the delta. A wave associated with the collapse event deposited blocks on the surface of the delta, 40 m inland of the sea cliff. One line of stations, set up to monitor movement of cracks on the active bench, disappeared into the ocean with the collapse. Following the event, the remaining lines recorded several centimeters of seaward movement. The cracks on the bench continued to widen throughout the month. Some of the larger cracks contained standing water.

"Surface activity was confined mostly to the W Kamoamoa/Lae Apuki bench; however, on 11 July, a surface flow broke out of the active tube on Pali Uli. This flow did not reach the ocean before stagnating. There were no significant changes in the Pu`u `O`o lava pond, which was 79 m below the crater rim in July.

"The ocean entries were intermittently explosive, following the 8 July collapse, due to smaller collapses along the front of the bench. Littoral explosions increased in frequency and magnitude later in the month. The most dramatic event began on the afternoon of 26 July. By the following day, large spatter bursts had built a 10-m-high littoral cone on the leading edge of the Kamoamoa/Lae Apuki bench. Explosive activity was initially episodic but was continuous by at least 1810 on 27 July. At 2025 a cascade of lava, about 5 m wide, ripped out of the tube on Pali Uli, from the same area as the 11 July flow. Within 50 minutes, the explosive activity at the ocean had subsided. The cascade on Pali Uli fed flows that eventually stagnated the following day. Activity at the ocean paused briefly, but by 1112 on 28 July, plumes were again visible off the Kamoamoa/Lae Apuki bench. Surface flows broke out on the bench, and by the end of the month extended the bench 5-10 m W."

Information Contacts: T. Mattox, HVO.


August 1994 (BGVN 19:08) Citation IconCite this Report

New lava flow advances over a fault scarp; ocean entries remain active

"Lava continued to enter the ocean in the W Kamoamoa/Lae Apuki area. Surface flows broke out on the bench, directly behind the littoral cone formed in July. These flows extended the active bench area 300-400 m W and formed a new tube parallel to the shoreline. Lava initially entered the ocean along a 500-m-wide front, but by the end of August entries had consolidated and lava entered the ocean along a 150-m-wide front. Additional breakouts resurfaced much of the older part of the bench early in the month. Small bench collapses and moderate-sized littoral explosions were observed towards mid-month. High surf on 23-24 August deposited sand and debris 50 m inland, along the entire front of the bench. Breakouts immediately behind the active ocean entries covered parts of the new bench and the storm deposit. There were no major bench collapses during the last half of August; material swept in by the storm appeared to support and slow the seaward movement of the bench.

"On 16 August a small pahoehoe flow broke out of the tube at 90 m elevation. A much larger channelized aa and pahoehoe flow broke out at 285 m on 20 August and rapidly advanced below 90 m elevation. The flow was active along its entire length, and by the end of the month fingers of active lava extended below the Paliuli fault scarp.

"The pond in Pu`u `O`o was active throughout August and its surface fluctuated at 79-84 m below the crater rim. Circulation in the pond was sluggish."

Information Contacts: T. Mattox, HVO.


September 1994 (BGVN 19:09) Citation IconCite this Report

One active ocean entry; small breakouts on E side of flow field

Lava continued to enter the ocean in the Kamoamoa/Lae Apuki area during the first half of September. Flows from the tube extended the bench, stranding the littoral cone built in July. Activity appeared to diminish in early September, and by 5 September the only active entry was SE of the littoral cone. The entry was moderately explosive through 12 September. Small pahoehoe and 'a'a lava flows continued to break out on the E side of the flow field between 270 and 15 m elevation.

Information Contacts: T. Mattox, HVO.


October 1994 (BGVN 19:10) Citation IconCite this Report

Laeapuki ocean entries still active and new lava flow reaches ocean

"In September, lava continued to enter the ocean in the Laeapuki area . . . . The W branch of the tube on the bench stopped transporting lava, and flows entering the ocean consolidated in front of the 27 July littoral cone. Littoral explosions increased in size and frequency coincident with the consolidation of the littoral tube system. On 14 September, ~10-15 m of the active bench collapsed into the ocean. The bench built out into the ocean until 1 October, when part of the active bench collapsed again. Flows built a small, thick bench following each collapse. Near the end of September, the flux at this ocean entry appeared to diminish, possibly because of the diversion of lava to a prolific E flow. Lava continued to enter the ocean in this area until 5 October, when the eruption paused for the first time since April.

"The large surface flow that broke out on 20 August at 270 m elevation continued to cover new land on the E side of the Kamoamoa flow-field. Throughout most of September there were active breakouts on this flow from the base of Pulama pali to below Paliuli. All of these breakouts were fluid pahoehoe toes and sheet flows. Sheet flows on the E margin of the flow field frequently ignited methane explosions, which were recorded by the Wahaula seismometer. Breakouts began to close the gap between the Kamoamoa and Kupaianaha flows; <200 m separated the two flow fields. Lava from this E flow entered the ocean on the E side of the Kamoamoa flow field intermittently during 2-9 October.

"Two pauses in October were only the 4th and 5th to occur since E-53 began in February 1993. On 6 October, all surface activity stopped, no lava entered the ocean, and there was no lava in the tube system. By the following morning lava had reoccupied the tube all the way to the Laeapuki ocean entry and fed breakouts close to 270 m elevation. Lava also continued to ooze and dribble into the ocean on the E side of the flow field. Following this pause, a number of breakouts were observed on Pulama pali and on the E flow. Lava entering the ocean in the Laeapuki area began to build a new bench E of the littoral cone formed on 27 July. Lava from the E flow entered the ocean once again on 22 October. On 24 October, the eruption appeared to be sputtering — flows slowed and then surged, entries died and then reactivated. By 25 October, all surface activity had stagnated. The eruption restarted the following day, and this time the tube system was reoccupied to only 550 m elevation. Below this elevation, large channelized aa and pahoehoe flows swept down the flow field. By 31 October, these flows had cascaded over Paliuli and begun to make their way to the ocean.

"Pu`u `O`o pond was a little more dynamic during this interval. From 13 September to 6 October, the pond level slowly dropped from 79 to 88 m below the crater rim. At its lowest level, the entry of lava from the W side of the pond was clearly visible. In October, the pond level rose from 88 to 60 m below the crater rim and activity on the pond surface became more vigorous. There was little change around the active vents, except that the collapse pit on the W flank of Pu`u `O`o doubled in size during September."

Information Contacts: T. Mattox, HVO.


December 1994 (BGVN 19:12) Citation IconCite this Report

Lava-flow breakouts cover new land and reach the ocean

Following a short pause . . ., lava flows broke out on 26 October and entered the ocean on 4 November in the same location as the previous Laeapuki entries. These flows quickly formed a tube system with many skylights and fluid pahoehoe breakouts active from the top of Pulama pali to the ocean. Lava flows extended to the W margin of the flow field, covering new land and burning more of Chain of Craters road. Flows were soon at the same level as the former sea cliff W of the eruption site. Lava entered the ocean across a broad front, but by 15 November the flow began to consolidate. On 23 November, flows active along the W side of the flow field were entering the ocean in the Laeapuki area. On the 25th, lava entry into the ocean slowed, eventually stopping altogether, coincident with a breakout on Pulama pali. Many flows were active on and above Paliuli during 25-28 November, but not on the coastal plain. On the 29th, a flow cascaded over Paliuli and advanced almost 300 m towards the ocean. The eruption paused the same day; this was the 6th pause since the beginning of 1994. By 30 November there were no active flows on the coastal plain, and only minor surface breakouts above Paliuli. The skylights were noticeably cooler and the flow in the tubes was low and sluggish. Pasty breakouts continued from the W side of the flow field as the system drained. At the end of November, a collapse pit on the W flank of Pu`u `O`o, immediately upslope of the E-51 vent, grew to ~80 m in diameter (4-5 times its former size).

On the morning of 1 December, no active surface flows were visible from the coastal area. By early afternoon, large channelized surface flows broke out between 630 and 180 m elevation. In the days that followed, much of the surface of the flow field above Paliuli was covered by new flows. By 5 December the flows had begun to consolidate. Two flows, on the W and the central part of the flow field, had come together and were close to Paliuli W of the Laeapuki area. One large flow had advanced down the E side of the flow field on Pulama pali, and on 6 December cascaded over Paliuli inland of the former Kamoamoa village site. Fingers from this flow headed for the ocean but stagnated within 200 m of the coast on 16 December. The E flow continued to break out at the base of Paliuli, and by 19 December the distal end was close to the ocean in the Kamoamoa area. Lava on the W side of the flow field cascaded over Paliuli on 7 December. This W flow appeared to be less voluminous than the E flow, and by 19 December breakouts from this flow had only advanced 500 m from the base of Paliuli. Both the E and W flows had breakouts active along much of their length above and below Paliuli. Lava flows were active on Pulama pali for most of this interval. On 20 December, the E flow entered the ocean in the Kamoamoa area. By 2 January 1995 the new entry had not yet consolidated, and several small streams were entering the ocean across a 300-m-wide area. Breakouts were active on this flow for much of this period, particularly near Paliuli. The W flow remained active and fed multiple active breakouts below Paliuli. By the end of this interval, the terminus of this flow was within 500 m of the ocean. Flows continued to break out above Paliuli and on Pulama pali, but none advanced to the coastal plain.

The collapse pit on the W flank of Pu`u `O`o grew during this interval, eroding more tephra on the uphill (E) side of the pit. If this growth continues, the summit of Pu`u `O`o may soon be engulfed. The pond in Pu`u `O`o was active throughout December, at 80-88 m below the crater rim.

Eruption tremor . . . persisted in banded patterns near background levels, alternating with amplitudes of 2-3x background. The number of microearthquakes was low beneath the summit and rift zones. Banded tremor continued up to about 1 January, when the STC (Steam Crack) seismic station, located near Pu`u `O`o, began to register an over-all low-level tremor with minimal banding. Intermediate-depth long-period events were marginally high in number during 22-25 December. Only a few of these events were large enough to be located. The number of short-period microearthquakes was low beneath the summit and rift zones.

Information Contacts: T. Mattox, HVO.


January 1995 (BGVN 20:01) Citation IconCite this Report

Lava flows active on coastal plain and at ocean entries

"Two large lava flows were active on the coastal plain throughout January (figure 96). These flows broke out of the active tube system on Pulama pali, on 1 December. Both flows reached the coastal plain in December, and the E flow entered the ocean on 20 December. Throughout January, the E flow entered the ocean from multiple points along a kilometer-wide front, never really consolidating into a tube entry. The W flow did not enter the ocean until 7 January, and the entries were active intermittently, eventually stagnating altogether by late January. The W flow, despite not entering the ocean, continued to be very active throughout January. There were multiple small breakouts active on this flow below Paliuli. The flow also inflated dramatically during this time, forming a prominent tumuli field. In contrast, the E flow had many large sheet flows active on the coastal plain with moderate inflation. Multiple aa and pahoehoe flows cascaded down Pulama pali during January. There were no changes at the vent area. The lava pond in Pu`u `O`o crater was active and 86 m below the crater rim."

Figure (see Caption) Figure 96. Kīlauea lava flows in the Kamoamoa area since 1982, including flows active during December 1994-February 1995. Courtesy of HVO.

Eruption tremor levels . . . were steady just slightly above background. The number of LPC-A (shallow long-period, 3-5 Hz) microearthquakes was moderate to high during 12-18 Jan; low-level amplitudes persisted throughout, with minor fluctuation. Daily counts of microearthquake activity remained low beneath the summit and rift zones except for the LPC-A category, with only a very small number large enough to process for location.

Information Contacts: T. Mattox and P. Okubo, HVO.


February 1995 (BGVN 20:02) Citation IconCite this Report

Lava flows on coastal plain; four active ocean entry points

Both the Lae`apuki and Kamoamoa lava flows had many breakouts on the coastal plain during February, and several aa and pahoehoe flows were observed on the Pulama pali flow field (figure 96). Poor weather conditions and thick fume clouds obscured the Pu`u `O`o lava pond during the first half of February, but it was very active and 75 m below the crater rim on 24 February.

On 2 February, lava that broke out of the Kamoamoa tube system at ~600 m elevation fed flows that burned forest and cascaded down Pulama pali. This fast-moving pahoehoe flow reached Paliuli on the 14th, 700 m W of the Lae`apuki flow, and headed for the Chain of Craters Road, burning grasslands and setting off methane explosions. The flow front stagnated within 150 m of the road on 27 February. Lava broke out of the tube again on 10 February at ~615 m elevation and formed a channelized aa flow 1 km W of the main flow field that reached the base of Pulama pali by the 13th. In the second half of February the Lae`apuki flow had several breakouts between Paliuli and the ocean that spread W, covering new land and starting brush fires and methane explosions.

Lava flows were active at four ocean entries during the month (figure 96). Lava continued to enter the ocean across a wide front on the Kamoamoa flow, and built benches into the ocean. Explosions following a small bench collapse at the W Kamoamoa entry spread spatter 30-40 m inland of the sea cliff. A lava flow also advanced to the E edge of the Kamoamoa flow field and on 10 February entered the ocean within a few hundred meters of the Kupaianaha flow (Kamokuna entry). This entry then built a large bench that merged with Kupaianaha flows.

Low-amplitude tremor dominated the east rift zone throughout the first half of February. The number of microearthquakes was low beneath the summit and rift zones except for a slight pickup in LPC-C activity (5-13 km depth, 1-5 Hz) on 10-11 February. A series of three small earthquakes in the lower east rift on 10 February (M 2-2.5) originated from a shallow source near Puʻulena Crater, E of the Leilani Estates subdivision; a few residents felt the events. Tremor amplitudes in the second half of February were slightly higher at a fairly constant level 3x background, interrupted by a few bursts of higher-amplitude tremor. Activity beneath the summit and rift zones was low except for a steady swarm of LPC-C events. During 24-27 February, intermediate, long-period microearthquake counts were high, averaging nearly 200 events on 26-27 February.

Information Contacts: T. Mattox and P. Okubo, HVO.


April 1995 (BGVN 20:04) Citation IconCite this Report

Lava flows, breakouts, tremor, and more

The 12-year-long eruption on Kīlauea's E rift zone continued in March-April, with vents on the SW flank of the Pu`u `O`o cone feeding directly into lava tubes. Recent heights of the lava lake are at the bottom of table 4 and a map showing recent flows appears on figure 97 (for comparison, the previous map appeared in BGVN 20:02).

Table 4. Summary of Kīlauea seismic data, lava flux rate, and lava pond heights for stated dates or intervals in 1995. Courtesy of HVO.

Date/Interval Observation Type Comment
Late Feb-03 Mar 1995 Earthquakes Intermediate depth activity remained high, slowly decaying to background levels.
Late Feb-10 Mar 1995 East Rift Zone Tremor Tremor with stable amplitudes ~3-4x background.
03 Mar 1995 Pu`u `O`o lava pond 79 m below rim.
10 Mar 1995 East Rift Zone Tremor Tremor dropped to 2x background with intermittent bursts of higher amplitude (similar to banded tremor) at 1900.
14 Mar-15 Mar 1995 Earthquakes In a 37-hour period beginning at 0900 on 14 March there were 134 intermediate-depth events.
14 Mar-27 Mar 1995 East Rift Zone Tremor Tremor continued.
19 Mar 1995 Earthquakes M 4.3 earthquake at ~50 km depth, W of the Island of Hawaii.
21 Mar 1995 Pu`u `O`o lava pond 75 m below rim.
27 Mar 1995 Earthquakes M 4.1 earthquake at 25 km depth beneath the upper E rift zone.
28 Mar-10 Apr 1995 East Rift Zone Tremor Tremor fairly constant at 2-3x background.
28 Mar-10 Apr 1995 Pu`u `O`o lava pond 75-81 m below rim.
11 Apr-24 Apr 1995 Earthquakes Shallow, long-period microearthquake counts were slightly above average. The number of short-period events was low.
11 Apr-24 Apr 1995 East Rift Zone Tremor Tremor continued, amplitudes were low, ~1.5-2x background. Shallow, long-period microearthquake counts were slightly above average.
11 Apr-24 Apr 1995 Pu`u `O`o lava pond 90-86 m below rim. Continued lava circulation from W to E in the pond.
03 May 1995 Earthquakes Swarm of 13 located earthquakes, the largest M 3.9; they were interpreted as shallow crustal adjustments beneath Hilina Pali.
10-30 Apr 1995 Lava flux rate ~400,000 m3/day (Volcano Watch, 1995).
Figure (see Caption) Figure 97. Kīlauea lava flows grouped into three time intervals: 1983 to 1992; 1992 to April 1995; and 11-20 April 1995. Heavy dashed line indicates lava tubes, and the contour interval is 500 m. Courtesy of USGS.

During 28 February-13 March fluid pahoehoe breakouts spread W and covered more of the Chain of Craters road. The eruption slowed during 14-16 March. Flows became more viscous and the amount of lava entering the ocean dwindled. On 16 March, cooler temperatures were measured on a thermocouple hanging through an opening in the roof of an active lava tube. By the morning of 17 March all flows entering the sea had temporarily stopped, but temperatures rose to normal values in the active tube and by early afternoon lava began escaping the tube system at three elevations; one reached within 500 m of the highway by 27 March.

In the 24 March-10 April interval, two tubes diverging toward the E and W sides of the flow field, the Kamoamoa and the Lae'apuki tubes, respectively, continued to feed flows on the coastal plain. The Highcastle lava flow escaped from the E tube (figure 97), advancing toward the ocean as a sheet flow, covering the lower part of another recent flow (the Jason flow), and reaching the ocean on 29 March. By 6 April, the Highcastle flows had built a 500-m-wide lava bench 20-30 m oceanward. On 7 April, a large breakout from the 104-m elevation on Paliuli headed towards the ocean on top of previously emplaced flows. By 8 April, flows on the coastal plain had stilled and the amount of lava entering the ocean decreased. The east rift zone eruption paused briefly on 11 April and flows on the coastal plain stagnated.

When the eruption later resumed, lava broke out of the tube system on Pulama pali, feeding numerous aa and pahoehoe flows. Two lava flows entered the ocean on about 18-20 April. Pahoehoe lava engulfed an older cone that had been created by littoral explosions in July 1994, leaving only a remnant of the cone visible on 20 April. The following day, a seismic station in the coastal area recorded a bench collapse-littoral explosion and at the same time observers saw the steam plume abruptly increase in size.

On the topic of a public policy issue relevant to volcanologists and public access to volcanoes, in 1992 US and local government personnel rescued a movie cameraman trapped on a ledge above Pu`u O`o lava lake. Although rescue workers were cited for valor, an Associated Press news report (Miller, 1995) also mentions how local authorities made subsequent attempts to gain partial reimbursement for $75,000 in rescue expenses. These latter efforts were unsuccessful. According to the news story, in the United States two strategies appear to have emerged for dealing with rescue and related costs: 1) stiff fees paid by park users (eg. $150 for a climbing permit in Denali National Park, Alaska), and 2) rules or laws that specifically dictate that fees be billed to those rescued.

References. Miller, Angela S., 1995, When Risk Leads to Rescue, Who Pays the Cost?: Associated Press, 10 February 1995.

Information Contacts: Tari Mattox and Paul Okubo, USGS Hawaiian Volcano Observatory, Hawaii Volcanoes National Park, HI 96718, USA.


May 1995 (BGVN 20:05) Citation IconCite this Report

Lava flows and ocean entries very active in the Highcastle area

Eruptive activity along the E rift zone continued into early June, spilling lava into the ocean at the Highcastle and Kamoamoa sites. Breakouts from the Highcastle flow covered new land on the W margin and continued to burn Chain of Craters Road. Between 25 April and 8 May, inflation of the Highcastle flow was dramatic, and the old sea cliff was less distinct where active lava tubes crossed it. The Highcastle bench continued to grow and extend into the ocean, with as many as five active entries. Explosive activity was reported around 22 May. From late April to early June, the Kamoamoa entry was small but continuously active, dribbling lava into the ocean on the E side of the delta. By 5 June, almost all of the lava was confined to tubes. A few large surface flows were active on and above Pulama Pali from late April to mid-May; a breakout at 665 m burned through a large kipuka before stagnating.

Pu`u `O`o pond was 81-94.5 m below the crater rim throughout this period. The pond was at its lowest level on 2 May when lava poured into a NE cavity of the pond, eventually plugging it and returning the pond activity to normal. Two large lava cascades on the SW side of the pond, which appear when the level is low, were also visible at that time. On 16 May the pond was circulating slowly from SW to NE, with spatter activity concentrated in the center.

A number of rockfalls between 25 April and 8 May enlarged the upper collapse pit on Pu`u `O`o's W flank, dusting the N flank of the cone with fine red cinder. Sometime during 2-8 May, a 100 x 5-10 m piece of the SE crater rim collapsed, taking trail markers and a sampling box with it. Possibly as a result of this collapse, several meters of the SE crater wall were covered with a sheet of spatter.

Tremor intensity remained at ~2x background level until the morning of 27 April when ~7 rockfall events were recorded at the seismic station nearest Pu`u `O`o. Tremor amplitude then decreased to near background, where it persisted with occasional scattered bands of increased amplitude through 17 May, when a steady, gradual increase in amplitude (to ~3x background) began. By early June tremor intensity was again at background levels. Microearthquake counts were low beneath the summit except for 5 May, when LPC-A events totalled 194. Microearthquakes along the E rift zone were generally low in number until early June, when they rose to average levels. On 3 June, a M 3.6 earthquake hit the uppermost end of the E rift zone, slightly E of the caldera. Despite a flurry of aftershocks, no damage or injuries were reported.

Information Contacts: Tari Mattox and Paul Okubo, USGS Hawaiian Volcano Observatory (HVO), Hawaii Volcanoes National Park, HI 96718, USA.


July 1995 (BGVN 20:07) Citation IconCite this Report

Continued collapse of the Pu`u `O`o cone; lava flows and ocean entries

Much of the lava starting at the SW flank of Pu`u `O`o was delivered to the ocean via a system of lava tubes. One of the ocean entry points, the Highcastle entry, was continuously active and intermittently explosive throughout July.

On 22 July the lower Highcastle bench and a stranded littoral cone on the upper bench collapsed, an event followed by littoral explosions. The collapse displaced an area ~100 x 15 m in size that dropped into the ocean. Around 21 July a small skylight opened allowing a view into the tube carrying the Highcastle flow. The flow was initially visible in the skylight, but within a week a crust formed over the flow.

Although the Highcastle entry vented lava during 1-14 August, its output seemed variable, perhaps influenced by the fluctuating discharge of flows upslope. For example, mild explosive activity was observed on 7-8 August, an interval when no lava escaped onto the coastal plain. Two pahoehoe flows were noted upslope on 3 August, originating at 660 and 650 m elevation. The upper flow was not active on 11 August; however, that day the lower flow was still active and burning forest at the 590 m elevation. On August 11 observers looked through the skylight at 735 m elevation and measured a stream of lava 15 m wide and 19 m deep.

The volume of lava escaping at the Kamoamoa entry diminished during late-June; on 4 July, lava from the Kamoamoa tube stopped entering the ocean. Lava escaping at the base of the slope called Paliuli fed a flow that intermittently entered the ocean around Lae'apuki. This flow stagnated on 13 July. On 21 July a sheet flow from 375 m elevation burned through the Thanksgiving kipuka, formerly an easily discernible island of vegetated land within the Kamoamoa flow at the base of Paliuli. Having stagnated around 28 July, this flow did not reach the ocean. Active flows were observed on the coastal plain on 23 June and 1 July. They were also sporadically active on the slope of Pulama Pali (390-175 m elevation) and, on 17 July, one flow reached within 100 m of Paliuli.

On 1 August, a flow began escaping from the Kamoamoa tube at ~490 m elevation and cascaded down Pulama Pali. By 3 August the flow had spilt into three distinct parts, including a voluminous flow on the E, a pahoehoe sheet flow with many active streams on the W, and an 1,800-m-long aa-pahoehoe flow following a channel in the middle. By mid-August, the W flow had reached the base of Pulama Pali, the E flow had crossed the flats between Pulama Pali and Paliuli, and the middle flow had stopped moving.

Continued collapse of the Pu`u `O`o cone caused a black dust plume seen on 4 July. On 6 July a new debris deposit was noticed on the crater floor. The active lava pond within the crater of Pu`u `O`o was 90-95 m below the N spillway rim in late June, but was not visible after 4 July. Later in the July, the lava pond remained small and deep, ~95 m from the N spillway rim. The pond at Pu`u `O`o continued to shrink and during the first half of August its surface was over 100 m below the N spillway rim. A sluggishly moving crust had formed over much of the pond, and its only open areas were on the W and N edges.

There were two episodes of "gas-piston" bursts. One episode took place during 3 June-30 July, consisting of intermittent bursts of 1- to 2-minutes duration. Another episode took place during 26-28 July, consisting of frequent bursts of about 1-minute duration.

Tremor on the East Rift Zone during July through mid-August was chiefly of low amplitude. In the interval from 4 to 17 July, tremor bursts and banded tremor were both occasionally seen. During 18-31 July, tremor reached 2x background; bursts on 13-15 July reached to 4-5x background. During 30 June-31 July there was a low number of microearthquakes beneath the summit area and low to average number beneath the East Rift Zone. On 1-2 August the number of microearthquakes increased to high levels, but then decreased through mid-August.

Information Contacts: Tari Mattox and Paul Okubo, USGS Hawaiian Volcano Observatory (HVO), Hawaii Volcanoes National Park, HI 96718, USA.


September 1995 (BGVN 20:09) Citation IconCite this Report

Numerous lava flows upslope and on the coastal plain; new ocean entry formed

A large lava flow broke out of the E (Kamoamoa) tube on 1 August at 490 m elevation and cascaded down Pulama Pali (a fault scarp); by 3 August the flow had split into three lobes. The E flow was the most voluminous and advanced down the W side of the flow field as an aa/pahoehoe flow with multiple channels. The W flow was a large pahoehoe sheet flow with many active streams. The middle flow was an 1,800-m-long channelized aa/pahoehoe flow, but had stagnated by mid-August. On 17 August the W lobe cascaded over Paliuli and spread out along its base over the next five days. That same day the E lobe reached the coastal plain and on 18 August was within 200 m of the WHA seismometer, which was removed the next day. Two pahoehoe flows were noted upslope on 3 August, originating at ~660 and ~650 m elevation. The upper flow was not active on 11 August; however, the lower flow was still active and burning forest at 590 m elevation. The Highcastle ocean entry was active but variable in August, with mild explosive activity on 7-8 August. During sampling on 11 August, a lava stream visible through a skylight at ~635 m elevation was 15 m wide and 19 m deep. A lava flow 300-400 m long was active close to the 600-m elevation, but all flows and the Highcastle ocean entry stagnated when the eruption paused on the evening of 22 August.

The eruption resumed on 25 August, and the first flows broke out of the tube system at 660 m elevation. Later breakouts were noted at 600 and 510 m elevations. The tube system appeared to be reoccupied only as far as the 510-m elevation, from which point a large aa flow cascaded down the E side of the flow field. By the 28th, flows had advanced to 240 m elevation. By 29 August the Kamoamoa lava tube had been reoccupied as far as the top of Pulama Pali. Several surface breakouts burned kipukas above the pali, and numerous shallow skylights developed. On the slope of Pulama Pali, aa and channelized pahoehoe flows advanced in two major fronts down the E side of the Kamoamoa flow field, burning forest along the edge. The leading edge of these flows reached the base of Pulama Pali on 29 August and advanced as pahoehoe sheet flows toward the coast, entering the ocean on 7 September. Through 11 September, pahoehoe spilled into the ocean at several discrete locations in a zone ~200-300 m wide on the far E margin of the Kamoamoa flow field.

On 12 September, voluminous channelized and sheet flows were observed at the coast and on Pulama Pali; surface flows on the slope were limited to intermittent breakouts. These lava flows continued to burn forest along the E edge of the flow field. Pahoehoe sheet flows several hundred meters wide continued to enter the ocean at the E edge of the Kamoamoa flow field (Kamokuna) in late September. A new ocean entry 1 km W of the other flows (Kamoamoa) was established on 21 September. By 9 October a major ocean entry fed by a tube was well established at Kamokuna and generating a large plume from a diffuse, ~100-m-wide entry zone of surface pahoehoe flows; there was only minor explosive activity. Smaller, intermittent entries were observed farther W at Kamoamoa, where surface pahoehoe flows occasionally reached the ocean. On the slope of Pulama pali, most of the lava was traveling in tubes, though small surface flows were frequent.

The pond at Pu`u `O`o continued to shrink in early August, and a sluggish crust had formed over much of the pond; the only open areas were on the W and N edges. The pond remained locally crusted and fairly small in late August; it was often >95 m below the crater rim, but it rose slightly during the pause. Between 25 August and 1 September the pond rose ~30 m, but subsequently dropped back to around 100 m. During this interval very vesicular tephra were deposited on the crater rim. By 5 September, the lava pond had risen to 60 m, overlapping the old crater floor formed in February 1992, but again receded to ~100 m depth by 12 September. The level of the lava pond then remained unchanged at roughly 80 m below the crater rim through 9 October. Sloshing lava in the ~15-m-diameter circular pond occasionally overflowed onto the adjacent crater floor formed during August.

Eruption tremor levels along the East Rift Zone remained low, with sporadic bursts of higher amplitudes during 6-9 August. Microearthquake counts were high on 1-2 August, but were below average beneath the summit and rift zones through mid-month. Low-level tremor persisted until the evening of 22 August, when it decreased in amplitude. Amplitudes remained at nearly background levels until the morning of the 26th, gradually increasing to nearly 2x background. On 24 August, counts of shallow (LPC-A) and intermediate-depth (LPC-C) long-period earthquakes were high. The counts remained high through the 26th for the LPC-C events and through the 27th for the LPC-A events. On the evening of 24 August a shallow M 3.2 earthquake beneath the upper edge of the East Rift Zone was felt mildly by a few nearby residents. Eruption tremor levels were fairly high until early on 30 August. Tremor amplitudes in early September dropped to nearly background levels with bands of higher amplitudes of one-half to three hours duration.

The number of intermediate, long-period microearthquakes was high during 5-8 September (nearly 500 events). Tremor levels were relatively low during 12-25 September except for isolated higher-amplitude bursts. Eruption tremor amplitudes were ~2x background until 30 September. From 1 October, tremor levels dropped slightly, and by 4 October, banding patterns of low amplitudes alternating with higher amplitudes became apparent. Also, from 1 October, intermediate-depth long-period (LPC-C) earthquake counts began to increase. The most intense days were 5-7 October, with total daily counts of 167, 434, and 214, respectively; many were large enough to locate. Short-period microearthquake activity remained low to moderate beneath the summit and rift zones from August through early October.

Information Contacts: Tari Mattox and Paul Okubo, Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, Hawaii Volcanoes National Park, HI 96718, USA.


December 1995 (BGVN 20:11) Citation IconCite this Report

Surface lava flows, lava tubes, and ocean entries still active

The East Rift Zone eruption continued in the last quarter of 1995 with lava erupting from the 780-m elevation flank vent next to the Pu`u `O`o cone (figure 98). The lava immediately entered subsurface tubes and traveled SE toward the coast, a distance of ~11 km.

Figure (see Caption) Figure 98. Map of recent lava flows from Kīlauea's east rift zone, October 1995. Contours are in meters and the contour interval is approximately 150 m. Courtesy of the USGS Hawaiian Volcano Observatory.

Activity during 10 October-6 November. Most surface flows broke out from the tubes on the steep slope of Pulama Pali and on the coastal plain. Some of these flows burned vegetation and extended the flow field at the base of Pulama Pali several hundred meters E. On the flats at the coast, surface flows occurred just upslope from the ocean entry at Kamokuna, and also 1 km farther W, near the old Kamoamoa campground. A major bench collapse at the Kamokuna entry on 16-17 October was accompanied by explosive activity that built two littoral cones.

A portion of the crater floor in the Pu`u `O`o cone collapsed, leaving a pit ~50 m in diameter that was partially filled by a large rockslide from the base of the W crater wall. The timing of the pit formation probably coincided with seismic events either on 19 and/or 29 October. The lava pond rose to ~75 m below the N spillway. On the upper slope above Pulama Pali, new skylights in the roof of the lava tubes continued to appear and crust over rapidly. Surface flows in this area and on the slope of Pulama Pali were small and infrequent. Most of the lava traveled via lava tubes to the coastal plain on the E side of the Kamoamoa flow field. Isolated breakouts occurred in the central part of the flow field, below Paliuli. The ocean entry at Kamokuna continued to produce a large acidic plume. Interaction between lava and seawater was occasionally explosive and formed two littoral cones on the bench.

Eruption tremor levels remained relatively low with amplitudes ~2x background. Long-period events from both shallow- and intermediate-depth sources continued at low-moderate rates. The number of short period microearthquakes was low beneath the summit and rift zones.

Activity during 7 November-4 December. A brief pause during the night of 10-11 November was immediately preceded by increased shallow seismic tremor and slight summit deflation. By the morning of 11 November lava was no longer entering the ocean at Kamokuna; however, activity at the eruption vent and the Pu`u `O`o cone had already resumed. During the afternoon, the lava pond was very active, its level fluctuating at least 10-15 m within 30 minutes, with spattering up to a height of 30 m. By the following day, lava was once again entering the ocean. Since this short pause, the lava pond has maintained a level ~75 m below the N rim. The floor of the large collapse pit was partially resurfaced by new lava flows after the pause.

Surface flows on the lower slope of Pulama pali and on the coastal plain continued to expand the Kamoamoa flow field E into forest and grasslands. At the shoreline, advancing pahoehoe flows filled the gap created by Kupaianaha eruptions in 1992, at the E edge of the current Kamoamoa flow field. These flows have produced a new ocean entry ~500 m E of the Kamokuna entry.

A large bench at the West Kamokuna entry collapsed on 23 November. Sustained explosive activity on 26 November built a new littoral cone (3-4 m high) on the bench. Lava was entering the ocean at 2-3 locations along a new East Kamokuna bench, located inside the W edge of the old Kupaianaha flow field. Breakouts from the relatively immature tube system were continuously active on the coastal plain near this entry. An older tube continued to feed isolated breakouts in the middle of the Kamoamoa flow field. The long-lived skylight at 735 m elevation finally crusted over in late November, leaving the tube system completely sealed off for the first 4 km from the vent. However, new skylights continued to appear and crust over near the top of Pulama Pali.

Eruption tremor was low and relatively steady, with a few isolated increases in amplitude in banded patterns. Shallow, long-period microearthquakes were slightly above average on 11, 12, and 16 November, with daily counts of nearly 100. Intermediate-depth, long-period counts were high on 2 and 3 December. Short-period summit and rift microearthquake counts were low.

Activity during 5 December-1 January. Small surface breakouts were observed high on Pulama Pali and on the coastal plain. The West Kamokuna entry occupied a large, mature bench; on 12 December, explosive activity at this entry built a new littoral cone. The East Kamokuna entry continued building a new bench. A pause in the eruption began at 1500 on 14 December and lasted until midnight on 15-16 December. The plume from the ocean entries stopped completely by 16 December. When the eruption resumed, lava again flowed through the existing tube system and reached the ocean at West Kamokuna bench on the afternoon of 17 December. The East Kamokuna entry was not reactivated after the pause.

Just prior to the 14-16 December pause, only a solid crust was visible where the Pu`u `O`o lava pond had been, at 80-90 m below the rim. By 19 December the lava pond had risen to ~68 m below the rim of the cone and was actively circulating. The pond level then subsided several meters and stabilized by 28 December. Surface flows occurred high on Pulama Pali, between 675 and 570 m elevation, and in the area from the 300-m elevation on Pulama Pali, down to the far eastern side of the flow field, to the coastal plain and ocean entry. Flows moved E into the grassland and brush near the base of Pulama Pali. A single ocean entry at West Kamokuna was active in late December, where a major collapse between 30 December and 1 January took out a section of the bench ~50-70 x 200-300 m in surface area, including several littoral cones. Explosive activity was observed at the ocean entry both before and after the collapse, but the most energetic and spectacular activity was reported on 1 January, immediately following the bench collapse. This activity included lava bubble burst and spatter and tephra ejections to heights estimated at 60 m. These explosions built a new littoral cone.

Eruption tremor levels remained low at ~2-3x the background. Shallow, long-period (LPC-A, 3-5 Hz) microearthquake counts were high on 5 December and again from 15-18 December. On the 15th and 16th, LPC-A counts were 200/day, gradually diminishing on the 17th and 18th. Shallow, long period (LPC-B, 1-3 Hz) microearthquakes were also high in number during 16-18 December, peaking on the 17th, with more than 150 events counted. Both types of LPC events are from a source 0-5 km in depth. They differ in frequency, suggesting a possible change in the condition of the source.

Shallow summit activity continued in the second half of December, with many hundreds of long-period (LPC-B, 0-3 Hz) events per day. The high counts peaked on 22 and 24 December with daily totals of 1,730 and 1,346, respectively. By 26 December, LPC-B counts appeared to be decreasing, while a slight increase of LPC-A was noted. The increase of shallow activity was coincident with the mid-December eruptive pause. Microearthquake counts were below average.

Information Contacts: Dave Clague, Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, Hawaii Volcanoes National Park, HI 96718, USA.


January 1996 (BGVN 21:01) Citation IconCite this Report

Eruptive pulse on 1 February almost results in a summit eruption

The eruption on the East Rift Zone continued in January with the usual activity consisting of surface lava flows and lava traveling through tubes to enter the ocean. However, an unusual event on 1 February almost resulted in a summit eruption. Following this event an eruptive pause began that continued through mid-February.

Normal activity in January. Surface flows during the first two weeks of January covered ~4 km2 on the E side of the Kamoamoa flow field. On the slopes of Pulama pali, lava breakouts followed the E margin of older flows as far as 1 km, sometimes burning adjacent forest and grassland. On the coastal plain, inflating sheet flows were widespread. At the West Kamokuna entry the bench was rebuilt following the collapse of 1 January (BGVN 20:11/12), and two littoral cones were created.

The Great Pit, a collapse pit on the SW slope of Pu`u `O`o cinder cone, was enlarged by several collapses since late December, expanding toward a second collapse pit over an Episode-51 vent. This vent, which has continued to issue lava during the current Episode 53, is connected to the Pu`u `O`o lava pond; a series of collapses in recent months defined a line from this pit across the rim of the cone to the lava pond inside and probably resulted from breakdown of the roof in the underlying plumbing system.

Almost daily explosive activity at the Kamokuna bench in the second half of January included bubble bursts and spattering to 50 m height, as well as steam and ash jetting to 150 m. On 25 January a small collapse removed a 40 × 100 m area of the lower bench, along with part of a littoral cone. The collapsed area was rebuilt within three days, and explosive activity constructed a new littoral cone. On the night of 30 January a large bench collapse at Kamokuna occurred over a period of six hours, during which time approximately 800 × 200 m of the bench slid into the ocean accompanied by frequent explosions that threw blocks as far as 300 m inland. Lava flows were continually active on the slope of Pulama pali, particularly around the base and on the coastal plain within 1.5 km of the ocean entry. Pahoehoe flows burning into forest and brush caused loud and abundant methane explosions. Lava flows on the coastal plain advanced E to within 500 m of the Royal Gardens access road.

Eruption tremor remained low with minor, irregular variations. Tremor amplitudes in the second half of January measured ~2x the background level on the STC seismic station near Pu`u `O`o. Shallow, long-period activity at the summit was about average. Short-period microearthquake counts were low beneath the summit and rift zones.

Eruptive pulse of 1 February. Unusual and dramatic activity started on the morning of 1 February with a large increase in shallow tremor at the summit caldera and rapid inflation of the summit, suggesting that an eruption from the summit or upper East Rift Zone might be imminent. As a result, most of Hawaii Volcanoes National Park, including the local airspace, was closed for several hours. However, no new ground cracks or eruptive fissures formed. Instead, the increase in tremor was followed three hours later by an order-of-magnitude increase in the volume of lava flowing into tubes from the vent on the flank of Pu`u `O`o cone.

Excess pressure in the tube system caused the lava to gush out of four skylights, forming dome fountains at 735, 720, 695, and 675 m elevations. Prior to this event, no surface flows had occurred above 675 m since early 1993. Heights of the fountains in mid-afternoon were 1.8-7.6 m. Lava from the largest fountain formed a channelized flow that ran E into the forest, and then descended Pulama pali as a fast-moving aa flow. Inside Pu`u `O`o, the actively circulating lava pond rose to at least 60 m below the rim, and sloshed another 15-20 m higher. Spatter from the pond was thrown 50 m beyond the S crater rim.

Over the next three days, the level of activity gradually decreased. The Pu`u `O`o lava pond exhibited cycles of influx and drainback, but remained relatively deep (65-80 m below the rim). Lava flows from the skylights started and stopped, as did surface flows on the coastal plain. The Kamokuna ocean entry paused for 11 hours on 2 February, probably because of blockage in the tube system, and then flowed at diminished volume on 3-4 February. Late on 4 February the eruption stopped. Sometime during the next night, an explosion in the Great Pit blasted out fragments (up to fist-size) of mostly reddish oxidized rock. The smaller fragments were carried ~9.5 km NE by Kona winds. The pause continued through 12 February.

The change in lava effusion rate was attended by an episodic increase in gas release. Fumaroles at the summit and East Rift Zone showed abnormally high CO2 levels starting on 1 February, possibly reflecting a pulse of gas-rich magma. Ambient SO2 in the HVO parking lot topped 4 ppm on 2 February and was greater than 1 ppm near the NPS Visitors Center. SO2 emission rates measured near the eruption site were as high as 2,000 metric tons/day on 2 February. SO2 emission rates and fumarole chemistry from the summit and east rift were approaching near-normal for an eruptive pause by 12 February.

Seismicity and deformation. Tremor amplitudes remained at 2-3x background level until the morning of 1 February. Shortly after 0800, tremor on the STC station gradually increased; summit seismicity increased at the same time. Tremor, as well as a swarm of shallow, short-period earthquakes, registered on the summit seismic stations as a result of the intrusive episode. Several hundred microearthquakes were counted. Seismicity at the summit began to subside shortly after noon with a notable decrease in summit tremor and short-period earthquakes. An increase of shallow and intermediate long-period earthquakes followed. By 1600, tremor amplitudes on the STC station were high and remained relatively steady until about 1200 on 2 February. Tremor amplitudes again increased on 3 February at 0700 and remained at elevated levels until 0200 on the 4th. From then through 12 February amplitudes fluctuated in banded patterns of a few minutes to a few hours of increased tremor, alternating with low- level tremor.

The Uwekahuna short-base water-tube tiltmeter recorded summit inflation, with ~11 µrads of N-S tilt and ~15 µrads of E-W tilt during the seismic swarm of 1 February; the maximum tilt was read at 1246. Summit deflation followed at a rate of ~1.5 µrads/hour, coincident with the increase in activity at Pu`u `O`o. By 0830 on 2 February, the E-W component had recovered to the pre-swarm level of deflation and the N-S component to ~2/3 of the pre-swarm level. A permanent-glass EDM monitor spanning the summit caldera of Kīlauea from the flank of Mauna Loa to the Kalanaokuaiki fault recorded the maximum extension between the N caldera rim and a site 1 km S of Halemaumau. This was also the area in which the earthquake swarm was localized. Measurements on 6 February showed contraction to pre-swarm values in conjunction with the summit deflation.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, Hawaii Volcanoes National Park, HI 96718, USA.


March 1996 (BGVN 21:03) Citation IconCite this Report

Heightened activity on 1-4 February followed by 10-day pause; bench construction

Unusually heightened activity along Kīlauea's East Rift zone on 1-4 February was followed by a pause that began on 4 February and ended at midnight on 14 February (BGVN 21:01). Tilt in the N-S direction increased roughly 3-fold; in the E-W direction, roughly 4-fold. Daily counts of shallow, summit SPC earthquake counts rose from around 10/day to 580/day.

During the 14-day pause, lava continued circulating inside the lava pond at Pu`u `O`o cone but no lava was seen flowing in downstream tubes. The lava pond rose to 60-70 m below the rim as the eruption restarted and lava re-entered the tubes around mid-day on 14 February.

Lava subsequently broke out of the tubes to reach the surface at numerous locations (including those at 750-, 720-, 700-, 450-, and 90-m elevations and on the coastal flats). About 31 hours later lava reached the ocean via the old tube system. Despite these numerous sites where lava had been escaping from tubes on 14-15 February, in the days following lava generally ceased reaching the surface and feeding lava flows. Lava did emerge at elevations of 60 to 100 m and on the coastal plain between Kamokuna and Kamoamoa (figure 99). The surface of the lava pond dropped by 19-21 February, possibly reaching 90 m below the rim. Still, on 23 February aa emerged at 270 m elevation. The same day, 23 February, explosive activity at the Kamokuna bench built a new littoral cone.

Figure (see Caption) Figure 99. New land and active entries in the Kamokuna area, March 1996. Index map shows the swath of 1992-96 lava flows. Courtesy of HVO.

As late as 9 March, flows confined to the area below Pulama Pali and the coast covered much of the S half of the Kamoamoa flow field but failed to reach either adjacent grasslands or the sea. During the early hours of 29 February the entire lower coastal bench, a roughly 30 x 100 m area, fell into the ocean. The event was recorded seismically at an instrument 10 km distant. Since then, freshly erupted lava began constructing a new coastal bench.

During the second half of February through early March, low-amplitude tremor in the East Rift continued; during 13-26 February and 12-25 March tremor amplitudes were ~3x background but showed fluctuations. During the February interval microearthquake counts were low beneath the summit and rift zones. Shallow, long-period microearthquake counts were high on 4-5 March and briefly again on 8 March. On 2, 5, 7, and 8 March there were four events > M 3.0 in the 7-33 km range. Deep tremor from the usual SW source was recorded in three episodes during 14-15 March: a total of 90 minutes on 14 March and 108 minutes on 15 March. Counts of shallow, long-period earthquakes increased during 19-23 March reaching a maximum daily total of 1,750.

On 24 March, 2 hours of elevated tremor (4-5x background) took place without accompanying shallow short-period earthquakes. That same day, the summit inflated rapidly for an hour and then deflated for several hours. The rate of inflation was similar to that of 1 February but the summit acquired only 3 µrads of tilt compared with the 15 µrads seen on 1 February. As the summit deflated on the afternoon of 24 March, the eruption site on the East Rift zone probably received a small magma surge resulting in moderate-sized breakouts in the early afternoon. The breakouts, which originated from the lava tube at the 820-, 750-, and near the 600-m elevations, produced small pahoehoe flows that were mostly stagnant by the next morning. On the night of the 24th, bright glow from Pu`u `O`o indicated turbulence in the lava pond. Except for these flows on 24 March, surface lavas mainly appeared below the base of Pulama Pali.

At the coast, spectacular explosions, some as high as 70 m, began on 19 March. Though diminishing thereafter, they persisted until at least 6 days. Observers saw lava bubble-bursts, lava fountains, and steam jets. These explosions built up five new littoral cones ~130 m W of the earlier Kamokuna entries inside the National Park (figure 99).

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA.


May 1996 (BGVN 21:05) Citation IconCite this Report

Surface flows, ocean entries, and bench collapses; summit inflation episode

Surface flows were limited to the area below 180 m elevation in late March and early April (figure 100). Through the end of March, the Kamokuna ocean entry exhibited frequent explosive activity. On 6 April the volume of lava entering the ocean diminished as breakouts from the tube increased. By the 8th, the entry was producing a moderate-sized plume, and many small pahoehoe flows were active on the coastal plain. Most of the activity during 9-22 April took place below 165 m elevation, near the base of Pulama Pali. The surface flows on the coastal flats below Paliuli entered the ocean, forming three new entries in addition to the long-lived Kamokuna entry. On 9 April, surface flows entered the sea at the E end of the 1994 Lae'apuki bench (figure 100). Another flow entered the sea in the Kamoamoa area on 15 April, about halfway between the E Lae'apuki and Kamokuna entries. On the 22nd, a small lobe of the flow feeding the E Lae'apuki entry branched off to the W and produced a small new entry. The Pu`u `O`o pond was ~80 m deep as of 18 April and had divided into two active areas separated by a 30-m-wide segment of stationary crust.

Figure (see Caption) Figure 100. Map of recent lava flows from Kīlauea's east rift zone, April 1996. Contours are in meters and the contour interval is approximately 150 m. Courtesy of the USGS Hawaiian Volcano Observatory.

The three active ocean entries were mostly nonexplosive from 23 April to 6 May. On the night of 28 April a large collapse of the Kamokuna bench removed a piece roughly 100 m wide by 400 m long. Surface flow activity was concentrated on the coastal plain. A moderate size "rockfall" registered on 2 May at local seismic stations, suggesting a possible collapse near Pu`u `O`o.

Surface flows during 7-20 May were diminished compared to those of previous weeks and limited to small, short-lived pahoehoe breakouts on the coastal plain inland of the Lae'apuki ocean entry. Lava continued to enter the ocean at Lae'apuki, Kamoamoa, and Kamokuna, with only 10-20% of the total volume entering at Kamoamoa. A major bench collapse at Kamoamoa on 16 May removed the entire bench, along with a significant piece of older inland terrain, for a total area of 375 x 60 m. Coastal explosions were recorded on 9 and 16 May, possibly related to bench activity. The lava pond inside Pu`u `O`o was visible on 16 May and appeared unchanged at a level of 80-90 m below the rim.

On the afternoon of 11 May, two short bursts of rapid summit inflation during a three-hour period were accompanied by shallow seismic tremor up to 6x background level. They were followed by four hours of deflation. This event did not noticeably affect the location or volume of lava flows on the east rift zone.

Through 29 May the eruption continued with three active ocean entries and small pahoehoe breakouts on the coastal plain from the lava tube supplying the Kamoamoa entry. A large pahoehoe sheet flow was observed at 180 m elevation on 29 May. On 29-30 May the eruption gradually shut down over 18 hours. By the morning of 30 May, the ocean entries had died and the 13th pause of Episode 53 had begun. During the pause, the level of the lava pond in Pu`u `O`o cone fluctuated by as much as 30 m, rising to a high point of 58 m below the rim on 3 June. Lava also appeared on the floor of the Great Pit in the outer wall of the cone. This pause in the eruption lasted until 4 June.

Seismicity. Eruption tremor continued with amplitudes averaging ~2-3x background level from 26 March through 3 June. There were three episodes of weak, deep tremor from a SW source on 31 March, 2 April, and 5 April. A fourth tremor of moderate size from the same source occurred on 7 April. Daily counts of shallow, long-period summit events were moderate to low with a maximum of 119 on 27 March. Microearthquake counts then remained generally low beneath the summit and rift zones through 20 May. Shallow, long-period microearthquake counts increased during 21-22 May and again from 30 May to 3 June. A flurry of shallow earthquakes at the uppermost end of the Upper east rift zone began on 30 May. High counts persisted and peaked on 3 June, with >200 events for the day. The number of short-period events was low beneath the summit from 21 May to 3 June.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA.


July 1996 (BGVN 21:07) Citation IconCite this Report

Surface flows, ocean entries, and bench collapses; continued eruption tremor

The eruption along the East Rift Zone continued in June and July after a pause from 30 May to 4 June (BGVN 21:05). On the morning of 4 June, lava began to fill a large collapse-pit over the tube near the base of Pu`u `O`o. Soon thereafter, a breakout at 690 m elevation fed a broad, slow-moving pahoehoe sheet flow. By the late afternoon of 4 June, channelized aa flows were streaming down the face of Pulama Pali (a fault scarp) from breakouts and large pahoehoe sheet flows were emanating from the tube near the base of the pali. Surface flows continued to spread W across the coastal plain below Paliuli. On the morning of 6 June, the flow front reached the ocean near Lae`apuki. By 13 June, three additional ocean entries were established spanning 1.6 km of coastline. All four entries remained active through 14 June, and surface flows diminished to a few breakouts on the coastal plain. After rising to 58 m below the rim on 4 June, the pond in Pu`u `O`o receded to a depth of 80 m.

During 18 June-1 July, tubes delivered lava to the ocean at three points (West Lae`apuki, Lae`apuki, and Kamoamoa) along a 1.8-km stretch of coastline within Hawaii Volcanoes National Park. Just before midnight on 22 June, a large collapse at the Lae`apuki entry removed roughly 12,000 m2 of the bench and the area immediately inland. Surface flow activity was concentrated on the coastal plain inland of the entry points. A few breakouts were intermittently active on the slope of Pulama Pali. The lava pond at the bottom of Pu`u `O`o Crater remained active at ~85 m below the rim.

Throughout July lava flowed to the ocean through an 11-km-long tube system. Approximately 95% of lava that reached the ocean entered at Lae`apuki; the remaining 5% entered from a 200-m-wide zone of surface flows at West Lae`apuki. At the main Lae`apuki bench, two skylights appeared over the tube within 150 m of the shoreline.

A small collapse of the West Lae`apuki bench was witnessed at 1920 on 10 July. A major collapse at the main Lae`apuki bench claimed several acres at 2000 on 12 July. Both bench collapses were accompanied by explosions and spattering at the shoreline. The Lae`apuki bench was completely rebuilt by 25 July. Explosive activity at this ocean entry was common during the week of 21-28 July, and by 27 July a littoral cone had been constructed. However, the entire Lae`apuki bench collapsed into the ocean again on the evening of 28 July.

Surface flows during the first half of the month were confined to the coastal plain in the center of the Kamoamoa flow field. Later in the month surface flows on the coastal plain occurred within 150 m of the ocean at West Lae`apuki. These flows came within several meters of the kipuka and remnant of the old coastal road at Highcastle and covered 25% of the black sand beach below the Highcastle overlook. Two surface flows occurred at higher elevations. On 23-25 July, a pahoehoe flow from a skylight traveled 300 m down the face of Pulama Pali. In addition, a 300-m-wide lava flow issued from the skylight at 690 m elevation between 26 and 29 July.

Inside Pu`u `O`o, gas pistoning in two distinct lava ponds was observed over several hours on 9 July. The pond levels rose and fell by 15 m during 10-minute cycles. However, the level of the lava pond generally remained at 80-85 m below the rim during most of June and July.

Seismicity. Eruption tremors continued along the East Rift Zone of Kīlauea with amplitudes fluctuating between background and 2-3x background levels in June and July. Microearthquake counts were low to moderate beneath the summit and rift zones. There were several episodes of weak to strong deep tremor from the usual SW source, the strongest of which occurred between 0637 and 0716 on 12 June. Explosive events were detected along the coast of Kalapana between 2330 on 22 June and 0017 on 23 June, at 1900-2300 on 12 July, and at 1700-1900 on 28 July. Several of these events were equivalent to, or greater than, an M 2.8 earthquake. Between 1700 and 1800 on 12 July, a small burst of long-period intermediate-depth events was located beneath the summit.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA.


September 1996 (BGVN 21:09) Citation IconCite this Report

Eruptive activity continues; ocean entry and lava bench collapses

During August and September, the eruption along the east rift zone continued without significant change and flows entered the ocean only at Lae`apuki in Hawaii Volcanoes National Park (figure 101). During the first ten days of August, the lava pond within Pu`u `O`o was sluggish and ~100 m below the lowest part of the rim. Glows from the pond reflecting off the fume cloud over the cone were often seen at night. After a short eruptive pause on 21 August, most of the lava was confined to tubes all the way to the sea, with only a few small surface flows from breakouts. Shortly after midnight on 29 August, a large collapse removed two-thirds of the active lava bench at Lae`apuki. During the early morning of 19 September, a large block of the Lae`apuki bench slid into the ocean. Sufficient energy was transferred to the ground for the HVO seismic network to detect the event, which lasted for eight minutes.

Figure (see Caption) Figure 101. Map of recent lava flows from Kīlauea's east rift zone, June-September 1996. Contours are in feet. Courtesy of the Hawaiian Volcano Observatory, USGS.

The lava flow field from this eruption that began in 1983 covers 23,475 acres, and ~820 acres of the flow field have been resurfaced by new lava since the beginning of June, when the eruption restarted after a five-day pause (BGVN 21:05). A total of 540 acres of new land has been added to the island since lava began entering the ocean in late 1986. As has been the case with other long-lived ocean entries, bench collapses at Lae`apuki have increased in frequency and are occurring about every two weeks. After each collapse, a severed lava tube or incandescent fault scarp is exposed and violent explosions follow. Types of explosive events observed at Lae`apuki after mid-August included sudden rock blasts, sustained and powerful steam jets, lava fountains, and "bubble-bursts" from holes in the tube above the entry.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: http://www.soest.hawaii.edu/hvo/).


November 1996 (BGVN 21:11) Citation IconCite this Report

Eruptive activity continues; lava-bench collapses

During October and November, eruptive activity along the east rift zone continued without significant change. Lava issued at a rate of 4.6 m3/second from a vent on the W flank of the Pu`u `O`o cinder cone, and flowed through a network of lava tubes for 10 km to the ocean entry at Lae`apuki (figure 102). The lava pond within Pu`u `O`o was 75-85 m below the crater rim during October and November, and was divided into two reservoirs that circulated, drained, and filled independently. The lava tubes were quite stable, and almost no surface flows were seen after the end of August. Large, billowing steam plumes, tinged with red at night, marked the main points of discharge, which lay near the central edge of a 100-m-wide lava bench. Mild explosive activity and splattering were sometimes observed when lava flowed into the surf. Small littoral cones, a few meters high, grew sporadically above the discharge points. Bench collapses occurred during the week of 2-8 November, and about a quarter of the bench slid into the sea.

Figure (see Caption) Figure 102. Map of recent lava flows from Kīlauea's east rift zone, June-November 1996. Contours are in feet. Courtesy of the Hawaiian Volcano Observatory, USGS.

The current eruption began in January 1983 and has emitted >1 km3 of lava, which has destroyed 181 homes and the National Park visitor center.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: http://www.soest.hawaii.edu/hvo/).


January 1997 (BGVN 22:01) Citation IconCite this Report

New, short-lived eruptive episode (54) in Napau Crater; Pu`u `O`o pauses

During December and most of January, the dynamics of eruptive activity along the east rift zone continued without significant change; however, there were two prominent changes in landforms. On 2 December the coastal bench collapsed, removing 0.1 km2 of shoreline bench and 0.03 km2 of existing land that created a crescent-shaped embayment nearly 900 m long with widths up to 100 m. New lava continued to travel from a vent on the W flank of the Pu`u `O`o cinder cone through a 10-km-long network of lava tubes to the ocean entry at Lae'apuki (figure 103), quickly building a new subaerial bench in the W half of the embayment.

Figure (see Caption) Figure 103. Map of recent lava flows from Kīlauea's east rift zone, February 1992 - 30 January 1997. Contours are in feet (3.28 feet = 1 meter). Courtesy of the Hawaiian Volcano Observatory, USGS.

The large collapse pits, including the "Great Pit" and the episode-51 collapse pit that previously pocked the W side of the Pu`u `O`o cone, enlarged into a single pit during a sequence of slope failures. Rockfalls at the cone were recorded during the 14-hour period from 1347 on 8 December until about 0400 on 9 December. The pit was elongate in a N60°E direction and was aligned with fissures on the E rift zone in that area. Blocks continued to spall off, creating plumes that covered the W and S side of the cone with red rock dust. The summit crater to the E remained intact and the level of the lava pond remained 80-90 m below the crater rim.

Around 0243 on 30 January a new eruptive episode began, designated episode 54 by the Hawaiian Volcano Observatory. Three fissures formed within and just E of Napau Crater ~3 km up-rift from Pu`u `O`o. Lava fountains from the fissures reached tens of meters in height. By 0716 all three fissures stopped emitting lava but continued spattering intermittently. The lava flows generated during this phase covered ~190,000 m2 (figure 104, A and C).

The eruption continued as two new fissures formed at about 1239 and 1639 E of Napau Crater. These fissures emitted lava flows that covered ~58,700 m2 before fountaining ended around 1840 (figure 104, D and E). Fountaining resumed from a new fissure on the W rim of Napau crater at about 0033 on 31 January. Lava emitted from this fissure covered ~10,000 m2 (figure 104, F).

Figure (see Caption) Figure 104. Map of Episode-54 lava flows, 30 January 1997. Letter indicate fissure locations. Courtesy of the Hawaiian Volcano Observatory, USGS.

In total, six fissures emitted more than 300,000 m3 of lava within 24 hours, covering ~258,700 m2 of mostly unvegetated land. A series of intense seismic tremors preceded the eruption, the largest of which were felt at the summit and measured M 3.3 at 2336 on 28 January and 0300 and 0710 on 29 January. More than 30,000 shallow long-period summit earthquakes (high of 5,400 on 2 February) and over 3,000 shallow east rift events were counted during the eruption. Harmonic tremor was recorded near the eruption site for ~7.5 hours and was accompanied by summit deflation (17 µrads). Deflation throughout the eruptive episode totaled ~30 µrads.

Following the eruption, activity at the Pu`u `O`o cinder cone paused. The summit and west side of the cone were removed by collapse, the lava lake drained, and the crater floor dropped an estimated 100 m to a depth of ~250 m below the crater rim (~60 m below the pre-1983 surface). The collapse generated a red dust plume ~800 m high. Lava stopped flowing through the lava tube down-slope from the vent, and the ocean entry produced only intermittent steam plumes.

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea (figure 105). The latest Kīlauea eruption began in January 1983 along the east rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extend from Napau Crater on the uprift end to ~8 km E on the downrift end. Activity eventually centered on what was later named Pu'u' O'o.

Figure (see Caption) Figure 105. Map of the southeastern part of the island of Hawaii and adjacent offshore, showing the principal features of Kīlauea. Modified from Tilling and others, 1987.

Between July 1986 and January 1992, the Kupianaha lava lake was active ~3 km NE (downrift) of Pu`u `O`o (figure 103). It was during this period that the town of Kalapana and a majority of the 181 homes lost were destroyed. In December 1991, one month prior to the shut down of Kupianaha, eruptive activity returned to Pu`u `O`o. Activity had remained there until this latest episode (episode 54). More than 1 km3 of lava has erupted during the 14 years of activity (January 1983 - January 1997).

Reference. Tilling, R.I., Heliker, C., and Wright, T.L., 1987, Eruptions of Hawaiian volcanoes: past, present, and future: U.S. Geological Survey series of general-interest publications, 54 p.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: http://www.soest.hawaii.edu/hvo/).


February 1997 (BGVN 22:02) Citation IconCite this Report

Lava returns to Pu`u `O`o

Kīlauea remained quiet for three weeks following the pause that began on 31 January and the subsequent collapse of the summit of Pu`u `O`o (figures 106 and 107). At 0740 on 24 February, a helicopter pilot reported fresh lava in the Pu`u `O`o crater. USGS scientists noted that the new lava pond was positioned ~190-200 m below the crater's N rim, an elevation only slightly higher than the crater floor during the pause in activity and substantially below the 80-m depth that characterized the pond prior to the pause.

Figure (see Caption) Figure 106. Oblique aerial view of Pu`u `O`o looking SW before the late-January 1997 (episode 54) summit collapse (date uncertain). Photographer unknown; courtesy of Richard Fiske, Smithsonian Institution.
Figure (see Caption) Figure 107. Oblique aerial view of Pu`u `O`o looking SW taken shortly after the late January 1997 summit collapse. Photo by G. Brad Lewis; courtesy of Jane Takahashi, USGS.

Although the crust of the pond was overturning locally and molten lava sloshed through small holes, overall the activity appeared relatively sluggish compared to the vigorous, sloshing pond seen in the past. Similarly, fume at Pu`u `O`o emanated from the E wall of the cone but was minimal compared to pre-30 January levels. There has been no lava visible in the tubes on the flow field since their draining on 30 January. The resupply of magma into the crater occurred without the heightened seismic tremor that marks substantial movement of magma through the rift zone.

Since the pause in activity began on 31 January, the summit inflated 21 µrad. This inflation followed the 30 µrad of deflation that was observed during the short-lived Episode 54 eruption (BGVN 20:01). With minor exceptions, very low tremor was detected at station STC beginning at 0701 on 24 February and continuing at least through 10 March. Shallow, long-period summit earthquakes numbered between 2,000 and 4,000 events/day between 11 and 16 February, but had decreased to ~200 events/day by the end of February.

Eruptive history. Between July 1986 and January 1992, the Kupaianaha lava lake was active ~3 km NE (downrift) of Pu`u `O`o. It was during this period that the town of Kalapana and a majority of the 181 homes lost were destroyed. In December 1991, one month prior to the shutdown of Kupaianaha, eruptive activity returned to Pu`u `O`o. More than 1 km3 of lava has erupted during the 14 years of activity (January 1983-January 1997).

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. The latest Kīlauea eruption began in January 1983 along the east rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift (towards the summit) end to ~8 km E on the downrift end (towards the sea). Activity eventually centered on the area and crater that was later named Pu`u `O`o.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: http://www.soest.hawaii.edu/hvo/); Richard S. Fiske, Smithsonian Institution, NHB MRC 119, Washington, DC 20560 USA.


March 1997 (BGVN 22:03) Citation IconCite this Report

Lava flows outside of Pu`u `O`o for the first time since 31 January

Between 11 and 27 March, activity at the Pu`u `O`o vent along Kīlauea's E rift zone was confined to the lava pond within the crater. Pond activity remained sluggish, with periodic resurfacing and localized overturning of the crust. On 21 March, the pond's surface rose to within 84 m of the NE rim of the crater, as indicated by a crusted-solidified shelf on the W floor of the crater, then subsided 14 m to 98 m below the crater rim. Reports of the crater glowing at night were thought to correspond with periods when the level of the pond's surface rose. Fumes emanating from the eruption site remained at low levels.

During these two weeks, the summit of Kīlauea showed 8 µrad of inflationary tilt. In total, the summit recovered 29 µrad of the roughly 30 µrad of summit deflation that occurred on 30 January (BGVN 22:01).

On 28 March, lava was observed outside of the Pu`u `O`o crater for the first time since 31 January. Lava emanated from a collapse pit on the episode 51 shield that flanks the W side of Pu`u `O`o. This lava flowed into a depression to the S before it entered the old tube system, abandoned 30 January, through collapse pits and skylights. The following day, lava was seen flowing through the old tube system at the 2,400-ft (770 m) skylight. Also, the level of the pond in Pu`u `O`o rose to within 52 m of the NE rim, a level comparable to before the 30 January drain-back.

Three substantial lava flows escaped from the lava tube on 3 April. The lowest of the three breakouts fed a surface flow at the 721-m level. This flow progressed to the edge of the flow field and ignited vegetation along its edges as it advanced to elevations as low as 640 m. The next day, geophysical measurements showed that there was no lava flowing through tubes below the 705-m level. Through 7 April, flows repeatedly inflated, advanced, and stagnated.

Shallow, long-period summit earthquakes and earthquakes along the E rift zone remained at high to very high levels.

This latest resumption of activity, designated episode 55 by the Hawaiian Volcano Observatory, was considered likely to spread flows S over Pulama pali to the coast.

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the summit caldera to the sea. This latest Kīlauea eruption began in January 1983 along the E rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift (towards the summit) end to ~8 km E on the downrift (towards the sea) end. Activity eventually centered on what was later named Pu`u `O`o. Between January 1983 and December 1996, erupted lava totaled ~1.45 km3.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


April 1997 (BGVN 22:04) Citation IconCite this Report

Lava issuing from three sites; Pu`u `O`o lava lake 20 m from W crater rim

Between 8 and 21 April, lava continued to issue in a steady stream from a vent on the W flank of Pu`u `O`o that began erupting on 28 March 1997 (BGVN 22:03). This vent formed during episode-51 vent and sits on a broad shield, also constructed during that episode. The 8-21 April flows mainly advanced S and either remained at the surface as sluggish moving lobes or collected in terraced pools and pits that fed into pre-existing tubes. On 13 April, a spatter cone began to build and by 21 April had reached a height of 15 m above the shield (figure 108).

By 15 April, flows emitted at elevations of ~685-705 had ceased to spread. A flow emitted near 685 m stagnated within 1 km of a steep escarpment (pali) that slopes downward to the coast.

Figure (see Caption) Figure 108. Photograph of the W flank of Pu`u `O`o showing the breached crater rim and the new spatter cone, 28 April 1997. Courtesy of Steve O'Meara.

On 17 April, lava issued from the S flank of Pu`u `O`o 270 m downslope from the active spatter cone. This lava flowed in a channel to the SE; advancing at 1 m/minute, it became 3 km long flowing as pahoehoe upslope and aa downslope. This lava's source remained ambiguous; magma at the nearby spatter cone could have traveled to the new discharge point, or it may have traveled from a deeper origin beneath the Pu`u `O`o area.

Between 22 April and 5 May lava issued from three sites: 1) a sluggish spatter cone within the Pu`u `O`o crater; 2) a more robust spatter cone on the SW flank of the Pu`u `O`o cone (figure 108); and 3) an uplifted mound of lava and tephra on the S flank Pu`u `O`o. The first site discharged pahoehoe flows onto the crater floor. Also, the level of the lava lake in the Pu`u `O`o crater was within 20 m of the low point on the W rim. Although the previous low point on the crater rim was the N spillway, since the 30 January collapse (BGVN 22:01) the W rim has remained the low point (figure 108).

Pahoehoe and aa lava flows from the latter two sites continued to mantle an area within 2 km of Pu`u `O`o. The second site, the spatter cone on the SW flank, issued low-level fountains and draped enough thick sheets of molten lava onto the cone to generate small flows that oozed outward. Periodically, this fountaining became more vigorous than typically seen. Spectacular footage of this fountaining appeared on television newscasts; unfortunately, in some cases the fountaining was incorrectly described as marking a fundamental change in Kīlauea's volcanic activity. Both fountaining and lava flows are characteristic of this particular cone.

The third site, informally called "the uplift" by HVO, formed early in episode 55 (BGVN 22:04) when crusted lava flows were pressed against the flank of Pu`u `O`o and pushed a large wad of tephra upward by 3-4 m. A near-constant stream of lava issued from the uplift; it passed onto the flow field and in many cases it commonly ponded behind its own flow front to form broad pools. Once ponded, the lava generally drained SE forming a complex field of aa lava.

Shallow, long-period summit earthquakes peaked during and shortly after the episode-54 eruption on 30 January (BGVN 22:01) and have since continued to decrease (figure 109). Between 8 April and 5 May, eruption tremor along the E rift zone had amplitudes between background and 3x background. For example, at 0346 on April 16, tremor amplitudes decreased to background levels for over an hour. At about 1900 on 24 April, there were bursts of high tremor that lasted nearly six hours. Around 1700 on 25 April tremor amplitudes dropped to very low levels for several hours. Continuous high tremor was recorded at about 0100 on 28 April, and by about 0001 on 3 May, tremor had dropped to near background levels for ~5 hours.

Figure (see Caption) Figure 109. Kīlauea summit tilt and seismicity recorded from 1 November 1996 to 21 April 1997. The larger tick marks on the horizontal scale represent monthly intervals and the smaller tick marks represent 10-day intervals. The tilt plot is made of wet-tilt readings taken from the Uwekahuna vault, located across Crater Rim Drive from HVO. Both LPC-A and LPC-B earthquakes are from shallow (0-5 km) sources and have frequencies of 3-5 Hz and 1-3 Hz, respectively. Courtesy of HVO.

Thirteen episodes of deep tremor occurred from the usual source to the SW. Amplitudes ranged from very low to very high. The two largest tremors occurred during 0400-0448 on 24 April and 1543-1631 on 25 April.

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the summit caldera to the sea. This latest Kīlauea eruption began in January 1983 along the E rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift (towards the summit) end to ~8 km E on the downrift (towards the sea) end. Activity eventually centered on what was later named Pu`u `O`o. Between January 1983 and December 1996, erupted lava totaled ~1.45 km3.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Steve O'Meara, PO Box 218, Volcano, HI 96785, USA.


July 1997 (BGVN 22:07) Citation IconCite this Report

Fountaining from Pu`u `O`o vents; lava flows reach ocean again

Eruptive activity continued at the Pu`u `O`o Crater from mid-May through mid-August 1997. The 55th episode of Kīlauea's 14.5-year-long East rift zone eruption began on 24 February 1997 after a 24-day hiatus in activity. This hiatus followed a brief fissure eruption at Napau Crater in late January 1997. The last long hiatus was in mid-1986, when volcanism switched from episodic 300- to 500-m-high fire fountains to continuous effusion. Episode 55 has seen shifting vent locations on the flanks of the Pu`u `O`o cone and a build-up of the lava shield. The lava pond within the Pu`u `O`o crater has intermittently risen to produce flows on its E and W margins. Surface activity was limited in the early days of Episode 55, occurring only deep within the Pu`u `O`o crater. On 28 March the lava level in the Pu`u `O`o crater rose and moved through lava tubes that fed small cones just S of the cone (BGVN 22:04). Eruptive activity in recent months has been focused at a spatter cone in Pu`u `O`o and vents on the S exterior flank of the crater.

Eruptive pauses during May. From mid-April through 9 May most of the lava erupted on the S and SW flanks of the Pu`u `O`o cone ponded near its base. These ponded flows were responsible for most of the glow seen at night and frequently fed channeled aa flows S and SE. The longer flows advanced as far as 2.6 km. Lava issued from two areas on the SW flank of the cone, both of which were topped by spatter cones 10-12 m high. A pit crater below one of these spatter cones intermittently filled with lava and overflowed.

Beginning on 10 May and continuing through the 15th there were eruptive pauses for periods of up to 10 hours. A small new vent became active on 12 May (figure 110) midway between the "55 Spatter Cone" (a vent that became active on 28 March; BGVN 22:03) and the "Uplift" vent (a vent that became active on 17 April; BGVN 22:04). Following a 15-hour pause on 23 May, activity resumed with fountaining from the 55 Spatter Cone, followed by brief periods of quiescence. Multiple flows from two active vents on the S flank of the Pu`u `O`o cone fed aa flows that traveled 1.5 km (figure 111). Occasional fountains up to 15 m high were observed from the flank vents. Activity within Pu`u `O`o raised the floor of the crater to within 10 m of the lowest section of the rim.

Figure (see Caption) Figure 110. Sketch map showing four new vents in the Pu`u `O`o crater area of Kīlauea, 28 March-12 May 1997. Courtesy of the USGS Hawaiian Volcano Observatory.
Figure (see Caption) Figure 111. Map of recent lava flows from Kīlauea's east rift zone, 23 May 1997. Contours are in meters and the contour interval is approximately 150 m. Courtesy of the USGS Hawaiian Volcano Observatory.

Activity during June and early July. On 2 June several earthquakes (up to M 3.5) were felt in the Namakani Paio campground area of the National Park. In the first four hours of the swarm 60 earthquakes were located. Early in the first week of June vents on the SW flank of Pu`u `O`o fed flows that traveled up to 1.5 km SE from the cone. As activity from the SW flank vents waned, a W-flank vent restarted early on 4 June and fed a flow moving NW that burned trees in the national park. Occasional fountains up to 40 m high were observed from the W vent.

During 6-13 June the lava flow field expanded N and E of the shield for the first time since 1992. The Pu`u `O`o crater floor, with no active lava pond, was repeatedly resurfaced by pahoehoe flows from a vent near the collapsed W wall. This vent built a 30-m-high by 40-m-wide spatter cone on the crater floor ("Crater Cone"). The crater floor itself rose to within 4 m of the W rim. Intermittent spatter fountains from the flank vents commonly reached heights up to 50 m. As of 13 June lava flows from the flank vents had spread over the shield, forming perched lava ponds that spilled over to feed channeled aa flows that extended 4 km from the vent.

At 0100 on 16 June spattering intensified within the Pu`u `O`o crater. By 1430, the crater overflowed through the gap in the W wall of the cone formed by the collapse of 30 January 1997, sending a large open-channel pahoehoe flow N. This activity lasted for 1.5 hours, followed by a few hours of repose and a few more hours of eruption. For the first time since July 1986, lava flows spilled out of Pu`u `O`o crater. On 17-18 June the 10th pause of episode 55 occurred. During 18-28 June flows were confined to the general vicinity of the Pu`u `O`o vent, helping to build up the lava shield an additional 35 m. Such a rapid buildup has not been seen since 1992. Spectacular episodic fountaining resumed from a few of the spatter cones ringing the southern outside edge of the Pu`u `O`o cone.

The 55 Spatter Cone was the least active of the three vents during 17-30 June, but on the nights of 18 and 20 June lava fountains over 50-m high played above the cone for several hours. Perched lava ponds on the S side of the Pu`u `O`o cone, assumed to be fed by a tube from the 12 May vent, produced long flows to the S and SW over the episode 50-53 flow field. Near the flow field's W edge, flows descended to 685 and 700 m on 28 and 30 June, respectively.

An earthquake on 30 June shook the entire Island of Hawaii at about 0547. The earthquake had an estimated magnitude of 5.3-5.5 and took place within the S flank of Kīlauea, ~10 km SSE of Pu`u `O`o, at a depth of ~7 km. The earthquake was felt throughout the island, but minor damage was reported only in the SE part of the island. The earthquake was located in the same area as the much larger M 7.1 Kalapana earthquake of 29 November 1975. The earthquake caused no observable change in the eruption.

Eruptive activity continued through the end of June and early July with intermittent action from three areas. Crater Cone continued to produce flows which episodically resurfaced the crater floor. Fountains from the W flank vent intermittently sent flows S, W, and N for distances of <1 km. Other small channeled lava flows from a perched lava pond on the S side of Pu`u `O`o extended <1.5 km S.

During 3-11 July the level of the lava pond in the eastern part of the Pu`u `O`o crater fluctuated with activity from Crater Cone. Lava flowed over the W rim for brief periods on 7 and 11 July. The discontinuous character of these outflows could be traced to both the sporadic output of lava and to draining through unseen conduits in the crater floor. On 3 July, a flow from the South Shield vent (~300 m S of Pu`u `O`o) stopped at 613 m elevation near the top of the Pulama pali escarpment. This was overtaken by an aa flow slightly to its W that quickly advanced down the pali, reaching 183 m elevation by 7 July.

During 17 June-14 July, eruption tremor amplitudes fluctuated between background and up to 5x background. There were moderate numbers of shallow, long-period microearthquakes; however, more than 200 appeared on 25 June. Intermediate long-period earthquakes were moderate to low in number. Earthquake counts along the upper E rift zone were low to high during late June and low during early July. More than 170 events were counted on 25 June.

Lava reaches the coastal plain on 10 July. On 10 July a lava flow was nearing the extreme SW end of Royal Gardens subdivision. This was the first flow over Pulama pali onto the coastal flat since last January. By the morning of 10 July the narrow flow had reached just beyond the National Park. When the flows reached the base of the pali they burned and covered the Akia coastal forest. On 11 July, the flow continued across the flats.

Renewed entry of lava into the ocean began on the night of 12 July for the first time since January 1997. The flow, fed from a perched lava pond on the S side of Pu`u `O`o, followed the eastern margin of the episode-53 flow field and entered the ocean near Kamokuna (figure 112). When lava reached the ocean it was less than 460 m W of Waha`ula Heiau, a 700-year-old rock-walled Hawaiian temple; lava last flowed up to and around this structure in December 1990. The flow front on 12 July was 300-500 m wide with many small lava rivulets entering the sea and contributing to a large steam plume; an unstable delta was constructed 30-40 m beyond the old coastline. The lava bench grew to 300-m long and 50-60 m wide by 14 July. The flow into the sea nearly stopped on 17 July because of blockages in the tube system that caused lava tube breakouts onto the surface. As of 18 July there were numerous surface flows and an active ocean entry.

Figure (see Caption) Figure 112. Map of recent lava flows from Kīlauea's east rift zone, 17 August 1997. Contours are in meters and the contour interval is approximately 150 m. Courtesy of the USGS Hawaiian Volcano Observatory.

Beginning about 18 July another flow from South Shield followed a more easterly course toward the upper edge of the Royal Gardens subdivision. On 28 July the flow was burning into the forest edge 1.6 km above the subdivision. South Shield shut down early on 29 July, allowing the tubes to drain, but it resumed erupting that night. By the morning of the 30th lava had reoccupied the upper reaches of the tube; within two days the tube was reoccupied down to the coastal plain. Breakouts on 30 July formed channeled aa flows on the upper slopes of Pulama pali, sending new flows along the course of the earlier July flows.

Ocean entry of lava continued through 28 July. During 19-28 July surface flow activity on the coastal lava bench was extremely limited, with most flows occurring in lava tubes that broke out at the coast. At Pu`u `O`o the lava shield surrounding the main cone and a few of the spatter cones ringing its S side continued to expand. A fern glen was burned and partially covered by lava from the advancing flows. On 29 July the flow feeding the ocean entry ceased when its lava tube clogged. Soon thereafter, a new flow began moving downslope away from the vent.

South Shield has been the prolific producer of flows, including all large flows in July and early August. From 12-29 July a tube-fed flow from this vent entered the ocean at East Kamokuna and built a 60-m-wide lava bench ~350 m along the shoreline. The ocean entry was marked by a large steam plume and mild explosions that hurled spatter onshore, building two small littoral cones.

Activity continued during the last week of July with cyclic filling and lowering of the Pu`u `O`o lava pond. During the morning of 29 July, lava flowed over the E and W rims of the crater and down the sides of the cone for several hours. A blockage in the tube system caused the supply of lava entering the ocean to diminish. Lava stopped entering the ocean shortly after noon on 29 July. A new aa flow from a breakout above the blockage was several hundred meters W of the old flow, and the terminus of the new flow was 400 m from the ocean.

During the pause at the coast activity at Pu`u `O`o was continuous. Peter Mouginis-Mark and colleagues observed from the air a spectacular lava overflow from the pond occupying the E crater floor on 6 August that sent rapidly moving flows out of the SE side of the cone. The flows formed a lobate sheet that extended ~1.5 km. None of these flows were active for more than three hours. Lava began flowing into the sea again at the East Kamokuna entry on 4 August. A lobe from this flow branched at the foot of Pulama pali and advanced to within 800 m of Waha`ula Heiau, located 450 m E of the East Kamokuna entry. Vigorous activity within Pu`u `O`o lit the skies on the night of 7 August with moderate fountaining.

Lava covers Waha`ula Heiau in mid-August. On 8 August, lava buried a 300-m section of jeep road that provided access to the Royal Gardens subdivision. That lobe progressed seaward, slowly encroaching upon Waha`ula Heiau. On 11 August at 0124, lava began to overrun the heiau; flows were moving across the floor of the temple by 0300. By 0730 lava had covered most of the structures. It had been one of the few remaining major archaeological resources left in the Kalapana coastal section of the Park. The Waha`ula complex contained structures that tradition associated with the 13th-century high priest Pa`ao. A more recent structure in the complex was used by Kamehameha I and remained in use until 1819. Over the past 13 years thousands of significant archaeological features have been covered by lava flows from the Pu`u `O`o eruption.

Another Pu`u `O`o crater overflow event occurred on 12 August. Until at least 17 August lava continued to enter the sea at the Waha`ula entry and also ~900 m farther W, near Kamokuna. The lava built low benches and generated steam plumes. Activity continued at Pu`u `O`o through mid-August with cyclic filling and lowering of the lava pond. Sporadic fountaining was observed from the Crater Cone and the 55 spatter cone vents.

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the summit caldera to the sea. This latest Kīlauea eruption began in January 1983 along the E rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift (towards the summit) end to ~8 km E on the downrift (towards the sea) end. Activity eventually centered on what was later named Pu`u `O`o. Between January 1983 and December 1996, erupted lava totaled ~1.45 km3.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Ken Rubin, Mike Garcia, and Peter Mouginis-Mark, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.html); Jim Martin, Superintendent, P.O. Box 52, Hawaii Volcanoes National Park, HI 96718-0052 (URL: http://www.nps.gov/havo/).


September 1997 (BGVN 22:09) Citation IconCite this Report

Lava effusion and overflows

Since mid-August, eruptive activity has been concentrated at a vent on the Pu`u `O`o crater floor and at the S shield, a new lava shield ~300 m S of the Pu`u `O`o cone. Lava continuously effused from a spatter cone inside Pu`u `O`o crater during 17 August-23 September. The flows caused occasional overflows of a lava pond in the E part of the crater, and sometimes disappeared into cracks on the crater floor. A voluminous 6 August overflow (BGVN 22:07) produced 1.2-km-long pahoehoe flows; eruption rates were estimated at 100,000- 900,000 m3/day. Lava flows also occurred at a small vent on the S shield; these flows fed lava tubes leading to the coast, where lava entered the sea at Waha`ula and Kamokuna (figure 113).

Figure (see Caption) Figure 113. Map of recent lava flows from Kīlauea's east rift zone, 21 October 1997. Contours are in meters and the contour interval is approximately 150 m. Courtesy of the USGS Hawaiian Volcano Observatory.

During 28 September-3 October flows from the S shield vent moved within lava tubes. Lava was only visible through occasional skylights in the tube's roof and during two brief episodes when lava escaped onto the coastal plain. During this time eruption rates were ~500,000 m3/day. The Pu`u `O`o spatter cone subsided, creating an ~40- m-diameter pit that was the source of lava issuing into the crater. On 28 September a lava overflow fed a small flow that moved a few meters W and a few tens of meters E of the crater rim.

On 18-19 October another lava overflow episode at Pu`u `O`o resulted in flows from the low points in the E and W rims of the crater beginning at 0400. By the evening of 19 October, the flows had created broad areas of incandescent lava whose glow was visible up to 45 km away. Lava flow in the ocean-bound tubes was reduced to a trickle and steam plumes at the sea entry sites disappeared at 1200 on 18 October but resumed the next morning.

Sulfur dioxide gas emission from the Pu`u `O`o vents increased from 1,000-1,500 tons/day on 2 October to 1,500-2,000 tons/day by 21 October.

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the summit caldera to the sea. This latest Kīlauea eruption began in January 1983 along the E rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift (towards the summit) end to ~8 km E on the downrift (towards the sea) end. Activity eventually centered on what was later named Pu`u `O`o. Between January 1983 and December 1996, erupted lava totaled ~1.45 km3.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Ken Rubin and Mike Garcia, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.html).


November 1997 (BGVN 22:11) Citation IconCite this Report

Bench collapse and pit formation; lava flows continue to reach the coast

Activity within the Pu`u `O`o crater was at a diminished level during late October-23 November 1997. Lava in the crater was visible only from the crater walls. The Pu`u `O`o vent rarely effused lava onto the crater floor during November; the magma column remained 10-20 m below the rim. Magma in the vent circulated below the crusted lava surface, where it was not visible except from the air.

Lava from the S shield continued to travel ~10 km to the coast in tubes; travel time was estimated at ~3 hours from the vent to the ocean. The eruption rate was 500,000-600,000 m3/day. Although lava continued to flow into the ocean at East Kamokuna and Waha'ula, no breakouts of lava from the tubes onto the coastal plain occurred after the 18-19 October event (BGVN 22:09).

At East Kamokuna, a bench collapse in the first week of November removed 1.9 hectares of recent deposits and created a new cliff a few meters high and ~50 m long; after the collapse, lava began building a shelf at the foot of the new cliff. Curtain-like steam plumes rose continuously from the 500-m-long edge of the lava flow. A smaller lava bench collapse (0.26 hectares) occurred on 24 November.

Sulfur dioxide emissions from Pu`u `O`o remained high during November. Although during late October the emission rate had been 1,500-2,000 metric tons/day (t/d), during November it increased to 2,800 t/d and occasionally reached 5,000 t/d. On 16 November, eastern Hawaii, especially Hawaii Volcanoes National Park, was engulfed in one of 1997's worst volcanic-smog episodes. Elevated levels of volcanic smog were detected as far away as Oahu (~330 km NW). Gentle winds from the SE pushed SO2 emissions from Kīlauea's E rift zone inland, resulting in levels of airborne SO2 that exceeded Environmental Protection Agency standards; the National Park Service thus closed headquarters at the Kīlauea summit for the day. On 7 December, SO2 emissions were 4,300 t/d.

Although visible activity within Pu`u `O`o crater remained diminished, visitors and nearby residents heard roaring sounds during 24 November-5 December. Tephra fell up to 10 km from the vents and included "Pele's hair" (thin strings of solidified lava ~2.5 cm in length). During 28-30 November, a particularly active period of tephra deposition occurred; the associated emission events were detected on seismic instruments near the Pu`u `O`o vent.

On 7 December the SW flank of Pu`u `O`o cone collapsed, creating a funnel-shaped pit ~50 m in diameter at the surface midway between the S base and rim. A small glowing hole on the floor of the pit revealed that the pit intersected the magma supply system underlying the cone and flank vents. The new collapse pit resembled the Great Pit that formed on the cone's W slope in early 1993 (BGVN 18:02 and 18:03); the Great Pit later enlarged, causing the cone's W wall to collapse in January 1997 (BGVN 22:01). Pits of this type form when Pu`u `O`o is undermined by magma feeding the on-going eruption.

Lava output inside Pu`u `O`o crater visibly increased during 7-8 December; flows from the crater vent filled the crater's E side. The increased activity may have been related to the formation of the new collapse pit.

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originated primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the summit caldera to the sea. This latest Kīlauea eruption began in January 1983 along the E rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift end to ~8 km E on the downrift end. Activity eventually centered on what was later named Pu`u `O`o. Between January 1983 and December 1996 the volume of erupted lava totaled ~1.45 km3.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Ken Rubin and Mike Garcia, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.html).


December 1997 (BGVN 22:12) Citation IconCite this Report

Surge in activity on 15 January

During mid-December-5 January, Pu`u `O`o spilled lava across the crater floor more frequently than in previous weeks (BGVN 22:11). Prior to November, magma issued nearly continuously from the throat of the crater vent, but overflows diminished greatly during November-early December when lava remained mostly within the vent (figure 114). On 29 December, numerous spills resumed; however, none of the lava escaped from Pu`u `O`o crater.

Figure (see Caption) Figure 114. Oblique aerial photo looking SW across Pu`u `O`o on 4 December. Lava flows in foreground are E-directed overflows from August and October. Distance between N and S summits is 200 m. The crater vent lies at the base of the dense fume cloud in Pu`u `O`o crater. Courtesy of HVO.

Lava from the S shield continued to travel in tubes to the coast and the eruption rate remained at ~500,000- 600,000 m3/day. Lava occasionally escaped from the tubes to form small new surface flows; a flow traveled at least 100 m on 30 December. During the first two weeks of January, several flows broke through the surface; one flow built a pad of lava measuring ~49 x 49 m and 2.1 m thick near the old visitor center. Breakouts from weak points in the tube roof were initiated by lava surges from the vent or by downtube blockages. During the breakouts, the weak sections of roof were rafted away by the outward flow of lava. Continuous, curtain-like steam plumes continued to rise where the lava, ~1,150°C, entered the sea along a 500-m-long section of coast.

The discharged lava continued to build benches beyond the low sea cliffs. At East Kamokuna, one of the sea entry sites, a bench collapse sometime during 23-26 December removed ~4.4 hectares along the coast. On 3 January, another bench collapse resulted in the loss of 1.6 hectares. After the second collapse, a large river-like lava flow broke onto the surface and flowed into the ocean.

On 10 January, Mike Garcia (University of Hawaii) reported observations of the lava sea entry at Kamokuna. Ribbon-like lava entered the sea in several places, solidified, and broke into pieces that were carried offshore. Observers noted that explosions at the site sent debris 25 m into the air. On the ground near the entry area, a coating of glassy debris had developed from recent lava-seawater explosions. A 3-m cliff from a recent bench collapse ~20 m from the coast and the formation of a new lava bench beyond the older cliff were observed. In addition, there was a new littoral cone resulting from lava spatter accumulation.

Sulfur dioxide emissions from the Pu`u `O`o vents remained high during the last two weeks of December, with rates as high as 7,000 tons/day. On 2 January, atmospheric sulfur dioxide levels reached 2 ppm, causing the National Park Service to close the visitor center for a few hours.

A rapid 2-hour pulse of inflation occurred at the summit starting around 1830 on 14 January. The activity was accompanied by numerous small earthquakes that signaled an abrupt movement of magma into the summit reservoir. Within minutes of the earthquakes, tiltmeters recorded more than 8 µrad of tilt (figure 115) on the rim of Kīlauea caldera. Despite the upward movement of magma, there was no surface eruption and the crater did not overflow. Immediately after the inflation event, deflation occurred as the new pulse of magma surged through the dike system of the E rift zone toward the Pu`u `O`o vents. The summit returned to its previous inflation level early on 16 January.

Figure (see Caption) Figure 115. Tilt at the Uwehakuna summit tiltmeter during 13-17 January. Courtesy of HVO.

At the Pu`u `O`o vents, activity increased substantially in response to the surge in magma supply. Lava fountains 15-20 m high and several surface flows were reported on the S flank of Pu`u `O`o. The flows were mostly confined to the older flow field (figure 116), but wood ash falling near Mauna Ulu indicated that some lava had burned vegetated areas. Although a strong glow during the event caused concern among nearby residents, no new areas were endangered. Some surface flows surged from openings in preexisting lava tubes; the sea entry sites remained active during the event. By 2200 on 15 January, the ocean entries were quiet, and a bench collapse had occurred at Kamokuna. Late on 16 January, lava returned to the tube system; on 17 January, sea entry conditions returned to pre-inflation levels.

Figure (see Caption) Figure 116. Distribution of lava flows from Kīlauea's E rift zone during 1983-1998 including flows from the surge of 15 January. Contours are in meters and the contour interval is approximately 150 m. Courtesy of HVO.

Observations from the air on 15 January revealed that an a'a flow had issued from a vent S of Pu`u `O`o and moved downslope onto the base of Pulama pali. Two more surface flows advanced a short distance SW and a few hundred meters E of Pu`u `O`o. Several breakouts from tubes along the coastal plain caused small pahoehoe flows.

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originated primarily from the summit caldera or along one of the E and SW rift zones that extend from the summit caldera to the sea. This latest eruption began in January 1983 along the E rift zone. The early phases, or episodes, occurred along a portion of the rift zone from Napau Crater on the uprift end to ~8 km E on the downrift end. Activity eventually centered on what was later named Pu`u `O`o. Between January 1983 and December 1996 the volume of erupted lava totaled ~1.45 km3. More than 223 hectares of new land have been added to the island and local communities have suffered more than $100 million in damages.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Ken Rubin and Mike Garcia, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.html).


January 1998 (BGVN 23:01) Citation IconCite this Report

Surface flows; 27 January earthquake swarm

On 14 January, a surge of magma beneath Kīlauea caldera caused a rapid 2-hour inflationary pulse (BGVN 22:12). Immediately following the surge, a swarm of of M 1-2.2 earthquakes occurred at the summit and lava discharged from vents on the S side of Pu`u `O`o (17 km to the E). The surge and earthquake swarm interrupted the typical steady behavior of the 15-year eruption.

In the days following the magma surge, lava flows from Pu`u `O`o were unsteady. During 18-22 January, several surface flows of pahoehoe and aa broke from the tube system. On 20 January, a new aa flow surfaced on Pulama Pali (figure 117) at an elevation of ~500 m and flowed 2/3 of the way down the escarpment in 5 hours. On the coastal plain, pahoehoe escaped from lava tubes. The next day, parts of an access road to the Royal Gardens subdivision (figure 117) were covered by further pahoehoe flows.

Figure (see Caption) Figure 117. Distribution of lava flows from Kīlauea's E rift zone during 1983-98 including flows emplaced in January 1998. Contours are in meters and the contour interval is ~150 m. Courtesy of HVO.

At the ocean, lava output was also unstable during 18-22 January. For example, lava ceased to emerge on 19 January but resumed the next day and continued through 22 January. During 14 January-3 February, Kīlauea's summit slightly inflated and deflated several times (figure 118). During this time, coincident with episodes of inflation and deflation, the lava supply to the tube system was interrupted at least twice. Consequently, the steam plumes periodically weakened and vanished for a day or two at a time. However, farther up slope magma flux through the tube system remained relatively constant, ~6 x 105 m3 per day, varying by ~10% when measured over a 30-minute interval on 22 January.

Figure (see Caption) Figure 118. Tilt recorded on the NW edge of Kīlauea's summit during 14 January-3 February. Courtesy of HVO.

The Pu`u `O`o vent area's appearance remained relatively unchanged in the weeks following the 14 January surge. Lava issued profusely from the crater and at vents on the S flank until about 26 January. After that until 3 February, intense fuming indicated magma degassing in the shallow subsurface, but it was visible only periodically in the vent orifices. Consequently, night glow from the Pu`u `O`o area was slight to absent.

Beginning at 1739 on 27 January and persisting into the next day, a swarm of earthquakes struck 2 km NW of the summit (beneath Namakani Paio campground). Several of these earthquakes rattled houses in the area and were felt from Hilo to Ocean View Estates, 40-50 km from the epicenter (figure 119). The largest earthquake of the sequence was M 4.4. The earthquake swarm roughly coincided with the onset of a more stable pattern of tilt at the summit.

Figure (see Caption) Figure 119. Earthquake epicenters at Kīlauea during January 1998. Heavy lines indicate faults. Courtesy of HVO.

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originated primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the summit caldera to the sea. This latest Kīlauea eruption began in January 1983 along the E rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift end to ~8 km E on the downrift end. Activity eventually centered on what was later named Pu`u `O`o. More than 223 hectares of new land have been added to the island and local communities have suffered more than $100 million in damages since the beginning of the eruption.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Ken Rubin and Mike Garcia, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.html).


February 1998 (BGVN 23:02) Citation IconCite this Report

Steady, low activity during February

During 4 February-5 March, the Pu`u `O`o eruption returned to steady-state activity after a brief magma surge and two seismic swarms in January (BGVN 22:12 and 23:01). Seismicity was low and little inflation or deflation was detected at Kīlauea's summit. Magma moved through shallow conduits towards the E rift zone without disturbing the ground surface.

The Pu`u `O`o vent area remained relatively unchanged in appearance during February. Fumes issued from cracks in the cone and surrounding area. Profuse fumes from new cracks near the N rim obscured the views of remote surveillance cameras and observers on helicopter overflights.

Lava continued to travel in tubes from the Pu`u `O`o vents to the ocean; however, during 4-24 February surface lava flows were sparse. Every 4-5 days a small flow issued from the lava tubes across the coastal plain. Most of the surface flows were near the Waha`ula ocean entry. At Kamokuna, lava continued to form a low shelf or bench at the foot of a 10-15 m cliff bordering the ocean. A bench collapse at the Kamokuna coastal entry occurred between 16 and 19 February. The collapse destroyed 4 hectares of land that had formed since the most recent collapse on 15 January (BGVN 22:12). The lava supply to the coastal tube system was interrupted briefly on 21 February, causing the steam plumes at the sea entry to dwindle for most of the day.

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originated primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the summit caldera to the sea. This latest Kīlauea eruption began in January 1983 along the E rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift end to ~8 km E on the downrift end. Activity eventually centered on what was later named Pu`u `O`o. More than 223 hectares of new land have been added to the island and local communities have suffered more than $100 million in damages since the beginning of the eruption.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Ken Rubin and Mike Garcia, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.html).


March 1998 (BGVN 23:03) Citation IconCite this Report

Steady eruption but low seismicity, sparse surface flows

The E rift zone eruption at Kīlauea remained steady during March. Seismicity was low, little inflation or deflation occurred at the summit, and magma moved through shallow conduits towards the E rift zone without disturbing the ground surface. The eruption has continued in this fashion since a brief surge in January (BGVN 22:12).

On 11 March glowing holes were observed in the Pu`u `O`o crater floor and in the crater vent; however, no lava escaped from the area. Researchers at the University of Hawaii also observed several large fissures and cracks within the cone edifice. Fumes issued from the cracks and surrounding area; during the last two weeks of March, profuse fumes obscured views of the crater vent. Skylights S of Pu`u `O`o cone revealed lava flowing toward the sea.

Although lava continued to travel in tubes from the Pu`u `O`o vent area to the ocean, surface flows have been sparse since early February (BGVN 23:02). Lava broke out of tubes on the Pulama Pali on 2 and 10 March, but both flows lasted less than a day. Small flows issued from weak points in the lava tubes on the coastal plain on 3-7, 10, and 14 March. Most of the breakouts were near the Waha`ula ocean entry.

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originated primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the summit caldera to the sea. This latest Kīlauea eruption began in January 1983 along the E rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift end to ~8 km E on the downrift end. Activity eventually centered on what was later named Pu`u `O`o. More than 223 hectares of new land have been added to the island and local communities have suffered more than $100 million in damages since the beginning of the eruption.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Ken Rubin and Mike Garcia, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.html).


April 1998 (BGVN 23:04) Citation IconCite this Report

Brief magma surge on 5 April, bench collapse 13-14 April

During April, Kīlauea's steady eruption continued. On most days lava issued quietly from an area near the S flank of Pu`u `O`o and traveled ~12 km in tubes to the coast. At the coast, the tube system discharged ~300,000-400,000 m3 of lava per day and built benches at Waha`ula and Kamokuna. In past months these sites have discharged roughly equal amounts of lava, but in April the Kamokuna site discharged a higher percentage of the lava. On 13-14 April a bench collapse removed 1.5 hectares of newly formed land at Kamokuna. Before the collapse the bench was 400 m long and 80 m wide at its greatest breadth.

On 4 April the magma supply to the tube system was obstructed, causing activity at the coastal entry sites to dissipate. Coincident with the blockage, the summit area inflated gradually (figure 120), gaining about 3 µrad of tilt. The inflation ended roughly coincident with a M 4.1 earthquake near the summit at 1243 on 5 April. Deflation at the summit sent a surge of magma into the tube system; lava issued from numerous weak points in tubes at the top of Pulama Pali. The surface flows lasted about 12 hours, and by the next day, the tube system had returned to normal activity. These short-lived pauses have occurred irregularly; since March 1997, 16 such pauses have occurred.

Figure (see Caption) Figure 120. Tiltmeter record showing the N-S component at Kīlauea's Uwekahuna 7-m borehole site during 2-6 April 1998. Courtesy of HVO.

Three small, recent pits on the crater floor periodically spilled small lava flows across the floor during 1-17 April. All these flows remained within Pu`u `O`o's crater. In mid-April, a new collapse pit ~50 m in diameter formed on the outer S flank of Pu`u `O`o. This and another pit 70 m to the SW were adjacent to a large December 1997 collapse pit (BGVN 22:11). These pits were formed when magma moving beneath Pu`u `O`o entrained blocks from its conduit into the tube system, causing the ground surface to collapse where the conduit was shallow.

During the last week of April, eruptive activity within Pu`u `O`o crater subsided; lava was not seen on the crater floor during 25 April-7 May and no night glow was visible. Residents of the Big Island felt 5 earthquakes, M 3.3-4.3, during 3-7 May. The largest earthquake occurred on 7 May and was located in the Pahala region of Ka`u (immediately W of Hawaii Volcanoes National Park) at 8.6 km depth.

During 10-11 May, University of Hawaii professor Steve Self observed a sequence of lava effusion and drainage that had developed within Pu`u `O`o cone. The E pit of the crater filled with lava from 1-2 vents over 10-20 minutes, followed by lava overspill back to the main Pu`u `O`o vent. Minor lava fountaining in both pits accompanied the pit-filling phases. After 10-20 minutes of vigorous mixing of the lava in the pits, a brief period of lava fountaining occurred followed by rapid drainage to the tube system. This activity was accompanied by 30-m-high fountains and vigorous gas release, although none of the fountaining lava fell outside the crater wall.

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originated primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the summit caldera to the sea. This latest Kīlauea eruption began in January 1983 along the E rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift end to ~8 km E on the downrift end. Activity eventually centered on what was later named Pu`u `O`o. More than 223 hectares of new land have been added to the island and local communities have suffered more than $100 million in damages since the beginning of the eruption.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Ken Rubin and Mike Garcia, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.html).


June 1998 (BGVN 23:06) Citation IconCite this Report

Pause in lava flow during May; benches collapse during May-July

Episode 55 of Kīlauea's east rift zone eruption continued during May and June. Thick volcanic fume in the inner crater of Pu`u `O`o often prevented scientists from observing details of activity there. They did observe that over several-hour periods, lava would emerge from one or more vents, sometimes reaching to within 10-30 m of the crater rim, and then suddenly drain back into the vents. Such fill and drain cycles occurred irregularly.

A new crater floor pit developed at the base of the E crater wall on 7 May. Such pits form by undermining; magma beneath the crater floor erodes parts of the solidified crust. Where the crust becomes thin, the floor collapses to form a pit, which may become a new vent or a place where lava can drain back into the main magma conduit system beneath the cone. These pits periodically overflow and spill small lava flows across the crater floor. Generally, these flows remain contained within the crater of Pu`u `O`o; the most recent crater overflow occurred in January 1998. Observers also noted a series of new cracks curving around several adjacent pits on the SE flank of the Pu`u `O`o cone. These cracks suggested this part of the cone was subsiding and may develop into a single large pit.

Lava erupted quietly from vents on the SW flank of Pu`u `O`o and traveled about 12 km through lava tubes to the coast. Typically, between 300,000 and 600,000 m3 of lava entered the ocean every day at the Waha`ula and Kamokuna entry points. A temporary pause in the supply of magma on 19-20 May permitted lava within the tube system to drain completely so that lava ceased flowing into the ocean. After lava began re-entering the tube system during the evening of 20 May, several "leaks" (breakouts) occurred. The most voluminous breakouts began early in the morning of 21 May on the steep slope of the fault scarp (pali) between 335 m and 610 m.

During a pause, the roof and walls of drained tubes are prone to collapse. When lava reenters the tube system, blockages or irregularities in the tube cause the lava to back up and escape (breakout) through skylights or other weak points. A prolonged period of surface-flow activity resulted in lateral expansion of the lava-flow field, because the middle of the field is usually higher than the sides and new surface flows are diverted to the edges. During this most recent pause, however, the tube system quickly accommodated nearly all of the lava. The Kamokuna entry point resumed abruptly at about 1240 on 21 May. Sixteen similar pauses have occurred since episode 55 began in March 1997.

The Kamokuna entry was the more active outlet. New land built outward from a large littoral cone, which formed on the seaward edge of the new bench (figure 121), and frequently collapsed into the ocean. Following such a collapse sometime during 1-4 May, a new bench began to form, growing to ~ 90 m wide by 2 June. Two additional significant collapses occurred on 11 June and 6 July. The large collapse event on 6 July removed about 3.7 ha of new land. Bench collapses are life endangering because numerous explosions ensue when the hot lava interacts with the ocean water; the reaction can spark lightning and roiling clouds. Accordingly, the National Park Service restricted access to the area.

Figure (see Caption) Figure 121. An aerial view of Kīlauea on 2 July looking to the NE across the lava bench at Kamokuna entry point. The shot was taken just days before the entire bench collapsed. The large littoral cone lies in the left center of image (below the left tip of the steam plume). Courtesy of HVO.

Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. The latest Kīlauea eruption began in January 1983 along the east rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift (towards the summit) end to ~8 km E on the downrift end (towards the sea). Activity eventually centered on the area and crater that was later named Pu`u `O`o.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Ken Rubin and Mike Garcia, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.html).


August 1998 (BGVN 23:08) Citation IconCite this Report

Eruptive pause (No. 20) followed by a new pahoehoe flow to the sea

Lava continued erupting from vents on the SW of Pu`u `O`o and traveling 12 km to the coast through lava tubes. Following a pause in the magma supply on 12-14 August, lava escaping from the tubes resulted in a new pahoehoe flow at the base of the fault scarp (pali), but a new lava tube eventually developed within the flow. The flow front reached the sea on 30 August, entering ~400 m W of the long-established Kamokuna entry.

Above the shoreline, spreading lava formed small pahoehoe toes along its margins. The new flow was extremely hot and made the approach from the W difficult and hazardous. Lava at the new entry initially poured over a sea cliff (created by previous bench collapses) onto a black-sand beach. Material arriving at both new and old entry points added to the Kamokuna bench.

Twenty pauses, lasting from a few hours to a few days, have occurred since Episode 55 began in March 1997. These short-term interruptions in magma supply to Pu`u `O`o result from blockages in the conduit system between the summit magma reservoir and Pu`u `O`o. The most recent pause (No. 20) began on 12 August and lasted approximately 42 hours, during which time Kīlauea's summit inflated ~2 µrad. The slight inflation indicated magma was still rising into the summit but not moving to the rift zone.

When lava reemerged from Pu`u `O`o and again flowed through the tubes, several flows broke out on the pali and at its base (figure 122). The largest flow originated from the same breakout point that was active following a pause in July (BGVN 23:06). Daily lava-discharge rates from Pu`u `O`o remained little changed; surveys made during the last few weeks of August indicated that ~250,000 m3 of lava per day traveled through the tube. Since March 1998, the average daily lava discharge was ~300,000 m3.

Figure (see Caption) Figure 122. Close-up view of Kīlauea lava flowing through a new shallow lava tube that developed in lava-flow breakouts following pause No. 20 of Episode 55, mid-August 1998. Lava from this tube fed the new pahoehoe flow. Courtesy of HVO.

Seismologists noted a series of more than two dozen seismic signals at Pu`u `O`o on 26 August. The signals had a frequency lower than is typical of most earthquakes, and were likely caused by the partial collapse of a spatter cone on the W flank of Pu`u `O`o (figure 123). By 3 September the the spatter cone crater had grown to ~50 m in diameter.

Figure (see Caption) Figure 123. Aerial view of Kīlauea on 27 August 1998 showing the Episode 55 spatter cone located on the W of Pu`u `O`o. The low notch is the missing part of the cone, which probably collapsed the day before the photo was taken. Courtesy of HVO.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Ken Rubin and Mike Garcia, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.html).


October 1998 (BGVN 23:10) Citation IconCite this Report

Lava from Pu`u `O`o continues to build bench

The eruption of Pu`u `O`o continued in October as lava moved 11 km to the sea through both small, intermittent surface flows and through a lava tube that developed after a pause on 12-14 August (BGVN 23:08).

By 19 October, a 300-m-wide lava bench had grown W of the prominent littoral cone at a new ocean entry, extending 60 m beyond the old shoreline. Surface flows obscured the old sea cliff that once marked the relatively safe visitor viewing areas (figure 124).

Figure (see Caption) Figure 124. An aerial view of the Kamokuna lava bench on the SE coast of Kīlauea, 24 September 1998. Note location of the former sea cliff. The bench was ~ 150 m wide at the W entry area, near the larger white plume. Photograph by J. Kauahikaua; courtesy HVO.

Dense volcanic fumes from Pu`u `O`o obscured its crater for several weeks, and no lava has been seen in the crater for many months, although there have been reports of glow at night near the summit. In late October, Pu`u `O`o was releasing ~2,000 tons/day of SO2. This discharge is equivalent to the gas contained in ~400,000 m3 of lava, in concurrence with measurements of lava discharge above the lava tube ~5 km from the vent.

A new skylight formed above the lava tube at 635 m elevation showed lava moving 7-9 m below the surface. This part of the tube formed in August 1997, and since then flowing lava eroded the underlying flows to form a tube that is taller than it is wide.

Pu`u `O`o is the only active vent at Kīlauea. The vent area is complex and slowly forms new pits, cracks, and collapse areas. Since the current eruption began in January 1983, a mosaic of flows has buried 16 km of the coastal highway to a depth of 23 m and created nearly 2.6 km2 of new land. Recently, lava has flowed into the sea at three entry points near Kamokuna, 4.8 km E of the end of the "Chain of Craters Road" in Hawaii Volcanoes National Park. The easternmost entry has been active since August 1997, but is slowly dying as ruptures in the main tube divert lava elsewhere. Other entry points evolved in September and October 1998. The deltas or benches formed at sea entry points are unstable, collapsing without warning. The largest such collapse occurred a few years ago and involved 10 ha of bench material (105 m2).

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Ken Rubin and Mike Garcia, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.htm).


November 1998 (BGVN 23:11) Citation IconCite this Report

Continuing flow from Pu`u `O`o; major bench collapse

A significant collapse of the lava bench on the coast SE of Kīlauea occurred in early December. Lava continued to flow into the sea via a tube from the Pu`u `O`o vent, and a pit at the vent continued to grow.

A large part of the active lava delta on the SE coast collapsed into the sea sometime between 1200 on 10 December and 0930 on 11 December. A comparison between the shoreline as mapped on 11 and 24 November (figure 125), and the shoreline on 11 December, showed that ~5.8 hectares (ha) was lost. The missing shoreline included ~3.4 ha of land built since August and ~2.4 ha built W of the current lava-entry area (indicated by the steam cloud at the top of figure 125) between 1992 and 1997. Judging from observations of earlier bench collapses, the collapsed area most likely slid into the sea in several segments over a period of tens of minutes to several hours.

Figure (see Caption) Figure 125. View of the Kīlauea lava entry point area looking S on 24 November 1998. Courtesy HVO; photograph by J. Kauahikaua.

The eruption of Pu`u `O`o continued in November as lava flowed to the sea through a lava tube that developed on the coastal plain after a major pause in magma supply to the vent on 12-14 August (BGVN 23:08). Another brief pause occurred on 7-8 November (pause #21 of the current eruptive episode) leading to several small `a`a and pahoehoe flows on the coastal plain, none of which reached the sea. Scientists measured a slight increase in the discharge of lava from the tube system—from 3/day in late October to just over 400,000 m3/day in early December. Dense volcanic fumes continued to obscure various pits within Pu`u `O`o most of the time, but sloshing sounds of lava degassing could be heard from the crater rim.

A new pit that developed high on the S flank of Pu`u `O`o about one year ago enlarged significantly in 1998, and recent measurements of cracks around the edge of the pit showed that its walls were slumping slowly into the pit.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Ken Rubin and Mike Garcia, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.html).


January 1999 (BGVN 24:01) Citation IconCite this Report

Pause in eruption leads to new surface flows

The eruption at Pu`u `O`o continued to deliver lava to the sea through the lava-tube system that developed on the coastal plain in August 1998 (BGVN 23:08). In early February a pause in the magma supply, number 22 in this eruption, produced changes throughout the system.

During November 1998-February 1999 there were very few surface flows on the volcano, although small pahoehoe flows continued on the active lava delta. This situation changed abruptly on 7 February following a brief pause in the supply of magma to Pu`u `O`o. When lava re-entered the tube system leading from Pu`u `O`o, lava spilled from several skylights and fed both `a`a and pahoehoe flows above and below the pali (figure 127). Some flows were still moving when photographed on 8 February.

Figure (see Caption) Figure 126. View of pahoehoe flow on the coastal plain of Kīlauea, taken 7 February 1999. Courtesy HVO; photo by H. McGiffert.
Figure (see Caption) Figure 127. Surface flows from Kīlauea on Pulama pali as seen on 8 February 1999. The white line marks the edge of an `a`a flow that spilled down the pali (fault scarp). Courtesy HVO; photo by C. Seaman.

Kīlauea's summit region showed significant tilt changes in early February (figure 128). The tilt record shows an episode of deflation beginning on 5 February that coincided with a cutoff of magma supply from Pu`u `O`o. Supply of lava to the tube system dwindled, and by early afternoon on 6 February the steam plume at the coast had ceased. Early on 7 February the summit underwent an abrupt 7-µrad inflation that lasted a little more than one hour and was followed by a summit deflation. About two hours later a substantial supply of magma reached the vent area. GOES satellite imagery showed a thermal spike between 0315 and 0330. By dawn, lava flows were visible from the end of the Chain of Craters road, a popular viewpoint for park visitors.

Figure (see Caption) Figure 128. Record showing tilt at Kīlauea along azimuth N50°W from a summit borehole tiltmeter at Uwekahuna vault. Tilt is recorded in µrad. Courtesy HVO.

When the eruption at Pu`u `O`o resumed on 7 February, lava poured from several skylights to feed surface flows above and below Pulama pali. Spectacular explosive activity took place in mid-January at the lava delta, which was ~150 m wide on 8 February (figure 129). White fume clouds rose from areas where lava was entering the sea. The littoral cone near the SE edge of the delta was built by explosive activity in mid-January, caused when water temporarily gained access to the lava tube within the lava delta. Fumes in upper left were escaping from a lava-tube skylight.

Figure (see Caption) Figure 129. Aerial view of the lava delta (light toned surface) looking E on 8 February 1999. Courtesy HVO; photo by C. Seaman.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Hawaii Center for Volcanology, University of Hawaii, Department of Geology and Geophysics, 2525 Correa Road, Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/hcv.html).


March 1999 (BGVN 24:03) Citation IconCite this Report

Large delta collapse on 8 March nearly claims victims

During February and early March the eruption of Pu`u `O`o continued to deliver lava to the sea through the lava-tube system that developed on the coastal plain in August 1998 (figure 130). During this time no changes were observed at the Pu`u `O`o vent.

Figure (see Caption) Figure 130. Map showing three groups of Kīlauea lava flows, including those as recent as 8 February 1999. A lava tube delivers lava to the ocean W of a prominent littoral cone (star) at the Kamokuna entry point. Courtesy of HVO.

Favorable wind conditions permitted a good view into the crater of Pu`u `O`o during late February. Lava was visible in the bottom of one pit as were several ledges around the edges of the pits; these ledges are remnants of the crater floor that collapsed into the pits as lava beneath Pu`u `O`o lowered during the past year. The most recent overflow of lava from the crater occurred in January 1998 (BGVN 22:12); the decline in crater activity since then is thought to be due to a change in an outlet in the local tube system located beneath the S flank of Pu`u `O`o. This outlet has moved downward as the lava tube has eroded through more than 20 m of loose tephra. As lava eroded the tephra, the lava level within the crater fell because the outlet is presumably hydraulically connected and in equilibrium.

On 8 March nearly all of the new land built since 11 December 1998 (BGVN 23:11 and 24:01) slid into the ocean. Several associated explosions hurled lava landward and the collapse removed part of the old sea cliff on the E and W sides of the active delta. Prior to the collapse, the ~10 hectare lava delta stood ~700 m long and extended as far as 200 m seaward from the previous shoreline's cliff face (figure 131). On the E side of the delta (foreground in figure 131), the former sea cliff was completely buried by lava, allowing easy though unauthorized access for visitors hoping for closer views of lava entering the sea. Landward of the W part of the delta, however, was a cliff standing 10-15 m tall, a vestige of a delta collapse on 11 December 1998 (BGVN 23:11). Warning signs posted by the National Park Service were at least 50 m landward of this cliff.

Figure (see Caption) Figure 131. W-looking aerial view taken on 4 March 1999 of the shore around the Kīlauea's Kamokuna entry point. Area seaward of the white line fell into the sea on 8 March. Photograph by J. Kauahikaua; courtesy of HVO.

According to an anonymous eyewitness, seven people were on the delta when the 8 March collapse began. The first sign of a change in activity was a strong explosion that rocked the eyewitness where he lay on the ground above the buried cliff. An initial, energetic burst of lava from the edge of the delta threw spatter up to 70-80 m into the air (an estimate scaled from the people on the delta next to the explosion source). As large splatter clots fell around them, the seven retreated from the shoreline but became temporarily trapped by the sea cliff on the W side of the delta. The eyewitness used his flashlight to guide the endangered people to safety across to the E part of the delta.

Based on the eyewitness account, the collapse probably occurred between 0030 and 0200. The eyewitness left the area after the explosions began, and the delta was gone the next morning. The experience reinforced Park Service warnings that the ocean entry area remains extremely hazardous; visitors remain advised not to venture onto the active lava delta. After the collapse, lava began constructing a new delta into the sea (figure 133).

Figure (see Caption) Figure 132. Aerial view of Kīlauea's shoreline near the Kamokuna entry point as seen on 11 March 1999, three days after the delta collapse. The black line indicates previous shoreline. Courtesy of HVO.
Figure (see Caption) Figure 133. Aerial view of Kīlauea's shoreline as seen near the Kamokuna entry point on 18 March 1999 (10 days after the delta collapse) showing new delta growth. A black line indicates the previous shoreline. Courtesy of HVO.

When seawater and lava mixed within the confines of the lava tube, a steam explosion often resulted, sometimes blasting lava up through a hole in the roof of the tube. In figure 134 such a steam-driven explosion sent a dome-shaped sheet of lava, the skin of a bursting bubble, about 5 m into the air. Similar but larger explosions occurred intermittently for several days after the delta collapse on 8 March. As lava began rebuilding new land into the sea, water was apparently able to enter the developing lava-tube system within the delta.

Figure (see Caption) Figure 134. A series of still images from a video of a bursting lava bubble at Kīlauea on 17 March. Video by J. Johnson, Ka'Io Productions; courtesy of HVO.

New tiltmeter. A new tiltmeter station was successfully installed in February near Pu`u `O`o in order better to monitor the middle east rift zone and the intermittent pauses in supply of magma to the vent. The new site design and improved electronics have yielded data 10 times better than those from older tiltmeter stations. This was the first of several new tiltmeters planned for Kīlauea and Mauna Loa. Because the new instrument is about 5 m below the ground, the daily temperature effects on the rocks around the instrument are much less than for the older, shallower instruments, which were typically less than 1 m deep.

Figure (see Caption) Figure 135. View into the crater of Pu`u `O`o, looking toward the western side on 25 February. Courtesy HVO; photograph by J. Kauahikaua.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


May 1999 (BGVN 24:05) Citation IconCite this Report

Bench collapse on 13 April; a 33-hour eruptive pause on 5 May

The eruption of Pu`u `O`o continued to generate a variety of effects on the pali (cliff or fault scarp) and coastal plain during April and May as lava traveled from the vent through a lava-tube system to the ocean. At the coastal lava-entry area the lava bench repeatedly changed as new deposits built up and collapsed. Frequent explosions threw lava fragments into the ocean, onto the bench, and to the top of the adjacent sea cliff.

In the past, the supply of magma to the vent has been cut off for short periods; the 23rd such pause in the eruption began at about 1300 on 4 May and ended around 2200 on 5 May, only about 33 hours. That was long enough for both the steam plume at the ocean-entry area to stop (figure 136) and for a sluggish 6-week-old pahoehoe flow on the coastal plain to cease advancing. The eruption resumed slowly, and as lava moved through the tube system, only a few small sluggish flows broke out onto the pali and coastal plain (figure 137). Lava finally reached the ocean through the preexisting tube system on 7 May.

Figure (see Caption) Figure 136. View of Kīlauea on the island of Hawaii's SE flank looking W on the morning of 6 May 1999, about 12 hours after the eruptive pause ended. The entire area from the ocean and lava bench (bottom) to Pu`u `O`o (top) can be seen. Courtesy of HVO.
Figure (see Caption) Figure 137. A short-lived pahoehoe flow at Kīlauea that began after pause #23 (4-5 May 1999) had ended. Courtesy of HVO; photograph by S.R. Brantley.
Figure (see Caption) Figure 138. A pahoehoe flow from Kīlauea on the coastal plain emerging after pause #23 and inflating with new lava. Note the crack at the top of the flow; this crack formed when the top crust fractured as the molten interior of the flow swelled or inflated with new lava. Courtesy of HVO.
Figure (see Caption) Figure 139. Another view of the same Kīlauea pahoehoe flow shown on figure 138 taken as the lava spread laterally. Typical of pahoehoe flows, this moved forward as lava spread across the ground in budding toes and small sheets. The lava flow inflated as molten material continued to move through its main body. Courtesy of HVO.
Figure (see Caption) Figure 140. Location of the source of a breakout from the main lava tube on the coastal plain as seen on 31 March. The surface of the new pahoehoe flow is about 2 m below the top of the rise at its source. Courtesy of HVO; photograph by J. Kauahikaua.

Lava broke out from the tube system on 26 March about 2 km from the ocean. The breakout fed a wide, slow-moving pahoehoe flow for the next five weeks. The flow had advanced to within ~700 m of the ocean when the supply of lava was shut off by the pause on 4 May.

No significant changes have occurred recently at the Pu`u `O`o cone. Observations into the deep crater of Pu`u `O`o are usually not possible because of the thick plume of steam and SO2 gas. The vent continued to release an average of 2,000 tons of SO2 gas each day during April and May. Lava was sometimes visible in the northernmost pit on the crater floor; and when viewed on 6 May, a small spatter cone was visible in this pit.

Explosions at lava bench on 13 April. A series of strong explosions from the active lava bench on 13 April was likely related to the progressive collapse of the leading edge of the delta. As the lava tubes were sheared off by the collapses, seawater entered the tube system and a much larger than usual volume of lava was suddenly exposed to seawater. Both processes led to strong steam-driven explosions that hurled lava bombs and hot rocks into the air as high as 80 m and inland nearly 100 m from the bench's edge (figure 141). These ballistics did not land behind the warning signs posted by the National Park Service about 90 m from the sea cliff above the bench.

Figure (see Caption) Figure 141. Lava bombs flying inland from the site of steam explosions at the ocean entry point on 13 April. Courtesy of HVO; photograph by J. Wightman.

USGS observers said that when they arrived at the ocean entry area at 1400 on 13 April two plumes rose from the edge of the active bench. The widest part of the bench was ~40-45 m, where a few hours earlier the bench was as wide as 80 m. Starting just before 1600 the W plume area began venting steam from a hole (probably a skylight) just inland from the outer edge of the bench; the venting sounded like a jet engine. A few moments later explosions from this new vent hurled spatter into the air and formed bubble fountains as large as 10-15 m in diameter.

This activity turned highly explosive within a few minutes, hurling spatter and rocks into the air (average height of spatter was between 50 and 60 m). Ejected materials fell to the ground atop the sea cliff more than 75 m from the source. Explosive activity continued steadily for about 90 minutes and returned intermittently during the next few hours. One explosive episode caused lightning in the plume. When the witnesses returned to their car, parked 5 km away at the end of the Chain of Craters road, they found a thin layer of tiny brown flakes of glass from the explosions on the windshield.

Background. Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. The latest Kīlauea eruption began in January 1983 along the east rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift (toward the summit) end to ~8 km E on the downrift end (toward the sea). Activity eventually centered on the area and crater that were later named Pu`u `O`o. Between July 1986 and January 1992, the Kupaianaha lava lake was active ~3 km NE (downrift) of Pu`u `O`o. It was during this period that the town of Kalapana and most of the 181 homes lost were destroyed. In December 1991, one month before the shutdown of Kupaianaha, eruptive activity returned to Pu`u `O`o. More than 1 km3 of lava was erupted from January 1983 through January 1997.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


September 1999 (BGVN 24:09) Citation IconCite this Report

Abrupt changes in tilt, tremor, and extrusive output due to an inferred intrusion

Early on the morning of 12 September monitoring instruments detected a swarm of small earthquakes and volcanic tremor on the east rift zone, and a sharp deflation (tilt) of the summit area and parts of the east rift zone. A pause in on-going eruptive activity also occurred. These effects were interpreted as due to a new intrusion of magma. Apparently, magma moved from both the summit area and from near Pu`u `O`o into the upper rift zone, forming a dike in the area between Pauahi Crater and Mauna Ulu.

Figure 142 shows the seismic record for part of 11-12 September. After tremor associated with the seismic swarm ceased, another pause in episode 55 of the Pu`u `O`o-Kupaianaha eruption began at 0131 on 12 September. This change was thought to be due to the above-mentioned intrusion.

Figure (see Caption) Figure 142. Part of the 11-12 September seismogram for station STC near Pu`u `O`o at Kīlauea. There is a time difference of 15 minutes between each horizontal line and 1 minute between each small tic. Volcanic tremor was normal before the seismic swarm of 12 September but absent afterward. This absence of tremor was due to a pause in eruptive activity during the time of the swarm. Courtesy of the Hawaiian Volcano Observatory.

The onset of seismic activity and tilting on 12 September was abrupt and simultaneous to within the one-minute resolution of the tilt data. Strong tilt commenced early on 12 September, as indicated by the vertical line on figure 143, where tilt for a station was toward the caldera. A swarm of small earthquakes along the upper rift zone accompanied the ground deformation. The downward tilt (figure 143) suggested that magma was moving away from and out of the summit reservoir. Data from two other tiltmeters on the E rift zone (E of Pauahi Crater and just uprift from Pu`u `O`o) indicated that the magma was moving into the rift zone. The reversal of summit tilt about 4-6 hours later suggests that when the intrusion stopped, magma once again moved into the summit reservoir. An inspection of the ground above the intrusion on 12 September did not reveal new ground cracks, which indicated that the intrusion remained 1-2 km below the surface. On the other hand, leveling across the zone of intrusion on 14 September showed elevation changes indicative of a dike, but its size and depth remained to be calculated. It was estimated that 3-5 million cubic meters intruded into the rift zone.

Figure (see Caption) Figure 143. Kīlauea tiltmeter record for early September 1999 at Uwekahuna (tilt along an azimuth of N50W). Courtesy of Hawaiian Volcano Observatory.

About eight hours after the start of the intrusion, the active lava bench on the S coast of Kīlauea began collapsing into the sea. Several small collapses were observed by scientists on 12 September. The lava bench began to collapse during 0800-0915 on 12 September and this process continued for most of the day (figure 144). By the evening of 13 September, about 2 x 104 m2 of the S coast had been removed. The discharge of lava into the sea stopped completely in the afternoon of 13 September.

Figure (see Caption) Figure 144. W-looking view of the lava bench on the S coast of Kīlauea as it appeared on 9 September (left) and at about noon on 12 September 1999 (right). Photo courtesy of J. Kauahikaua.

Background. Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions have originated primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. The latest Kīlauea eruption began in January 1983 along the east rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift (toward the summit) end to ~8 km E on the downrift end (toward the sea). Mike Garcia has compiled a tabular summary of the episodes, now available on the web.

Activity eventually centered on the area and crater that were later named Pu`u `O`o. Between July 1986 and January 1992, the Kupaianaha lava lake was active ~3 km NE (downrift) of Pu`u `O`o. It was during this period that the town of Kalapana and most of the 181 homes lost were destroyed. In December 1991, one month before the shutdown of Kupaianaha, eruptive activity returned to Pu`u `O`o. More than 1 km3 of lava was erupted from January 1983 through January 1997.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii Volcanoes National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Mike Garcia, Hawaii Center for Volcanology, University of Hawaii, Dept. of Geology & Geophysics, 2525 Correa Rd., Honolulu, HI 96822 USA (URL: http://www.soest.hawaii.edu/GG/HCV/puuoo-episodes.html)


January 2000 (BGVN 25:01) Citation IconCite this Report

Ground deformation continues through June; earthquake swarms begin in December

This report covers activity during June through 12 September 1999; however, data for the interval 5 July to 11 September were not available when this report was compiled in early 2000.

In early June very little changed in the eruptive activity at the Pu`u `O`o vent. Lava continued to travel through the lava-tube system to the coast where it has built a lava bench, extending into the ocean. Frequent collapses of the bench prevent it from extending seaward more than ~ 200 m from the former shoreline. Slow-moving pahoehoe flows continued to occasionally break out from the tube system and spread out over the broad coastal plain. In mid-June the 24th pause in the current eruptive episode (55) occurred.

During 19-20 June a tiltmeter at the summit showed an outward tilt (inflation) taken as indicating that magma moved into the summit reservoir. Just after the 24th pause began, the tiltmeter near Pu`u `O`o recorded a slight increase in tilt away from the E rift zone. This tilt suggested that some magma entered the rift zone at the same time that magma was accumulating in the summit reservoir. The pause may have resulted from a blockage beneath or immediately uprift of Pu`u `O`o. This tilt reversal pattern was also seen during the eruptive pause in May 1999. During parts of June no lava traveled underground to the coast. The tube drained soon after the intrusion. As the tube's roof began to cool and shrink, it fell in places, forming holes and partial dams along the tube. Later, when lava reentered the tube, these created points where lava escaped to the surface. Apparently the dam at about 530 m elevation remained intact and sealed the tube from draining significant lava below that point.

During the night of 2-3 July the seaward margin of the bench, a segment up to 75 m long, slid into the ocean removing ~1.7 hectares of new land. Strong explosions occurred intermittently during the next few days, climaxing on 4 July. Below is a description from a scientist who witnessed these explosions on 2-3 July.

"Major explosions and jetting started on the bench at 1814. Bubble bursts were occurring from three locations and lava fountaining was occurring from a vent on the western part of the bench. Lava was thrown up to 150 m into the air by the fountaining. The fountain produced a nested pair of cones, approximately 30-45 m in diameter and 5-7 m tall. The bubble bursts took place about 20-40 m inland of where the waves could reach . . . [The bubbles were tens of meters in diameter.] The entire cone and surrounding bench undulated like a liquid during the most vigorous bubble-burst activity. Between explosive episodes, a series of surface flows broke out, covering most of the visible bench. One flow that poured into the ocean built a tube through the surf, which led to a series of underwater explosions about 25 m offshore."

A press release noted that early on the morning of 12 September, a swarm of small earthquakes and volcanic tremor occurred on the E rift zone. A sharp deflation of both the summit area and parts of the E rift zone was associated with a new intrusion of magma. Magma moved from both the summit area and from near Pu`u `O`o into the upper rift zone, forming a dike in the area between Pauahi Crater and Mauna Ulu. Preliminary analysis of the data suggested that 3-5 million cubic meters of magma intruded into the rift zone. About 8 hours after the start of the intrusion, the active lava bench on the south coast of Kīlauea began collapsing into the sea. Several small collapses were observed on 12 September, and by the evening of 13 September, about 2 hectares had been removed. The discharge of lava into the sea stopped completely in the afternoon of 13 September.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


April 2000 (BGVN 25:04) Citation IconCite this Report

An eruptive pause occurred in September; intrusion of magma in February

The period of activity at Kīlauea between 13 September 1999 and May 2000 was marked by multiple lava breakouts that were caused by damming of the lava-tube system. The lava flows traveled from Pu`u `O`o crater, down Pulama pali, and along the coastal plain towards the sea, covering an area several kilometers wide (figure 145).

On 12 September 1999 magma intruded into the upper rift zone of the volcano (BGVN 25:01), with most of it draining underground afterwards leaving a small lava lake near the center of Pu`u `O`o crater. By 16 September the lake was 50-60 m in diameter and ~92 m below the E rim of the crater. From September to mid-October the level of the lava lake was ~63 m below the E rim of the crater with periods of episodic ascent by 10-15 m. During the intrusion and withdrawal of the lava lake a new collapse pit, termed the West Gap Pit, formed in the W gap of the crater. The pit is 30-50 m wide and 12-15 m deep.

Figure (see Caption) Figure 145. Distribution of lava flows from Kīlauea's E rift zone during January 1983-May 2000. Contours are in meters and the contour interval is ~ 150 m. Courtesy of HVO.

After the intrusion of magma, the 25th eruptive pause of the current eruptive episode (55) occurred when the supply of lava to a well-established lava-tube system, that ended near Kamokuna, stopped. Activity recommenced 23 September when lava erupted from a new spatter cone termed the 'mini-vent,' in Puka Nui collapse pit. Puka Nui is located on the S side of Pu`u `O`o crater. The pit formed in December 1997 and has been growing ever since by the collapse of tephra from the north wall of the pit and by engulfing other cones and smaller pits. Lava had not previously erupted from Puka Nui.

From 12 September through 22 October the lava-tube system was blocked by dams made up of debris that fell from the roof and walls of the tube. After the lava drained from the tube following intrusion, the walls cooled, shrank, and broke, causing the roof to collapse in places and the walls to crumble forming piles of debris. When lava re-entered the system it was blocked by a dam at 530 m elevation and reached the surface through cracks and holes in the tube upstream of the dam. Upslope breakout points were originally thought to be perched ponds (low shield-shaped structures with a pond of lava on top), but because the features were not vents and there was no ponded lava at the sites, they are referred to as breakout points from the lava tube. The lava traveled down Pulama pali towards the sea, but did not reach it. By 16 October activity occurred at the West Gap Pit with spattering from a vent in the floor of the pit, and by 18 or 19 October it filled with lava and overflowed, producing a shelly pahoehoe flow 160 m long.

Over the next several months the lava continued to flow down Pulama pali and just after sunset on 13 December lava reached the sea for the first time since the September intrusion. This took place at Highcastle entry and continued until 17-18 December. On 19 December lava reached the sea at the Lae`apuki lava bench, which had not been active since January 1997. As the lava flowed to the sea, it traveled down the sea cliff with some of it eventually cooling and solidifying to form wonderful examples of lava drapery (structures resembling the drips of wax down a candle). Throughout January lava continued to flow towards the sea causing the Lae`apuki bench to grow. On 3 February a second ocean entry became active at Waha`ula, 4 km E of Lae`apuki. Waha`ula was last active in July 1997 to late 1998.

On 23 February at 0142 tiltmeters at the summit showed a downward tilt toward the caldera (figure 146). The downward tilt indicated that magma was moving out of the summit reservoir; data from two other tiltmeters on the east rift zone indicated that the magma was moving into the rift zone. Concurrently, seismometers recorded a swarm of shallow earthquakes at the upper rift zone of the volcano. The swarm was centered near Pauahi Crater, ~7 km SE of Halema`uma`u Crater along the Chain of Craters Road. Hawaiian Volcano Observatory staff believed that the swarm probably recorded the movement of magma intruding to within 1-2 km of the ground surface. Such swarms commonly precede new fissure eruptions, but they more often record intrusions rather than eruptions. The reversal of the summit tilt a few hours later indicated when the intrusion stopped and magma once again moved into the summit reservoir. No new ground cracks were noted. The intrusion caused minor, but noticeable, changes in the ongoing eruption. Lava continued to enter the tube system at Pu`u `O`o, but blockages in the lava-tube system above the Pulama pali resulted in many breakouts on the active flow field. Lava stopped flowing to Lae`apuki entry on 25 March and intermittent ocean entries began along 2 km of coast centered on Waha`ula, which is currently the main entry.

Figure (see Caption) Figure 146. Kīlauea tiltmeter record for 22-24 February 2000 at Uwekahuna (tilt along an azimuth of N50W). Courtesy of HVO.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


June 2000 (BGVN 25:06) Citation IconCite this Report

During May-July 2000, continued frequent surface flows and earthquakes

The period from 1 May through 17 July 2000 was characterized by frequent surface flows and earthquakes. On 9 May a thick steam and sulfur dioxide fume formed SW of Pu`u `O`o; such fumes, or vog, have often obscured the crater for the past few months. The prominent fumes came from skylights (holes in roofs of lava tubes) along the active tubes leading to a narrow dark aa flow that emerged onto the surface on 6-7 May.

On 15 May lava broke frequently onto the surface, widening the active flow field toward the E. During 16-25 May very little activity took place. On 26 May at 0457, heavy vog hung over Pulama pali and slowly drifted downslope. The ocean entry at Waha`ula remained vigorous over the past several weeks, building a bench 40-45 m seaward of the former coastline (figure 147).

Figure (see Caption) Figure 147. Map of Kīlauea showing lava flows (black) on Pulama pali and the coastal plain active since October 1999 through 1 July 2000, as well as flows erupted earlier from Pu`u `O`o and Kupaianaha. Courtesy of the USGS Hawaiian Volcano Observatory.

On the afternoon of 29 May two successive earthquakes occurred on Kīlauea's S flank. The earthquakes had a preliminary magnitude of 4 and were felt in the town of Hilo 45 km NW of Kīlauea.

Observations of the Pu`u `O`o cone on 1 June revealed no significant changes in the crater or collapse pits on the S and W flanks (figure 148). On the E crater rim, gentle "sloshing" sounds were heard, indicating lava at a shallow level. Direct observation into the vent was prevented by heavy fume. The Pu`u `O`o crater contains three pond vents and two hornitos. Most of these originated during September-November 1999 intracrater activity. Since then the crater has often been obscured by fume, but occasionally HVO observers have witnessed active lava within these vents.

Figure (see Caption) Figure 148. A diagram of the Pu`u `O`o cone and surroundings at Kīlauea as of March 2000 showing the area covered by lava since February 1997 during episode 55 (light gray). Inside the crater of Pu`u `O`o, the "trough" is the drained lava pond of September-October 1999. The central portion of the trough was briefly filled with active lava in February 2000. Puka Nui is the prominent collapse pit on the SW flank of Pu`u `O`o, which was floored with lava during September-October 1999. Puka Nui is a slowly expanding collapse crater that has consumed part of the tephra cone and surrounding shield on Pu`u `O`o's SW flank. Flank vents active in 1997 have built the south shield, minishield, and 55 cone. Courtesy of Steven Brantley and Christina Heliker, USGS Hawaiian Volcano Observatory.

The S shield (figure 148) has about 20 m of relief; the minishield, less than 10 m. The episode 55 cone was about 10 m high; yet has subsided into a slowly expanding collapse crater. The cracks adjacent to the pit wall show the expansion of the 55 cone's pit. These cracks are as wide as 1-2 m and some have slight vertical offsets. Major subsidence occurs in abrupt stages. Entire collapse craters 10-30 m deep and 50 m across form in a few hours or less. The cracked ground then remains stable for weeks or months. The W gap, which formed in January 1997, is the result of the subsidence along the E-rift axis. An E-rift intrusion in September 1999 led to a temporary shutdown of volcanic activity at Pu`u `O`o. When activity resumed, new small spatter cones were active briefly, shedding the lava flows shown as 1999 flows on the sketch map.

Throughout the week of 11-17 June activity remained stable. Lava continued to flow to the sea from Waha`ula entry, and from the entry to its W. Surface lava flows were visible sporadically on Pulama pali and elsewhere. Volcanic tremor near Pu`u `O`o remained weak to moderate.

On 13 June rain cleared vog from Holei Pali and enabled good views of the flow field in the morning. Lava continued to enter the ocean, not only at the Waha`ula entry but also at other entries a few hundred meters to the W (figure 147). Surface flows were apparent several hundred meters inland, and visitors reported breakouts near the western edge of the present flow field for the past several days. Pulama pali remained dark, but the fumes rolling down the pali came from active lava tubes feeding the active ocean entries and surface breakouts. Due to rain clouds and volcanic gas in the crater center, Pu`u `O`o was dark on the morning of 14 June. Seismicity was low across the island. Volcanic tremor near Pu`u `O`o remained weak to moderate. Kīlauea's summit tilt and the tilt near and on Pu`u `O`o and all along the E rift zone were flat and stable.

Two moderate steam plumes rose from coastal entries on the afternoon of 15 June. Summit and rift-zone tilt remained steady, volcanic tremor at Pu`u `O`o was moderate and continued, and there was no unusual earthquake activity. Apparently on 15 June the eruption continued through tubes, with relatively little entering the sea.

On 16-17 June the lava bench at the Waha`ula entry was 30-50 m wide. On top of Pulama pali lava moved through the tube at a speed of ~10 km/hour. On 17 June, from 1330 to 1415, observations during a helicopter flight revealed more lava on the flow field a few hundred meters inland of Waha`ula. As movement of lava continued in Waha`ula, for the first time in several weeks a surface breakout was visible on Pulama pali between 1830 and 2030 on the evening of 17 June. The lava appeared from a distance to be aa and moved slowly down the middle third of the pali, near the eastern edge of the flow field W of Royal Gardens. On the evening of 17 June the Waha`ula entry , and another entry ~800 m to the W became active for several hours.

No breakouts were visible on 20 June on Waha`ula, Pulama pali, or the coastal flat. Fume continued to blanket the flow path down the pali. Above Pulama pali a new ledge was observed on 25 June, only ~1 m below the surface, at 642 m elevation. The ledge indicated that the level of lava in the tube rose temporarily and then subsided, and a breakout was observed at 686 m elevation.

During July there were frequent surface flows. On 6 July a substantial new pahoehoe flow began from a breakout point at about 200 m elevation on Pulama pali. The flow was ~500 m long and 150-200 m wide. Lava continued to spill into the sea at three sites. The most vigorous entry remained at Waha`ula, which generated two steam plumes on 6 July. The Kamokuna entry, the westernmost active bench, was less vigorous than Waha`ula but created a substantially larger steam plume. During mid-day 16 July, several entries were active: Waha`ula was the most active and Kamokuna the second most active. Several moderate-size surface flows were active in the eastern part of the flow field, between Royal Gardens and the coast. Heavy fume continued to flow down Pulama pali above the lava tube system.

Overall the seismicity and volcanic tremor for the months of May through July remained moderate and stable in the area around Kīlauea's summit. Within the summit of Kīlauea activity has remained slightly elevated.

Background. Kīlauea is one of five coalescing volcanoes that comprise the island of Hawaii. Historically its eruptions originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. The latest Kīlauea eruption began in January 1983 along the E rift zone. The eruption's early phases, or episodes, occurred along a portion of the rift zone that extends from Napau Crater on the uprift end (towards the summit) to ~8 km E on the downrift end (towards the sea). Activity eventually centered on the area and crater that was later named Pu`u `O`o.

Between July 1986 and January 1992, the Kupaianaha lava lake was active ~3 km NE of Pu`u `O`o. It was during this period that the town of Kalapana and a majority of the 181 homes lost were destroyed. In December 1991, one month prior to the shutdown of Kupaianaha, eruptive activity returned to Pu`u `O`o. More than 1 km3 of lava has erupted during the 14 years of activity (January 1983-January 1997).

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


October 2000 (BGVN 25:10) Citation IconCite this Report

Continued lava production during late-July to mid-November; two hikers dead

The entry of lava into the ocean and the frequent surface flows that occurred from May until mid-July 2000 (BGVN 25:06) continued during late-July to November, the interval discussed in this report. In overview, this interval included several key events. First, during 24-26 August, lava entry along the coast paused. Second, after renewed lava breakout from the tube, the point of lava entry into the sea shifted from the Waha`ula to the Kamokuna area. Third, during 24-25 September, a surge of magma caused a brief period of summit inflation and subsequent deflation. Finally, on 5 November, the bodies of two hikers were found near the sea.

During the end of July lava flowed into the sea mainly at the Waha`ula, Kamokuna, and E coastal entries. Surface flows and inflating pahoehoe flows were abundant, especially on the E edge of the flow field. During 29-31 July a swarm of small (M 2-3), shallow (0-5 km depth) earthquakes occurred just NW of the Hawaiian Volcano Observatory (HVO) in the area of Namakani Paio and the lower Ka`oiki fault system. On 31 July two new vents were observed in the E half of Pu`u `O`o crater, marking the first notable change in the crater in several months. Lava was observed streaming into the sea from atop the narrow bench below the sea cliff in the form of a "fire hose," with the lava stream entering the water ~10 m from the base of the 12- to 15-m-tall cliff (figure 149).

Figure (see Caption) Figure 149. Photograph of lava entering the sea in the form of a "fire hose" taken at 0913 on 31 July 2000. The inset shows the location of the lava "fire hose." The view is SE across the coastal plain of the volcano. In the inset he active ocean entries are marked by steam plumes, including Waha'ula the most vigorous entry at the lower left. Courtesy of USGS Hawaiian Volcano Observatory.

Volcanic activity during most of August was similar to activity in July, i.e. lava flowing into the ocean and several surface flows. Seismicity on the lower SW rift zone, which had begun with a swarm of earthquakes on 19-20 July, increased again during 1-3 August. The swarm consisted of small earthquakes at moderate depths (typically 10-20 km), accompanied by occasional bursts of deep tremor. On 12 August the volcanic tremor near Pu`u `O`o, which had been weak-to-moderate in early August, increased slightly, but returned to weak-to-moderate amplitude the next day. By mid-August the most active coastal entry site was Waha`ula, with little observable activity at the other recently active entry areas.

Pause in activity 24-26 August. A significant change in activity took place on the morning of 21 August when the flow of lava at the Waha'ula entry waned and then stopped. By 24 August all coastal activity, surface flows, and pahoehoe inflation ceased as well. This was the first pause in the delivery of lava to the surface since 11-14 November 1999. During the pause, Kīlauea's summit inflated slightly more than 4 µrad on 26 August as measured by two tiltmeters, one located across Crater Rim Drive from HVO and the other just N of Kīlauea Iki. At Pu`u `O`o cone, a tiltmeter measured an inflation of 3.5 µrad, which started ~5 hours after Kīlauea's summit began to rise. The Pu`u `O`o tiltmeter continued to detect inflation after the rate of summit tilting had drastically declined.

The pause in activity ended sometime on 26 August. Based upon tiltmeter measurements, the pause ended at 2145 that day. By then, tilting associated with inflation at Kīlauea's summit and Pu`u `O`o cone had stopped and may have reversed. Presumably at this time lava broke through to the surface, removing pressure on the plumbing system. In the past an increase in summit tilt has generally accompanied the onset of a pause, but in this case field observations suggested that the pause started about two days before the tilt began to change. Thus, HVO staff concluded that the observational pause lasted about 3 days, while the pause measured by the tiltmeters lasted ~20 hours. After the pause ended (27 August), lava extruded at ~700 m elevation (2,300-ft-elevation). This was the same spot below Pu`u `O`o where lava extruded prior to the pause.

During September lava flowed down Pulama pali and E across the coastal flat. During the afternoon of 23 September, lava reached the ocean for the first time since the August pause. It entered the ocean at the Kamokuna entry, located ~1.5 km WSW of Waha`ula, the previous main area of entry. Initially lava entered the sea sporadically and in very small amounts, but by the morning of 24 September a steady, small steam plume was being produced.

Surge of magma causes brief period of inflation. On the night of 24 September a surge of magma traveled down Kīlauea's E rift zone from the summit reservoir to Pu`u `O`o cone. At 2100 tiltmeters at the summit began to record steep inflation, and about 20 minutes later the tiltmeter on Pu`u `O`o also showed inflation. After 48 minutes the summit abruptly began to deflate and at about 0200 on 25 September the Pu`u `O`o cone started to deflate, which is probably when the surge reached the eruption site.

There were reports of a bright glow over Pu`u `O`o cone in the early morning hours of 25 September. The main source of the glow was from the large collapse pit in the West Gap of the cone where the lava had ponded. About the same time, fresh breakouts probably occurred from the overloaded tube system. Throughout the surge, lava entry at Kamokuna was unaffected and continued to produce a small steam plume. By 0830 lava escaped from a point at the 700 m elevation. Venting occurred in an area ~1km long and a few small breakouts also occurred along the tube at the top and bottom of the fault scarp (pali). By mid-morning, the activity diminished and, at about 1000, the pond inside the West Gap pit drained and did not refill. By 1300 the breakouts from the ~700-m-elevation point had greatly diminished and by 26 September the eruption returned to normal with the Kamokuna ocean entry persisting as an outlet and with additional scattered breakouts of lava on the costal plain (figure 150).

Figure (see Caption) Figure 150. Map of Kīlauea showing lava flows (black) active in September 2000 above and on Pulama pali and on the coastal plain, as well as flows erupted earlier from Pu`u `O`o and Kupaianaha. The eastern part of the active flow field (February 1997-September 2000 flows) extended to the Royal Gardens private access road on 11 January 2000 and entered the sea near Waha'ula on 3-14 February. That flow stopped in mid-August. A new flow (black) descended Pulama pali and crossed the coastal plain in September, with lava entering the sea at Kamokuna, an area about 1.5 km WSW of Waha`ula. Courtesy of USGS Hawaiian Volcano Observatory.

During October there were numerous surface flows and lava continued to enter the sea mainly at the Kamokuna entry. The state of the entry benches changed often, with several collapses accompanied by small littoral explosions. Volcanic tremor gradually increased beginning on 21 October, but returned to a moderate level by 23 October.

Volcanic activity during November was similar to that of the previous months, with lava entering the sea mainly at the Kamokuna entry. No major changes in seismicity occurred at the volcano, but for several hours on the night of 15 November a giant earthquake (M 8.0) in New Ireland, Papua New Guinea caused slow oscillations at Kīlauea's summit amounting to more than 12 µrad (peak-to-peak). Alarms at two tiltmeters were set off by the oscillation's large and comparatively rapid tilts.

At 1408 on 16 November tour pilots reported a large collapse of the bench at Kamokuna. About 30% of the bench disappeared in ~6 seconds as ~1 hectare separated from the rest of the bench along a crack that opened parallel to the shore and then the whole chunk calved off at once. A large explosion followed, with a significant amount of spatter and a big, billowing, mostly white plume that rose an estimated 600-1,800 m into the air. The interior of the bench, exposed by the collapse, was brightly incandescent.

Two deaths on 3 November. At about 1330 on 5 November the bodies of two hikers who died on 3 November were found ~6.4 km W of the end of Chain of Craters road. According to a press release from the National Park Service, the hikers' bodies were located above the sea cliff ~200 m from where lava was entering the ocean. A Park Service press release "ruled out death by [homicidal] violence or trauma" but officials were awaiting autopsy results before concluding the cause of death.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


September 2001 (BGVN 26:09) Citation IconCite this Report

Branching lava flows, ocean entries, and elevated seismicity into September 2001

Throughout this reporting interval, December 2000-September 2001, volcanic tremor near Pu`u `O`o and in Kīlauea's caldera remained low to moderate. Tiltmeters in the summit area and along the E rift zone showed no deformation. Branching lava flows, occasional sea entries of lava, and several seismic events took place. Small-to-moderate steam plumes originating at the ocean entries were visible on 10 December, on 5, 7, 26, and 30 May, and on 13 June. On 14 August a large steam plume was visible. Sulfur dioxide output from the Pu`u `O`o area was high on 15 May.

Lava flows. Beginning on 17 December 2000, lava moved down the Pulama Pali slope and across the coastal flat, along E, W, and middle branches, through a combination of tubes and surface flows (figure 151).

Figure (see Caption) Figure 151. Map showing lava flows erupted during Kīlauea's 1983 to 30 September 2001 activity. The flows active from 17 December 2000 through 30 September 2001 appear in dark gray. Note the strand-like W flow shown extending several kilometers in length and entering the sea at Kamoamoa. Courtesy of HVO.

Lava frequently broke out of the tube system beginning in January and February 2001. One breakout on 23 February along the E side of the flow field at the private access road to the Royal Gardens subdivision was quite substantial; a house in Royal Gardens was destroyed and an abandoned car was half-submerged in lava in front of it.

By mid-March the leading edge of the 1.5-m-wide flow front was within about 300 m of the coastline, headed for the sea E of Kupapa'u Point. During the end of March, activity was robust near the truncated road that formerly accessed Royal Gardens. In that area, surface flows occurred at dozens of points and rapidly inflated. Ground observers reported hearing methane explosions from burning vegetation along the base of the Pulama Pali slope.

During early April 2001, surface activity was confined to a small sluggish flow in the E branch of the flow field; most of the lava was encased in tubes and thus not flowing on the surface. At midday on 29 April, a tongue of lava began to pour into a crack paralleling the shoreline that separated a narrow sea cliff from stable ground inland. Eventually the lava wedged the crack open so much that the unstable block of land fell into the water, generating an explosion that tossed rocks onto dry land.

On 13 May, the active flow was 300-500 m from the nearest house in the Royal Gardens subdivision, but the homes were protected from the lava by a barrier of aa deposited in 1983. On 3 September, a lava flow, ~3.6-5.5 m wide, crossed the viewing-access road W of Kalapana, isolating the viewing area. The road, which was opened on 17 August, was closed on 30 August after about 10,000 visitors had used it over the previous two weeks. The flow across the access road stopped on 5 September, and road crews prepared to reopen it.

Ocean entry. Lava entered the sea on several occasions during this report period. The W arm of the coastal flow reached the sea in late December 2000 then quickly stagnated, remaining barely active as late as September 2001. During 21-29 January 2001 lava entered the sea just W of Kamokuna, and during 25-29 April lava entered the sea a few hundred meters NE of Kupapa`u Point, developing a large bench at the E Kupapa`u entry site.

On the afternoon of 13 May observers found three ocean-entry benches along the SE corner of the active flow field, NE of Kupaupau Point and 120-790 m outside the national park. The benches increased in area and width eastward, from 10 m wide near the boundary to nearly 60 m wide at the eastern bench. The eastern bench was 2 hectares in area, was the most active, and nearly coalesced with the middle bench. Sand beaches 10-15 m wide filled the gaps between the benches. Vigorous venting of lava into the sea occurred at the SE corner of the active flow field during the evening of 13 May.

Lava entered the ocean on several other occasions, including 20 and 31 May, and 2 and 18 June, mostly through the E Kupapa`u entry (figure 152). By 22 May, only the ocean entry at the SE corner of the flow field was active, indicating that lava was still coursing through the system but was confined to tubes for at least most of the way from Pu`u `O`o to the sea. Ocean entry at E Kupapa`u was fairly vigorous during the evening of 14 August, with a large steam plume, an open lava river pouring into the sea, and numerous mild-to-moderate steam explosions.

Figure (see Caption) Figure 152. Kīlauea view from E of E Kupapa`u ocean entry at dusk on 10 July 2001. The bench was comparatively large, reaching out about 120 m from the sea cliff. Note the new black sand beach formed by deposition of glass created when lava enters the sea. Courtesy of HVO.

Geophysical activity. During 1500-2400 on 6 January 2001, deflation events occurred at Kīlauea's summit and at Pu`u `O`o, amounting to ~1.7 µrad and ~2.8 µrad, respectively. The intensity of volcanic tremor increased beneath Kīlauea's caldera around the same time, though the tremor remained low-to-moderate in strength.

At about 0625 on 7 January, the tiltmeter near the observatory began to show very rapid inflation, jumping up to ~1.4 µrad in 32 minutes and eventually peaking at ~2.6 µrad by 1323. The sharpest inflation was accompanied by nearly 30 minutes of increased tremor beneath Kīlauea's caldera-even above that caused by the deflation event the previous day. By 8 January tilt and seismicity at the summit and Pu`u `O`o appeared to have returned to background levels. On the morning of 11 January, a burst of strong tremor in the caldera lasted about 30 minutes.

A small (~0.4 µrad) deflation occurred shortly before 1230 on 10 February. A weak swarm of shallow earthquakes within the caldera on 18-19 February ended by 20 February. On 20 February at 1317 a M 3.7 earthquake in the summit area was centered ~5 km SE of Halemaumau at a very shallow depth.

A swarm of earthquakes on the NE flank of Mauna Kea occurred during 22-24 February. The earthquakes in the swarm were all about M 3 and came from depths of 2-12 km. During early to mid-March, small low-frequency earthquakes took place below the caldera.

On 7 April tiltmeters recorded a summit deflation up to ~3 µrad. The deflation ended in early afternoon, but the heightened tremor below the caldera continued. The tilt record at Pu`u `O`o cone suggested that it began to deflate on the morning of 6 April at about 0600, stabilized in the afternoon, and started to inflate the morning of 7 April shortly after 0400. This inflation may have eventually led to later eruptive activity on the crater floor.

By 8 April the tiltmeter had recovered ~1.4 µrad and was increasing. Tremor below Kīlauea's caldera was nearly at background levels. Starting at about 0200 on the morning of 8 April, the summit began to inflate. By about 0300, the amplitude of tremor and the rate of long-period earthquakes began to decline to nearly background levels. Summit tilt leveled out at about 1000, regaining 2.5 µrad of the 3 µrad lost during the deflation that occurred on 7 April.

A slight deformation of the summit occurred during 23-25 April. In the afternoon of 25 April, a M 4.4 earthquake occurred near the observatory that produced a few small aftershocks during the following week. A swarm of long-period (LP) earthquakes that began beneath Kīlauea's caldera on 18 April had nearly ended by 2 May.

Volcanic tremor was higher than normal during 12 and 13 May and small earthquakes were recorded in the caldera. During mid-May, earthquake activity and volcanic tremor near Pu`u `O`o and in Kīlauea's caldera were at moderate levels with periods of rather strong ground motion.

On the afternoon of 20 May the largest tilt event to occur at Kīlauea in more than 4 years took place. Beginning at 0500 the summit began to slowly deflate (~2 µrad) until about 1630 when it very abruptly began to inflate (~10 µrad). It peaked at 1735 and began to deflate at 1750. The tiltmeter on the cone of Pu`u `O`o, and another one nearby, both recorded sharp inflation starting at about 1650, approximately 20 minutes later than the start of tilt at Kīlauea's summit.

At about 1920, a lava pond was observed to be forming in the crater of Pu`u `O`o. The surface lava flows showed no boost from the inflation. Instead, observations on 21 May revealed that the pond had drained.

No earthquakes were felt during the tilt event and no lava erupted in the caldera. The event was accompanied by strong tremor, which ended a prolonged period of small earthquakes in the caldera that had lasted, with a 9-hour break on the night of 18 May, for several days. Small earthquakes of the LP type, suggestive of magma movement, began again in the caldera and gradually increased from 21 to 22 May to a reasonable swarm. The tilt event ended on 22 May, as Kīlauea lost most of the positive tilt it had acquired.

Summit tilt started to rise on the afternoon of 22 May at a moderately rapid pace but slowed the morning of 23 May. Pu`u `O`o cone showed some inflation.

On 3 June a pause in volcanic activity may have begun at about 0900 with slow deflation (~2.6 µrad) occurring at the tiltmeter closest to HVO. It ended around 2400 and at 0125 rapid inflation (~2.7 µrad) began with most of the inflation occurring in about 55 minutes. Slow deflation (0.9 µrad) occurred at Pu`u `O`o during 1015-2200 on 3 June, with slow inflation occurring to at least 4 June. Background volcanic tremor at the summit gradually increased starting in mid-morning on 3 June, after deflation had begun. There was no significant change in the tremor at Pu`u `O`o.

Generally weak, steady tremor and related long-period earthquakes continued beneath Kīlauea's caldera throughout June. There was a slight increase in long-period caldera earthquakes for several hours on 18 June. Tremor remained weak to moderate near Pu`u `O`o and seismicity was at normal levels elsewhere. On 26 June from about noon until the evening a small amount of deflation occurred at the summit and ~0.5 µrad at Pu`u `O`o cone.

An earthquake with a preliminary magnitude of 3.5 rattled through the lower E rift zone of Kīlauea the evening of 16 July at about 1803. Located about halfway between Pahoa and Kapho, the earthquake was shallow (about 1.5 km deep) and felt locally by many residents. A swarm of earthquakes began on 21 July and ended by 25 July. Weak tremor began on 30 July near Pu`u `O`o.

Tremor near Pu`u `O`o was weak- to-moderate during August. During the afternoon of 15 August the intensity of volcanic tremor increased abruptly at both Kīlauea's summit and Pu`u `O`o but remained only moderate to low.

On 25 August a small but sharp inflation of Kīlauea's summit took place in the morning, amounting to slightly more than 1 µrad. The inflation began a little after 1000 and followed several hours of slow deflation. The inflation was mostly completed by noon, having recovered most of the tilt lost during the deflation. Pu`u `O`o cone underwent a very sharp inflation ~1 hour before the summit began to inflate and, just as at the summit, the inflation of the cone followed several hours of slow deflation. No upswing in seismicity accompanied the ground tilts. Small sharp earthquakes from beneath the summit continued but remained infrequent. As of early September, Kīlauea's summit was deflating very slowly.

Lava flow . A summary of statistics of the Pu`u `O`o- Kupaianaha eruption is provided in table 5. Since the start of the eruption in 1983, lava has covered 104 km2, which is just over 7% of Kīlauea's land surface. Some areas mantled repeatedly and are now buried beneath more than 30 m of basalt. Kīlauea's surface is comparatively young: ~70% is paved with flows younger than 600 years; 90% is younger than 1,100 years.

Table 5. Summary of statistics for the Pu`u `O`o-Kupaianaha eruption as of the end of the year 2000. Courtesy of HVO.

Description Statistics
Area covered by lava flows during January 1983-31 December 2000 104 km2 (40 square miles)
Net area of new land created along the coastal margin during November 1986-31 December 2000 207 hectares (510 acres)
Net area of new land created along the coastal margin during 2000 only ~7.5 hectares (18.5 acres)
Volume of lava erupted during 1983-2001 2 km3 (0.5 cubic miles)
Structures destroyed during 1983-1991 184
Structures destroyed during 2000 3 (all in Royal Gardens)

An eruption during the 14th century was fed from a vent just E of the summit area and probably continued discharging for about 50 years. Flows from this eruption covered a very large area N of the E rift zone, about 430 km2 (30 percent of Kīlauea's land surface). The 2-year-long Mauna Ulu eruptions (1969-71 and 1972-74) covered about 50 km2 and 44 km2, respectively.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


December 2001 (BGVN 26:12) Citation IconCite this Report

Low-to-moderate tremor, surface lava flows and ocean entry through early 2002

During September 2001 through at least early 2002, minor seismic events occurred and tremor remained low to moderate at Kīlauea's summit and at Pu`u `O`o. Tiltmeters across the volcano showed some deformation, which is normal for Kīlauea. A significant tilt event occurred on 9 December, but was not accompanied by unusual seismicity or change in eruptive activity. A survey of vertical and horizontal movement concluded that during 2001 Kīlauea's summit continued to subside at a maximum rate of 7cm/year as magma moved from the summit reservoir to the Pu`u `O`o vent; the S flank moved seaward at a maximum rate of 7cm/year. Lava broke out of the tube system and continued to flow down the Paluma Pali slope, resulting in bench growth at the new Kamoamoa ocean entry.

Geophysical activity. Small deflation events occurred at Kīlauea's summit on 12, 13, and 28 September, a large decrease followed by tremor on 17 October. By 21 October tremor at Pu`u `O`o became rather continuous; however, short bursts of higher amplitude tremor returned by 24 October. During 1-8 November weak, long-period earthquakes occurred frequently at the summit. On 8 December rapid deflation (~2.4 µrad) took place at Kīlauea's summit, followed shortly thereafter by deflation (~1.9 µrad) at Pu`u `O`o cone. On 9 December abrupt inflation (6 µrad) at Kīlauea's summit was followed by much weaker inflation at Pu`u `O`o. Strong earthquakes and tremor accompanied the inflation. A shallow M 3.4 earthquake was registered beneath the SE corner of the caldera. The end of summit inflation and beginning of deflation were notably abrupt. By 10 December, seismicity had returned to normal levels at the summit and tremor at Pu`u `O`o remained moderate.

On 1 January during 1200-2300, deflation occurred at Kīlauea's summit (~2.3 µrad), followed shortly thereafter by deflation (~2.5 µrad) at Pu`u `O`o cone. On 3 January during 1210-1950, inflation (~1.6 µrad) was again recorded at Kīlauea's summit. A small deflation followed on 11 January.

Through mid-January numerous small, long-period earthquakes with bursts of tremor registered at Kīlauea's summit and tilt across the volcano showed no significant deformation.

Lava flow. On 6 September a surface lava flow broke out in the E part of the flow field at an elevation of ~ 600 m on the Pulama Pali slope. The lava followed the route of the E tube from the top to the base of the slope, across the coastal flat and into the ocean at the E Kupapa`u ocean entry. On 13 September two surface flows were active along the W tube system of the Pulama Pali slope. During 28-29 September, a lava flow located W of the active flow field began to enter the ocean at a new area S of an old Kamoamoa camping area. The new W flow developed a tube system by 30 September that could reroute lava from East Kupapa'u to the Kamoamoa entry.

Throughout October lava broke out of the Kamoamoa tube system and flowed on the surface along the entire Puluma Pali slope. Flows increased along the main tube and E Kupapa'u. Around 13 November the Kamoamoa flow was confined to the tube system with at least five points of sea entry. Through the end of November, lava was mostly confined to the tube systems with a few surface flows that broke out of the tubes and produced patches of incandescence.

During December, surface flows and breakouts occurred along all tube systems from just below Pu`u `O`o to the coast. On 10 December, major breakouts were in progress just below Pu`u `O`o. On 18 December two parallel flows moved down Pulama Pali, both along the track of the Kamoamoa tube. The flows, which were sluggish and more than half crusted over, broke out from the tube in the upper half of the slope and descended to the lower third before becoming entirely crusted over. On 20 December a 3-m tall hornito formed at an elevation of ~700 m from a break in the roof of the main lava tube (figure 153).

Figure (see Caption) Figure 153. On 20 December at Kīlauea a 3-m tall hornito formed at an elevation of ~ 700 m from a break in the roof of the main lava tube. Incandescence was observed at the base of the hornito. Courtesy HVO.

During early January 2002, surface lava flows were visible on Pulama Pali coming from the Kamoamoa lava tube system. A surface flow reached 1.5-2 km down the upper portion of the flow field above the Pulama Pali slope.

Ocean entry. Through most of September lava generally continued to flow down the Pulama Pali slope, across the coastal flat, and into the ocean at the E Kupapa'u ocean entry. The ocean entry tube and the W tube carried lava that broke out on the coastal flat, and the E Kupapa'u bench remained active. Field mapping on 18 September revealed that the relatively larger W flow was within ~ 625 m of the coastline about 1.8 km W of the entry location at East Kupapa`u. Lava flows located W of the active flow field began to enter the ocean at a new area on 28-29 September. By 30 September a new lava bench and an adjacent black sand beach began to form. The new entry, fed by the W flow, was located 500-600 m seaward of the old site of Kamoamoa, 3.7 km from Chain of Craters road.

By 2 October the Kamoamoa bench had widened ten's of meters. The E bench was no longer active and showed signs of rapid erosion under heavy surf. The W bench extended 70 m farther W, reaching a length of about 190 m parallel to the shoreline and extending 60-70 m out from the old sea cliff. The feeding tube, called the Kamoamoa tube, remained small, with supply estimated to be about 15% of the total flux coming from Pu`u `O`o. By mid-October, lava continued to enter the ocean at both E Kupapa'u entries.

On 14 October surf erosion was gradually claiming the eastern part of the bench. Several small-to-moderate littoral explosions were observed at the point where lava entered the sea. By 28 October activity had decreased at the Kamoamoa entry and its bench reached 120 m from the old sea cliff. Surface flow had ended and all lava reached the bench through tubes. On 31 October a new entry point was observed roughly midway between E Kupapa'u and Kamoamoa.

Lava continued to flow into the sea at the Kamoamoa, Kupapa'u, and E Kupapa'u entries through November and December. By 18 November the Kupapa'u entry was inactive, and by 5 December much of the Kupapa'u bench had fallen into the ocean. By 20 December, the Kamoamoa bench was 360 m long, 130 m wide, and was littered with blocks and black sand.

During early January 2002, lava flowed into the ocean at the Kamoamoa entry from multiple locations, mostly at the tip of the bench and especially in the western third or quarter of the bench. The amount of lava entering the ocean at the E Kupapa'u entry was very small.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


March 2002 (BGVN 27:03) Citation IconCite this Report

Lava stops entering sea during January, tilting in late March-April 2002

This report discusses activity at Kīlauea during mid-January through mid-April 2002. The flow of lava into the ocean in September (BGVN 26:12) at the Kamoamoa entry and, to a lesser extent, at the E Kupapa'u entry, terminated by the end of January. During February through mid-March lava flowed on the surface at elevations above or on the Pulama Pali slope and along the Kamoamoa lava tube system. Volcanic tremor occurred at moderate levels, and long-period (LP) earthquakes were registered below the caldera. In mid-March incandescence was visible from Pu`u `O`o crater. Incoming lava flooded the floor of Pu`u `O`o crater and excess lava flowed through lava tubes down the Pulama Pali slope to the coastal plain. Heightened activity continued and in early April a series of deflation and inflation events occurred. LP earthquakes increased and on 6 April observations of the crater lake in Pu`u `O`o crater revealed that the lava had risen to 17 m below the E rim.

Geophysical activity. Tiltmeters across the volcano showed no significant deformation until mid-March, although an M 4.1 earthquake had occurred at 0118 on 18 January. The earthquake was located 4 km SSE of the Pu`u `O`o crater at a depth of 9.1 km. During the following several days volcanic tremor remained moderate to strong at Pu`u `O`o. The swarm of long-period (LP) earthquakes at the summit continued through March. Just after 0300 on 27 March a small earthquake beneath the caldera triggered more than 30 minutes of increased tremor and small earthquakes.

Sharp deflation at Pu`u `O`o on 28 March accompanied a change in eruptive activity at the cone. On 31 March volcanic tremor was low-to-moderate at Pu`u `O`o and the continuing weak tremor below the caldera was broken occasionally by small LP earthquakes. Associated tilt across the volcano was flat or only changed slightly.

During 4-6 April, a series of deflation and inflation events occurred. In terms of tilt, at ~2100 on 4 April, Kīlauea's summit deflated (~1.7 µrad); 30 minutes later Pu`u `O`o followed (~9 µrad). This was reversed at 1600 on 5 April when rapid inflation began at the summit and ~12 minutes later at Pu`u `O`o. At 1700 inflation ended at the summit, and it abruptly deflated, as did Pu`u `O`o at 1800. Subsequently, tilt at Pu`u `O`o oscillated three times between rapid deflation and slower inflation. The tilt temporarily decreased, but at 0508 on 6 April another interval of 4.5 oscillations occurred followed by resumed tilt and slow, bumpy inflation. During this turbulent period LP earthquakes increased at the summit while tremor remained steady at Pu`u `O`o. By 7 April tilt was relatively steady, volcanic tremor at Pu`u `O`o was moderate, and tremor at the summit was low to moderate.

Lava flows. During mid-January surface lava traveled along the upper portion of the flow field above the Pulama pali slope and onto the coastal flat. Surface lava also emerged along the Kamoamoa lava tube system and traveled down the Pulama pali slope. These surface flows continued to be visible through February, although the flow reaching the coastal plain had stopped at the end of January. At times during early March several rootless shields (a pile of lava flows built over a lava tube rather than over a conduit feeding magma) were active. During 12-19 March a bright glow was widely visible over Kīlauea from Pu`u `O`o crater and from a rootless shield near 665 m elevation where the most intense surface activity occurred.

By 18 March lava had flooded the floor of Pu`u `O`o crater resulting in surface lava flows and lava flowing through tubes. Lava spread out on the lower fan and adjacent coastal flat, although the fronts of the flows remained ~2.3 km from the ocean. At the base of the lava fan and on the adjacent coastal flat the rootless shields remained active and small surface lava flows persisted through mid-April.

Eruptive activity changed on 28 March, as noted above, and overflight observations revealed new lava located W of the main crater. Observers also saw lava fountaining and forming a circulating pond. By 31 March a lava flow was visible on the floor of Pu`u `O`o crater and several vents were incandescent. During a brief visit to Pu`u `O`o on 6 April observers noticed that the crater lake had risen ~8 m since 29 March (the lake surface was 17 m below the E rim), several cones were active, and lava was flowing into the lava lake from two vents. By the following day activity had decreased and by 8 April incandescence was no longer visible at Pu`u `O`o.

General References. Decker, R.W., Wright, T.L., and Stauffer, P.H., 1987, (eds.), Volcanism in Hawaii: USGS Professional Paper 1350, 1667 p. (64 papers).

Ryan, M.P., 1988, The mechanics and three-dimensional internal structure of active magmatic systems: Kīlauea volcano, Hawaii: JGR, v. 93, p. 4213-4248.

Dzurisin, D., Koyanagi, R.Y., and English, T.T., 1984, Magma supply and storage at Kīlauea volcano, Hawaii, 1956-1983: JVGR, v. 21, no. 3/4, p. 177-207.

Heliker, C., Griggs, J.D., Takahashi, T.J., and Wright, T.L., 1986/7, Volcano monitoring at the U.S. Geological Survey's Hawaiian Volcano Observatory: Earthquakes and Volcanoes, v. 18, no. 1, p. 3-71.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


May 2002 (BGVN 27:05) Citation IconCite this Report

New lava flows during early May burn over 1,000 hectares of forest

Surface activity and seismicity continued at Kīlauea during mid-April through early June 2002. Volcanic tremor was moderate at times and was accompanied by frequent long-period (LP) earthquakes during mid-May. Lava flows erupted during January and April 2002 (figure 154) were fed by several rootless shields located directly above the lava tube at elevations between 2,200 and 2,050 feet. Three significant lava flows began during mid-April and early May (figure 154) and had not yet terminated by the end of the report period. Two of these flows originated in the rootless shield area, and the third broke out from the lava tube system to the SW of Pu`u `O`o crater. The two flows from the rootless shields were the Boundary flow, along the edge of the national park, and the Royal Gardens flow, which approached the uppermost part of Royal Gardens subdivision on 21 May. The Royal Gardens flow entered the subdivision during the night of 22-23 May. From near Pu`u `O`o, the 12 May flow passed along the W side of the flow field and into the forest. The most recent ocean entries at East Kupapa'u and Kamoamoa stopped in mid-January and late January, respectively.

Figure (see Caption) Figure 154. A map showing lava flows erupted during the 1983-present activity of Pu'u 'O'o and Kupaianaha craters at Kīlauea. Flows during 1-21 May (shown in black) originated from two sources, the area of the rootless shields and an area just SW of Pu'u 'O'o. Courtesy HVO.

Geophysical activity. Seismicity was at background levels and tiltmeters showed no significant activity until 23 April, when 10.1 µrad of rapid inflation was recorded at Pu`u `O`o crater. The inflation was inferred to be shallow because other tiltmeters recorded less inflation at greater distance from Pu`u `O`o. The summit showed little accompanying tilt change for this event.

Seismicity and tilt returned to normal levels until 28 April when Pu`u `O`o deflated rapidly and shortly thereafter began again to inflate slowly. Major deflation began on the morning of 12 May, and by 13 May Pu`u `O`o had deflated 18 µrad. Tremor increased to levels above those prior to the deflation and was accompanied by small LP earthquakes at the summit and Pu`u `O`o. Seismicity continued to increase beneath the caldera with one small LP earthquake every ~30 seconds. This swarm ended abruptly on 22 May, and by 24 May seismicity returned to normal background levels with tilt flat or fluctuating slightly. During 5-10 June swarms of frequent LP earthquakes occurred in the caldera accompanied by moderate tremor below Pu`u `O`o, which continued through 15 June.

Lava flows. Observers reported incandescence on 18 April in the East Pond vent and South Wall complex of the Pu`u `O`o crater. Partss of the rootless shield area were also glowing brightly. On a 24 April overflight observers reported a bright glow from the Puka Nui area and a small lava flow from the same area traveling SE. On the same day a lava flow had moved onto the floor of the Pu`u `O`o crater. By 2 May most activity in Pu`u `O`o had subsided to low incandescence.

Around 30 April a bifurcating lava flow originated in the SE corner of the rootless shield; it formed two of three significant flows during May; one occurred along the boundary of Volcano National Park and the other moved towards the Royal Gardens subdivision.

Incandescence waned but the rootless shield flows continued until 12 May when the two large surface flows broke out from the upper tube system near the SW base of Pu`u `O`o. On 12 May at about 1100 a video recording showed that the flows were ~3 m wide and extended an unknown distance downslope. During mid-May activity of the flow along the Park boundary fluctuated on the Pulama pali slope, but all three flows continued. By the end of the report period the 12 May flow was 800-1,000 m from the end of the Chain of Craters road after cascading down part of the 1995 Jason flow (BGVN 20:04). The Royal Gardens flow had advanced into the subdivision and the boundary flow showed dim incandescence and continued its movement along the park boundary.

The 12 May flow ignited fires as it traveled through the wooded areas above the Pulama pali. The fires burned over 1,000 hectares through 1 June and prompted the closure of the Chain of Craters road. By 10 June the fires were 65% contained and the road was reopened for nighttime viewing. No ocean entries occurred during the report period.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


August 2002 (BGVN 27:08) Citation IconCite this Report

Lava flowed over land and poured over the sea cliff during parts of mid-2002

During June through early September 2002 at Kīlauea, seismicity was generally at background levels with the exception of a swarm of long-period (LP) earthquakes and tremor that has been occurring at Kīlauea's crater since 5 June. The swarm increased slightly in late July but decreased in mid-August. On the morning of 18 August, the number of LP earthquakes increased. By late August, seismicity was back to normal levels. The swarm of LP earthquakes and tremor fluctuated but typically remained high. In early September, the swarm that had been occurring since early June returned to moderate-to-low levels. Pu`u `O`o deflated through June and early July, then inflated briefly in late July before remaining essentially unchanged through early September.

Surface lava flows continued from Kīlauea's SW flank; late in July a spectacular show began as lava flowed into the sea. This continued into mid-August, stopped briefly, and resumed in early September.

Geophysical activity. At the start of the report period seismicity was at background levels, except at the Pu`u `O`o crater, where a swarm of LP earthquakes has occurred since 5 June. Moderate tremor took place at Pu`u `O`o in mid-June. In late July, the seismicity swarm increased slightly returning to normal by mid-August. The swarm of LP earthquakes fluctuated through the remainder of August and decreased to moderate-to-low levels by early September.

During 11-12 June, ~2 µrad of deflation was measured at Pu`u `O`o. Overall deflation continued at Pu`u `O`o and Kīlauea's summit during the remainder of June, with 0.9 µrad occurring on 26 June. No significant deformation was detected. Slow deflation was recorded at Pu`u `O`o from 4 July until 6 July, when inflation began to occur. Slow inflation continued until at least 9 July, followed by a period of slow deflation that ended in late July. A brief period of inflation occurred on 26 July. No further signs of significant deformation were observed through the end of August. On 2 September it was observed that Pu`u `O`o was slowly deflating. This was followed by small episodes of inflation and deflation at Uwekahuna and Pu`u `O`o for several days ending on 9 September.

Lava Flows. During June through early July, several surface lava flows (incandescent at times in late June) were often visible at Kīlauea. By 10 July, surface lava flows were visible traveling down the Pulama pali scarp and Paliuli, the steep slope and cliff below Pulama pali and just above the coastal flat. On 20 July at 1900 part of the westernmost lava flow reached the Chain of Craters road, and by 0445 the next day lava was entering the sea in two areas. The active flow front moved 610 m in 18 hours on nearly flat ground (3.6 m/hour), relatively quickly for Kīlauea. During the final week of July, hundreds of spectators flocked to Kīlauea to see the spectacular show of lava flowing into the sea at the end of easily accessible Chain of Craters road. Surface lava flows were observed traveling down Pulama pali, Paliuli, and on the coastal flat.

By 6 August, only the Wilipe`a entry was active, with lava from five or six lava tubes pouring off the bench into the water. The West Highcastle bench was steaming but had no lava. At the Highcastle kipuka, two actively advancing lobes of lava were found, one 160 m and the other 170 m from the western and eastern remnants, respectively, of the Chain of Craters road, themselves only 40-60 m from water. Each lobe was moving very slowly (figure 155).

Figure (see Caption) Figure 155. Aerial view on 2 August 2002 of Kīlauea's active flow field between Wilipe'a and West Highcastle benches and Paliuli. The new flows are the lightest gray color. The medium-gray color on the left shows the vegetated flows (probably 600-900 years old) and the dark gray shows the 1992-97 flows. View looks NE. Courtesy HVO.

On 7 August at 1427 the W Highcastle lobe reached the sea. On the evening of the 7th littoral explosions on the E side of the most seaward tip of the lava bench sprayed spatter and solid rocks back onto the bench. A lava bench began to grow near the W Highcastle flow 10 m from the shoreline; it was 30 m long and parallel to the sea cliff by 11 August. Surface lava flows also cascaded down Paliuli at times (figure 156).

Figure (see Caption) Figure 156. View of the western group of lava falls at Highcastle entry, taken at 0557 on 10 August 2002. Sense of scale is provided by the people standing near the sea cliff to the left (W) of the flowing lava. Courtesy HVO.

Lava flows sporadically entered the sea during mid-August, traveling to the coast through lava tubes and over the surface. On the morning of the 18th several people witnessed part of a lava bench collapse into the sea. On 21 August lava entered near the Highcastle stairs (the more easterly ocean entry), but by the 25th no lava was entering the sea. During late August and early September, lava continued to flow SE down Paliuli and Pulama pali, and many surface lava flows were visible on the coastal flat. Lava began to enter the ocean again on 3 September.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


November 2002 (BGVN 27:11) Citation IconCite this Report

Inflation-deflation episodes and lava flows through 2 December 2002

Surface activity and seismicity continued at Kīlauea during mid-September through early December 2002. At times lava was visible flowing on the coastal flat, and farther upslope on steep slopes and cliffs (at Paliuli, a steep zone just above the coastal flat, and Pulama Pali, a larger steep zone farther upslope). Seismicity was generally at normal levels. There were short periods of inflation and deflation at Uwekahuna and Pu`u `O`o.

Lava flows. During 11-30 September, lava continued to travel SE down Pulama pali and Paliuli, and many surface lava flows were visible on the coastal flat. Lava flowed onto the Wilipe'a bench directly seaward of the end of the Chain of Craters Road. Lava entered the sea at several points on the NE portion of the front of the bench. A great, elongate tumulus was forming directly above the buried pavement of the Chain of Craters Road, near the end of the exposed pavement. On 16 September, it was 3-5 m high, very steep sided, and elongate along the direction of the old road. Also on 16 September, two flows on either side of the West Highcastle lobe threatened to enter the sea. Both flows sent lava onto an old bench. One flow was more or less along the W edge of the West Highcastle lobe, and the other was split into two fingers near the old sea cliff forming the back side of the old bench; one finger was along the E side of the West Highcastle lobe, and the other midway between the Highcastle and West Highcastle lobes. The two flows were fed by the burgeoning West Highcastle lobe, supplied mainly by lava coming over the eastern part of Paliuli. On 22 September, the Highcastle and West Highcastle lobes of the Mother's Day flows were filled in by active lava. A new delta (bench) was being built seaward of the 1995 delta; on 22 September, the new addition was about 20 m beyond the old coastline. During late September visitors saw several sudden collapses of the front of the bench. Lava entered the sea at several points along the two active lava deltas (Middle Highcastle and Wilipe`a) during 1-23 October. No surface flows were visible on the deltas; lava either entered the water via lava tubes or inflated the delta underneath the surface. Several surface flows were visible on the coastal flat, and sporadically on Paliuli and Pulama pali. During late October and early November, surface lava flows were not visible on the coastal flat, but were occasionally seen near Paliuli and Pulama pali. Similar activity continued through mid-November, when spots of incandescence were visible on Paliuli, on the gentle slope below Pulama pali, and above Pulama pali.

From 21 November through 2 December lava continued to flow into the ocean at low-to-moderate levels at the West Highcastle and Wilipe`a entries. West Highcastle was the more active of the two lava deltas, with sporadic explosions coming from one of its entry points. Several surface lava flows were visible on the coastal flat (figure 157).

Figure (see Caption) Figure 157. Map of lava flows erupted during 1983 through 25 November 2002 from Pu`u `O`o and Kupaianaha. Lava renewed draining into the sea at the Wilipe`a ocean entry on 3 September, and continued as of 25 November. Lavas also renewed draining into the sea at the West Highcastle entry during 16-17 September; they died away during the night of 18-19 September, but returned soon thereafter to continue through at least 25 November. The E arm of the Mother's Day flow branched from Highcastle lobe in late October. After that, this arm of lava sent three fingers into the ocean: at Highcastle on 15 November, at West Lae`apuki on 19 November, and at Lae`apuki on 20 November. Of these, only Lae`apuki (the eastern of the two entries labeled "Lae`apuki") was still active on 25 November, but it had stopped by 29 November. Courtesy HVO.

Geophysical activity. During mid-September seismicity was generally at normal levels. There were short periods of inflation and deflation at Uwekahuna and Pu`u `O`o. For several days before 18 September, there was a period of repetitive inflation and deflation at Uwekahuna and Pu`u `O`o. After the 18th no significant deformation was recorded. The swarm of long-period earthquakes and tremor beneath Kīlauea's caldera that originally began in June was fairly weak.

On 3 October the swarm of long-period earthquakes and tremor picked up strongly, with numerous long-period events persisting for about a day. Elsewhere there was no unusual seismicity. Around the time of increased seismicity, small periods of inflation and deflation occurred at Pu`u `O`o and Uwekahuna. Otherwise, tiltmeters recorded no unusual deformation.

Small swarms of long-period earthquakes and tremor occurred beneath the caldera during mid-October through at least 2 December. Periods of deflation and inflation continued to occur at Pu`u `O`o and Uwekahuna. A small deflation event began on 28 October that was recorded at the Uwekahuna and Pu`u `O`o tiltmeters. Small deflation may have occurred at the Uwekahuna and Pu`u `O`o tiltmeters on 10 November. Gentle deflation occurred at Pu`u `O`o during 13-24 November.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


May 2003 (BGVN 28:05) Citation IconCite this Report

Continued lava flows during December 2002-June 2003 enter the ocean

From December 2002 through June 2003, lava from Kīlauea continued to flow down the S flanks and into the ocean at several points. Seismicity generally continued at normal (background) levels. The Mother's Day flow, which began erupting 12 May 2002, continued through June 2003 (figure 158).

Figure (see Caption) Figure 158. Map of lava flows erupted during 1983 through 16 May 2003 from Pu`u `O`o and Kupaianaha. The most recently active flows are on the SW side of the flow-field. Courtesy of HVO.

Lava flows. During December 2002, lava continued to flow into the sea at entry points from two lava deltas. Moderate-to-large littoral explosions tossed spatter onto the front of the West Highcastle delta. Surface lava flows were visible on the coastal flat. On 15 December, shortly after 0700, the Wilipe'a lava delta partially collapsed, losing about 1/3 of its area. The tip of the delta retreated shoreward about 260 m and most of the collapse was in the central part of the delta. Around 15 and 16 December a substantial collapse occurred at the West Highcastle delta. On 28 December moderate collapses occurred at the Wilipe'a lava delta, apparently in the area of the 15 December collapse. Surface lava flows were visible on the coastal flat and upslope on Pulama pali.

During January and February 2003, lava continued to flow into the sea at the West Highcastle entry. Surface lava flows were visible on the coastal flat and upslope of it on Paliuli. Most of the surface lava flows on the coastal flat crusted over, so that less incandescence was visible than previously. Relatively large surface lava flows were visible starting on 21 January around 2035. Around 28 January a large lava breakout occurred from the West Highcastle lava tube about 170 m inland from the old sea cliff. As of 2 February the area of the new breakout was about 6.15 hectares (6.15 x 104 m2), and surface flows and lava in lava tubes traveled down the Pulama pali fault scarp. The Chain of Craters road was closed due to a wildfire that was started by lava flows. Surface lava flows continued to travel through vegetation, igniting fires and causing methane explosions. Rangers' office huts, restrooms, and signs were moved out of the path of the lava flow, which reached the Chain of Craters Road on 19 February at 1005. Beginning 15 February and going into March, lava flowed into the sea at the Kohala entry. Fresh lava oozed out of the cooling Kohala lava flow, both within the body of the flow and along its E margin.

During 26 February to 3 March lava continued to enter the sea at the West Highcastle entry, but the lava-flow rate was reduced to a small trickle at the Kohala entry. Small surface flows occurred along the W edge of the Kohala lava flow and surface lava flows were visible above the Pulama pali fault scarp. Tongues of lava were visible traveling down Pulama pali, part of the activity that began on 12 May 2002 (named the Mother's Day flow).

Through April 2003, Kīlauea continued to erupt, sending lava down its SE flank either traveling over the land surface or through tubes. Lava entered the sea at the West Highcastle entry; activity there was sometimes weak, though one or more glowing areas were typically seen. On 16 April a large tract of land not over-run by surrounding lava (a kipuka or ahu in the local parlance) remained within the Kohola lava flow, still ~30 cm above the top of inflated lavas that surround it. On the eastern margin of the swath of lava flows going down the steep slopes of Pulama pali, one partly crusted-over lava stream was highly visible. The crater of Pu`u `O`o was dark and obscured by fumes, but eruptive activity at Pu`u `O`o continued unabated. The flows on Pulama pali were frequently visible at night as streams of incandescence from the top of the pali down to the coastal flats. Late in April, the E arm of the Mother's Day flow split in two with the W segment being more active. A new ocean entry near Lae'apuki only lasted a day before the flow stagnated. Scattered surface breakouts were seen throughout the inflating Kohola flow, especially on its W side. As of 24 April, lava entered the ocean at two points along the West Highcastle delta.

In early May, lava flows continued to descend the S flanks and pour into the sea. On 12 May lava began to enter the sea again at the West Highcastle lava delta. Surface lava flows were visible on the coastal flat and the Pulama Pali fault scarp. During June, lava continued to flow down Kīlauea's SE flank, with surface lava flows occasionally visible on the coastal flat and upslope at Pulama pali, and Paliuli. Small amounts of lava continued to flow into the sea at Highcastle beach.

Geophysical activity. During December 2002 and January 2003, seismicity was generally at normal levels. The swarm of long-period earthquakes and tremor beneath Kīlauea's caldera, occasionally seismically active since June 2002, continued to show some short bursts of tremor interspersed with small earthquakes. Small inflation and deflation events occurred at Pu`u `O`o and Uwekahuna tilt meters. The Pu`u `O`o tiltmeter showed deflation for about one week from 10 to 17 December. During 27-28 December, slight deflation occurred at the Uwekahuna and Pu`u `O`o tiltmeters.

Kīlauea's summit began to deflate on 20 January 2003 at 1710, and Pu`u `O`o began to deflate a few tens of minutes later. Both areas deflated well into the next day. On the 21st at 1610 rapid, brief inflation began at the summit. The inflation and preceding deflation were centered near the NE corner of Halemaumau Crater, the normal center of small deformation events. Seismicity increased with the deformation events, returning to normal levels afterwards. By 22 January seismicity had returned to its normal level, with the long-lasting swarm of long-period earthquakes and tremor at Kīlauea's summit continuing at weak-to-moderate levels.

During February and March, seismicity was at background levels. The long-lasting swarm of long-period earthquakes and tremor at Kīlauea's summit continued at low-to-moderate levels. On 9 and 10 February, short periods of deflation and inflation occurred at the Uwekahuna and Pu`u `O`o tiltmeters. Moderate tremor was recorded by the nearest seismometer to Pu`u `O`o until the seismometer broke on 5 March. Moderate deflation occurred on 8 March, first at the Uwekahuna tiltmeter and then at the Pu`u `O`o tiltmeter. According to a news report, a member of a tour group suffered burns on 10 March when he fell on hot lava while hiking near Chain of Craters road.

For about a week in early April, volcanic tremor at Pu`u `O`o was relatively high and small deformation changes occurred, mostly at Pu`u `O`o. During 16-17 April, the Uwekahuna tiltmeter at Kīlauea's summit recorded three small inflations, the last apparently right at its crest. Pu`u `O`o has generally followed suit, though in this case showing only two of the inflations very well. These tilts are not major but continue to illustrate the clear connection between Kīlauea's summit, where most tilt events start, and Pu`u `O`o, 20 km away, where the tilt events follow a few minutes later. Seismicity during the week was at low to normal levels. Instruments continued to register the summit swarm of long-period earthquakes and tremor, which began last June. Volcanic tremor at Pu`u `O`o remained elevated, as has been the norm for more than a week.

During 30 April to 6 May, distances measured across Kīlauea caldera between two points ~10 km apart, remained stable as they have since early 2003. There had been consistent progressive lengthening of this distance during late 2001 through mid-2002, and some minor fluctuations after that. In general, tilt during late April through 2 May changed little at Uwekahuna station (W side of the caldera), and showed a progressive decline at Pu`u `O`o station (E of the caldera). In the first few days of May slight inflationary tilt appeared at both stations.

Seismicity at Kīlauea's summit was at moderate-to-high levels from about 1 June through 14 June, with many small, low-frequency earthquakes occurring at shallow depths beneath the summit caldera. The tiny earthquakes occurred at the notably high rate of 2-4 per minute. Little or no volcanic tremor accompanied the swarm, however. Volcanic tremor at Pu`u `O`o remained moderate to high, as is the norm. A quasi-cyclic inflation and deflation occurred at Kīlauea's summit and at Pu`u `O`o during the week of 6-13 June, but did not culminate in significant overall tilt.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


September 2003 (BGVN 28:09) Citation IconCite this Report

Active surface lava flows from June through mid-October

During 2003, lava from Kīlauea continued to flow down the S flanks and into the ocean at several points. The Mother's Day flow, which began erupting from Pu`u `O`o on 12 May 2003, remained active. Seismicity generally persisted at normal (background) levels. A recent report from the U.S. Geological Survey, edited by Heliker, Swanson, and Takahashi (2003) described the nearly uninterupted Pu`u `O`o-Kupaianaha eruption that started 3 January 1983 and continues today.

Lava flows. Lava entered the sea mainly at the Highcastle ocean entry during 11-17 June and surface lava flows were visible on the coastal flat and Pulama pali during June and July 2003. However, no lava flowed into the sea during the later half of July and into early August.

Deflation that began on 8 August amounted to ~ 1.8 µrad at the Uwekahuna (UWEV) tiltmeter and ~ 4 µrad at the Pu`u `O`o tiltmeter, both located near the Kīlauea summit (figure 159). The deflation was accompanied by a drop in the level of lava in a lava tube, as seen by field workers at midday. Inflation began later that day at 1928, and in ~ 3.5 hours ~ 3.5 µrad of inflation was recorded at Uwekahuna and ~6 µrad at Pu`u `O`o.

Figure (see Caption) Figure 159. Map of selected deformation stations at Kīlauea, 2003. Courtesy of HVO.

A lava breakout occurred on 9 August between 0200 and 0300, ~ 1.3 km SE of the center of the Pu`u `O`o cone. A very large sheet flow emerged from the up-tube side of a rootless shield formed on 21 January. Observers saw a lava stream up to 40 m wide. By 0600 the flow covered ~ 5.2 hectares (0.052 km2).

Later in August and into September, surface lava flows were visible on Kīlauea's coastal flat, in some areas flowing to within 500 m of the sea. On 2 October lava began to flow westward after filling West Gap Pit on the W flank of Pu`u `O`o cone. Fairly vigorous spattering was visible in the pit, but decreased to only sporadic bursts later in the day. The flow appeared to have stopped by 4 October when no glow was observed coming from the pit.

Lava flows have erupted from 1983 through 10 October 2003 from Pu`u `O`o and Kupaianaha. The area of recent lava flows on the W side of the flow-field has been designated the Mother's Day flow, which began erupting on 12 May 2002 and continues to the present (figure 160). Through September and into early October, lava was moving along the E and W sides of the Mother's Day flow. The E-side lava (mentioned previously as the 9 August breakout) came from the 9 August rootless shield, itself fed by the main Mother's Day tube from Pu`u `O`o. The W-side lava, known as the Kohola arm of the Mother's Day flow, branched off the tube system below the rootless shield. In early October, the E-side flow stopped moving, the W-side flow died back to a trickle, and the rootless shield gained prominence. By 16 October, however, the shield had partly collapsed, leaving several drained perched ponds. Upstream from the shield, many hornitos and small flows formed over the Mother's Day tube.

Figure (see Caption) Figure 160. Map sequence showing Mother's Day lava flows that began on 12 May 2002 (darkest shade) from the Pu`u `O`o cone at Kīlauea as of 21 May 2002, 25 November 2002, 16 May 2003, and 10 October 2003. Modified from original maps created by the USGS Hawaiian Volcano Observatory.

Geophysical activity. During the second half of June and into August 2003, seismicity at the summit was at moderate-to-high levels, with many small, low-frequency earthquakes occurring at shallow depths beneath the summit caldera at a rate of about 1-2 per minute. Little or no volcanic tremor accompanied the swarm at the caldera, however. Volcanic tremor at Pu`u `O`o remained at moderate-to-high levels, as is the norm. A quasi-cyclic tilt pattern ended at Kīlauea's summit and Pu`u `O`o on 13 June after lasting about a week. Small periods of inflation and deflation occurred during July and into August.

During the deflation on 8 August, there was an increase in small, low-frequency earthquakes and changes in their frequency content. Some larger events occurred at depths of a few kilometers, as during the previous several weeks. A magnitude 5.0 earthquake 10 km beneath Kīlauea's central S flank on 26 August at 2024 was the largest since 2 April 2000, which occurred in almost exactly the same spot. No significant damage was done, no cracks or rockfalls were seen, and there was no change in the eruption. Generally, following that event and into September, summit seismicity continued at moderate levels with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger events at depths of a few kilometers.

At about 1500 on 20 September 2003, first Uwekahuna and then Pu'u O'o started to deflate. Pu'u O'o lost ~ 1.5 µrad during the deflation, and Uwekahuna lost ~ 0.9 µrad. The deflation ended with a sharp inflation in the early morning on 21 September, which lasted until early on 22 September, when the tilt flattened.

Reference. Heliker, C., Swanson, D.A., and Takahashi, T.J. (eds), 2003, The Pu`u `O`o-Kupaianaha eruption of Kīlauea Volcano, Hawaii: The first 20 years: U.S. Geological Survey Professional Paper 1676, Denver, CO.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


November 2003 (BGVN 28:11) Citation IconCite this Report

Moderate seismicity and minor activity on the lava-flow field

Through September and into early October, lava was moving along the E and W sides of the Mother's Day flow. The E-side lava (known as the 9 August breakout) came from the 9 August rootless shield (see figure 2 in BGVN 28:09), itself fed by the main Mother's Day tube from Pu`u `O`o. The W side lava, known as the Kohola arm of the Mother's Day flow, branched off the tube system below the rootless shield. In early October the 9 August breakout stopped, the Kohola died back to a trickle, and the rootless shield gained prominence. By 16 October, however, the shield had partly collapsed, leaving several drained perched ponds behind. Upstream from the shield, many hornitos and small flows formed over the Mother's Day tube.

During 1-7 October, surface lava flows were sometimes visible on Kīlauea's coastal flat and upslope areas. On 2 October lava began to flow W after filling West Gap Pit on the W flank of Pu`u `O`o cone. Fairly vigorous spattering was visible in the pit, but died to only sporadic bursts later in the day. The flow appeared to have stopped by 4 October when no glow was observed coming from the pit. During 8 October-17 November, a few areas of surface lava were visible upslope of Kīlauea's coastal flat. On 5 November, two small breakouts occurred. The freshly escaping lava was seen on the Kohola arm of the Mother's Day flow just below the top of Pulama pali. Observers watching a 30-40-m-diameter crater on the SW side of Pu`u `O`o noted a new lava pond, a new lava flow, and a fuming cone-pit. Visits to active flow fields on 7 November resulted in observations of hornitos, a 200-m-wide rootless shield, and the leading edge of a 45-m-wide flow.

Seismicity at the summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera during October and November 2003. Volcanic tremor at Pu`u `O`o remained moderate to high, as is the norm. There were some larger earthquakes at depths of a few kilometers.

Also, there were small inflation and deflation events during this period. Tiltmeters on the NW side of Kīlauea's caldera rim (Uwekahuna) and on the NW flank of the active vent along the East rift zone (Pu`u `O`o cone) showed several microradians of radial tilt during 5-11 November, but the patterns were complex and plagued by instrument problems. During 12-17 November, small amounts of inflation and deflation occurred, including inflation on 17 November that started when the surface waves from a M 7.5 earthquake at Rat Island in the Aleutians reached Kīlauea. The inflation was small, ~0.5 rad at Pu`u `O`o tilt station and 0.3 rad at Uwekahuna station. Small amounts of inflation and deflation were recorded through the week of 19-25 November with sharp deflation beginning at both Uwekahuna and Pu`u O`o early on the morning of 25 November.

Moderate, shallow seismicity was recorded beneath the summit, and moderate to high seismicity occurred beneath Pu`u O`o. The seismic record at Kīlauea's summit during 15-16 December was nearly devoid of earthquakes, though the background is steady weak tremor. Tremor at Pu`u `O`o was continuously at a moderate level. Otherwise, seismicity at Kīlauea was at a low level during this period.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


February 2004 (BGVN 29:02) Citation IconCite this Report

Activity through April 2004 focuses in upper flow field (maps and diagrams)

Kīlauea continued to be active at Pu`u `O`o during December 2003 through early March 2004. Figure 161 shows simplified maps and a diagrammatic cross-section on the Island of Hawaii, emphasizing local geography, and known and inferred conditions at Kīlauea. During the reporting interval observers noted incandescence and surface lava flows at Kīlauea's upper flow field. In general, surface lava flows were not seen on the coastal flat or Pulama pali. Various vents within Pu`u `O`o were active, and new lava flows covered parts of the crater floor. Seismicity at Kīlauea has generally included a few small earthquakes recorded at the volcano's summit, along with steady weak tremor. Tremor occurred continuously at moderate levels at Pu`u `O`o.

Figure (see Caption) Figure 161. A map and cross-sectional diagram illustrating the island of Hawaii (the 'Big Island,' the largest and southernmost in the Hawaiian chain) showing selected volcanological features and some local geography. The inset shows how the island of Hawaii consists of five volcanoes (old to young): Kohala, Hualalai, Mauna Kea, Mauna Loa, and Kīlauea. The larger map emphasizes Kīlauea's features. Kīlauea is cut by two rift zones, the SW and E rift zones. The east rift zone extends 55 km from the summit caldera to the eastern tip of the Island of Hawaii. The E rift zone contains a string of craters, including Pu`u `O`o. The cross-sectional diagram displays a simplified model of Kīlauea's internal structure. Note the location of vents, at Pu`u `O`o and elsewhere, along the SW rift zone. The diagram also shows a lava tube running from Pu`u `O`o to the sea. The map and diagram both omit the details of recent eruptive events; for that, see later figures. Courtesy of the Hawaiian Volcano Observatory, U.S. Geological Survey.

During 0550 to 0830 on 18 January 2004, a large period of tilt occurred at Kīlauea's Pu`u `O`o cone, amounting to 18.1 microradians of net deflation. During this period a fissure opened at the SE base of Pu`u `O`o, trending approximately radial to the cone. Lava was emitted from the fissure and from three to four vents nearby. The initial flow reached about 1.5 km S of the cone. The S side of Pu`u `O`o was cut by many new fractures. The longest fracture constituted the N boundary of a shallow graben (a linear trough bounded by faults) that was ~ 75 m long and up to 1 m deep. Surface lava flows were emitted from the E end of the graben, at the base of Pu`u `O`o. The area S of Pu`u `O`o cone appeared to be quite unstable, so Hawaiian Volcano Observatory (HVO) scientists warned that no one should venture into the area. Seismicity at Kīlauea's summit during 15-20 January was at low levels, while tremor at Pu`u `O`o was continuous and at moderate levels. The tremor picked up during the formation of the graben on 18 January. As of 20 January tilt continued to steadily decline following the 18 January deflation event.

On 22 January lava was emitted from the vent formed on 19 January. The vent and lava flow S of Pu`u `O`o cone were named MLK in honor of the activity that began on the American civil rights leader M.L. King Jr.'s birthday (19 January; see figures 162 and 163).

Figure (see Caption) Figure 162. A sketch map showing Kīlauea's lava flows erupted during 1983-23 January 2004 activity of Pu`u `O`o and Kupaianaha. Lava flows began erupting from new MLK vent at the base of Pu`u `O`o (star) on 18 January 2004. Stars indicate centers of recently active, or still active, rootless shields in Mother's Day flow. New shields form often and not all shields appear on this map. Courtesy of the Hawaiian Volcano Observatory, U.S. Geological Survey.
Figure (see Caption) Figure 163. Sketch map of Pu`u `O`o region through 26 January 2004 identifying numerous vents, groups of lava flows, and other features referred to in this and previous issues of the Bulletin. Note the names assigned to intra-crater vents in the oval-shaped interior of Pu`u `O`o cone (stars 1-7) and the various rootless shields farther to the W. Courtesy of Hawaiian Volcano Observatory, U. S. Geological Survey.

A term that has come into common use at Kīlauea is "rootless shield." Local geologists define this as a pile of lava flows built over a lava tube rather than over a conduit feeding magma from within the Earth. Rootless shields along the tube system commonly have flat tops containing shallow lava ponds. In the reporting interval, there were also surface lava flows at the W side of the rootless shield called Amalgamated Bend, a feature located SW of Pu`u `O`o (figure 6). By 26 January there were no surface lava flows at the MLK vent, and incandescence was only visible at the S part of the rootless shield complex. On 23 January moderate-to-strong tremor stopped beneath Kīlauea's caldera and lessened at Pu`u `O`o. On 26 January deflation that began on 18 January ended at Pu`u `O`o after reaching 24.7 microradians. This was probably the largest deflation event since early 1997.

During 29 January to 1 February mild volcanic activity occurred at Kīlauea, with incandescence visible at vents in Pu`u `O`o's crater and small surface flows on the central or southern part of the rootless shield complex. Starting on 18 January, when the MLK vent formed, the distance across the summit caldera decreased significantly, ending a period of increasing extension rate since the Mother's Day event in May 2002. During the report period, weak tremor occurred at Kīlauea's summit along with a few long-period earthquakes. Tremor at Pu`u `O`o remained moderate. During much of February 2004 and into early March, lava flows and incandescence were sometimes visible in Pu`u `O`o's crater and at the rootless shield complex (an area ~ 0.5 km SW of Pu`u `O`o). Weak background tremor occurred at Kīlauea's summit along with a few long-period earthquakes. Tremor at Pu`u `O`o was at moderate-to-low levels. Small deflation and inflation events occurred at the summit and at Pu`u `O`o.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


June 2004 (BGVN 29:06) Citation IconCite this Report

Surface lava flows and renewed ocean entries; lava tubes in June

During mid-2004 lava flows erupting from Kīlauea once again began reaching the ocean, where they slowly added new land to the SE coast of Hawai`i Island (figure 164). Lava began spilling into the ocean on 30-31 May 2004. Nearly a year before that, on 9 July 2003, the lava tube system feeding flows to the ocean ceased carrying lava, which instead escaped in a series of breakouts and numerous surface flows between the Pu`u `O`o vent and the coast. Hundreds of breakouts occurred between July 2003 and May 2004 within ~ 5 km of the vent.

Figure (see Caption) Figure 164. Map of lava flows on the S coastal part of Kīlauea as of 21 May 2004. The key at the right distinguishes 9 map units, lava flows erupted at various times. The Mother's Day flow began erupting on 12 May 2002 and continues to the present. More recent lava flows that erupted in November 2003 through 21 May 2004 included the Banana flow (labeled), which developed gradually, starting in the middle of April 2004. Stars indicate centers of formerly active, but now dead, rootless shields that formed along one or more lava tubes in the Mother's Day flow. The Kuhio flow (named for Prince Kuhio Kalaniana`ole and abbreviated on the map as PKK), was active most of the time from 20 March to 21 May 2004. As of May 21, most activity was located S of the rootless shield complex in the Banana flow. Courtesy U.S. Geological Survey Hawaiian Volcano Observatory.

One of these flows, termed the Banana flow (see figure 164), started to advance down Pulama pali in April 2004. The Banana flow developed from breakouts from part of the Mother's Day lava tube, centered near the former Banana Tree kipuka (an "island" of undisturbed land completely surrounded by one or more lava flows). The breakouts became prominent in the middle of April, and lava started down Pulama pali shortly thereafter. The Banana Flow eventually reached the coastal flat on 2 May. It took nearly a month for the Banana flow to creep across the flat and enter the sea off Wilipe`a lava delta on 30 May. Interaction of the lava and water was not explosive. A spectacular set of photos of lava pouring into the ocean at this time appears on the Hawaiian Volcano Observatory website (figure 165, for example).

Figure (see Caption) Figure 165. Lava entering the ocean on 23 July 2004 at the Wilipe'a delta. As waves broke upon the delta, the lowermost entry points of the advancing lava became totally submerged and quenched, forming a dark crust. As the water receded, the crust ruptured and molten lava spilled out. This cycle continued with each incident wave. Courtesy U.S. Geological Survey Hawaiian Volcano Observatory.

On 13 June, two collapses occurred at Kīlauea's lava delta along its W sector, sending sizable chunks of the delta into the sea (figure 166). On 14 June, most lava was being supplied to the ocean through lava tubes, but several surface lava flows were visible on the delta and traveling down the old sea cliff behind the Wilipe`a delta. The larger eastern part of the lava delta had several active lava entries into the ocean, in general larger than those on the western part of the delta. All vents were active in the crater of Pu`u `O`o.

Figure (see Caption) Figure 166. Aerial view on 23 July of the eastern part of the Banana flow lava delta, looking W. Streams of molten lava enter the ocean in the lower center part of the photo. The patchwork pattern on the delta partly results from numerous surface breakouts of lava from tubes during several previous days. A rope barrier cuts across the photo's upper right-hand corner. The barrier marks the limit of visitor access to the delta for their safety. Courtesy U.S. Geological Survey Hawaiian Volcano Observatory.

Since March 2004, very weak background tremor continued at Kīlauea's summit along with a few long-period earthquakes. Tremor at Pu`u `O`o remained at its typical moderate levels through early June 2004, after which some higher levels were observed. Several episodes of inflation and deflation occurred during this time. One deflation-inflation event began 20 March and culminated 23 March with lava emerging from the S base of Pu`u `O`o cone. A weak swarm of low-frequency earthquakes and a 2-hour period of moderate-to-strong volcano tectonic earthquakes were recorded during 24-25 March.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


September 2004 (BGVN 29:09) Citation IconCite this Report

June-October 2004 period has lava entering ocean and ample lava flows

Scientists at the Hawaiian Volcano Observatory (HVO) noted that throughout June and July 2004, lava from Kīlauea continued to enter the ocean at several points, culminating in several new lava deltas. Some small littoral explosions were reported, but otherwise the ocean entry was passive. Many small lava flows were observed in the area of the ocean entries, on the coastal flat, in the Paliuli area, and in the Kuhio area. Incandescence and some minor spattering was observed at Pu`u `O`o throughout the week. On 13 June, two collapses occurred at Kīlauea's western lava delta, sending sizable chunks of the delta into the sea.

On 14 June, most lava was being supplied to the ocean through lava tubes, but several surface lava flows were visible on the delta and traveling down the old sea cliff behind the Wilipe`a delta. The larger eastern lava delta had several active lava entries into the ocean, mostly larger than those on the western delta. Seismicity at Pu`u `O`o was moderate to high, but the overall seismicity at Kīlauea was low. Several episodes of inflation and deflation were recorded. Relatively large deflation events occurred on 29 June and 11 July, with no obvious accompanying changes in eruptive activity. An episode of deformation consisting of deflation, inflation, then deflation began at Kīlauea on the morning of 27 July. It was accompanied by increased surface activity at several places. During inflation, seismicity greatly increased below Kīlauea's caldera. Field observers reported that deformation may have occurred at the S flank of Pu`u `O`o. Aside from the deflation-inflation-deflation event, seismicity was weak beneath Kīlauea's summit and tremor at Pu`u `O`o was at moderate-to-high levels.

During August and September 2004, no lava entered the sea. Surface lava flows were active on the coastal flat and the Pulama pali fault scarp, and the vents in the crater of Pu`u `O`o were incandescent. Seismicity was weak beneath Kīlauea's summit and tremor was at moderate-to-high levels at Pu`u `O`o. In addition, there were small periods of inflation and deflation. HVO scientists reported that all vents in Pu`u `O`o's crater were incandescent during parts of both August and September.

From 30 September to 18 October 2004, patches of incandescence were visible at the PKK lava flow on the Pulama pali scarp, and all vents in the crater of Pu`u `O`o were incandescent. Seismicity was weak at Kīlauea's summit, with essentially no tremor recorded. An M 4.0 earthquake occurred on 11 October. It was focused ~ 32 km beneath Kīlauea's summit and affected tilt meters. Taking earthquake- and rainfall-induced tilts into account, the volcanic tilt was minor. On 13 October 2004 an M 4.5 earthquake occurred at 1318 ~ 6 km S of Pu`u `O`o at a depth of ~ 9 km. The earthquake permanently offset the Pu`u `O`o tiltmeter and several others on the volcano. Tremor was moderate at Pu`u `O`o. In addition, small amounts of inflation and deflation occurred.

On the morning of 24 October 2004 HVO scientists noted activity at that the three arms of the PKK flow (the Kuhio flow, named for Prince Kuhio Kalaniana`ole). Largest and most vigorous, the W arm descended down to an elevation of ~ 200 m, well out onto the gentle slope below Pulama pali. A series of channels and incandescent fingers were visible along a 600-m-long stretch, and tiny spots marked the upstream course of the arm, roughly following the E side of the Mother's Day flow.

The middle arm had advanced 100-200 m since the previous morning (23 October) and reached down to an elevation of ~ 335 m. It was the smallest of the three active arms.

The E arm was quite active that morning, its front also located on the gentle slope below Pulama pali at ~ 300 m elevation; it was nearly continuously incandescent up to ~ 440 m elevation. The distance between the W and middle arms was about 400 m and between the middle and E arms, about 600 m. These distances changed constantly as flows widen and narrow. Figures 167 and 168 show lava flows since 1983 to aid the reader in locating features discussed in this Bulletin report.

Figure (see Caption) Figure 167. Map of lava flows from Pu`u `O`o and Kupaianaha from 1983 to 24 August 2004. Features shown include the Mother's Day flow field, which began erupting on 12 May 2002 and continues to the present. Lava flows erupted during November 2003-24 August 2004 include the Banana flow, which developed gradually starting in the middle of April. The MLK flow, located just S of the Pu`u `O`o vent, erupted in January and, in brief subsequent spurts. The Kuhio (PKK) flow was active most of the time from 20 March to 24 August 2004. As of 24 August, most activity was located in the Banana flow, fed by the Banana branch of the Mother's Day tube. The PKK flow also remained active. Courtesy of U.S. Geological Survey Hawaiian Volcano Observatory.
Figure (see Caption) Figure 168. Map of Pu`u `O`o and vicinity as of 24 August 2004 showing vents, lava flows, and other features near Pu`u `O`o. The West Gap cones are just outside the boundary of the crater—the oval-shaped depression containing the seven numbered vents (now down to six after Humble Vent was buried by lava flows erupted from Dave's Pit/Vent in March). The Mother's Day flows in the lower left have been erupted since 12 May 2002. Other flow areas are labeled accordingly with names and dates of activity. Light shading indicates episode-55 flows erupted between March 1997 and August 2002. Courtesy of U.S. Geological Survey, Hawaiian Volcano Observatory.

Moderately bright glow came from the 640- to 670-m elevations farther upstream in the PKK flow. All vents in Pu`u `O`o's crater were incandescent on 24 October, creating a glow visible from several distant places. Seismicity was weak at Kīlauea's summit, with essentially no tremor recorded. Tremor was moderate at Pu`u `O`o. Kīlauea's summit deflated moderately during 23 October and then took a plunge during the middle of the night. It lost about 0.3 microradians before the plunge began just before midnight, and it lost another 0.5 microradians thereafter. Pu`u `O`o, too, was deflating rapidly, shifting up and down a little but maintaining an overall flat tilt until the plunge began. It also lost about 0.5 microradians after midnight.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


June 2005 (BGVN 30:06) Citation IconCite this Report

During November 2004-January 2005 lava flows continued to enter the sea

Activity at Kīlauea through October 2004 was previously reviewed in reports that included maps showing the extent of key lava flows through most of August 2004 (BGVN 29:09). During November 2004 through January 2005, lava flows were abundant and made complex patterns. Their overall advance can be seen by comparing maps of the extent of the lava flows as of late August 2004 (figure 169) and 2 February 2005 (figure 170).

Figure (see Caption) Figure 169. Kīlauea lava flows erupted during activity from 1983-August 2004 of Pu`u `O`o and Kupaianaha. Note the location of Kupaianaha, the active vent area during 1986-1992, ~ 4 km ENE of Pu`u `O`o. Courtesy of the U.S. Geological Survey's Hawaiian Volcano Observatory.
Figure (see Caption) Figure 170. Kīlauea lava flows erupted during activity from 1983-2 February 2005 of Pu`u `O`o and Kupaianaha. Courtesy of the U.S. Geological Survey's Hawaiian Volcano Observatory.

On 4 November 2004 lava from the Prince Kuhio Kalaniana `ole (PKK) flow entered the sea, forming a new delta seaward of the E end of the old Lae'apuki delta. The PKK flow has been continuously active since 26 July 2004, and lava continued to enter the sea through 26 November 2004. This was the first time lava entered the sea since the Banana lava flow ceased in early August 2004. The Banana flow developed from breakouts when lava escaped from the confines of the Mother's Day lava tube, emerging near the former Banana Tree kipuka. This flow stagnated early in September 2004, and the Mother's Day tube ceased carrying lava late in 2004.

During the first week in December 2004, the lava flow at Lae'apuki abated. Activity resumed during the second week along all areas of the PKK flow from high on the Pulama pali fault scarp. By 13 December lava again entered the sea at the East Lae'apuki delta. The flow moderated during the second half of December with only several areas of visible surface lava apparent on the Pulama pali fault scarp and on the coast.

New vents opened at the southern base of Pu`u `O`o on 19 January 2004 and fed the Martin Luther King (MLK) flows (figure 11). The PKK flow originated from two vents ~ 250 m S of the base of Pu `u `O`o. By 2 February 2005 the PKK flow had entered the sea at West Highcastle, Lae'apuki, and Ka`ili`ili (figure 11).

During January 2005, surface lava was visible along the three main arms of the PKK flow as they advanced downslope towards the coast (figure11). The middle arm of the PKK flow was comparatively small, and it failed to reach the ocean during this reporting interval; it remained high on Pulama pali. In contrast, lava from the E and W arms of the PKK flow began to enter the ocean on 31 January. The large E arm of the PKK lava flow fed the larger Ka`ili`ili entry. The W branch of the PKK lava flow once supplied lava to Lae'apuki (an E branch of the W arm), but later also began feeding the West Highcastle ocean entry (the W branch of the W arm, figure 11).

Seismicity. After seven months of relative quiescence renewed seismicity and numerous small long-period (LP) events again became visible in November 2004 on the North Pit seismogram. Elevated activity began on 16 November, peaking at over 2,000 events a day by late November (figure 171). Nearly all of these earthquakes were too small to catalog. To obtain this plot, a daily event count was extrapolated from a representative part of the North Pit (NPT) seismogram. Scientists combined the counts for two shallow (0-5 km deep) earthquake types, those designated by HVO as short-period summit or short-period caldera (SPC) and those designated as shallow, long-period (long-period caldera A, LPC-A) earthquakes. The similar frequency content of these two kinds of earthquakes make them difficult to distinguish on the drum record. In addition, small-magnitude deeper earthquakes, designated as long-period earthquakes originating at depths over 5 km, may have also registered within the summit caldera to appear on the plot, although they would be expected to contain a lower dominant frequency of oscillation than the LPC-A earthquakes. Tremor episodes were rare or absent.

Figure (see Caption) Figure 171. A time series of Kīlauea's daily earthquakes (SPC, LPC-A, and possibly LPC-C types) registered at the summit during October 2004 through January 2005. Courtesy of U.S. Geological Survey's Hawaiian Volcano Observatory.

A minor peak in seismicity occurred in later January, during the two days before and after the 25 January inflation-deflation event. Most of the events on 25 January appeared to be of the SPC variety.

Tilt and deformation. The tiltmeter record at Kīlauea summit (UWE) and Pu`u `O`o (POC) showed numerous correlated tilt changes, with a short time delay between UWE and POC stations and larger magnitude delays at POC (figure 172). One of the largest of these deformations took place on 25-26 November and resulted in about 3 microradians of tilt at UWE, and 5 microradians at POC. This was similar in character to the tilt events of recent months, starting with fairly rapid deflation, followed by a similar rate and magnitude of inflation. Though they differ in character from the deflation-inflation-deflation (DID) cycles of the past few years, they seem to be originating from the same shallow storage area near Halemaumau, the crater at Kīlauea's summit.

Figure (see Caption) Figure 172. Electronic tiltmeter records from the N flank of Pu`u `O`o cone (POC) and NW rim of Kīlauea caldera (UWE) for (A) October and November 2004 and (B) December 2004 through January 2005. Only the radial component is plotted, i.e., the direction that maximizes signal from the most common sources of tilt at both locations. Courtesy of U.S. Geological Survey's Hawaiian Volcano Observatory.

Kīlauea continued to inflate over this reporting period. The extension rate across the summit increased dramatically in early January 2005, from an average rate of about 8 cm/yr to over 40 cm/yr. There was a short inflation-deflation event on 25 January, followed by about 2-3 days of extremely rapid movement of the S flank; continuous GPS stations on the S coast were displaced by up to 2 cm. The pattern and rate of motion are very similar to the slow earthquake of November 2000. The slip event occurred during a swarm of earthquakes (see seismic section above), but the cumulative magnitude of these earthquakes was not nearly as great as the estimated equivalent moment magnitude of the slip.

Other large episodes of correlated multistation tilt occurred on 14 December 2004 and 25 January 2005. In December, both UWE and POC recorded deflationary tilts of about 4 and 2.5 microradians, respectively, over about 12 hours. In mid-January, the summit started showing a high rate of inflationary tilt, coinciding with the increase in cross-summit extension, measured by continuously recording GPS. In the early morning of 25 January, summit tiltmeters and POC recorded a rapid inflation (about 5.5 microradians in an hour at UWE, 2 at POC) followed by an equal amount of deflation over the next day. The event was similar to the fairly frequent deflation-inflation-deflation (DID) events at Kīlauea. Similarities included the apparent source regions of the inflation, the seismic signature, the delay time between the summit and the rift zone, and the timing of increased activity.

SO2 emission rate measurements. Summit SO2 emission rates for October/November ranged from 80 to 130 metric tons per day (t/d) with an average of 105 t/d (standard deviation, s.d.=20 t/d for 36 measurements made over 6 days). Although this represents a slight decrease over emission rates measured during the previous reporting period, it does not represent a significant change. Correlation spectrometer (COSPEC) SO2 measurements along the Chain of Craters Road yielded SO2 flux rates of 1,080-1,660 t/d with a mean value of 1,270 t/d (s.d. of 260 t/d for 27 measurements made over 4 days). The drop in emissions, which began in May 2004, had continued through November 2004. A lack of trade winds hindered SO2 flux measurements during November and December. Six traverses on 6 December yielded an emission rate of 105 t/d (s.d.=10 t/d) consistent with the more frequent measurements made during September-October 2004. The return of the tradewinds in early February allowed measurements to resume and showed that summit emissions had decreased markedly, likely due to the heavy rainfall on 4 February.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


April 2006 (BGVN 31:04) Citation IconCite this Report

Maps of past year's surface lava flows and photos of lava entering the sea

This report covers the interval 31 January 2005 to 7 February 2006 and is drawn exclusively from U.S. Geological Survey Hawaiian Volcanic Observatory (USGS HVO) sources. During this interval, active lava flows during tended to remain along the W to central portions of the existing field (figures 173 and 174). On 31 January 2005, lava from Kīlauea began pouring into the ocean at two entry points. The Ka`ili`ili entry to the E of the flow field was the largest and was fed by the large W arm of the Prince Kuhio Kalaniana (PKK) lava flow. The West Highcastle ocean entry was supplied by the W branch of the W arm of the PKK lava flow.

Figure (see Caption) Figure 173. A series of maps portraying Kīlauea's surface lava flows at various times during 31 January 2005 to 7 February 2006. New vents opened at the southern base of Pu`u `O`o on 19 January 2004. Map panels are as follows: a) A map with features as of February 2005, b) as of April 2005, c) as of May 2005, d) as of 31 July 2005, and e) as of 30 September 2005. Courtesy of Christina Heliker, USGS HVO.
Figure (see Caption) Figure 174. Map portraying Kīlauea's near-shore and coastal lava flows areas in the vicinity of East Lae'apuki and East Kamoamoa as of 23 September 2005. Courtesy of Christina Heliker, USGS HVO.

From 7 February 2005 to 20 February 2005, lava flows were visible on the Pulama pali fault scarp and on the coastal flat. Instruments recorded a few small earthquakes and no tremor at Kīlauea's summit. At Pu`u `O`o, volcanic tremor remained moderate. Small amounts of deformation were recorded.

On 21 February 2005 a new ocean entry formed, named E Lae`apuki. The entry was located between the other two ocean entries (Ka`ili`ili and West Highcastle) that had been active since 31 January 2005. This was the first time there had been three ocean entries active since early 2003 (figures 173-175).

Figure (see Caption) Figure 175. Photos of Kīlauea activity taken along the coast on 21 February 2005. (A) A photo showing the walls of a large crack into which lava pours at E Lae`apuki. Sea cliff is to the right, at shelf's edge beyond the glow. (B and C, respectively) The top and bottom of lava falls at E Lae`apuki ocean entry looking W. (D) A closer view focused on showing the base of the lava falls. The sea cliff's height is ~ 12 m. Courtesy of HVO.

During 23-26 February 2005, lava from Pu`u `O`o entered the sea at three ocean entries–West Highcastle, East Lae'apuki, and Ka`ili`ili–spots along 4.7 km of the island's SE coast (figure 176). Lava may have stopped flowing into the sea at the W entry (West Highcastle) on 26 February 2005. The number of surface lava flows diminished in comparison to the previous weeks, and small earthquakes continued to occur at Kīlauea's summit without accompanying tremor. Tremor remained at moderate levels at Pu`u `O`o, and as of 28 February 2005, deflation had occurred at Pu`u `O`o for more than a week and at the summit since 24 February 2005.

Figure (see Caption) Figure 176. A Kīlauea photograph taken on 23 February 2005 depicting active lava delta construction at E Lae`apuki ocean entry. Note the fan building outward from the sea cliff and the person (upper right) for scale. Courtesy of USGS HVO.

During the month of March 2005, lava from Kīlauea continued to enter the ocean at the Ka`ili`ili and E Lae`apuki, but there were no signs of activity at the West Highcastle entry. Surface lava flowed down the Pulami pali fault scarp and the coastal flat. Small earthquakes occurred at Kīlauea's summit, and no tremor was recorded. Tremor remained at moderate levels at Pu`u `O`o.

On 29 March 2005, lava from Kīlauea entered the ocean at five areas. The largest, named Kamoamoa, consisted of six or more places where lava entered the water along the front of a growing lava delta (figure 177). At one of the two Highcastle entries, a cascade of lava streamed down the old sea cliff. A bright glow came from Ka`ili`ili entry, and a weak glow from E Highcastle entry. Seismicity remained above background levels at Kīlauea's summit, consisting mainly of tremor and some long-period earthquakes. Surface waves from an M 8.7 earthquake on 28 March 2005 off Sumatra, Indonesia disturbed tilt measurements at Kīlauea but otherwise the tilt change was small.

Figure (see Caption) Figure 177. A photo taken 25 March 2005 showing Kīlauea's new Kamoamoa ocean entry, located just NE of East Lae'apuki. Descending lava poured over an old sea cliff to land upon, and flow across, an old delta; it then dropped into the sea, forming a new delta. Courtesy of USGS HVO.

Lava from Kīlauea continued to flow into the ocean at several points during 1-13 April 2005. Seismicity remained above background levels at Kīlauea's summit, consisting mainly of tremor and some long-period earthquakes. Volcanic tremor was at moderate levels at Pu`u `O`o. During 14-19 April, surface lava flows from Kīlauea were visible on the Pulama pali fault scarp but lava was not seen entering the ocean.

Seismicity remained above background levels at Kīlauea's summit during 14-19 April 2005, consisting mainly of tremor and some long-period earthquakes. Volcanic tremor was at moderate levels at Pu`u `O`o. Episodes of inflation and deflation occurred during the week.

During 21-25 April, there were fewer surface lava flows visible at Kīlauea than during the previous week. On 24 April a small amount of lava again began to enter the sea. Seismicity remained above background levels at Kīlauea's summit, consisting mainly of tremor and some long-period earthquakes.

During 27 April-3 May 2005, lava entered the ocean at the Kamoamoa entry. Numerous surface lava flows were visible on the coastal flat. Seismicity remained above background levels at Kīlauea's summit, consisting of both tremor and long-period earthquakes.

A third ocean entry, in the E Lae`apuki area, became active on 5 May 2005. That entry and the Far E Lae`apuki entry were both being fed by lava falls down the old sea cliff and were relatively small. Based on the brighter glow, the Kamoamoa entry was thought to be more substantial. By the morning of 9 May lava was streaming over the old sea cliff in four locations: two falls went into the sea and two other falls landed on an old delta. The branch of the PKK flow feeding E Lae`apuki sprung numerous new lava flows on 9 May. The next day, the middle branch of the PKK flow developed an open-channel stream on the Pulama pali; it was 10-20 m wide, 500-600 m long, and moving rapidly.

Ocean entries remained active during 11-17 May 2005 in the E Lae`apuki and Kamoamoa areas. By 16 May the E Lae`apuki and E Kamoamoa entries both had benches ~ 350 m long and up to 75 m wide. A large plume from West Highcastle on 10 May probably recorded a collapse of part of that lava delta, which has been inactive for the past several weeks following growth in March and April. The middle branch of the PKK flow remained active and extended down Pulama Pali. The E branch reached out farther but was narrower and contained fewer breakouts. The W branch was reduced to a cluster of breakouts about halfway down the pali. Glow was seen from all of the Pu`u `O`o crater vents, as well as the MLK vent at the SW foot of the cone.

During 18-31 May 2005, lava from Kīlauea continued to enter the sea at three areas. Surface lava flows were visible on the coastal plain and on the Pulama pali fault scarp. During 1-4 June 2005 lava entered the sea at three points along the S flank of Kīlauea, and then at only two points through 7 June. Small surface lava flows were visible on the Pulama pali fault scarp and the coastal flat.

Lava again entered the sea at three points on 13 June. During the 14-21 June lava continued to enter the sea and there was a small number of lava flows on the Pulama pali fault scarp. On 22 June lava in the W branch of the current flow descended onto the coastal flat for the first time in several months. On 24 June it was noted that Kīlauea's summit continued its inflation, while Pu`u `O`o was deflating during the same period.

On 27 June part of the active E Lae`apuki lava delta collapsed. Lava stored within the delta gushed out onto the surface and into the water. Fountains of lava reported to be about 25 m high spurted from the central part of the delta soon afterward. Lava also entered the sea during 4-5 July and a few surface flows were on Pulama pali.

During 6-19 July 2005, lava continued to enter the sea at E Kamoamoa and E Lae`apuki. The latter entry was much larger, with several entry points. E Kamoamoa barely glowed. Surface lava was visible along the PKK lava flow throughout the month of July. Background volcanic tremor remained above normal levels at Kīlauea's summit and at moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano. An M 4.5 earthquake occurred on 25 July at 2209 along the SE edge of Kīlauea's SW rift zone at a depth of ~ 30 km.

Up to seven ocean-entry points were visible off the W-facing front of the E Lae`apuki lava delta during 3-9 August; still others were hidden from view off the E-facing front. On Pulama pali, the W branch of the PKK flow reached its greatest extent of the week on 5 August, when it broadened to include hundreds of meters of scattered breakouts and reached from 460 m down to 260 m elevation. During 15-16 August 2005, surface lava at Kīlauea was again visible on the W and E branches of the PKK lava flow. Lava continued to enter the sea at the E Lae`apuki entry through 5 September. Background volcanic tremor was near normal levels at Kīlauea's summit and at moderate levels at Pu`u `O`o cone. There were small periods of inflation and deflation at Kīlauea's summit and Pu`u `O`o. By 22 August, surface lava on the W branch of the PKK lava flow was no longer visible. On 27 August, part of a lava-bench collapsed.

Throughout September, lava entered the sea at the E Lae`apuki area with surface lava flows visible on the Pulama Pali fault scarp. Lava filled a scar left by the lava-bench collapse on 27 August. Background volcanic tremor continued to remain around normal levels at the summit. Volcanic tremor was at moderate levels at Pu`u `O`o. On 11 September, substantial deflation at the volcano was followed by sharp inflation. On 19 September, several small shallow earthquakes occurred along the Kao`iki fault system with small amounts of inflation and deflation.

In October 2005, lava from Kīlauea continued to enter the sea at the E Lae`apuki area, and surface lava flows were visible along the PKK lava flow. Lava flows continued to enter the sea at E Lae`apuki area, mostly NE of the point of the lava delta. On 18 October, weak surface lava flows were visible at Kīlauea and one cascade of lava flowed off of the western front of the E Lae`apuki delta.

Activity during November 2005 was similar to the previous month. Lava continued to enter the sea at the E Lae`apuki area and surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kīlauea's summit.

A lava-bench collapse in the E Lae`apuki area on 29 November 2005 was the largest bench collapse of the current eruption, which began in January 1983. The collapse lasted several hours, sending the 137,588 m2 of bench and an additional 40,467 m2 of adjacent cliff, into the sea. The collapse left a 20-m-high cliff, from which a 2 m thick stream of lava was emitted from an open lava tube. Cracks had been observed on the inland portion of the bench several months earlier; visitors were not allowed near the bench, but a viewing area was provided ~ 3 km away. Growth of the new delta at E Lae`apuki was continuing as of 6 December 2005. At that time breakouts were also active on Pulama Pali.

During December, lava from Kīlauea continued to enter the sea at the E Lae`apuki area and surface lava flows were visible on the Pulama pali fault scarp.

From 28 December 2005 to 9 January 2006, lava from Kīlauea continued to enter the sea at the E Lae`apuki area building a new lava delta with surface lava flows visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kīlauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of deformation occurred. On 10 January, the summit deflation switched abruptly to inflation after a loss of 5.2 µrad. Relatively high tremor occurred at this time. The tremor quickly dropped, becoming weak to moderate when deflation ended, with seismicity punctuated by a few small earthquakes. By 13 January, background volcanic tremor was near normal levels at Kīlauea's summit and reached moderate levels at Pu`u `O`o. On 14 January, the lava delta was about 500 m long (parallel to shore) and still 140 m wide. By the end of the month the lava delta was 615 m long and 140 m wide. Background volcanic tremor was near normal levels at Kīlauea's summit, with numerous shallow earthquakes occurring at the summit and upper E rift zone during several days.

During 2-7 February 2006, lava from Kīlauea continued to enter the sea at the E Lae`apuki area and surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor was near normal levels at Kīlauea's summit, with numerous shallow earthquakes continuing to occur at the summit and upper E rift zone. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of inflation and deflation were reported. From mid-to-late February, surface lava flows were not visible on Kīlauea's Pulama pali fault scarp due to lava traveling underground through the PKK lava tube until reaching E Lae`apuki lava delta and flowing into the sea. Observations on 7 February 2006 revealed that the lava delta had broadened 120 m W since 30 January 2006.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


August 2006 (BGVN 31:08) Citation IconCite this Report

Lava entering the sea at E Lae`apuki; small bench collapse on 30 July 2006

Much of the activity at Kīlauea has remained the same since last reported in BGVN 31:04. This report covers the time interval 8 February through most of July 2006. Lava continued to enter the sea at the East Lae`apuki area with volcanic tremor near normal background levels at Kīlauea's summit. Numerous shallow earthquakes continued to occur at the summit and upper E rift zone. Volcanic tremor reached moderate levels at Pu`u `O`o. Slow, steady inflation continued at Kīlauea's summit as it has more or less since mid-January 2006. A 4-hectare (10 acre) bench collapse occurred 30 July 2006 (figure 178).

Figure (see Caption) Figure 178. An aerial view of the E Lae`apuki entry at Kīlauea showing the area of the 30 July bench collapse. A four-hectare chunk of the W side of the bench broke off and fell into the water. The black line marks approximate edge of the bench before the collapse. Courtesy of USGS-HVO.

Beginning on 8 February, surface lava flows were not visible on the Pulama pali scarp due to lava traveling underground through the PKK lava tube.

On 1 March, lava emerged from the PKK lava tube at elevations between 45 and 75 m, and proceeded in lava streams extending 200-400 m to the coast. The lava streams continued to flow off of the lava delta and into the ocean throughout this reporting period.

Inflation on 16 May was accompanied by an abrupt drop in volcanic tremor at Kīlauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small lava flows were visible on 19 May and minor incandescence was observed on 21-22 May at Kīlauea's East Lae`apuki lava delta. Incandescence was visible from East Pond vent, January vent, and Drainhole during 24-30 May, and from the South Wall complex on 24 and 30 May and throughout June.

On 24 June, lava that flowed over a sea cliff was fed from a breakout point about 50 m inland from the cliff. The area of East Lae`apuki lava delta was estimated to be approximately 21 hectares (52 acres). The floor of Drainhole vent in Pu`u `O`o's crater collapsed and produced a 30 x 25 m lava pond with dynamically active lava on the SE side of the pit. Lava from the Campout flow and tube, located on the E margin of the PKK shield, advanced 1.2 km towards the Pulama pali during about 19-24 June.

On 30 June, surface lava flows originating from the Campout lava tube were visible on the upper part of the Pulama pali fault scarp, which had not been seen since 8 February. Incandescence was visible from Drainhole vent in Pu`u `O`o's crater and tremor remained at moderate level at Pu`u `O`o. By the end of July, the Campout flow was ~ 1.7 km from the sea at Ka`ili`ili, about 440 m from the observed terminus on 14 July.

A 4-hectare (10-acre) area of the lava delta at Kīlauea's East Lae`apuki collapsed into the ocean at 1247 on 30 July. The collapse represented less than 15% of the delta's total area (figures 178 and 179). During the collapse, explosive activity bombarded the older lava delta and sea cliff on the western side of the bench, sending spatter and rock debris up to about 40 m inland—nearly half the distance to the rope barricade.

Figure (see Caption) Figure 179. A view of the East Lae`apuki bench from the W photographed at unstated date and published on 4 August 2006. The dashed line shows the approximate seaward extent of the area lost to the bench collapse on 30 July 2006. Photo courtesy of Greg Santos, Honolulu Advertiser.

During 2-8 August, lava from the PKK lava tube flowed into the ocean at two entries on the SE flank, East Lae`apuki and about 3.5 km E at East Ka`ili`ili. Tilt at the Pu`u `O`o cone displayed a saw-tooth pattern and tremor remained at a moderate level. A leveling survey revealed an inflationary trend at the summit of Kīlauea, in areas S of Halema`uma`u crater. Elevations have increased 11 cm in the past 6 months and continued to increase during the reporting period.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Honolulu Advertiser (URL: http://the.honoluluadvertiser.com/).


October 2006 (BGVN 31:10) Citation IconCite this Report

PKK lava tube active August-November 2006; 10 October collapse pit at Pu`u `O`o

-Lava from Kīlauea continued to flow through the PKK lava tube from its source at Pu`u `O`o to the ocean during this reporting period from late August to the end of November 2006. About 1 km S of Pu`u `O`o, the Campout lava flow branches off from the PKK tube. Through November, the PKK and Campout systems fed two widely separated ocean entries named East Lae`apuki and East Ka`ili`ili, respectively. Kīlauea's activity during this reporting period included numerous small breakouts from the Campout flow, new skylights along the PKK tube, and variable activity at the ocean entries, including small streams of lava crossing the coastal bench. Intermittant lava fountaining 15 m inland of the W edge of the East Lae`apuki bench was noted in late September-early October. Incandescence was also intermittently visible coming from the East Pond and January vents, the South Wall complex, and the Drainhole vent in Pu`u `O`o's crater. In general, during this reporting period the inflationary trend continued at the summit of Kīlauea, in areas S of Halema`uma`u crater and tremors remained at a very typical moderate level at Pu`u `O`o.

During 30 August-12 September, crews reported visible lava streams on the W side of the East Lae'apuki delta and occasionally from the East Ka'ili'ili entry. On 1 September, the East Lae'apuki lava bench was an estimated 22 hectares (54 acres) and East Ka`ili`ili was an estimated 2.3 hectares (5.8 acres). On 30 August, and 1 and 6 September, the Campout flow escaped from the PKK tube. On 11 September, Park Service field crews reported two lava flows visible down the entire length of the pali. Incandescence was intermittently visible from the East Pond and January vents, the South Wall complex, and the Drainhole vent in Pu`u `O`o's crater.

During 13-23 September, lava from the Campout and PKK systems continued to flow off of a lava delta into the ocean and breakout flows were visible on the pali. On 20 September, a tour pilot reported seeing three large lava flows from a breakout 10 m inland from the old sea cliff at East Lae`apuki (figures 180 and 181). On 23 September, incandescence from above Pulama pali in the direction of Pu`u`O`o was likely due to several new and reactivated skylights on the upper PKK tube.

Figure (see Caption) Figure 180. Aerial view of the lava bench at East Lae`apuki, looking NE on 20 September 2006. An active lava flow is going over the sea cliff in roughly the center of the arcuate fault scarp in the widest part of the lava bench below it. White steam plumes from the ocean entry were blown towards along the coast towards the left. In the colored version of this shot the adjacent seawater contains a greenish hue. Courtesy of HVO.
Figure (see Caption) Figure 181. A lava flow at Kīlauea breaks out to the surface 10 m inland from a sea cliff on 20 September 2006 . The lava pours over the cliff in places as thick curtains and elsewhere as smaller rivulets and dripping falls. After the fall the lava proceeded across the upper bench as a series of braided streams. Toward the left, some readers might claim they see a slender Pelé, dancing with arms upraised. Courtesy of HVO.

Littoral fountaining on 27 September was reported about 15 m inland of the W edge of the East Lae`apuki bench. Lava jetted about 30 m in the air accompanied by loud rumbling and jetting sounds. Observers reported ground shaking. Over the next couple of days, 3-4 lava streams were visible on the W side of East Lae`apuki entry, as were incidents of tephra jetting and lava fountaining 15-23 m (50-75 ft) high. Glow had been visible from the East Lae`apuki entry and the Campout flow breakout on the pali, but not from the Ka`ili`ili entry. The consistent lack of visible glow from the Ka`ili`ili entry was due to the absence of a very large bench, forcing lava to remain hidden at the base of the seacliff.

Observers reported that on 28 September the floor of the Drainhole vent had been replaced by an overturning lava pond. As of 29 September, a new tube and flow that formed on the E side of the Campout flow extended ~ 180 m. Another flow went W and butted up against the PKK tube. The USGS field crew also found a small stagnant breakout of lava at ~ 60 m elevation. It flowed E to cover a little more of the long-abandoned Royal Gardens subdivision. In the Pu'u O'o vicinity, a new collapse pit photographed in early October had engulfed pre-existing spatter cones (figure 182).

Figure (see Caption) Figure 182. Two views of Kīlauea's W gap area illustrating morphologic changes there. (top) Aerial view of Pu`u `O`o taken in July 2006 shows two spatter cones.. Note helicopter above label for scale. (bottom) An aerial photo taken on 13 October 2006 shows a new collapse pit that grew to engulf the spatter cones. The bottom of the pit, which formed on the night of 10 October, is hidden by fume. Courtesy of HVO.

During October and November, breakout flows were intermittently visible on the Pulama pali, at the base of the pali, or on the sea cliff and incandescence from vents in Pu`u`O`o was visible. For example, on 25 October, two separate break-out lava flows were visible on pali. The upper flow at about 320 m (1,050 ft) elevation consisted of 'a'a and pahoehoe and the lower flow at 114 m (375 ft) was solely pahoehoe. On 3 and 4 November, tephra jetted at the tip of the East Lae`apuki bench. On 15 November, breakouts resumed on top of the seacliff after a few weeks without activity. On 18 November, the Drainhole vent twice ejected spatter as high as 25 m above its rim. On 19 November, observers saw small explosions at East Lae`apuki ocean entry as well as well-defined streams of lava entering the ocean. The next evening, six rivers of lava flowed over the bench and into the ocean at the W entry. When weather permitted, incandescence was visible from the East Pond, the South Wall complex, the January vents, and Drainhole vent.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawaii National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


May 2007 (BGVN 32:05) Citation IconCite this Report

Lava flows entering the ocean between December 2006 and March 2007

Lava from Kīlauea has continued to flow from a lava delta into the ocean at the East Lae`apuki and East Ka`ili`ili entries from early December 2006 through the end of March 2007. Incandescence remained visible on the Pulama pali fault scarp and coastal flats in the vicinity of the Campout flow while incandescence at the East Pond vent, January vent, South Wall complex, and Drainhole and Beehive vents in Pu`u `O`o's crater remained intermittent. On 5 December 2006, a large breakout on Pulama pali resulted in downed and burned trees. On 27 and 28 December, lava streams were seen descending to the ocean to re-establish the Kamokuna entry (figure 183).

Figure (see Caption) Figure 183. View of the Kamokuna ocean entry of the Campout flow from Kīlauea, taken from the sea cliff, 27-28 December 2006. Photo courtesy of Ralf Krug.

During January and February, lava continued to flow from a lava delta into the ocean at East Lae'apuki, Kamokuna (figure 184), and East Ka'ili'ili entries with incandescence intermittently visible on the pali from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu`u `O`o crater. On 12 January, the summit tilt network recorded the start of the tenth deflation-inflation (DI) event; after 7 microradians of deflation the largest of the earlier events was approximately 2 microradians. Inflation began on 13 January with increased and decreased tremor near Pu`u `O`o in response to the DI event. On 24 January, breakout lava from the Campout flow advanced approximately 1.6 km per hour. A USGS field crew reported several smaller breakouts of lava from the flow at the base of the pali that flowed E and burned trees near the long-abandoned Royal Gardens subdivision.

Figure (see Caption) Figure 184. Visible steam plumes from the Kamokuna ocean entry at Kīlauea, 22 February 2007. Courtesy of HVO.

Breakout surface lava from the Campout flow produced seven lava falls over the seacliff behind the East Lae'apuki bench on 15 February and continued throughout the week. On 22 February, HVO field crews reported gas jetting from vents on the S side of Pu`u `O`o.

On 10 March, lava stopped flowing at the East Ka`ili`ili ocean entry, possibly due to branching off W towards the Royal Gardens subdivision. `A`a flows from the Campout flow were seen on the pali on 14 and 27 March. During 28-29 March, there was an unusual increase in the number of earthquakes located near the Halema'uma'u and Koko'olau craters and on the S flank. Then on 31 March, a major lava breakout from the Campout flow caused trees to ignite on a nearby island of vegetation and produced small explosion from trapped gas.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


June 2007 (BGVN 32:06) Citation IconCite this Report

April to June 2007 activity; rift zone earthquakes and extension

According to the Hawaiian Volcano Observatory (HVO) of the U.S. Geological Survey (USGS), Kīlauea's eruption that began in 1983 had by January 2007 emitted 3.1 km3 of lava, covering 117 km2 of land surface, and adding 201 hectares (201 x 104 m2) to Kīlauea's southern shore. HVO has divided the multi-decade eruptive interval into a series of episodes, and on 19 June 2007 they announced the start of episode 56. This background section provides context on the later report consisting of subsections discussing 1 April-19 June 2007 (episode 55) activity and some large earthquakes during 2006 and 2007.

Figure 185 provides an overview of the E and SW rift zones. The lower diagram shows relationships between major features on the surface and those inferred at depth. The ongoing eruption has often emitted lavas from it's upslope vent, Pu`u `O`o, leaving an upper flow-field laden with a complex series of lava flows, lava tubes, and related features.

Figure (see Caption) Figure 185. Plan-view and cross-sectional diagrams illustrating the island of Hawaii (the largest and southernmost in the Hawaiian chain) showing selected volcanological features. The inset shows the five volcanoes that comprise the island (old to young): Kohala, Hualalai, Mauna Kea, Mauna Loa, and Kīlauea. Kīlauea is cut by the SW and E rift zones, and the summit caldera lies near their intersection. From the summit caldera the E rift zone extends 55 km to the eastern tip of the island. Along that path lies a string of craters, including Mauna Ulu and Pu`u `O`o. The cross-section displays a simplified model of Kīlauea's inferred internal structure. Note the location of vents, at Pu`u `O`o and elsewhere along a fissure, along the E rift zone. The diagram also shows a lava tube running from Pu`u `O`o to the sea. Courtesy of HVO-USGS.

Figure 186 consists of a map of the Pu`u `O`o region of Kīlauea and the names applied to many of the features there as of June 2006. For comparison, maps current through parts of 2004 appeared previously (BGVN 29:02 and 29:09). A newer map created during late 2006 extends coverage slightly farther to the S (figure 187). The Campout flow discharged from the Prince Kuhio Kalaniana`ole (PKK) lava tube at a spot ~ 1 km S of Pu`u `O`o.

Figure (see Caption) Figure 186. Map of Kīlauea's upper SE flank made in June 2006. The map shows the Pu`u `O`o cone and crater ("rim" points to the crater's NW rim), along with nearby vents, lava flows, and numerous other features. Approximate area is outlined in figure 185. Features active in 2005-06 included the numbered vents in the crater, the MLK vent complex and associated lava flows, and the Puka Nui vent. The upper PKK (Kuhio) lava flow, with an associated tube (solid line) feeds lava flows that reach the ocean. Courtesy of USGS-HVO.
Figure (see Caption) Figure 187. Map of Kīlauea showing events at Pu`u `O`O and vicinity through December 2006. The map shows the upper flow field, including the location of crater and flank vents, collapse and subsidence areas, lava tubes and new shatter rings, and the upper Campout flow. Courtesy of HVO (HVO, 2006).

The Campout flow emerged during May 2006. It advanced over the surface and ultimately reached the ocean (figure 188). The Campout flow later evolved a lava tube system that extended 8-10 km S, bringing lava to an ocean entry at E Ka`ili`ili. A third entry, fed by an offshoot of the Campout flow, became active on 26 December 2006. The PKK lavas met the sea at E Lae`apuki.

Figure (see Caption) Figure 188. Map of Kīlauea's eruption site showing the location of lava flows, tubes, and ocean entries active during January-March 2007. Courtesy of HVO-USGS.

Activity during 1 April-19 June 2007. Our previous report noted lava flows reaching the ocean between December 2006 and March 2007 (BGVN 32:05). Earthquake swarms that began in mid-May along the upper rift are discussed in a separate subsection below.

During 1 April to 19 June 2007, several key pathways remained active down Kīlauea's flanks (figures 187 and 188). First, lava emerged from the PKK tube at the top of Pulama pali and then continued as surface flows down the pali. The Campout lava tube continued to provide lava to the coast at the Kamokuna ocean entry. The Campout lava tube also fed an eastward branch that emerged at the low-elevation end of the Royal Gardens, a long-abandoned housing subdivision (figure 188) where lava ignited fires on 11 April. The Campout lava tube also fed a westward branch to the coastal plain inland of the E Lae`apuki sea cliff, although the ocean entry was not visible. During the reporting interval, Kamokuna was the only consistently active ocean entry point.

During 4-24 April, incandescence was intermittently visible from several breakouts on the Pulama pali and from several vents in Pu'u 'O'o's crater. On 11 April, lava from the E arm of the Campout flow ignited fires at the base of the long-abandoned housing sub-division called Royal Gardens.

Throughout May, lava from Kīlauea continued to flow SE across a lava delta into the ocean at the Kamokuna entry. Incandescence was visible from several vents in the Pu'u 'O'o crater and from breakouts on, above, and at the base of the Pulama pali fault scarp. During 3-4 May, the Campout flow sent large channelized a'a' flows descending down the pali. On 4 May, a sheet flow ponded lava at the base of the Royal Gardens.

On 8 May, HVO scientists reported that for the past several months, Kīlauea caldera widened at a rate of 1.5 cm/month. Multiple updates around this time noted that Pu'u 'O'o crater was slowly collapsing. This was indicated by both new cracks on the S flank and subsidence of the N flank at a rate of 1 cm/month.

On 10 May, ~ 6.5 hectares of the E Lae`apuki bench collapsed, starting from the E-side and moving progressively westward. Observers saw the collapse during the time interval 1625-1900. The event generated the strongest seismic signals during 1711-1855. Each section of collapse generated steam-plume emissions occasionally blackened by rock fragments. The plumes resulted from the explosive interaction between seawater and incandescent rock exposed immediately after each section collapsed. On 11 May, HVO scientists surveyed the collapse and mapped cracks inland of the sea cliff. They found recently fallen fragments covering 1.2 hectares.

On 16 May, lava from the E-arm of the Campout flow advanced along the coastal plain from the base of the Royal Gardens to reach the ocean at Poupou, a spot ~ 1.6 km E of the Kamokuna entry. On 18 May, HVO field crews reported a delta there reaching 20 m wide. At Poupou, during 23 May-19 June, lava continued to flow SE across this growing lava delta into the ocean. By 24 May, lava had ceased entering the ocean at Kamokuna.

On 18 May, a large lava flow broke out of the PKK lava tube at the site of an old skylight named Petunia. The skylight connected to the PKK lava tube ~ 400 m SE from the tube's head. The Petunia skylight (figure 187) is located in the midst of the upper PKK flows. Color photos of the lava venting on 18 May (figure 189) indicate that the new lava flows have large tongues with prominent zones of incandescence.

Figure (see Caption) Figure 189. An oblique aerial photo showing a new vent in Kīlauea's upper flow field, 18 May 2007. On this date the former Petunia skylight served as the vent for a fairly large lava flow. The point of emission is at the lower left, with lava flowing towards the right (moving S or SE). The new lavas extruded amid the much broader PKK (Kuhio) flow. Courtesy of HVO.

The 18 May HVO update noted that on the coastal plain, 1-2 km2 of hot, inflating flows were oozing between Royal Gardens subdivision and the Poupou entry. The advance toward the coast had become three-pronged, two on either edge of the now inactive Ka`ili`ili branch of the Campout flow and one farther E. The middle prong fed the growing Poupou entry. The western prong, advancing along the the western edge of the same branch, is still more than 800 m from the ocean. A narrow eastern prong advanced along the far eastern boundary of the National Park, and still remained ~ 500 m from the ocean. This pattern of behavior continued through the rest of May.

The 2 June HVO report stated that the PKK lava tube, still the primary tube from Pu`u `O`o, fed the Campout and the Petunia lava tubes. The Petunia flow had advanced ~ 2 km but was not yet visible below the pali. The Kamokuna and E Lae`apuki ocean entries were not active.

During the week 6-12 June 2007, aerial and satellite observations confirmed that the Petunia flow remained active but was still about the same length. Surface flows were also documented inland of the Poupou entry on the E side of the flow field. On 14 June, the Petunia flow went over the top of the Pulama pali. On 16 June, the front of the Petunia flow advanced down the Pulama pali and was ~ 90-180 m wide.

An E rift intrusion was inferred from increased activity at Kīlauea's summit on 17 June. By the morning of 19 June, a small pad of lava was erupted on the NE flank of Kane Nui o Hamo shield. When crews conducted ground-based mapping of the new lava flow about a week later, HVO reported that the eruption occurred from two places along the fissure, separated by ~ 40 m.

Kiholo Bay earthquake, October 2006. On 15 October 2006 an Mw 6.7 earthquake struck off the NNW shore of the island of Hawaii (~ 11 km NNW of the town of Kalaoa). The focal depth was 29 km. Seven minutes later an Mw 6.0 event followed, part of over 50 aftershocks that occurred.

The intensity was strongest slightly NE of the bay, where it yielded a maximum Modified Mercali value of VII-VIII (very strong to severe). It was felt throughout the region; on Maui some areas may have reached intensity VI. Earthquakes of this type are generally inferred to result from bending stresses within the Pacific plate caused by the weight of overlying islands.

Twelve instruments on Hawaii recorded the shaking. Despite its moderate depth, the earthquake generated high accelerations to the epicenter's NE. An instrument at the Waimea fire station measured large peak ground accelerations nearly equivalent to gravity in both the vertical (0.88g) and horizontal (1.05g) components. These peak values, which indicate the high-frequency content of the ground motion, primarily affected acceleration-sensitive bodies, such as liquid in containers and nonstructural elements. The ground motions at longer periods (eg., over 1 second), however, were sufficiently small to avert full-scale building destruction. There were no reported deaths.

The earthquake triggered numerous landslides, closed roads, and damaged at least 1,173 buildings. Power outages occurred throughout the Hawaiian Islands. The damage estimates in a later report were high, over 100 million dollars, roughly twenty-fold larger than others in area, although several had larger magnitudes and intensities.

2007 earthquake swarm on the rift zone. A swarm of moderate magnitude earthquakes took place along Kīlauea's rift zone beginning 12 May 2007. Since 1998, a few earthquakes with magnitudes greater than 4.0 have occurred at shallow depths beneath the upper E rift zone.

For example, HVO recorded an M 4.7 earthquake at 0913 on 24 May, located beneath the upper E rift zone, near Kīlauea's summit at Puhimau crater (at the upper end of Chain of Craters road, figure 185) at a depth of 2 km. On 24 May an M 4.1 aftershock occurred 20 minutes after the main shock, located 1.5 km farther down-rift, beneath Koko`olau crater. An M 3.9 aftershock occurred at 1051 and was located 4 km farther down-rift than the M 4.7 at a depth of 1 km. An M 3.9 aftershock occurred at 1051 and was located another 2.5 km down-rift at a depth of 1 km.

On 17 June, a swarm of earthquakes and rapid deflation began at 0215 in the upper E rift zone. The earthquakes were centered ~ 1 km SW of Mauna Ulu and about 1.5-3 km deep. About 70 earthquakes were recorded in the first 2 hours; at least 10 of those earthquakes were M 3 or greater. National Park Service crews evacuated visitors and closed the Chain of Craters road and the Crater Rim Drive between Jaggar museum and the Thurston lava tube parking lot. Fresh cracks ~ 2 cm wide opened in the Chain of Craters road near the Mauna Ulu turnoff. GPS receivers in the area of most intense seismic activity near Makaopuhi crater documented ~ 10 cm of widening across the rift zone,. HVO observers noted rockfalls from the S wall of Pu`u `O`o cone and collapse of the crater floor around the vents.

Although these were clearly smaller and less damaging than the Kiholo bay earthquake, they occurred along the active vent and fissure system. Substantial earthquakes in this important region continued through at least mid-August (including an M 5.4 earthquake on 13 August).

References. Hawaiian Volcano Observatory, 2006, Quarterly Report of the USGS Hawaiian Volcano Observatory (HVO), October-December 2006.

Hawaiian Volcano Observatory, 2007, Quarterly Report of the USGS Hawaiian Volcano Observatory (HVO), January-March 2007.

Klein, F.W., Frankel, A.D., Mueller, C.S., Wesson, R.L., and Okubo, P.G., 2001, Seismic hazard in Hawaii: high rate of large earthquakes and probabilistic ground motion maps: Bulletin of the Seismological Society of America, v. 91, p. 479-498.

Robertson, I.N., Nicholson, P.G., and Brandes, H.G., 2006, Reconnaissance Following the October 15th, 2006 Earthquakes on the Island of Hawai'i: University of Hawaii, Department of Civil and Environmental Engineering Research Report, UHM/CEE/06-07 (URL: http://www.cee.hawaii.edu/).

U.S. Geological Survey Community Internet Intensity Map, 2006 (http://pasadena.wr.usgs.gov/shake/STORE/Xtwbh_06/ciim_display.html).

U.S. Geological Survey ShakeMaps, 2006, (URL: http://earthquake.usgs.gov/eqcenter/shakemap/global/shake/twbh_06/).

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Associated Press.


March 2009 (BGVN 34:03) Citation IconCite this Report

June to December 2007 activity; multiple fissure eruptions

The long-term eruption of Kīlauea, continuing since January 1983, is well documented in reports issued by the Hawaiian Volcano Observatory (HVO) and in the literature (eg., Poland and others, 2008), and is thus only episodically covered in our Bulletin. This report begins bringing coverage up to date by summarizing activity during the last half of 2007. Events included lava returning to Pu`u `O`o on 2 July, a fissure eruption on 21 July, and the Thanksgiving Eve Breakout (TEB) on 21 November. This report starts with a discussion of the Father's Day Intrusion, or Episode 56, an event heralded by increased summit activity on 17 June 2007 (BGVN 32:06).

Father's Day Intrusion (Episode 56) and Pu`u `O`o activity. According to HVO, on Father's Day, 17 June 2007, a swarm of earthquakes and rapid deflation began at 0215 in the upper E rift zone. The earthquakes were centered under Pauahi Crater ~ 1 km SW of the Mauna Ulu shield volcano, and ~ 1.5-3 km deep. Rapid ground tilting was detected at Mauna Ulu. About 70 earthquakes were recorded in the first 2 hours; at least ten of those were M 3 or greater. National Park Service (NPS) crews evacuated visitors and closed the Chain of Craters road and part of the Crater Rim drive.

Fresh cracks about 2 cm wide opened in the Chain of Craters road near the turnoff to Mauna Ulu. Within a few hours, GPS receivers in the area of most intense seismic activity documented an approximate 10 cm of widening across the rift zone, near Makaopuhi crater. The deformation and earthquakes were inferred as associated with magma intrusion that started in the Mauna Ulu area early on 17 June and subsequently moved slowly 6 km E along the East rift zone. HVO observers noted rockfalls from the S wall of Pu`u `O`o cone and collapse of the crater floor around the vents. Some parts of the crater floor subsided up to 80 m within a few days.

On 18 June, the earthquake swarm slowed to ~ 10-15 small earthquakes per hour. Strong tremor beneath the summit was recorded and deflation continued. GPS receivers continued to show extension across the East rift zone, to ~ 100 cm in some areas. Between 18 and 19 June, a new 50-m-long lava flow emerged from a 200-m-long fissure in the forest NE of Kane Nui o Hamo, about 6 km W of Pu`u `O`o. Steam plumes were spotted on the N flank of Kane Nui o Hamo (figure 190).

Figure (see Caption) Figure 190. Map of Kīlauea's Father's Day Intrusion showing Kīlauea caldera and key features and activity near the Makaopuhi crater on 20 June 2007. A small lava flow erupted from a 250-m-long fissure in the forest NE of Kane Nui o Hamo. The lava was cooling and not advancing when observed at 0700 on 19 June. Courtesy of USGS-HVO.

On 20 June, seismicity and extension decreased on the East rift zone. HVO scientists measured highly elevated sulfur dioxide gas concentrations, greater than 10 parts per million (ppm), in a broad area adjacent to Halema'uma'u crater. Elsewhere typical concentrations were generally negligible except for areas downwind of Halema'uma'u crater, where they reached up to 2.5 ppm in narrow zones.

During 21 June-1 July 2007, no fresh lava was visible on the flow field or at the site of the 18-19 June eruption. The summit area continued to inflate very slowly and seismic tremor values at Pu`u `O`o were below pre-June 17 levels. Ground-based mapping of the new lava flow indicated the eruption occurred from two places along the fissure, separated by ~ 40 m. The intrusion and extension processes had drained a substantial amount of magma from the summit reservoir; Pu`u `O`o's crater collapsed to a level 100 m deeper and the lava tubes drained.

Lava in Pu`u `O`o Crater (Episode 57). On 2 July, HVO scientists saw new lava flows at the bottom of the collapsing Pu`u `O`o crater; incandescence had last been seen there on 18 June. Two vents feeding the lake were identified: the W vent, initially the most active, and the E vent (figure 191). During 3-13 July, a lava lake grew and filled the crater to within 30 m of the rim. On the S wall of West Gap pit, intermittent incandescence and fuming from new vents that opened were observed during 13-14 July. In addition, the level of the lava lake dropped but lava continued to emit from the E vent. On 15 July, the E and W vents erupted small lava flows that drained onto the solidifying lava lake bed. Low lava fountains extruded from West Gap pit. Within a few days, lava filled the pit and overflowed into the main crater.

Figure (see Caption) Figure 191. Map of the Pu`u `O`o crater as of 20 July, 2007. The dark gray shaded area represents the composite area of collapse, including the main crater and flank vent pits, following the Father's Day event. The key identifies new lava (episode 57) erupted at Pu`u `O`o shown in light red in colored versions; areas mainly in the center of the crater. Vents active during episode 57 are shown as asterisks. Courtesy of USGS-HVO.

During 18-21 July, the E vent and dominant W vent in Kīlauea's Pu`u `O`o produced lava flows. New vents opened in the Puka Nui pit, in the SSW area of Pu`u `O`o crater, and produced lava flows that ponded there. A low lava fountain occasionally fed the lake from the vicinity of a spatter cone; an unseen source also fed the lake from the NW edge. A vent high on the S crater wall, adjacent to the Puka Nui Gap pit, produced spatter and propelled lava bombs 10 m into the air. Meanwhile, the lava lake in the West Gap pit continued to fill, overturn, and occasionally overflow. The spatter cone that built up around the S wall vent in West Gap pit was submerged beneath the lava lake surface on 20 July. Uplift of the crater interior continued. Earthquakes occurred beneath the upper E rift zone, S flank, and Halema'umau crater.

Fissures A-D. Late on 20 July, a tiltmeter recorded a nearly 300 microradian of change as Pu`u `O`o's crater floor started to subside. Early on 21 July, the West Gap lava lake and Puka Nui pit drained. A new eruption initiated along a set of fissures (figure 192) that extended 1.7 km E from a point about 150 m E of the E rim of Pu`u `O`o crater.

Figure (see Caption) Figure 192. Aerial view at Kīlauea showing Pu`u `O`o crater looking WNW on the morning of 13 July 2007. Viewers saw two active vents in the collapsed crater floor. The incandescent E vent is near the lower right part of the crater bottom, and the W vent (less incandescent in this image) is near the middle of the image. Courtesy of USGS-HVO.

Preliminary reports described two 600-800 m long, left-stepping, ENE-trending fissures between Pu`u `O`o and Kupaianaha. The easternmost fissure fed two lava flows, the longer of which reached ~ 2 km SE from the fissure. The lower fissure consisted of three segments, making a total of four. The four fissure segments, A, B, C, and D, defined an approximately 2 km-long line (figure 193).

Figure (see Caption) Figure 193. Map showing Kīlauea's eruptive fissure segments A, B, C, and D and aerial extent of lava flows from the 21 July eruption (as documented that day). Courtesy of USGS-HVO.

The westernmost fissure (segment A) was inactive by 21 July and the uppermost segment of the active lower fissure (segment B) was completely sealed by mid-morning on 22 July. The rest of the fissure erupted lava fountains 6-8 m high, constructing several small perched ponds that occasionally overflowed to feed a few longer lava flows. These formed as the edges of pools of lava hardened to create confining walls. These walls enabled the pond's surface to be much higher, in some cases as much as 18 m or higher than the surrounding land. The ponds were as large as 200 m in diameter.

During 23 July to mid-August, fissure segments C and D fed perched lava ponds created by the NE-advancing `a`a flow. The ponds both grew in thickness and spilled lava over the levees along their edges, or at breaches. By 31 July, segment B had become inactive. By about 12 August, lava ceased extruding at segment C.

During the rest of August through most of November, fissure segment D continued to feed advancing `a`a lava flows that frequently escaped the confines of the levees. Lava flows that branched from the main channel continued to advance, widening and lengthening the flow field. Lava occasionally escaped from lava tubes.

Fissure D and TEB. On 21 November, lava escaped from a perched channel near fissure D. This lava flow became known as the TEB (Thanksgiving Eve Breakout). The bypass of lava from the channel to the surface resulted in an estimated 10 m drop in channel levels. The redirected lava quickly formed two channelized pahoehoe flows; one advanced 300 m N and the second flow advanced 1 km SE.

During 23-27 November, lava built a low shield over the TEB and fed one flow that advanced 2 km. A small lava pond at the top of the TEB shield overflowed and fed lava flows in multiple directions. Clear web-camera views on 9 and 10 December revealed that the TEB shield continued to build vertically and was then an estimated 15 m high. On 16 December, a 4-5-m-high hornito at the summit of the TEB shield was active. On 17 December, fume puffed from the top of the shield about every 15-20 minutes when visible.

An overflight on 20 December revealed that lava from fissure D built up two more shields SE of the TEB shield. These shields were considered "rootless shields." That term is described by HVO scientists as "...smaller, shield-shaped mounds that form on active lava flows [and] are fed by shallow lava tubes that flow just below the surface."

During 25 December-1 January lava escaped at both the TEB shield and two satellitic shields. Short lava flows traveled SE and N.

Reference. Poland, M., Miklius, A., Orr, T., Sutton, J., Thornber, C., and Wilson, D., 2008, New episodes of volcanism at Kīlauea volcano, Hawaii: EOS, Transactions of the Am. Geophys. Union, v. 89, no 5, p. 37-38, 29 January 2008.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


January 2010 (BGVN 35:01) Citation IconCite this Report

2008 highlights: Thanksgiving Eve Breakout continues, Halema'uma'u Crater vent opens

This report summarizes Kīlauea activity for 2008. The previous report (BGVN 34:03) discussed the Father's Day Intrusion, lava in Pu`u `O`o Crater, and the Thanksgiving Eve Breakout (TEB), covering activity during the last half of 2007. The current report will very briefly highlight a few of the events previously discussed, leading into 2008, starting with a summary of the ongoing TEB activity. Other major events include activity in Pu`u `O`o crater and a vent opening in Halema'uma'u crater. All information is based on reports from the Hawaiian Volcano Observatory (HVO).

As discussed in BGVN 34:03, lava erupted from four fissures that extended 1.7 km E from an area near the E rim of Pu`u `O`o crater on 21 July 2007 (BGVN 34:03), defining an approximately 2-km-long segmented line. The fissures fed lava flows and created perched lava flows and lava ponds that frequently overflowed. By 12 August, only one fissure ("D") remained active.

On 21 November, lava escaped from a perched channel near fissure D and became known as the Thanksgiving Eve Breakout, or TEB. Flowing lava built rootless shields of various sizes. One large shield towered ~ 40 m above the pre-July 2007 surface; about 15 total were built in a 3-month period.

The TEB flow field and ocean entries. After the opening of the fissures on 21 and 22 July 2007 and the TEB event on 21 November 2007, lava flows continued to be active in 2008, expanding the flow field. The area of the flow field roughly doubled in 2008, rising from 11.5 to 25.1 km2 (figure 194).

Figure (see Caption) Figure 194. Map of Kīlauea showing the expansion of the lava flow field during 2008. Fissures A, B, C, and D appear as an almost continuous line between Pu`u `O`o crater and the TEB vent. The darker color shows the area covered by lava in 2008 as the flows traveled S and E of the TEB vent, through the now-abandoned Royal Gardens subdivision, to the Waikupanaha and Ki ocean entries. Courtesy of USGS-HVO.

In January and February 2008, the perched channel that had previously been active filled a few times, and occasionally overflowed, sending lava flows S, SE, and E. After 10 February, no lava erupted in the perched channel through the rest of 2008. Occasional collapses at rootless shields generated local `a`a lava flows. Around 20 February, shallow lava in the main TEB vent disappeared and intense fuming ensued. About the same time, the TEB flow transitioned from shield-building activity to distributing pahoehoe lava flows. By the end of February, advancing `a`a lava flows had entered the Royal Gardens subdivision and split into two, a W lobe and an E lobe named Prince and Royal (after the streets they mainly were restricted to), respectively. By 7 March, six structures in the subdivision had been destroyed.

On 5 March the W lobe reached the ocean at the Waikupanaha entry, named for a nearby pond lava covered in the 1990s. This was the first lava flow to reach the ocean in almost a year, since 20 June 2007, following the Father's Day intrusion. The lava began building out the delta at multiple locations, and on 12 March, created the Ki entry at a new location 200 m E of Waikupanaha. There were a few small collapses on the newly formed deltas at the end of March. By 28 March, new land forming at the Waikupanaha and Ki entries merged to create a continuous 2.18-km-long, 115-m-wide delta, covering an area of 9.16 hectares. Lava poured into the sea at the Ki entry until mid-April.

Significant littoral explosions, characterized by tephra ejected 20 m high, were first seen at the W entry of Waikupanaha on 5 April. Explosions were occasionally seen throughout April and early May, and were last seen on 10 May. The explosions then occurred at different Waikupanaha locations through June; tephra jets were commonly less than 50 m high.

Incandescence from the TEB vent was noted during 31 March-15 April and 2 May-2 June. The tube system carrying the lava from the TEB vent down to the ocean was relatively stable during May and June. One surface flow, on the pali (fault scarp), was seen in May and a few flows were seen in June. In some stretches, the lava tube would split into two tubes and then merge again, forming braided structures. Near the ocean, the tube split and created multiple ocean entry points. On 6 May, spatter was seen at the multiple ocean entries of Waikupanaha, and on 9 May, a new littoral cone was seen. Littoral explosions were common during May and June. On 3 June, a collapse caused the delta shoreline to move back 30 m.

Tephra jets observed at Waikupanaha in the latter part of June (figure 195) continued into July. A bench collapse on 2 July was followed by a few days of intense bubble bursts and large tephra jets. On 9 and 10 July tephra jets were estimated to be ~ 40 m high.

Figure (see Caption) Figure 195. Airborne debris ejected from explosions was seen in the white steam plume generated from lava flow entering the ocean at Kīlauea's Waikupanaha ocean entry on 24 June 2008. Courtesy of USGS-HVO.

In early July, breakout lava flows originated from the rootless shield area. Lava also continued to flow SE through a lava tube system to the Waikupanaha ocean entry. On 7 July, a breakout from one of the shields (number 3) was comprised of three vents, each emitting lava fountains. One of the fountains was arch-shaped and reached 12-14 m high. It built a large spatter cone. Also, an `a`a flow resulting from the fountaining traveled 1.4 km E. Strands of Pele's hair created by the fountain were carried at least as far as the end of the Chain of Craters road. The lava flow was inactive by 17 July. Other breakouts on the pali were active until 25 July, when incandescence was not longer seen. On 30 July, less than one hectare (or 25 %) of the bench E of the ocean entry had collapsed.

On 9 August. Lava again flowed to the upper reaches of the Royal Gardens subdivision. On 20 August, geologists observed bursting lava bubbles from an area E of Waikupanaha that threw molten fragments 10-20 m into the air. A delta collapse ejected lithics up to 180 m inland. Rocks were mostly 5-10 cm in diameter, with many larger blocks around 25 cm across. Multiple surface lava flows on the pali were noted; on 16 October a channelized 'a'a flow was active in the Royal Gardens subdivision and a pahoehoe flow was seen on the W side of the active flow field. Lava destroyed one of two remaining intermittently occupied structures in the subdivision.

During August through December 2008 lava flowed SE through tubes underneath the TEB and rootless shield complex and flowed into the ocean at Waikupanaha with few pauses. Thermal anomalies detected by satellite and visual observations revealed intermittent active lava flows at locations on and at the base of the pali, at the TEB vent, and on the coastal plain. Periodic explosions during September, October, and early November ejected debris into the air.

Lava flows and a new gas vent in Pu`u `O`o Crater. During January through April 2008, intermittent incandescence was seen in Pu`u `O`o crater through the web camera. Heavy fume that sometimes obscured views was particularly dense from April through June, although thermal images revealed hot spots on the crater floor in late April.

A flash of incandescence on 20 May signaled a new gas vent opening. On 23 May, an overflight of Pu`u `O`o crater revealed that the new gas vent was about 6 m wide and centered 21 m below the E rim. It jetted gas at temperatures as high as 600°C. Gas continued to jet from the vent during 28 May-17 June.

The SO2 emission rate was high on 27 and 30 May and fluctuated between 2,740 and 4,700 metric tons per day (t/d). The background rate of about 2,000 t/d (averaged over the past 25+ years) was measured on 25 May and earlier. The rate continued to be above the background in early June, fluctuating between 1,530 and 3,080 t/d. Incandescence from two distinct sources in the E and W ends of Pu`u `O`o crater was observed on the web camera during 4-6 July. During this period, the SO2 emission rate fluctuated between 3,100 and 4,800 t/d. Diffuse incandescence was noted on 7 and 8 July, and then spattering was visible in the webcam on the crater's N rim.

Scientists that visited the area on 10 July heard gas bursts and spattering. They saw active lava with a Forward Looking Infrared Radiometer (FLIR) camera. It came from a spattering vent, corresponding in location to the West vent from July 2007 and to the Beehive vent from prior activity. This vent sat in the lowest part of the crater and fed lava that traveled SE and pooled. Spatter bursts ejected lava 20-30 m high. There was also very weak spattering from a vent at the SE edge of the lava pond and from a vent on the E side of the crater floor. The SO2 emission rate was very high at 6,300 t/d on 17 July. During the rest of July, incandescence was observed from vents and sporadic spatter in Pu`u `O`o crater.

SO2 measurements sporadically obtained at Pu`u `O`o during July and August showed that the rate remained above background levels, between 1,700 and 5,400 t/d. Sometime on 11 and 12 September incandescence flashed from multiple sources within the central and western parts of Pu`u `O`o crater. A little over a week later, the SO2 emission rate dropped to below or remained at the 2,000 t/d background rate and remained there until early November.

In early December, HVO noted that GPS stations spanning Pu`u `O`o had recorded almost 4 cm of contraction during the previous 3 months. On 16 December, a Pu`u `O`o webcam was hit with a small amount of debris, suggesting a collapse in the crater.

Vent opens in Halema`uma`u Crater. In early January 2008, SO2 emission rates at the summit increased as much as ten times the background value. The rate averaged 140 tons per day during 2003-2007 . The increased gas emissions at Halema`uma`u caused the temporary closure of the National Park in late February. The prevailing trade winds blow SW over the Ka`u Desert. However high concentrations of SO2 affected other areas of the National Park, such as Jaggar Museum, HVO, and the town of Hilo when the winds changed direction. Poor air-quality conditions resulted in park closings and evacuations twice during 2008.

On 12 March a new gas vent appeared just above the base of the SE wall of the crater (see map and cross section of the crater and vicinity in BGVN 32:06). The SO2 emission rate abruptly increased that day and remained at 1,600-2,500 during 12-16 March. On 16 March, emission rates reached 2,500 tons per day, the highest level at the summit since measurements began in 1979.

During 13-18 March, incandescence from the new gas vent originated from a spot ~ 30 m wide within the rubble at the base of the E crater wall. Cracking rocks, an effect possibly due to thermally-induced stress, were heard by scientists at the Halema`uma`u overlook. On 17 March, the area of incandescence appeared slightly enlarged with a new area higher on the crater wall and to the N.

On 19 March, gravitational collapses of rubble in the vent led to an explosion that scattered debris over an area of about 30 hectares, covering a portion of Crater Rim Drive and damaging the overlook. On Crater Rim drive, the ejecta were up to 2 cm in diameter and increased in size and thickness towards the overlook. The largest block ejected was ~ 1 m3. Small impact craters created by 30-cm-diameter blocks were abundant in the overlook area. Since no lava was ejected, the event was possibly driven by hydrothermal or gas sources. The event was the first such explosive activity in the crater since 1924.

Seven other explosive eruptions occurred during the rest of 2008, ejecting both juvenile and lithic material: 9 April, 16 April, 1 August, 27 August, 2 September, 12 October, and 14 October. The majority of the explosions were preceded by collapse of a portion of the vent rim or wall, coincident with high-frequency seismic signals.

A majority of the time after the vent had opened, emissions of steam and gas, often containing minor amounts of ash and variously shaped glass fragments, rose from the vent. Typically the white-colored plume that rose from the vent drifted SW with the prevailing winds (figure 196). Often incandescence was seen at the base of the plume. Rock clattering, booming noises, and "rushing sounds" were occasionally heard in the vicinity of Halema`uma`u crater.

Figure (see Caption) Figure 196. Aerial view on 8 August 2008 of the vent in Halema`uma`u crater that had opened on 12 March at the base of the E crater wall. A billowing white gas-and-steam plume is seen rising from the vent and drifting SW. On the rim, just above the vent, the damaged fence is visible. Courtesy of USGS-HVO.

SO2 gas affected residents living downwind, and caused crop damage. According to a news report, the Hawaii County Civil Defense issued a health advisory on 7 April for those living downwind of both Halema`uma`u and Pu`u `O`o craters. Residents of specified areas were then advised by the State Department of Health to evacuate because of projected dangerous levels of SO2. Residents of other areas were put on alert. A few weeks later, during 24-25 April, Hawaii Volcanoes National Park closed again due to elevated levels of SO2; about 2,000 people were evacuated.

On 21 August, an earthquake was accompanied by a 400-m-high jet of mostly gas that rose vertically, then drifted SW. The jet also contained some rock dust and bits of volcanic glass. Several small ash ejections occurred on 25 and 26 August.

On 5 September, scientists in a helicopter saw the surface of a sloshing lava lake, 50 m in diameter and ~ 100 m below the vent rim. The lake was later described as a roiling pond with multiple bursting bubbles that changed into a central upwelling circulation pattern. The level of the lake dropped slightly before the cycle restarted. The lava lake was seen several more times in the following weeks.

After the 14 October explosive eruption, collapses from the vent rim and walls caused "dusty" plumes, along with the almost constant steam plume. Thermal images collected on 24 October showed that the lava lake had drained from the vent's upper pit-like cavity and dropped out of sight below the mouth of a smaller (~ 15 x 30 m) lens-shaped opening near the base of the vent's northern (crater-side) wall. Other aerial views of the vent seen through 20 November showed a similar situation. On 4 December, a large collapse within the vent ejected a big "dust" cloud that blanketed the overlook area with reddish ash. Several more collapses during 5-6 December widened the vent by several meters; on 19 December, the vent was ~ 90 m in diameter. Small collapses continued to shed rubble into the vent through December 2008 and, by the end of the month, aerial views with an infrared camera showed that the lens-shaped opening at the bottom of the vent's pit had become choked with debris.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Honolulu Advertiser (URL: http://www.honoluluadvertiser.com); Associated Press (URL: https://www.ap.org/)


February 2013 (BGVN 38:02) Citation IconCite this Report

2009 highlights: Waikupanaha ocean entry ceases, lava enters Halema`uma`u

This report discusses eruptive highlights at Kīlauea during 2009, with occasional reference to earlier and later events. Within the E rift zone, Pu`u `O`o crater was relatively quiet during 2009, while lava flows escaping from the Thanksgiving Eve Breakout (TEB) tube system continued to feed emissions along the SE coast. Along the E portion of the TEB system, the Waikupanaha ocean entry remained active for up to 363 days during 2009 before ceasing altogether on 4 January 2010. Along the W branches and ocean entries of the TEB tube system, lava emissions halted in July 2009.

At Kīlauea's summit, lava returned to the active vent within Halema`uma`u crater in January 2009, ending a pause in lava emissions there that began in December 2008. The active vent's shape was explored using Lidar, and in mid-2009 the lava lake's surface sat ~200 m below the floor of Halema`uma`u crater. The active vent underwent numerous cycles of lava rise, surface cooling, and collapse. Unless otherwise noted, all information in this report is from USGS Hawaiian Volcano Observatory (HVO) reports.

Pu`u `O`o crater quiescence. During the first four months of 2009, heavy fuming at Pu`u `O`o prevented visual observation of areas within the crater. HVO reported gas-rushing noises, but nothing unusual in available views from Forward Looking Infrared Radiometer (FLIR) thermal imaging. FLIR instruments detect infrared radiation, and produce calibrated thermal videos and still images.

On 15 May, favorable wind directions provided clear views of the crater floor. Observers reported patches of less broken, ponded surfaces near locations previously observed as spattering vents, as well as a V-shaped trough that ran SW-NE traversing the length of the crater (figure 197). They also observed an incandescent, fuming vent emitting puffing sounds in the NE part of the crater (also heard during a later visit in June), and an unseen vent distinguished by sounds on the W end of the crater floor (figure 197). Until October, further observation was limited to FLIR imagery, showing a few small, hot vents on the crater floor.

Figure (see Caption) Figure 197. Map of Pu`u `O`o crater (dark gray) and vicinity showing active vents during 2009 (red dots) and the V-shaped trough (dashed line) that was observed on 15 May 2009. The webcam (POcam) location on the crater's rim is indicated by the yellow triangle. Other mapped units correspond to previous flow fields emplaced in 1983-1986 (light gray), 1992-2007 (tan and orange), and 2008 (pink, top right); during 1986-1992, lava flows were emplaced outside of the mapped area. A small lithic debris field observed on the NE rim on 2 December 2009 is also indicated. Courtesy of USGS-HVO.

Crater glow at Pu`u `O`o was observed via webcam on most nights during the last three months of 2009. Ground observation on 2 December revealed a small (estimated3) surficial deposit of lithic lapilli and small blocks on the NE rim from a small explosion estimated to have occurred as early as 23 September (figure 197). The lithic debris was most likely sourced from one of the nearby vents on the NE crater wall.

During 2009 (and possibly since August 2007), a series of collapses removed a significant portion of the N crater rim. HVO reported that the series of collapses removed some of the highest points of the summit of the Pu`u `O`o rim, thus lowering the local elevation by a few meters.

Flow field and coastal plain breakouts and changes. Lava flows emplaced during 2009 covered an area of 6.5 km2, most of which covered previous lava flows; only 0.8 km2 of vegetated land (chiefly forested kipukas within the flow field) was overrun by lava (2009 flow field changes are shown in figure 198).

Figure (see Caption) Figure 198. Map of the changes to Pu`u `O`o's 21 July 2007 eruption flow field during 2009. The pre-existing (July 2007-2008) extent of the flow field is shown in pink, and the 2009 flow field additions are shown in red. Note that the portions of 2009 lava flows that overran the 2008 flow field extent are not represented, only changes to the extent of the July 2007-2008 flow field in 2009. The TEB tube system is shown in yellow with points where lava escaped to the surface, breakout points, indicated ('B/O points'). Ocean entries are indicated and labeled along the coast. Pool 1 (green) indicates the location of a lava lake roof collapse (discussed in text). Flow fields active during 1983-86 are shown in light gray, 1986-92 shown in light yellow, and 1992-2007 shown in orange. Courtesy of USGS-HVO.

The TEB vent and rootless shields (a pile of lava flows built over a known lava tube rather than over a conduit feeding magma; explained in BGVN 27:03) showed little change in early 2009, with small (most <300 m long) breakout-fed lava flows occurring occasionally during February and March on the fault scarp and cliffs (pali) in the Royal Gardens subdivision (figure 198) and the upper flow field. In early March, a breakout-fed lava flow reached the ocean, establishing the Kupapa`u ocean entry, which was active for a few months (discussed below) and consisted of several points where lava entered the sea (entry points). The long-lived Waikupanaha ocean entry (active since 5 March 2008) frequently produced littoral explosions and underwent delta collapses.

Other short-lived ocean entries occurred during this time, stemming from coastal plain breakouts from the W branch of the TEB tube system. These breakouts often slowed or stopped in harmony with deflation-inflation (DI) events at the summit. DI events, measured by tiltmeters at Kīlauea's summit, are thought to result from changes in magma supply to a storage reservoir less than 1 km deep and just E of Halema`uma`u crater. These fluctuations often propagate through the magmatic system, and are usually measured by another tiltmeter at Pu`u `O`o crater a few hours later. Typically occurring over weekly timescales during 2009 (up to a few days of deflation, followed by up to a few days of inflation; figure 199), DI events often correlate to pulses and/or pauses in lava emission at E rift zone vents.

Figure (see Caption) Figure 199. Radial deformation recorded by tiltmeters at Kīlauea's summit (blue) and Pu`u `O`o crater (pink) during 2009. The sawtooth patterns delineate what have come to be called deflation-inflation (DI) events, which typically occurred over weekly timescales during 2009. The timing and behavior of DI events often coincided with vent collapses at Kīlauea's summit and decreases or pauses in lava effusion along the E rift zone. Courtesy of USGS-HVO.

On 8 March 2009, the pool 1 lava lake roof (labeled in figure 198, feeding a perched lava channel - a lava channel with walls built up from previous overflows - from the 21 July 2007 fissure eruption, BGVN 34:03) collapsed. Subsequent cooling and further collapses during 11-19 March caused the channel to seal. No further active lava was observed in pool 1.

By 29 April, surface lava flows leading to the Kupapa`u ocean entry were no longer visible. This observation was taken to indicate that a tube branch leading to the Kupapa`u entry had been established. Later, during May-June, the multiple entries at Kupapa`u coalesced into one entry point. This entry was weaker and less persistant than the Waikupanaha entry and never formed a significant delta. Lava flows at the Kupapa`u entry pulsated in a manner closely correlated to DI events, unlike flows at the Waikupanaha entry, and the Kupapa`u ocean entry ceased by 21 July.

The onset of a strong DI event correlated with a breakout on June 1 from the Waikupanaha branch of the TEB tube system. Although beginning slowly, it remained active through mid-August. As is common, the flows slowed during deflation stages of DI events, and advanced further during inflation stages.

The Waikupanaha entry underwent common delta collapses throughout the year. The vigor of lava effusion at the entry, however, made up for the area lost to collapses, and the size of the delta continued to increase. The only known pause in lava entering the sea at Waikupanaha during 2009 occurred during a DI event, when the entry stopped for two days during 28-29 September.

On 31 October, surface lava flows reached the ocean ~700 m W of Waikupanaha, and established the W Waikupanaha entry. The new entry point was fed by an inferred secondary lava tube crossing over the main Waikupanaha tube branch (see the dashed portion of the yellow line labeled 'E Tube Branch', figure 198). Following the termination of the W Waikupanaha entry on 17 December, HVO concluded that its feeder tube had eroded down into the main Waikupanaha tube, thus tapping off its supply. Breakouts and surface flows during the end of the year continued to be affected by DI events.

Second longest ocean entry ceases. A large and prolonged DI event at Kīlauea's summit in December correlated with a brief pause in lava effusion at the E rift zone. As a result, by 4 January 2010, lava ceased entering the ocean at Waikupanaha after 22 months of near-continuous lava entry. This was the second longest ocean entry in the history of the eruption, being about half a month shorter than the 2005-2007 E Lae`apuki entry.

Lava lake returns to Kīlauea's summit. A lull in activity at Halema`uma`u crater began in mid-December 2008; on 14 January 2009, rockfall sounds returned to the summit, attributed to rising lava digesting talus slopes along the steep walled vent. Four days later, gas-rushing sounds, increased temperature, and collapses of the vent rim (figure 200) occurred, dusting nearby areas with ash and further marking the summit's re-awakening.

Figure (see Caption) Figure 200. Time lapse photographs of a collapse of a portion of the Halema`uma`u vent rim, Kīlauea, taken one minute apart (at 1528 and 1529) on 18 January 2009. The black line in the left frame indicates the area of collapse, which is absent in the right frame. Courtesy of USGS-HVO.

Vent glow, temperature increases, gas-rushing noises, and production of vitric ash continued during early 2009, indicating fresh lava had ascended to a shallow level in the vent. These eruption related processes fluctuated in a manner that suggested that they were moderated by in-falling crater walls burying the vent bottom.

Onset of a DI event on 3 February correlated with the retreat of the lava within the vent, removing support for the rubble clogging the vent cavity and collapsing the rubble into the cavity. This disturbance was accompanied by an ash plume that was sustained for 8 minutes. FLIR images captured the following day disclosed a lava lake situated deep within the vent (the rubble clogging the vent cavity was gone). HVO noted upwelling on the lake's E side, draining and filling events (figure 201) and spattering from the lake. Similar fluctuations at Halema`uma`u occurred in concert with DI events through late April.

Figure (see Caption) Figure 201. Observational and geophysical data highlight filling (pink) and draining (gray) cycles at Kīlauea's summit vent within Halema`uma`u crater. (a) Filling and draining cycles over 3 hours on 6 February 2009 were observed with FLIR, and compared with seismicity (Realtime Seismic Amplitude Measurement - RSAM - , top) and infrasound (sound at lower than audible frequencies, bottom). RSAM provides rapid analysis of ground-motion amplitudes across multiple stations; measurements are unitless and usually reported as 'RSAM units'. (b) Filling and draining cycles over ~1 hour on 7 February 2009 were observed via acoustic noises and compared with tilt (top), seismicity (middle, reported in instrument counts, here representing the seismometer response to the vertical component of ground motion velocity), and infrasound (bottom). Courtesy of USGS-HVO.

On 28-29 April 2009, a series of collapses at the vent within Halema`uma`u dislodged rubble and tephra covering the lava surface within the vent. As a result, for the next two months, particle emissions became > 50% juvenile (figure 202). Tephra emissions (juvenile, or glassy, and lithic components) have been measured nearly daily at Halema`uma`u since April 2008 by collecting passively emitted tephra (i.e. derived from non-explosive activity) in an array of buckets deployed around the vent. The resulting assessments led to the compilation of isomass maps and calculations of the total mass emitted (Swanson and others, 2009). By 6 May, bubbling and churning at the lava lake surface was visible with the naked eye.

Figure (see Caption) Figure 202. Calculated monthly ejected mass of tephra from Kīlauea's summit during April 2008-January 2010. The histogram excludes any explosive eruptions during that period. Collected tephra were assigned to one of two components: juvenile (glass, shown in black) and lithic (lava, shown in gray). Note that more than half of the mass ejected during May-June 2009 was juvenile, following a series of collapses on 28-29 April. See text or Swanson and others (2009) for a description of the daily tephra emission measurement technique. Courtesy of USGS-HVO.

A strong DI event in early June (reflected in the E rift zone by breakouts on the pali on 1 June, see above) marked the peak of lava activity within Halema`uma`u crater during 2009. The vent's lava lake showed strong upwelling in the NE, at times forming a dome-shaped fountain. The surface of the lava lake was circulating rapidly enough to prevent any significant crust from forming. The lava lake's circulation and activity slowed near the end of June and its surface appeared almost completely crusted over. A tripod mounted Lidar (T-Lidar) survey of the vent during 10-12 June indicated that the lava surface was ~207 m below the floor of Halema`uma`u crater (figure 203).

Figure (see Caption) Figure 203. 2-D projection of 3-D reconstruction of the Halema`uma`u crater vent as measured by a T-Lidar survey on 10-12 June 2009. The reconstruction (gray) is shown on a black background. The T-Lidar was shot from the Halema`uma`u crater rim, adjacent to the active vent. The plane projected here trends approximately NNE-SSW. The lava surface (indicated in purple at the bottom) was measured to be ~207 m below the floor of Halema`uma`u crater (indicated in green). Various other dimensions of the vent's geometry are shown. Image by Todd Ericksen, University of Hawaii-Manoa; courtesy of USGS-HVO.

On 30 June, a series of significant collapses of the vent wall again clogged the vent with rubble. For the following several days, lava appeared through the rubble and established a ponded surface. The lava retreated during a DI event on 4 July, and the vent became very quiet until mid-August. On the night of 9 August, the vent emitted a faint glow. Areas of degassing appeared within days, but the vent floor lacked visible molten material.

On 13 September, lava reappeared briefly, but a DI event a few days later coincided with another vent-wall collapse, again covering the lava surface. The vent floor collapsed further on 26 September, and two days later, lava had re-entered the vent and webcam videos confirmed the filling and draining behavior of the lava surface. This collapse coincided with a strong hybrid earthquake with large very-long-period waveforms. Hybrid earthquakes at Kīlauea typically begin as high-frequency earthquakes (similar to local earthquakes or rockfalls), then transition to long- and sometimes very-long-period oscillations. During 2009, hybrid earthquakes (i.e. the 26 September event) and ongoing very-long-period tremor at Kīlauea's summit suggested a source location beneath the summit, and within ~500 m above or below sea level.

The lava level within the vent fluctuated until the lava surface froze and sealed shut. It collapsed again on 18 November, revealing a fresh and mobile lava surface. Similar fluctuations and crusting of the lava surface continued through the end of 2009, when the lava level again dropped out of view deep below the Halema`uma`u crater floor.

2009 deformation trends. Satellite based radar interferometry determined that broad-scale deformation at Kīlauea during 2009 was marked by subsidence of the summit and E rift zone (figure 204; see the report on Mauna Loa, BGVN 37:05, for an explanation of the technique). This pattern was interpreted as deflation of the magma system, with displacement of the S flank towards the sea. Deflation also occurred in the E rift zone, but ceased by September. 64 DI events were recorded during 2009, a record number of short-lived DI events since they have been monitored. The largest and longest DI events tended to coincide with decreases or pauses in lava effusion in the E rift zone, and vent collapses at the summit (discussed above, figure 199).

Figure (see Caption) Figure 204. Subsidence and deflation of Kīlauea and the E rift zone during 2009, as seen in an ENVISAT interferrogram spanning 12 January 2009 to 3 February 2010. Approximately 8 cm of subsidence occurred at Kīlauea's summit (Halema`uma`u crater, which is labeled), and ~6 cm of subsidence occurred in the E rift zone near Pu`u `O`o crater. Colored stripes indicate offsets as shown in the scale, top right (see Mauna Loa report in BGVN 37:05 for an explanation of the technique). The image was acquired with an incidence angle of 18° with the ground, looking W to E. Courtesy of USGS-HVO.

Hexahydrite spherules discovered at Kīlauea's summit.While collecting Pele's hair on 30 March, HVO scientists discovered and collected small (less than 3 mm diameter), extremely fragile, white spherules that were stuck into wads of Pele's hair (figure 205).

Figure (see Caption) Figure 205. Hexahydrite (MgSO4·6H2O) spherules discovered and collected from just S of Kīlauea's summit vent in 2009. Photomicrographs (a, b) with scales show surface and textural details of the spherules. An in-situ photograph (c, key for scale) shows the spherules as they were found, within wads of Pele's hair. From Hon and Orr (2011).

X-ray diffraction revealed that the spherules were nearly pure magnesium-sulfate hexahydrite (MgSO4·6H2O). Hon and Orr (2011) proposed that the spherules form from the percolation of rainwater through vesicular vent rocks, enriching the water in soluble sulfates. Magnesium sulfate resists precipitation owing to its higher solubility, and most other hydrothermal minerals would precipitate from the enriched fluid sooner. Hon and Orr (2011) suggested that boiling of the residual magnesium sulfate enriched fluids formed a foam of magnesium sulfate-coated bubbles, which formed the spherules when the bubbles were subsequently entrained into the eruptive plume.

Petrologic trends, shallow magma mixing. Through long-term petrologic monitoring and analysis of Kīlauea's summit and E rift zone lavas, HVO scientists noted that the weight percent MgO (an indicator of the temperature of tapped magmas) of E rift zone lavas indicated well-buffered, shallow magma conditions that were maintained by "near-continuous recharge and eruption." Similarly, textural and compositional evidence highlighted pre-eruptive magma mixing between a shallow, cooler, degassed component and a gaseous, hotter, recharge magma component. Combined, the two components are erupted as a hybrid lava at the E rift zone.

Interestingly, since 2001, increased magma supply (interpreted from cross-summit extension distance) has correlated with an increase in the shallower, degassed magma component in the E rift zone lavas (interpreted from MgO weight percent; figure 206). HVO reported that this inverse relationship (higher magma supply coincident with cooler erupted lavas) is explained by more efficient flushing of the shallow edifice during times of increased magma supply.

Figure (see Caption) Figure 206. MgO weight percent (green points and blue trend, left axis) plotted versus Kīlauea's cross-summit extension distance (red, right axis) during 2000-2009 shows an inverse relationship between magma supply (i.e. variations in cross-summit extension) and the temperature of erupted lavas (i.e. variation in MgO weight percent). Courtesy of USGS-HVO.

Summit gas emissions exceed health standards. Based on Flyspec measurements, the total SO2 emissions from Kīlauea in 2009 (~0.72 x 106 tons) were 35% less than in 2008 (the highest annual SO2 emissions since measurements began in 1979, correlating to the opening of a new vent in Halema`uma`u crater; BGVN 35:01). Of the total 2009 emissions, ~60% and ~40% were attributed to the E rift and the summit, respectively (figure 207). Although 2009 emissions were down from the previous year, a record number of Ambient Air Quality exceedences occurred at the summit during 2009 (figure 208).

Figure (see Caption) Figure 207. Daily average SO2 emissions from Kīlauea's summit (green) and from the E rift (pink) during 1992-2009. The total daily average emissions are shown in blue. 2008 marked an increase in emissions from the summit (and the highest annual SO2 emissions since measurements began in 1979) correlating with the opening of a new vent in Halema`uma`u crater (BGVN 35:01). In 2009, although total emissions were down 35% from 2008, summit emissions remained elevated. Courtesy of USGS-HVO.
Figure (see Caption) Figure 208. Histograms show the number of days per year that the Ambient Air Quality standard was exeeded, as monitored at the HVO building (left) and at the Kīlauea Visitor Center (right) since 2001. Since air quality monitoring began, the standard was exceeded most often in 2009. Courtesy of USGS-HVO.

Vog health concerns. A recent clinic study by Longo and others (2010) highlighted the health effects of increased volcanic air pollution (volcanic smog, or 'vog') exposure at Kīlauea, and identified population subgroups who are more susceptible to the effects of vog. They found that periods of increased vog emission and exposure coincide with increases in medical visits for "cough, headache, acute pharyngitis, and acute airway problems." Among previously identified population subgroups with increased susceptibility to health problems from exposure to vog, Longo and others (2010) found a specific correlation with Pacific Islander children living in exposed rural communities. The native children showed higher rates of acute respiratory effects both in times of low- and high-vog emissions. Longo and others (2010) suggested that this unique population showed the highest vulnerability due to physiological and genetic contributions, as well as the built environment and a lack of prevention efforts for vog exposure.

References. Hon, K., and Orr, T., 2011, Hydrothermal hexahydrite spherules erupted during the 2008-2010 summit eruption of Kīlauea Volcano, Hawai`i, Bulletin of Volcanology, 73(9), pgs. 1369-1375.

Longo, B.M., Yang, W., Green, J.B., Crosby, F.L., and Crosby, V.L., 2010, Acute health effects associated with exposure to volcanic air pollution (vog) from increased activity at Kīlauea in 2008, Journal of Toxicology and Environmental Health, Part A, 73(20), pgs. 1370-1381.

Swanson, D., Wooten, K., and Orr, T.R., 2009, Mass flux of tephra sampled frequently during the ongoing Halema'uma'u eruption [abs.], Eos, Transactions, American Geophysical Union, v. 90, no. 52 (fall meeting supplement), abstract no. V52B-01.

Information Contacts: Michael Poland, Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/).


May 2013 (BGVN 38:05) Citation IconCite this Report

Summary of highlights for 2010-2012

The following is a concise summary of reports by the U.S. Geological Survey-Hawaiian Volcano Observatory (HVO) on Kīlauea volcano covering the 3 years 2010-2012. Volcano highlights for 2009 were covered in BGVN 38:02.

Figure 209 shows a map of the lava-flow field on Kīlauea's east rift zone as of 26 July 2013. On this map some of the older lava flows are labeled with the years during which they were active. Other maps appearing in earlier Bulletin reports indicated important features such as Napau crater, Pu'u 'O'o. HVO posts both Daily and Weekly updates on Kīlauea activity (at links provided in the Information Contacts section below).

Figure (see Caption) Figure 209. Small-scale map showing Kīlauea's east rift zone flow field as of 26 July 2013. The Peace Day flow, carried lava from the vent area to the ocean, and the inactive Kahauale'a flow from early 2013, are light reddish orange and labeled "2011-2013.". The active flow called Kahauale'a 2 flow N of Pu'u 'O'o, is shown in shades of red, with bright red showing expanded coverage since June 2011. Older lava flows are labeled with the years in which they were active. Flows during 1983-1986 (episodes 1-48b) are shown in gray; during 1986-1992 (episodes 48c-49) in pale yellow; during 1992-2007 (episode 50-55) in tan; and during 2007-2011 (episodes 58-60) in pale orange. The location of the Peace Day lava tube is shown by the yellow line, but where the tube crosses the coastal plain it has not been mapped. The interval between the contours depicting the topographic high at Pu'u 'O'o is 5 m. Courtesy of USGS/HVO.

The Hawaiian Volcano Observatory (HVO) celebrated its centennial in January 2012 and the 30th year of Kīlauea's ongoing eruption, now active at its summit and east rift zone, on 3 January 2013.

Orr and others (2012) summarized Kīlauea's 30-year-long eruption, furnishing the following excerpt from the 2010-2012 period in that report.

Summary of 2010-2012. Regarding this interval, Orr and others (2012) made the following comments. "In January 2010 . . . the tube system broke down [enabling lava to escape from the tube] and surface flows began moving toward the east, encroaching on the Kalapana area once again. Three more houses were destroyed between July 2010 and March 2011, when the surface flows faltered.

"2011-2013: History Repeats Itself.

"Pu'u 'O'o began to refill slowly during 2010, and by early March 2011, the crater floor was within 65 feet (20 meters) of the crater's east rim. On March 5, 2011, following rapid summit deflation and increased seismicity, the crater floor of Pu'u 'O'o collapsed. Within a few hours, it had dropped 380 feet (115 meters). Shortly thereafter, lava broke to the surface between Pu'u 'O'o and Napau Crater, marking the start of the Kamoamoa fissure eruption, which was active through March 9. Reminiscent of Kīlauea's 1997 and 2007 East Rift Zone fissure eruptions, the Kamoamoa eruption cut the lava supply to the active tube, causing activity on the flow field to die.

"After 2 weeks of quiet, lava reappeared in Pu'u 'O'o on March 26, and a perched lava lake developed as the crater refilled. In late June, wholesale uplift of the crater floor raised the entire lava lake until its surface was higher than the eastern and western crater rims. Leaks from the "ring" fault bounding the uplifted area resulted in lava overflowing the crater for the first time since 2004, sending flows down the southwestern flank of Pu'u 'O'o. {Note that this is discussed further below.}

"On August 3, 2011, the crater floor of Pu'u 'O'o collapsed again when lava burst through Pu'u 'O'o's west flank, burying the western base of the cone in a massive flood of lava. The floor of the crater dropped 260 feet (80 meters), accompanied by the collapse of large slabs of rock from the crater walls into the resulting pit. The flow on the west side of Pu'u 'O'o diminished greatly after the first several hours but remained active until August 15.

"As in March, lava returned to Pu'u 'O'o within days of the August outbreak, but this time the crater filled quickly. By September 10, lava had begun to overflow the crater again, with flows spilling toward the northeast and southwest. This activity ended on September 21, when the northeastern flank of the cone fractured and lava began pouring out.

"Confined to a shallow valley between older Pu'u 'O'o flow fields, lava turned again toward the volcano's S coast. In March 2012, lava flows destroyed another house-the 214th since 1983-within the now-abandoned Royal Gardens subdivision {approximate location shown in figure 209}.

"Unlike past years, however, eruptive activity throughout 2012 was relatively weak. Lava flows were almost always active on the coastal flow field but failed to make significant forward progress. Finally, in late November, lava reached the coastline for the first time in nearly 11 months, forming a small and sporadic ocean entry. This marked the end to the longest period without an ocean entry since lava first reached the water in 1986.

"As the eruption enters its 31st year in 2013, it is showing no signs of stopping, despite the recent slow down in activity. What Kīlauea Volcano has in store next remains to be seen. Although recent patterns suggest continued activity on the East Rift Zone, this could change abruptly. Even a return to Kīlauea's more explosive past is possible (see USGS Fact Sheet 2011-3064, Kīlauea-an Explosive Volcano in Hawai'i, available at http://pubs.usgs.gov/fs/2011/3064 {Swanson and others, 2011}). What is certain is that Kīlauea will remain an active volcano for millennia to come."

More details on 2010-2012 events. HVO reporting disclosed events presented below (tables 6-8), including a brief summary of 2010-2012 events (table 5), a broad overview of the eruption during 2007-2012 (table 6), and several of the notable collapses during 2010-2011 (table 7).

Table 6. Brief summary of events at Kīlauea during the period 2010-2012. Courtesy of various USGS/HVO reports (periodic, fact sheets, etc.).

Date(s) Event
04 Jan 2010 Cessation of Waikupanaha ocean entry after 22 months
25 Jan-10 Mar 2010 Persistent flow through Royal Gardens and out onto the coastal plain
Feb or Mar 2010 Small collapse of E wall Pu'u 'O'o crater rim
29 Apr-30 Nov 2010 New ocean entries of lava at Ki, Puhi-o-Kalaikini, and 'Ili'ili
May, Jul, and Aug 2010 Portions of N rim of Pu'u 'O'o fall into crater
May-Jun 2010 Lava erupted on S wall and NE side of Pu'u 'O'o crater
Late July, 27 Nov 2010 2 houses destroyed in Kalapana Gardens subdivision
Sep-Dec 2010 Eruption of vent on W edge of Pu'u 'O'o crater
Nov 2010-Feb 2011 Increase in long-term inflation of Pu'u 'O'o crater
2011 East rift zone eruption episodes 58-61 (see Table 6)
Jan, early Feb 2011 Ocean entries at 2 previous areas, Puhi-o-Kalaikini and Ki
17 Feb 2011 House destroyed in Kalapana Gardens subdivision
05 Mar 2011 Beginning of eruption Episode 59 (see table 6); floor of Pu'u 'Æ crater began collapsing; new fissures opened between Napau Crater and Pu'u 'O'o
26 Mar 2011 Beginning of eruption Episode 60 (see table 6); lava filled collapse crater of Pu'u 'O'o and uplifted lake floor
24 July 2011 Lava flow from ring fracture along SW margins of Pu'u 'O'o crater
03 Aug 2011 Lava lake draining through from lower W flank of Pu'u 'O'o; lake completely drained within several hours, leaving a rubble-filled depression ~80 m below its pre-collapse level
20 Aug 2011 Beginning of eruption Episode 61; Pu'u 'O'o refilled and overflowed
21 Sep 2011 Lava broke through the upper E flank of the Pu'u 'O'o cone; Pu'u 'O'o crater subsided ~20 m; flow (Peace Day flow) resulted in a channelized 'a'a' flow to SW
22 Sep 2011 Channelized 'a'a' flow stalled; fissure and open channel crusted over by mid-Oct 2011
09 Dec 2011 Flow reached ocean entry by evening 9 Dec 2011
2012 Peace Day flow continued to be active
Early 2012 Subsidence in Pu'u 'O'o crater continued; outgassing events on crater floor
02 Mar 2012 House in Royal Gardens subdivision destroyed
End of Aug 2012 Deflation phase led to lowering of lava lake beneath Pu'u 'O'o crater ; lava began erupting and filled in NW pit by Sep 2012.

Table 7. An overview of the Kīlauea East Rift Zone (ERZ) eruption during 2007-2012 (eruption episodes 57-61) including (from left) episodes, dates, (approximate in some cases) vent locations, and estimated volume of erupted material. HVO subdivides 30-year-long Pu`u `O`o eruption into episodes. Each new episode denotes vigorous new eruptive activity either from a different vent or commencing after a pause or slowdown. Some episodes are well defined; others more arbitrary. The day and time of various episodes may vary slightly with different instrumentation. The dates in the table signify the duration of the episode or episodes. Courtesy of M. Patrick (USGS) and various USGS/HVO reports.

Dates Episode(s) Vent location Est. volume (km3)
1 Jul 2007-5 Mar 2011 57-58 Crater fill and fissures E of Pu'u 'O'o 0.63
05 Mar-09 Mar 2011 59 Kamoamoa fissures 0.003
26 Mar-15 Aug 2011 60 Pu'u 'O'o overflows and W flank vent 0.04
20 Aug 2011-present 61 Pu'u 'O'o overflows and Peace Day flow 0.15

Table 8. For Kīlauea, a list containing several notable collapses and/or explosive events during 2010-2011. Courtesy of various USGS/HVO reports and Matthew Patrick, USGS/HVO.

Date Time (HST) Notes
11 Feb 2010 1551 Collapse in vent; continuous lava lake started
26 Apr 2010 1409 Collapse in vent; lava lake doubled in size
17 Jan 2011 2311 Series of explosions
21 Jan 2011 1430 Explosion
14 Feb 2011 0908 Series of explosions
15 Feb 2011 0305 Series of explosions
20 Feb 2011 0049 Explosion
03 Mar 2011 1236 Series of explosions
21 Dec 2011 1655 Explosion

30-year long eruption summary comments. Table 9 and figure 210 present general information about the total 30-yr eruption period.

Table 9. Selected eruption statistics for the entire 30-year during 1983 to January 2013. Courtesy of Orr and others (2013) and various USGS/HVO reports.

Feature Statistic
Area covered 125.5 km2
New land on coast 2.02 km2
Volume erupted (dense rock equivalent) ~4 km3
Thickness along coast 10 to 35 m
Pre-1983 area covered in 2012 0.4 km2
Net total of land added to the island (Nov 1986–Dec 2012) 2.015 km2
Coastal highway covered by lava 14.3 km
Structures destroyed 214
Pu'u 'O'o maximum height 255 m in 1987; 171 m in 2012
Pu'u 'O'o crater size 300-450 m

Satellite images. To provide a comparison, NASA Earth Observatory prepared both a natural-color satellite image from 6 June 2011 (figure 210a), and a black-and-white aerial photograph from 25 March 1977 (figure 210b). As the authors noted, the images both show the landscape surrounding Napau Crater and Pu'u 'O'o. Lava flows that are more than a century old are covered by a dense forest of ohia lehua and tree ferns forest (green in the 2011 image). Flows from eruptions in 1965, 1968, and 1969 are much lighter than the forest in the 1977 image, but difficult to differentiate from one another. By comparison, the 2011 image shows profound changes in the landscape.

Weathered lava from the initial Napau Crater vent is almost indistinguishable from the older (1968 and 1969) lavas that cover most of the crater floor. In January 1997, a fresh line of fissures opened within Napau Crater, erupting lava during Episode 54 of the Pu'u 'O'o-Kupaianaha eruption. Additional cracks and fissures split the earth between Napau Crater and Pu'u 'O'o in the March 2011 Kamoamoa Fissure Eruption (Episode 59), spreading black lava through the forest. Scorched forest appears reddish-brown along the edges of the lava flows. Since 9 March 2011, lava flows have originated from Pu'u 'O'o(figure 210a, upper right). A lava pond is visible within the crater, and a system of lava tubes carries molten rock underground to the southeast. Brown lavas surrounding the crater flowed directly from the lava pond.

Figure (see Caption) Figure 210. Two images-a natural-color satellite image from June 6, 2011 (A), and a black-and-white aerial photograph from March 25 (B), 1977-show the landscape surrounding Napau Crater and Pu'u 'O'o. Lavas of different ages cover the surface. Lava flows that are more than a century old are covered by a dense forest (green in the 2011 image) of ohia lehua and tree ferns. Flows from eruptions in 1965, 1968, and 1969 are much lighter than the forest in the 1977 image, but difficult to differentiate from one another. The 2011 image shows dramatic changes in the landscape. Weathered lava from the initial Napau Crater vent is almost indistinguishable from the older (1968 and 1969) lavas that cover most of the crater floor. In January 1997, a fresh line of fissures opened within Napau Crater, erupting lava during episode 54 of the Pu'u 'O'o-Kupaianaha eruption. Additional cracks and fissures split the earth between Napau Crater and Pu'u 'O'o in the March 2011 Kamoamoa Fissure Eruption (Episode 59), spreading black lava through the forest. Scorched forest appears reddish-brown along the edges of the lava flows. Since 9 March 2011, lava flows have originated from Pu'u 'O'o (image upper right). A lava pond is visible within the crater, and a system of lava tubes carries molten rock underground to the southeast. Brown lavas surrounding the crater flowed directly from the lava pond. Images taken from Simmon (2012).

References. Orr, T., Heliker, C., and Patrick, M., 2012, The ongoing Pu'u'O'o eruption of Kīlauea Volcano, Hawai'i-30 years of eruptive activity, U.S. Geological Survey Fact Sheet 2012-3127, 6 p. (URL: http://pubs.usgs.gov/fs/2012/3127/; accessed 15 August 2013).

Simmon, R., 2012, 30th Anniversary of the Pu'u 'O'o Eruption on Kīlauea, NASA Earth Observatory (URL: http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=80091).

Swanson, D., Fiske, D., Rose, T., Houghton, B, and Mastin, L., 2011, Kīlauea-an explosive volcano in Hawai'i, U.S. Geological Survey Fact Sheet 2011-3064, 4 p (URL: http://pubs.usgs.gov/fs/2011/3064/; accessed 15 August 2013).

USGS/HVO, 2012, Kīlauea's east rift zone (Pu'u 'O'o) eruption 1983 to present, 13 April 2012, 14 p. (URL: http://hvo.wr.usgs.gov/kilauea/summary/#Mar2011; accessed 15 August 2013).

USGS/HVO, 2013, Maps, July 26, 2013 - Kīlauea, Kīlauea's east rift zone flow field, web site (URL: http://www.wr.usgs.gov/maps; accessed 15 August 2013).

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/, Daily updates, https://volcanoes.usgs.gov/observatories/hvo/activity/kilaueastatus.php, and Weekly updates, https://volcanoes.usgs.gov/observatories/hvo/volcanowatch/).


May 2014 (BGVN 39:05) Citation IconCite this Report

During 2013, a summit lava lake and lava flows on slopes and into ocean

This report summarizes observations and monitoring data from Kīlauea during January-December 2013; activity during 2010-12 was covered in BGVN 38:05. The primary reporting source was the U.S. Geological Survey-Hawaiian Volcano Observatory (HVO) which provided monitoring and communication resources for the Hawaiian volcanoes, namely Kīlauea, Mauna Loa, Mauna Kea, Hualalai, and Lo`ihi.

2013 Overview. During 2013, Kīlauea's summit lava lake persisted , and lava flows erupted from Pu'u 'O'o. Two minor ocean entries were visible during the year until mid-July; both were branches of the Peace Day flow while, later in the year, two lava flows (Kahauale'a 1 and Kahauale'a 2) extended N-NE from Pu'u 'O'o. Both lava flows crossed into the nearby forest, causing fires and significant smoke along their margins. Petrology of the summit tephra and East Rift Zone (ERZ) did not show significant changes during the year. SO2 emissions from both, the summit and the active ERZ were closely monitored by HVO and those observations led to new innovations in quantifying the flux. HVO reported that SO2 and also CO2 fluxes were relatively low but still above safe levels as established by the Centers for Disease Control and Prevention. Flank deformation and seismic monitoring determined that, although variable conditions were detected, very little accumulated change had occurred at Kīlauea.

Due to the Federal shutdown during 1-16 October 2013, HVO focused on only the most critical operations. Activities that were not directly related to critical operations were postponed, including research and outreach.

One such outreach opportunity that became curtailed was the first Great ShakeOut for Hawai`i which took place on 17 October 2013 and included almost 16,000 participants across all of the islands. This was a large-scale earthquake drill that followed in the tradition of The Great Southern California ShakeOut, which took place in 2008. HVO partnered with the State and County Civil Defense, Center for the Study of Active Volcanoes (CSAV), National Oceanic and Atmospheric Administration (NOAA), University of Hawai`i (UH-Hilo), American Red Cross, and FEMA. HVO staff generated a significant amount of information for the media including several press releases and web content; they also attended preparedness fairs and gave public talks.

Persistent thermal anomalies during 2013. More than 200 alerts per month were released by the MODVOLC program during 2013 for the Big Island of Hawai`i (figure 211). These alerts came from sites around the island that exhibited elevated radiance and were dominated by Pu'u 'O'o and the Kīlauea summit. One exceptional thermal anomaly was a site along the Mamalahoa Highway (Highway 190) in the NW sector of the island. News sources reported that, during 25-26 November 2013, a significant brushfire burned 300 acres in South Kohala. The burn site was near the highway mile marker 14 and caused segments of the highway to close while emergency crews contained the fire.

Figure (see Caption) Figure 211. More than 200 thermal alerts were posted each month in 2013 by the MODVOLC program for the island of Hawai`i. This image captures the thermal alerts registered during January-December 2013. Note the concentration of red-to-yellow thermal alert pixels at the summit of Kīlauea and at the Pu'u 'O'o vent along the E rift that also reached the sea. The anomalous pixel located N of Hualalai (green box) was attributed to a fire that burned near Highway 190 during 25-26 November 2013. Courtesy of MODVOLC.

Summit lava lake activity. "Now in its sixth year, the current summit eruption harks back to the persistent lava lake in Halema`uma`u during the 1800s and early 1900s, suggesting that it has the potential to last for many years" (Patrick and others, 2013). Based on Hawai`i's written record, one earlier summit lava lake occupied Halema`uma`u during 1823-1924.

During 2013, the summit lava lake within the Overlook crater, a nested crater within Halema`uma`u, fluctuated in height, by tens of meters, resulting in perched lava deposits (bathtub rings) and collapse of the crater walls. The crater englarged slightly as a result.

Also, observers frequently noted nighttime incandescence (figure 212). Local webcameras (infrared and visible-light) captured images of the lava lake from the Halema`uma`u Overlook site as well as from the highest point of the HVO facility.

Figure (see Caption) Figure 212. During 2008-2013, an active lava lake resided within the Overlook crater, a feature within Halema`uma`u crater at Kīlauea's summit. A) This shaded relief map indicates where HVO installed a thermal camera (HT cam) to view the entire surface of the lava lake. HVO and the summit tiltmeter (UWE) are 1.9-2.0 km from the lava lake. B) This oblique view is an aerial photo of the SE crater rim of Halema`uma`u. Modified from Patrick and others (2014).

The HT infrared camera occasionally documented crater rim collapse events in 2013. These events were relatively small-sized and tended to occur more frequently when the lava lake level was relatively deep within the Overlook crater (for example, a small collapse occurred when the lava lake was at a depth of ~75 m during 25-26 July 2013). When the lava lake was high, however, the interior walls were subjected to heating and cracking and HVO scientists concluded that collapse events could be triggered during these conditions as well. One collapse event, on 15 November 2013, was likely triggered by slumping due to heavy rain; several Park Rangers observed the event and the collapse was heard by an HVO scientist standing at the Jaggar Overlook (the same location shared with HVO on the crater rim).

A crust of lava had formed an inner rim within the Overlook crater and, on 25 July at 2033, a portion of that rim collapsed into the lava lake (figure 213). The main event was followed by smaller collapses of the deep inner ledge during the following day. Based on webcamera images, explosive events were not triggered by the collapse. HVO reported that, since the formation of the lava lake (March 2008), the largest gas-and-ash emissions from the summit were triggered by gravitational collapses along the crater rim; when rockfalls hit the convecting lava's surface, violent gas release could occur.

Figure (see Caption) Figure 213. These two thermal images were taken before (25 July 2013) and after (30 July 2013) the collapse of the inner rim of Kīlauea's Overlook crater. The inner rim had been constructed during high lake levels in October 2012 (~22 m below the Halema`uma`u crater floor). The webcam (HT cam) was located on rim of Halema`uma`u crater and it captured a new image every ~15 minutes; the temperature scale is in degrees Celsius up to a maximum of 500°C and it automatically scaled based on the maximum and minimum temperatures within the frame. At the time of these photos, the surface of the lava lake was ~75 m below the Overlook crater rim. Courtesy of HVO.

According to HVO, the lava lake level within the Overlook crater generally fluctuated 30-60 m below the rim during 2013. A laser rangefinder was used to obtain regular measurements during the year. Lava was closest to the rim and flooded part of the inner ledge of the crater in January 2013 (an event that also occurred in October 2012). Lava at the flooded lake's margin chilled and reinforced the bathtub-like ring that persisted above the active lava surface (note the "inner rim" in figure 213). In daily online reports, HVO noted: "The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation."

Starting in 2009, HVO scientists noted rise/fall events and determined that the pattern began with decreasing tremor from the summit at a time when lava rose within the lake, spattering would decrease or completely stop, and summit tilt would also decrease. "After a period of minutes to hours, the lava will abruptly drain back to its previous level amidst resumed vigorous spattering, seismic tremor amplitude will increase for a short time (a seismic tremor burst) before resuming background levels, and summit tilt will return to its previous level. Gas emissions decrease significantly during the high lava stand (the plume gets wispy), and resume during its draining phase. Taken together, the geophysical characteristics suggest that, during the high lava stand, lava is puffed up with gas trapped under the lava lake crust."

During 2013, explosive events at the summit rarely occurred; intermittent spattering and degassing dominated summit activity. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas, particularly downwind of the crater (figure 214). The Overlook crater diameter was 35 m in March 2008 and, by the end of 2013, the dimensions had increased to 160 x 215 m. The size increase followed minor explosions and rockfalls from the interior crater walls.

Figure (see Caption) Figure 214. Pele's hair (fine strands of natural glass) continued to accumulate downwind of Kīlauea's active summit crater. A) This photograph from 3 May 2012 was taken looking along the curb of the Halema`uma`u parking lot (closed to the public since the onset of summit activity in 2008), and shows a mat of Pele's hair accumulated on the windward side of the parking curb. Courtesy of Matthew Patrick, USGS. B) On 9 December 2013, a continuous carpet of Pele's hair was observed shining like gold near the Halema`uma`u Overlook trail next to the parking lot. Courtesy of Ben Gaddis, USGS.

Kīlauea's Overlook crater lava lake produced a small explosion during 2148-2149 on 23 August 2013 (figure 215). A portion of the overhanging SE crater rim collapsed and struck the surface of the lava lake. The debris had fallen into an area where nearly persistent spattering had previously been observed. The ensuing explosion generated a plume containing ash, lapilli, bombs (up to 34 cm in diameter), and lithics (ash, lapilli, and blocks up to 10 cm in diameter). The plume deposited material across the Overlook area. The level of the lava lake had been measured as ~38 m below the rim of Halema`uma`u crater earlier that day. Normal conditions prevailed after visibility returned within the camera's field of view at ~2149.

Figure (see Caption) Figure 215. Images captured between 2148 and 2149 on 23 August 2013 by the HT camera (see figure 212 for location) during a small explosion from Kīlauea's lava lake. The thermal images A-D highlight the incandescence that persisted from the lake's surface as well as the hot spatter and debris that exploded after a portion of the inner crater rim fell into the lava lake. Courtesy of HVO.

Pu'u 'O'o and East Rift Zone lava flows. The Pu'u 'O'o eruption consisted of three lava flows during 2013: the Peace Day, Kahauale'a, and Kahauale'a 2 flows (figure 216). The Kahauale'a flows were unique in that they traveled N of the rift zone, unlike the numerous other lava flows that have spread generally toward the ocean (including the Peace Day flow) (figure 217). This activity was considered the continuation of Episode 61, which began on 20 August 2011 and continued through the end of this reporting period (December 2013).

Figure (see Caption) Figure 216. The "spillway"—Pu`u `O`o's eastern flank—has been buried by flows fed mostly from a spatter cone on the NE side of the crater floor. Most of the dark-colored lava in the foreground is new lava that has resurfaced the spillway during the past year. The fume to the left is the trace of the Peace Day tube which carried lava to the coast and had been covered by lava flows from the crater . The tube carrying lava to the NE is inconspicuous, but extends toward the lower right side of the photo. Photo taken on 25 February 2013. Courtesy of HVO.
Figure (see Caption) Figure 217. Geologic map of Kīlauea's East Rift Zone and lava flows from the active vent, Pu`u `O`o. The distribution of lava flows emplaced during 2013 is shaded red (bright red, pink, and red-orange). The yellow lines extending from Pu`u `O`o represent the general path of lava tubes that directed the flows Peace Day, Kahauale'a 1, and Kahauale'a 2. Changes to the surface area of the Kahauale'a 2 and Peace Day flows are shaded bright red, corresponding to activity during 19 September-26 December and 19 September-2 November 2013 respectively. Note that Kahauale'a 1 was active during 19 January-17 April 2013. Courtesy of HVO.

The morphology of Pu'u 'O'o crater was relatively stable through 2013. The crater remained very shallow and at or near the level of the original E spillway rim (figure 216). There were four spatter cones, all consistently active and often exhibiting incandescent openings at their tops (figure 218). These cones also emitted gas-jetting sounds and occasional, effusive spattering. The main center of activity through the year was the NE spatter cone. This cone often hosted a small lava pond and served as the vent for the Kahauale'a and Kahauale'a 2 flows.

Figure (see Caption) Figure 218. A small lava lake, several meters in diameter, had persisted for nearly a year on the NE side of the Pu`u `O`o crater. The lake was perched several meters above the surrounding crater floor (seen behind the topographic high, shrouded in steam). The feature was near the top of a mound of lava composed of spatter cones and lava lake overflows. Flows from the lake and other nearby spatter cones had inundated the E rim of Pu`u `O`o's crater, which would normally be visible in the background just behind the area seen here. Photo taken on 31 January 2013. Courtesy of HVO.

In late 2012, Pu'u 'O'o crater was slowly infilling, and by the beginning of 2013, lava from the NE spatter cone reached the E spillway rim. A dramatic inflation event in mid-January triggered numerous overflows from the NE spatter cone, and the SE cone spread more lava across the crater floor but also sent flows over the E spillway. On 19 January, an overflow from the NE spatter cone sent lava down the E spillway in what would become the Kahauale'a flow. Over the next month, overflows from the cone covered much of the E spillway. Inflation in late April correlated with abundant venting and more overflows from four cones on the crater floor, with some spilling out toward the E, adding to the recent flows mantling the upper E flank of Pu'u 'O'o (figure 219). After the Kahauale'a flow eventually stalled in April, overflows in early May from the NE spatter cone fed a new flow, following the same course; this became the Kahauale'a 2 flow. Small overflows occurred sporadically from the cones through the remainder of the year, with larger events in mid-August and mid-November.

Figure (see Caption) Figure 219. This thermal image of Pu`u `O`o was captured on 27 November 2013. The SE and NE spatter cones had produced small flows that extended out of the crater, shown clearly here by their warm temperatures. The vent for the Kahauale`a 2 flow is at the NE spatter cone, and the lava tube supplying the Kahauale`a 2 flow is obvious as the line of elevated temperatures extending to the lower right corner of the image. The distance between the black scarps is ~ 300 m. Courtesy of HVO.

Coastal plain lava flows and ocean entries. The Peace Day flow (episode 61b) began on 21 September 2011, and it was active for much of 2013 before ceasing in November 2013. This lava flow reached the sea and generated scattered, branching flows (breakouts) on the coastal plain, as well as several isolated breakouts above the pali (fault scarp).

The ocean entry consisted of two main entry points during 2013, with an E entry at Kupapa`u (just E of the Park boundary) and a smaller, weaker entry immediately to its W (within the Park). These entry points were not vigorous; there were little-to-no-observed littoral explosions; a delta formed that extended several meters out from the sea cliff (figure 220 A).The view from the E margin of the Peace Day flow field on the sea cliff was relatively good, and the ocean entry provided a destination for guide services (not all sanctioned) operating out of Kalapana (numerous, possibly over 100 tourists made the hour-long walk out to the site each evening). As activity on the coastal plain declined in the summer, the W entry shut down in mid-July; the E entry ceased on 21 August.

Figure (see Caption) Figure 220. Thermal images have helped HVO geologists map Kīlauea's lava tube system. (A) This thermal image from 27 June 2013 shows Kīlauea's E ocean entry (spanning ~ 1 km along the shore) at Kupapa`u Point. Just inland from the entry point a patch of slightly warmer temperatures indicates an area of recent small breakouts. Inland from this warm patch you can see a narrow line of elevated temperatures that traces the path of the lava tube beneath the surface that is supplying lava to this ocean entry. Two plumes of higher temperature water (~50°C in areas close to the ocean entries) spread out from the entry point. Courtesy of HVO. (B) This image shows the Peace Day lava tube coming down the pali in Royal Gardens subdivision on 24 May 2013. The lava tube parallels Ali`i avenue (see figure 217 for the location of Royal Gardens), shown by the straight line of warm temperatures that represent asphalt heated in the sun. This tube feeds lava to the ocean entry and breakouts on the coastal plain. There is no active lava on the surface in this image - the warm surface temperatures are due to heating by the underlying lava tube. Courtesy of HVO.

Most of the Peace Day flow activity during 2013 was constrained to the coastal plain. From January through August, the coastal plain featured episodic of breakouts near the base of the pali in Royal Gardens. Those branches from the main flow slowly migrated toward the ocean before halting on the coastal plain (figure 220 B). Eventually, another breakout occurred at the base of the pali and sent out another flow that presumably drained supply from the previous flow. The new flow reached the location of the stagnating previous flow, and the flows became an indistinguishable mix of small, scattered breakouts in the middle of the coastal plain (figure 221). Minor, scattered breakouts were common on the coastal plain during January-August. Activity levels declined by August, the ocean entry diminished, and the last coastal plain flows ended around 8 September. With no ocean entry or surface flows, the coastal plain (and Kalapana-based lava tourism) became quiet again.

Figure (see Caption) Figure 221. Lava flows from Pu'u 'O'o consisted of only a few scattered breakouts near the shoreline on 18 January 2013, with most of the activity focused on the coastal plain closer to the base of the pali. This pahoehoe lobe (~1 m wide) was active near the E margin of the Peace Day flow field just a few hundred meters from the coastline. Courtesy of HVO.

Lava flow activity above the pali. From mid-January to the end of May 2013, a large amount of lava escaped the Peace Day tube to create a divergent flow above Royal Gardens. It did not advance very far until April, when it crept slowly downslope into the upper reaches of Royal Gardens. This breakout flow ceased on 30 May. As the coastal plain breakouts progressively decreased during September, two small flows appeared above the pali, presumably resulting from the abandonment of the lower Peace Day lava tube. The smaller of the two breakouts was at the top of Royal Gardens, about 6 km from Pu'u 'O'o, and appeared to start between 7 and 14 September but was inactive by mid-October (timing was determined in large part by satellite images as opposed to direct observation). This small breakout flow was visible from the Kalapana lava-viewing area.

The larger of the two breakouts began around 5 September and was about 3 km SE of Pu'u 'O'o, advancing a little over a kilometer before stalling. This breakout was active until 7 November, when it and the rest of the Peace Day flow stalled. This wasn't the end, however, and the Peace Day flow gasped a final breath when a very small, brief breakout occurred on the upper Peace Day lava tube, near Pu'u Halulu, on 15 November. It was probably active for only minutes or hours and marked the end of the Peace Day flow.

The Kahauale'a flow (episode 61c) began as an overflow from the NE spatter cone on 19 January 2013, occurring simultaneously as Kīlauea inflated. It advanced down the NE flank of Pu'u 'O'o, N of the Peace Day tube, until it hit flat topography N of the cone where it developed a lava tube and covered early Pu'u 'O'o 'a'a flows. The flow consisted of scattered pahoehoe lobes, and these migrated slowly (~50 m/day) E toward Kahauale'a cone, reaching it in mid-February (figure 222). From there, it followed the N margin of an earlier flow emplaced during the episode 58 flow. The path of this new flow abutted the steep northern slope of the 2007-2008 perched lava channel. This confinement led to a narrowing of the advancing flow front, resulting in increased advance rates (>100 m/day) in early March. As the front passed the perched channel, it became less confined, and advance rates dropped to under 50 m/day. By the first week of April, the flow had reached 4.9 km from the vent on Pu'u 'O'o but ceased on 17 April during a deflation-inflation (DI) event (see figure 199 in Bulletin 38:02 where DI events are illustrated). Due to infrequent overflights by HVO scientists during 2013 (resulting from budget cuts), staff relied heavily on satellite images--particularly EO-1 Advanced Land Imager images--to track the advance of the flow.

Figure (see Caption) Figure 222. Kahauale`a Cone, a local topographic high several hundred meters long, has long been a small oasis of vegetation in the midst of Pu`u `O`o lava. This photo from 19 March 2013 shows new lava from the active Kahauale`a flow surrounding the cone, which has also partly burned. Vent structures (such as episode 58, active from 2007 to 2011), are in the background just behind Kahauale`a. Pu`u `O`o is out of sight to the right. Courtesy of HVO.

HVO noted that the Kahauale'a flow was unusual in that the most recent flows from Pu'u 'O'o traveled S toward the ocean, providing minimal threat to residential areas. The Kahauale'a flow, however, was directed N of the rift zone, along a NE trend. This put the flow on a downslope trajectory that could have threatened residential areas of including Ainaloa and Paradise Park. HVO and Hawai'i County Civil Defense increased their communications through that time period but just a few weeks later, in mid-April, an abrupt change in magma supply occurred at Pu'u 'O'o and the flow ceased.

Inflation at Pu'u 'O'o produced another overflow from the NE spatter cone, which started on 6 May. This became the Kahauale'a 2 flow (episode 61d) and was directed slightly more to the N by the original Kahauale'a flow, reaching the forest boundary ~2 km NW of Pu'u 'O'o in early June. These flows invaded the forest a short distance and created steady forest fires. During July, the flow front took a more northeasterly course, following the N margin of the original Kahauale'a flow (figure 223). Its advance slowed during late July to mid-August, but during September the advance increased when the flow entered the previously mentioned narrow channel along the episode 58 perched lava channel.

Figure (see Caption) Figure 223. (top) A photo taken looking W from a helicopter on 19 September 2013 of the burning forest due to Kīlauea's Kahauale`a 2 flow (approximately 7 km long). This lava flow extended from Kīlauea's Pu'u 'O'o NE vent. Active breakouts on the Kahauale`a 2 were scattered over a broad area. Here, a breakout near the edge of the forest engulfed trees and burned dead foliage. Courtesy of HVO. (bottom) The flow front of the Kahauale`a 2 flow cut a narrow swath through forest NE of Pu`u `O`o. The narrow lobe at the front was inactive at the time of this photo on 27 November 2013, with the main area of surface flows about 2 km behind the end of this lobe. Some of these surface flows slowly expanded N into the forest, igniting fires. Pu`u `O`o is in the upper left, ~7 km SW. Courtesy of HVO.

By mid-October, Kahauale'a 2's narrow flow front had reached the distant forest boundary and surpassed the length of the original Kahauale'a flow. A narrow finger of lava forming the flow front advanced into the forest in mid-November, reaching just over 7 km distance from Pu'u 'O'o, before stalling soon after 20 November. Behind the flow front, branching flows began to migrate along a more northerly direction into the forest, triggering more fires. This area of breakouts soon turned NE, paralleling the narrow finger that had stalled in late November. By 26 December, the active flow front was 6.3 km NE of the vent and persisted into the New Year.

Petrology of the summit (Halema`uma`u) and rift (Pu`u `O`o) lavas. From 2013 to 2014, the juvenile component of Kīlauea's summit tephra remained essentially as it had during 2008-2013. The overall temporal variation of summit lava mimicked the MgO systematics of ERZ lava for the 2008-2014 interval, with summit glass compositions overlapping those of contemporaneous bulk ERZ lava but erupting 20° to 25°C hotter than at Pu'u 'O'o. There were no changes in trace-element signatures, which matched those of the East Rift Zone (ERZ) lava. Halema'uma'u vent tephra remained sparsely olivine and spinel phyric with ~2 volume percent of 100-300 μm, subhedral to euhedral olivine phenocrysts (typically with melt inclusions). Olivine in summit glasses was consistently complemented by >0.05 volume percent of chromian-spinel microphenocrysts.

2013 Pu'u 'O'o lava also did not show any significant petrologic changes. It contained a five-phase assemblage: olivine(-spinel)-augite-plagioclase-liquid. The assemblage was interpreted as the result of simultaneous growth and dissolution of phenocrysts, reflecting the modeled values for cooling, fractionation, and mixing in the shallow edifice prior to eruption. This multi-phyric condition (see figure 224 for photomicrograph examples from previous years), which had persisted in the steady-state ERZ lava for most of the last ~15 years, attested to a stable shallow magmatic condition perpetuated by near-continuous recharge and eruption.

Figure (see Caption) Figure 224. Two photomicrographs of Pu'u 'O'o thin sections sampled by HVO scientists from vent (a) and lava tube activity (b) during 1996-1998 (100 μm = 0.1 mm). Both show glass containing olivine phenocrysts with melt inclusions and opaque microphenocrysts of spinel. Image B shows an olivine phenocryst and spinel microphenocrysts in glass with round vesicles (one is located behind "b"). Modified from Roeder and others (2003).

SO2 emission rates. During 2013, HVO reported notable advances in measuring the dense, opaque summit SO2 plume. It was significant to note that the summit SO2 emission rates measured since 2008 represented a minimum constraint on emissions, whereas by the end of 2013 it was possible to determine a more accurate estimate of the amount of gas emitted from the Overlook crater. Because traditional gas measuring techniques are subject to multiple scattering effects from incoming radiation that can contribute to significant errors in the calculated SO2 emission rates, HVO scientists were pursued various approaches to achieve a more accurate emission rate.

HVO scientists addressed the issue of underestimation due to scattered light in two ways: (1) minimize and/or model the effects of scattering on the retrieved results and (2) measure farther away from the emission source where the plume is more dispersed and not as optically thick.

Using HVO's old metric for evaluating SO2 summit emissions, the total SO2 released in 2013 was first calculated as 266,000 metric tons. They had long recognized these value as among those that had persistently understated the true mass of SO2. To account for the summit emission rate underestimation, they used an initial preliminary correction. It was based on early Simulated Radiative Transfer- Differential Optical Absorption Spectroscopy (SRT-DOAS) values. This refinement increased the summit's traditional estimate 3-fold, yielding a summit total SO2 amount of ~800,000 metric tons for the year 2013.

HVO further reported a preliminary calculation of Kīlauea's 2013 summit emissions using their available Flyspec array data yielded ~1.0 x 106 metric tons for 2013. This was judged more accurate value for the total summit SO2 release.

East rift zone (ERZ) emissions for 2013 continued at the low level recorded since mid-2012. Early in the year, SO2 emissions increased coincident with the occurrence of the Kahauale'a lava flow, but emissions stabilized several months later and continued at a low level for the balance of the year. Rift emissions were consistently less than those at the summit for 2013 totaled ~113,000 metric tons (using the refined methods mentioned above). This was ~20% less than reported in 2012, and the lowest amount recorded since the ERZ eruption began in 1983. The low SO2 emissions from the ERZ were at least partially due to degassing at the summit.

Summit CO2 emission rates. During 2013, CO2 emission rates remained at the relatively low level measured since approximately 2009 (figure 225). The continued absence of a strong CO2 signature in 2013 confirmed that the current summit activity reflects shallow reservoir processes rather than deeper ones. All CO2 measurements in 2013 were made with the Licor LI-6252 gas analyzer.

Figure (see Caption) Figure 225. Daily average CO2 emissions from the summit of Kīlauea, as measured under trade-wind conditions, during 2003-2013. The vertical bars represent standard deviations of all traverses on a single day. The cyan symbols show CO2, calculated using filtered data to more confidently bracket CO2 emission rates. The black squares are raw CO2 area-count averages; these values provide a measure of CO2 independently of the C/S ratio and SO2 emission rates by accounting for the area traversed through the plume and integrating that area by gas concentration magnitudes (this method also takes into account the plume direction and speed). CO2 values were calculated without any correction to underestimated SO2 emission rates. Courtesy of HVO.

Quantifying summit and rift plume characteristics. In addition to emission-rate studies, HVO continued to monitor the summit and rift plumes using a variety of techniques, including multi-species sensor-based time-series measurements and open-path FTIR. In 2013, FTIR measurements of the summit plume reconfirmed the shallow nature of the degassing source, with plume chemistry characterized by low CO2, high SO2, high H2O, and significant HCl and HF (table 10). Measurements of the summit and rift plumes yielded similar chemistry, suggesting a common source for these gases. Also reconfirmed in 2013 were the previously observed short-term changes in gas chemistry correlating with behavior in Overlook crater.

Table 10. The composition of Kīlauea's summit plume for 2013 reported in moles and mole%. Courtesy of HVO.

Gas species moles mole%
H2O 1,117.98 88.23
SO2 81.46 6.43
CO2 64.69 5.11
HCl 1 0.08
HF 1.17 0.09
CO 0.84 0.07
total moles 1,267.14 100

Gas hazards. In 2013, the maximum ambient concentration of SO2 measured near the summit along Crater Rim Drive during traverses made with a car was 150 ppm, a value well above the IDLH (Immediately Dangerous to Life and Health) threshold. Concentrations measured inside the vehicle reached a maximum of 12 ppm. The inside-car levels were measured with all air-handling turned off, the operating conditions that minimize SO2 penetration into the vehicle. Fumarole sampling at the two locations on the rim of Halema'uma'u were subsequently paused during 2013 while shifting to alternative, less-hazardous measurement techniques.

HVO continued to operate the low-resolution SO2 sensor and rain collector network on Kapapala Ranch in 2013 (within 23 km SW of the summit). In general, maximum SO2 concentrations on the Ranch in 2013 were lower than in 2012. During the early years of the activity at the Overlook vent, the Ranch's livestock exhibited runny eyes, respiratory issues, weight loss, and tooth mottling and degradation (possibly indicating fluorosis). Additionally, fences and other metal infrastructure on the ranch had been deteriorating more rapidly than before the summit eruption began. New data showed SO2 one-minute values for 2013 (a single, one-second measurement per minute) up to 4 ppm. Hazard monitoring and communication with the ranch operators, veterinarians, and public health officials remained ongoing.

Ambient SO2 concentrations measured downwind of Halema'uma'u continued to reach very high levels (~150 ppm) along Crater Rim Drive near the Halema'uma'u parking lot, warranting continued caution along Crater Rim Drive in 2013. HVO scientists maintained communications with community groups and county, state, and federal agencies in order to relay the changing gas-hazard conditions associated with Kīlauea's ongoing eruptions.

In 2013, the National Park Service's (NPS) ambient air quality stations located at HVO and behind the Kīlauea Visitor Center continued to record periods of hazardous air quality resulting from the ongoing eruptions. The National Park continued to close the highly impacted areas of the park during poor air-quality episodes. Closing of park locations, including Kīlauea Visitor Center and Jaggar Museum, were based on the following criteria: a Visitor Center is closed when SO2 concentrations exceed 1 ppm for 6 consecutive 15-minute periods (1.5 hrs), 3 ppm for 3 consecutive 15-minute averages (45 minutes), or 5 ppm for one 15-minute average. NPS high-resolution SO2 analyzers located at the visitor centers operated in the extended 0-10 ppm range.

Flank deformation. The variable-rate inflation of Kīlauea that has been ongoing since 2010 continued through 2013. There were periods of slight deflation in March-May, late May, July-August, and September and November. The saw-tooth pattern created by the alternating inflation and deflation is most obvious in the distance change across the Halema'uma'u crater, but can also be seen in the tilt record at summit tiltmeters, such as at station UWE and subtly in the vertical changes at summit GPS sites (figure 226).

Figure (see Caption) Figure 226. (A) Radial tilt measured by borehole instruments at the summit (UWE) and at Pu'u 'O'o (POC) in 2013. Positive change indicating tilt away from the most common magmatic sources, usually indicating inflation, and negative change indicating tilt towards those sources, usually indicating deflation. (B) Changes in distance across Halema'uma'u (UWEV-CRIM) and elevation of GPS stations (HOVL V and OUTL V) from July 2012 through July 2013. Courtesy of HVO.

During 2013, there was a total of almost 10 cm of extension on the approximately 3.5-km baseline between UWEV and CRIM (figure 226 B) and about 10 microradians of inflationary tilt at UWE (figure 226 A). There was very little accumulated vertical change at the summit GPS sites over the year, however. This was also reflected in the lack of appreciable line-of-sight displacement in the interferograms from INSAR spanning 2013. There were 65 deflation-inflation (DI) events in 2013, similar to the rate of occurrence observed since the opening of the summit vent in 2008. Most of these were only weakly detected by the POC tiltmeter at Pu'u 'O'o.

At Pu'u 'O'o, the GPS site on the N rim (PUOC), recorded a fairly steady, slow rate of N-NW motion in 2013, with a slight acceleration in late April-early May. The direction of motion is usually indicative of inflation, but there was no appreciable uplift at the site. There was a net tilt of about 20 microradians to the NW at POC on the N flank, also usually indicative of inflation.

The pattern and velocity of GPS sites on the S flank of Kīlauea in 2013 were similar to the patterns and rates that have been observed in the recent past during times free of slow-slip events and ERZ intrusions.

Deformation monitoring equipment. Two continuous GPS sites (LEIA and SPIL) were lost to lava flows from Pu'u 'O'o in early 2013. After a data outage at the Malama Ki (MKI) tilt site on the lower ERZ in April, HVO discovered that thieves had dismantled the gate to the security enclosure and stolen everything except the actual tiltmeter. This had been part of a string of thefts at this site, forcing HVO to eventually abandon it. This was an unfortunate loss to the monitoring network, especially because the only other tiltmeter station on the lower ERZ, near Heiheiahulu (HEI) had also been stolen late during the previous year. In July, HVO installed a new tiltmeter in a less accessible location a few kilometers NW of Heiheiahulu.

Seismicity. In 2013, HVO's seismic network consisted of 57 real-time continuous stations (25 broadband, 21 strong-motion, 7 three-component short-period, and 25 vertical-component short-period instruments) (figure 227). The network coverage was most dense on and around Kīlauea. In 2013, HVO upgraded of the seismic network which involved installing the digital stations NAHU (to replace the analog station ESR) and TOUO (to replace analog station KII). They also established three arrays of infrasound sensors in order to better track acoustical waves in the air (infrasound) associated with volcanic processes.

Figure (see Caption) Figure 227. (top) Authoritative region of HVO (black line). Red triangles represent permanent, continuous seismic stations and Netquakes instruments, a new type of digital seismograph that transmits data to USGS via the internet after an earthquake. Stations from the National Strong-Motion Program (NSMP) are excluded here because their high triggering threshold means that they produce data for only a handful of earthquakes a year. (bottom) Map showing both HVO stations (red triangles) and Netquakes (blue triangles). Two boxes indicate regions of special interest for seismic monitoring. Netquakes instruments enable the USGS to achieve a "denser and more uniform spacing of seismographs in select urban areas. … The instruments are designed to be installed in private homes, businesses, public buildings and schools" (USGS, 2013a). Courtesy of HVO.

Seismic activity at Kīlauea was generally low in 2013 compared to that of other time periods since the 2008 start of the summit eruption (figure 228). Tremor was a ubiquitous feature of the seismicity near the summit, with discrete very-long-period (VLP) and long-period (LP) events occurring sporadically. Tremor amplitudes appeared to modulate in conjunction with the presence or absence of spattering in the lava lake within Halema'uma'u. In general, increased seismicity in the S caldera and upper ERZ were coincident with rapid increased lava lake level and tilt. None of these swarms were remarkable in number or size compared to previous swarms, especially those in 2011 and 2012.

Figure (see Caption) Figure 228. (A) January-December 2013 earthquake locations, Hawai'i Island, 0-60 km deep, M ≥ 3.0. Earthquake colors are based on depth. The symbol size of the earthquake is based on the preferred magnitude. All plotted earthquakes have been reviewed by an analyst. (B) January-December 2013 earthquake locations, Hawai'i Island, 0-5.0 km deep (shallow), M ≥ 2.0. Earthquake colors are based on time. Symbol sizes are based on the magnitude. Plotted events include both reviewed and automatically determined locations that have horizontal errors < 2 km and vertical errors < 4 km. Courtesy of HVO.

New interactive earthquake webpage launched. In October 2013, HVO launched a new interactive earthquake webpage, informally called Volcweb (USGS, 2013b). The new website used several new technologies that provided a better user-experience and a better compatibility with mobile devices. In addition to providing earthquake location information, the site also creates cross-sections, time-depth plots, cumulative number of earthquake plots, and cumulative magnitude plots for data up to a year old. Webicorders for all stations were available (updated every 10 minutes). The rollout of this website allowed HVO to retire the old "Recent Earthquakes" page.

References. Patrick, M., Orr, T., Sutton, A.J., Elias, T., and Swanson, D., 2013, The first five years of Kīlauea's summit eruption in Halema'uma'u crater, 2008-2013. Hawai`i National Park, HI: U.S. Geological Survey, Hawaiian Volcano Observatory, Fact Sheet 2013-3116.

Patrick, M.R., Orr, T., Antolik, L., Lee, L., and Kamibayashi, K., 2014, Continuous monitoring of Hawaiian volcanoes with thermal cameras, Journal of Applied Volcanology, 3:1.

Roeder, P.L., Thornber, C., Poustovetov, A., and Grant, A., 2003, Morphology and composition of spinel in Pu'u 'O'o lava (1996-1998), Kīlauea volcano, Hawaii. Journal of Volcanology and Geothermal Research, 123, 245-265.

USGS, 2013a (January). Earthquake Hazards Program, Netquakes: Map of Instruments. Retrieved from http://earthquake.usgs.gov/monitoring/netquakes/map/.

USGS, 2013b (December). Hawaiian Volcano Observatory, Recent Earthquakes in Hawaii. Retrieved from http://hvo.wr.usgs.gov/earthquakes/new.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai`i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Hawai`i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai`i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/); Hawaii 24/7 (URL: http://www.hawaii247.com); Great ShakeOut (URL: http://shakeout.org/hawaii/); and West Hawaii Today (URL: http://www.westhawaiitoday.com/).


September 2014 (BGVN 39:09) Citation IconCite this Report

1 January-26 June 2014: Waning stages of the Kahauale'a 2 lava flow

This report, taken largely from Hawaiian Volcano Observatory (HVO) reporting in their Daily Updates, weekly (Volcano Watch) articles, and online photo galleries, covers 1 January to 26 June 2014. Links to the HVO website appear in the Information Contacts section. The daily and weekly publications both feature online retrieval of older publications. This several page report condenses at least 400-1,000 pages of HVO reporting dedicated to this ~6 month reporting interval. Three observations stood out within this period.

1. Lava emissions persisted. On 3 January 2014 the current eruption surpassed 31 years in length; it had emitted just over 4 km3 of lava, had covered 128 km2 of land, and had destroyed 214 structures.

2. The lava flow of note during this interval was the Kahauale'a 2 flow, which had started in May 2013 (BGVN 39:05). That flow had, during April-June 2014, advanced erratically and HVO Daily Updates declared it inactive ("cutoff and dead") at or near the end of June. (A day after this reporting interval ended, a new flow later emerged adjacent to the Kahauale'a 2 flow. The new flow that emerged on 27 June 2014 became informally named by that date. That flow will be discussed in our next Bulletin report.)

3. The Kahauale'a 2 flow did not advance in the usual southerly direction nor did lava emerge from tubes at the sea, thus there was an absence of lava entering the ocean. Instead the flows during this reporting interval advanced to NE.

Many of the typical observations associated with the three-decade-long eruption persisted. Those typical events included the following:

• Advancing lavas developed new areas of flowing molten material ('breakouts'), which sometimes occurred at the margins of flows and advanced to enter vegetated areas where they started fires.

• The circulating lava lake that has resided at the summit area in Overlook crater since 2008 rose and fell during this reporting interval with several cases of the lake's surface reaching above the inner ledge at ~31-m depth below the Halema'uma'u crater floor. High stand for the lava occurred on 29 April 2014 at 30 m depth; the low stand, on 21 and 22 January 2014 at 69-70 m depth.

• Overlook crater also emitted products such as ash, spatter, and Pele's hair (glass strands or fibers).

• Emissions of gas and particulate at Overlook crater and at Pu'u 'O'o vent remained sufficiently elevated to pose downwind health considerations on many days. At closer range, in areas within 1 km downwind of vent areas, there could be potentially lethal concentrations of sulfur dioxide (SO2) gas.

• Observers noted glow in a variety of settings, including at cones, vents, flows, breakouts, and from lava thrown into the air. For one illustrative example of many sources of glow on the crater floor at Pu'u 'O'o, on 21 May 2014 glow was observed from the N, S, SE, and NE spatter cones there.

• Deformation-inflation events (sudden reversals in tilt lasting on the order of days) have dominated the tilt measurements since 2008. This pattern continued at both Halema'uma'u and Pu'u 'O'o.

Background. A colored sketch map emphasizing Kīlauea's main features appears on figure 161 in BGVN (29:02). The vents in this reporting interval were Halema'uma'u and Pu'u 'O'o, with the former containing a lava lake and the latter the only significant source of lava flows. As noted by HVO, the (first) Kahauale'a flow started from the NE spatter cone and lava pond at the NE edge of the Pu'u 'O'o crater floor in mid-January 2013; it ceased advancing and become inactive by middle to late April 2013, having advanced 4.9 km NE. A new flow (informally called Kahauale'a 2) began venting at Pu'u 'O'o in early May 2013 (BGVN 39:05).

Although NE-advancing lavas have been uncommon during the current 31-year-long eruption, a Volcano Watch report issued on 24 April 2014 noted that lava also flowed NE from Pu'u 'O'o episodically in 1983–1986 and for four months in 2007.

Overlook crater lies within Halema`uma`u crater, itself within the larger (roughly 4- by 2-km diameter) Kīlauea caldera (often also termed the summit caldera). Both of the volcano's rift zones intersect in the summit region (figure 161). The E rift zone extends over 100 km E and the W (or SW) rift zone at least 30 km WSW (figure 161).

The focus of most of the venting of lava at the surface has in recent years been from the E rift zone, most recently Pu'u 'O'o.

In the past, ocean entries (lava flowing into the sea) often resulted from lava that traveled from Pu'u 'O'o. In some cases the lava traveled extensive distances via lava tubes (see "lava tube" on simplified cutaway view at right on figure 161). Lava entering the sea ceased in August to September 2013 (BGVN 39:05) and as previously mentioned, ocean entries were absent during this reporting interval.

1 January to 26 June 2014. Both Halema'uma'u and Pu'u 'O'o were the subject of daily reports discussing the sometimes elevated levels of gases and particulates emerging from those craters and negatively affecting air quality (figure 229, top). Access close to the Halema'uma'u vent is potentially hazardous, resulting in closure of road, trail, and similar public access (figure 229, bottom).

Figure (see Caption) Figure 229. (top) Photo taken from the NE rim of Kīlauea caldera showing a billowing gas and condensate plume emerging from Halema'uma'u crater. The photographer captured this scene from the overlook by the Volcano House at 0625 on 30 January 2014. (bottom) Map of the Kīlauea summit caldera area. Note Halema`uma`u and the pit crater within it, Overlook crater. Overlook crater is indicated by the red area representing this crater-confined molten lava lake. The lake has been mostly active since invading the pit crater during a small explosive event in 2008. Overlook crater is cylindrical, vertical walled, and ~160 m in diameter. The lava lake's surface has varied in height, with distances below the rim ranging from 25 m to over 200 m (out of sight) below Halema`uma`u 's floor. Notice road and trail closures owing to high gas emission levels. Credits: (top) National Park Service photo posted online at their website (photographer not acknowledged). (bottom) HVO.

On their website, the Hawai'i Department of Health furnished general comments on air quality from Kīlauea's eruption. "An 'N95 type' disposable dust/particulate mask plus eye protection (goggles/safety glasses) will provide protection from ash and reduce exposures to particulates, but will not provide protection from SO2 or other gases. Many people may find it difficult to breathe while wearing a dust/particulate mask and should not use one. The safest way to eliminate exposure to significant levels of volcanic particulates, vog, or gases such as SO2 is to leave the area. The [Department of Health] maintains stationary ambient air quality monitors that measure SO2 and fine particulate levels in Hilo, Kona, Mountain View, Ocean View, Pahala, and Puna E (SO2 and [H2S,] hydrogen sulfide) on the Island of Hawai'i." (Hawai'i Department of Health, 2013).

Kroll and others (2015) discuss the atmospheric evolution of volcanic smog ("vog") from Kīlauea's summit area with measurements of oxidation, dilution, and neutralization within the volcanic plume based on sampling nearby and directly downwind 31 km SW of Halema'uma'u crater. Sampling dates did not appear in their abstract. The abstract noted that "The particles within the plume were extremely acidic, with pH values (controlled largely by ambient relative humidity) as low as −0.8 and strong acidity (controlled largely by absolute sulfate levels) up to 2200 nmol/m3."

SO2 flux data were extracted from HVO Daily Updates for the interval 24 December through 24 June 2014. Overall, SO2 fluxes at Halema'uma'u yielded values in the range 1750-7400 metric tons (tonnes) per day (t/d). Overall, fluxes for Pu'u 'O'o and associated E rift zone sources of degassing yielded values in the range 150-450 t/d. This is consistent with HVO statements in May Daily Updates that these fluxes "typically ranged between 150 and 450 t/d since July 2012."

HVO emphasized the following caveat. "Starting in 2014, [HVO began reporting] the emission rate estimated by a new, more accurate method. The numbers increase by a factor of 2-4 but the actual emission rate has not changed." The 19 December 2013 issue of Volcano Watch briefly described the methodology to that point in time (2013) as changing from a vehicle-based upward looking observation platform to a fixed-array technique. Further details await more detailed discussion by the authors for further context on the data collected after the article in order to elucidate the 24 December 2013 to 24 June 2014 dataset.

Volcano Watch regularly contains a subsection on Kīlauea's recent behavior. The Kīlauea section in the 2 January 2014 issue of Volcano Watch made these statements: "Unless there is a significant change at Pu'u 'O'o, the Kahauale?a [2] flow poses no imminent threat to infrastructure, but will likely continue advancing toward the [NE], burning forest as it does. It could eventually reach communities far downslope, but fortunately, the East rift zone eruptive output remains weak. At its current pace, the Kahauale?a [2] flow would take more than a year to reach populated areas."

The Kahauale?a 2 lava flow had reached 8.3 km NE of Pu'u 'O'o on 9 April 2014. Some metrics on the advance appear in a table below. As alluded to above, even early in the year 2014 the pace of advance was considered slow. In discussing the slow pace, the 6 June Daily Update said that the flow front had not advanced more than 1.8 km since the first time it stalled in early November 2013.

HVO's website contained maps depicting flow position and breakouts. HVO noted that most of the active flow field lay within closed-access areas thus restricting the public's direct viewing at close range to aerial approaches. Under clear weather conditions at night, distant glow from the active flows could be seen from favorable vantage points.

Figure 230 shows the Kahauale'a 2 flow's position at three points during 2014: (top) 24 January, (middle) 18 April, and (bottom) 6 June. These cases are each discussed further after the figure.

Figure (see Caption) Figure 230. The Kahauale'a 2 lava flow as mapped by USGS-HVO scientists at three dates: (top) 24 January, (middle) 18 April, and (bottom) 6 June 2014. Significant breakouts are indicated as red stars or red areas. Inferred lava tube feeding the flow is shown as a yellow curve. Topographic constraints channeled the flow NE, an uncommon direction of advance. Areas covered by the more typical direction of advance for the E rift zone lavas during the past 31 years, progressing to the S, appear as a broad swath of unlabeled gray or colored areas on the maps. Courtesy of HVO.

For the 24 January flow geometry the active area of breakouts (depicted in red on figure 230) were chiefly at the distal end. The Daily Update for the 24th reported the approximate linear distance for the total flow length from the vent at Pu'u 'O'o to the flow extreme at 7.5 km. That distance had been measured from a satellite image taken on 17 January.

For the 18 April flow geometry, the map lacks breakouts. As with the other two maps we see an inferred lava tube (in yellow) for that point in time. The flow front had remained fixed during the interval 9-28 April at a distance of 8.3 km from the vent. A measurement on 5 May showed farther advance, however and later breakouts also took place.

For the 6 June flow geometry, the active areas with breakouts appear as red stars. In this case three of the breakouts were inside the flow boundaries and one (the farthest from the vent) at the flow's N margin at 6.5 km linear distance from the vent. HVO reported the total flow length for 6 June at 8.8 km (based on a 14 May satellite measurement). No later refinements were posted and presumably this distance reflected the final state of advance for the Kahauale'a 2 flow.

The forward advance and to less extent the lateral spreading of the flows are summarized in table 11 as extracted from HVO daily and weekly reporting (and in some cases from the much shorter summaries in SI/USGS Weekly Volcanic Activity Reports). In addition to employing satellite images to discern the location of the flow front and breakouts, flow geometries were also measured with other approaches including spotters in aircraft, geologists in the field, and the gauging of flow behavior based on distant views or web camera images of smoke and fires. As noted above, the Kahauale'a 2 flow began at a complex of spatter cones actively venting lava at Pu'u 'O'o. The cones are described by their locations on the Pu'u 'O'o crater floor. A small lava lake (or lava pond) was generally present on the NE spatter cone during the reporting interval.

Table 11. Selected major and occasional minor events seen at Kīlauea during 26 December 2013 to 26 June 2014. Time intervals in this table are variable. Abbreviations used: Pu`u`O`o = P*; Halema`uma`u = H*; Kahauale'a 2 = K2. The column labeled L is the straight-line length of the Kahauale'a 2 flow (in kilometers) from source vent at Pu`u`O`o to the distal end. For example, in the second row "7.5 (17th)" reflects a length of 7.5 km from a measurement on 17 January. (Some measurements of L also appear in Comments.) Breakouts were often mentioned in HVO source data. We only included cases where both the distances from the vent were over a few kilometers and the distances were clearly specified. Some of this data came from compilations provided in the SI/USGS Weekly Volcanic Activity Reports. All the data were initially made public in HVO's weekly and daily reports.

Date range L Comments
24 Dec-14 Jan 2014 6.3 The NE spatter cone fed the K2 lava flow, which contained breakouts. During 1-2 January the SE spatter cone erupted 5 short lava flows. The Volcano Alert Level and Aviation Color Code both remained stable during reporting interval (at Watch and Orange, respectively).
15 Jan-21 Jan 2014 7.5 (17th) At the summit a deflation-inflation (DI) event began the 17th; during 21st-22nd the lava-lake at Outlook crater dropped more than 20 m to ~70 m below H* crater floor (the low stand for the 1st half of 2014). On 19th HVO noted the N side of the NE spatter cone at P*collapsed, possibly due to lowered lava lake corresponding to the DI event. The collapse exposed a lava pond.
22 Jan-28 Jan 2014 7.8 (24th) K2 was fed by the NE spatter cone. On the 23rd, minor lava oozed out of SE spatter cone. During 23-26 Jan lava rose in W-most spatter cone and flowed down its N flank.
29 Jan-04 Feb 2014 7.8 (27th) Scattered breakouts from K2 flow 4.8 and 6.7 km NE of P*. On 31st, brief lava overflow at two spatter cones at P*. A satellite image from 2nd shows breakouts 4.8 to 6.7 km NE of P*. Outlook crater lava-lake depth below H* floor during 29th-4th, 43-60 m.
05 Feb-04 Mar 2014 7.8 (2nd) On 12th, breakouts extended 7.2 km P*, mostly advancing over previously erupted lava flows.
05 Mar-11 Mar 2014 7.9 (7th) Outlook crater lava-lake depth below H* floor during 5th-11th, 40-49 m.
12 Mar-18 Mar 2014 8 (11th) On the 12th, lava from the S cone traveled to the S. Once on the 14th and twice on the 17th lava from the pond rose and spilled over the rim. Breakouts from the K2's main lobe.
19 Mar-25 Mar 2014 8.2 (21st) The P* NE spatter cone still hosted a lava pond, which on the 18-19th spilled over the rim occasionally.
26 Mar-01 Apr 2014 -- NE spatter cone at P* both hosted lava pond and fed the K2 lava flow. Satellite imagery for 27th defined breakouts at 5.5 and 8 km NE of P*.
02 Apr-08 Apr 2014 8.2 (7th) The K2 lava flow continued to advance. Breakouts from the main stalled lobe burned adjoining forest. Outlook crater lava-lake depth below H* floor during 2nd-8th, 23-47 m.
09 Apr-15 Apr 2014 8.3 (9th) At P*Crater, the lava pond continued in the NE spatter cone (during most of the reporting period).
16 Apr-22 Apr 2014 -- The K2 lava flow continued to advance, with breakouts from the main stalled lobe, and burned adjoining forest
22 Apr-29 Apr 2014 8.3 (28th) On the 28-29th, the lava lake surface in Overlook crater reached ~30 m below the crater floor, the highest measured since Feb 2013. Just before midnight on the 22nd, the N spatter cone produced a vigorous lava flow that traveled E, in minutes crossing P*'s floor and descending through the tube feeding the K2 flow.
30 Apr-06 May 2014 8.6 (5th) The S spatter cone periodically erupted lava flows that traveled N and SE beyond the crater rim. During 5-6 May the N cone ejected spatter and a small lava flow. Outlook crater lava-lake depth below H* floor during 30th-6th, 31-35 m.
07 May-13 May 2014 -- HVO reported "...the flow front has not advanced more than 1.6 km (1 mi) since the first time it stalled in early November 2013." On the 13th, HVO noted that "There was no lava activity on the Pu`u `O`o [P*] crater floor or on the flanks of the cone--the decrease in activity is probably a direct response to the ongoing deflation of the cone." The most recent sulfur-dioxide emission-rate measurement on the E rift zone was 200 tons per day on the 12th.
14 May-20 May 2014 8.8 (14th) K2 again advanced. P*'s NE spatter cone still hosted a lava pond. A satellite image from the 14th showed scattered breakouts on the flow field.
21 May-27 May 2014 -- Volcano Watch article on 12 June noted that with respect to P*, the flow front stalled at 8.8 km and breakouts from the main flow occurred as far away as 8.4 km. Summit tilt meters recorded continued weak inflationary tilt and the lava-lake surface was in the range of 51-53 m below H*'s floor. K2 lava flow remained active but advanced slowly. Tremor was elevated, as were summit earthquakes (35 were strong enough to be located in a 24 hour interval ending on the 21st; 10 struck the S flanks; and several, along the E rift zone). Measurements across Kīlauea caldera indicated continued extension. The extension rate since 2010 has averaged 10 cm/yr.
28 May-01 Jun 2014 -- P*'s lava pond at the NE spatter cone briefly overflowed its rim each morning. On 30 May HVO mapped three small breakouts on several lobes 1.8-6.2 km from P*.
02 Jun-17 Jun 2014 -- HVO commented that the slow-moving K2 flow appeared to be weakening over the past few months. On the 6th, HVO mapped 4 small breakouts in the flow's interior extending out to 6.5 km NE of P* (see map, figure 230, bottom). On the 16th the SO2 flux was 300 tons per day from all E rift zone sources. Outlook crater lava-lake depth below H* floor during 2nd-17th, 33-47 m.
11 Jun-26 Jun 2014 -- On the 17th HVO mapped 5 small breakouts as far as 7 km NE from P*; a satellite image for the 20th a satellite revealed multiple breakouts in the flow's interior extending to 7.1 km NE of P*. On the 19th lava started pouring out of the NE spatter cone and flowing N along the K2 lava flow for about 12 hours. The new lava erupting coincided with tilt at P* that included -0.7 microradians of abrupt deflation. Overall, the K2 lava flow moved slowly and showed signs of continued weakening. On the 21st the lava-lake surface in Overlook crater dropped, but by the 22nd it came back up to about 34-35 m below the floor of H*. On the 23rd, the lava pond was covered with a crust. On 24th, rockfalls triggered a small explosion; spatter fell on the closed tourist overlook at H*.

As previously noted, in table 11 the column L reflects the flow's linear distance between the vent area at Pu'u 'O'o on the E rift zone and the E-advancing Kahauale'a 2 flow front. When this distance (L) remained constant for days or longer the flow was described as 'stalled' although in many cases portions of the flow farther back may have continued to grow and spread laterally as evidenced by areas of freshly exposed lava (breakouts such as those listed in the table). These HVO distance data are preliminary.

DI events were the subject of an article in the 29 March 2012 issue of Volcano Watch, from which the following freely borrows. The term DI event stands for deflation-inflation of the edifice. DI events have been dominating deformation of the volcano since 2008. According to HVO Daily Updates, they remained common in both 2013 and this reporting interval. A sudden deflation often lasts for 1–3 days, followed by an equally sudden inflation that returns the tilt to pre-event levels. This gives the tilt events a V- or U-shaped appearance in tilt records. The article said, "The total amount of subsidence during deflation and subsequent uplift during inflation is usually only about an inch (2.5 cm) and appears to be caused by pressure changes about 1 km beneath the east margin of Halema'uma'u Crater."

Put simplistically, during DI inflation, magma pressure increases and lava feeds the active lava flow, allowing it to advance. During DI deflation, the magma pressure decreases, reducing the supply of lava, causing the flow to stall. When the cycle repeats, DI inflation returns. This returns more lava to the flow. The incoming lava typically breaks out well behind the stalled flow front.

DI tilt is recorded at both Halema`uma`u and at Pu'u 'O'o. According to the Volcano Watch article, tilt at the E rift zone's eruption site has the same overall form as that at the summit but lags behind by a few hours. HVO interprets this as a response pressure change moving from the summit to Pu'u 'O'o. DI events are often associated with changes in eruptive activity. During the deflation phase, lava effusion at Pu'u 'O'o tends to decrease and the summit lava lake surface in Outlook crater drops, while the inflation phase is accompanied by a rise in the lava lake and sometimes a surge in lava from Pu'u 'O'o. Exceptions to these generalizations are frequent, however.

According to HVO's weekly reports, deflation-inflation cycles (DI events) did not occur from mid-December 2013 through the week of 16 January 2014. Late on 17 January, a large DI event occurred and from 22-23 January a DI inflation event was also observed. Over the next two weeks, a total of four DI events were reported. Starting in mid-February through early March, cycles of DI events were observed. On 10 April, the deflation phase of a large DI event occurred and inflation then began on 14 April. Abrupt summit deflation was noted on 10 May and was followed by a gradual deflation. During the last week of May, summit inflation began and in early June, deflation was noted.

Most of the seismic data presented in Daily Updates were the preliminary location and magnitude of located events. According to a Volcano Watch article issued on 27 February 2014, the location and magnitude of an earthquake may change after more careful review. According to the article, after an earthquake is recorded by the seismic network the data are processed within seconds. An initial preliminary earthquake location and magnitude becomes available about 3 minutes later.

On the basis of the preliminary values in Daily Updates, located events during 2014 were generally lower than 40-50 events per day. On the most seismically active single days, instruments recorded slightly over 100 events, and on the least active, just a few per day. Tremor was often described as weak and steady. Areas with epicenters typically included the summit caldera, East and SW rift zones, and the S flank area.

References. Hawai'i State Department of Health, (May) 2013, Frequently Asked Questions and Answers on Vog and Volcanic Emissions from Kīlauea (6 pp., URL: Health.hawaii.gov/cab/files/2013/05/Kīlauea_vog_qa_1.pdf ) Accessed 24 March 2015.

Kroll, J. H., Cross, E. S., Hunter, J. F., Pai, S., Wallace, L., Croteau, P. L., ... and Frankel, S. L., 2015, Atmospheric evolution of volcanic smog ("vog") from Kīlauea: Real-time measurements of oxidation, dilution, and neutralization within a volcanic plume. Environmental science & technology (ASAP), American Chemical Society Publications (published 3 March 2015) DOI: 10.1021/es506119x

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai`i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/, Daily Updates, https://volcanoes.usgs.gov/observatories/hvo/activity/Kilaueastatus.php, and (weekly) Volcano Watch, https://volcanoes.usgs.gov/observatories/hvo/volcanowatch/); Recent maps, https://volcanoes.usgs.gov/observatories/hvo/maps); and SI/USGS Weekly Volcanic Activity Reports (URL: http://www.volcano.si.edu).


December 2014 (BGVN 39:12) Citation IconCite this Report

27 June-30 December 2014: Birth and rapid advance of the June 27th lava flow

This report, taken largely from Hawaiian Volcano Observatory (HVO) reports and online photo galleries, nominally covers 27 June to 30 December 2014 but adds a few details from earlier and later intervals. The lava flow just before this interval, called the Kahauale'a 2 flow, had started in May 2013 (BGVN 39:05). That flow had, during April-June 2014, advanced erratically (BGVN 39:09) and HVO Daily Updates declared it inactive ("cutoff and dead") by 30 June.

Prior to that, on 27 June, a new flow had emerged adjacent to the Kahauale'a 2 flow; it became informally named the June 27th breakout and then the June 27th lava flow. The June 27th lava flow made it to the outskirts of Pahoa, stopping at the end of 2014 with two lobes as close as about 0.7-0.8 km W of the major arterial road that passes through the town (HI-130).

The 27 June to 30 December 2014 interval was characterized by unusual developments shown here chiefly by a series of maps. The June 27th lava flow did not follow the usual pattern of flow from the summit or E rift zone to the sea. Rather, this June 27th lava flow, like the Kahauale?a 2 flow, generally progressed E to NE.

The HVO reporting during this reporting interval included a number of commonly seen processes in the over 3-decade-long eruption, which we largely omit here for brevity. We presented a summary of many of those processes in the introduction to our previous report (BGVN 39:09). They include, for example, glow, spatter, minor ash, pelee's hair, and similar emissions at either the summit vent's lava lake or along the E rift zone at Pu'u O'o crater. We have done little to track the details of breakouts on a daily or hourly basis, particularly in the near-vent area. It is also worth noting that monitoring was disrupted by Hurricane Iselle on and around 7 August 2014.

Subsections below are as follows: "Events at Pu'u O'o and Halema'ama'u"; "June 27th lava flow advance towards Pahoa"; "Graphical approaches to hazards and scientific communication"; "Lava lake heights in Overlook crater"; "Geophysical monitoring"; and "SO2 flux data." For readers seeking a deeper understanding a recent book delves into the characteristics of Hawaiian volcanoes (Poland and others, 2014).

Events at Pu'u O'o and Halema'ama'u. On 27 June the new breakout on the NE flank of Pu'u O'o erupted through fissures. HVO's online reporting in their Photo and Video section stated that the breakout reached 1.5 km long by 1100 local time. Several fissures on the upper NE flank of Pu'u O'o cone sent out flows to the NE, HVO noted. These flows partially overlapped with the existing Kahauale?a 2 flow, which had scattered surface flows that morning. Breakouts caused minor subsidence in the Pu'u O'o crater floor. This led to collapses of several spatter cones on the crater floor. Small lava ponds were revealed and the NE lava pond enlarged due to the collapse. HVO reporting at the time (27 June) described the Kahauale?a 2 flow as still active.

By 30 June HVO declared the Kahauale?a 2 flow inactive. The lava tube feeding the Kahauale?a 2 lost hydraulic connection to the NE lava pond when the level of that lake dropped. The entry to the tube could be seen stranded meters above the lava in the vent wall (figure 231).

Figure (see Caption) Figure 231. View of the wall (roughly 10 m high) above the lava pond in the NE portion of Pu'u O'o crater. The lava pond surface is in the lower portion of the photograph. The dark hole in the upper part of the photograph is the entrance to the ~2-m diameter lava tube that had been supplying lava to the Kahauale?a 2 flow. When the lava level dipped well below the entrance to the lava tube, lava ceased entering the tube, leaving the Kahauale?a 2 flow inactive. Look direction unstated. Courtesy of HVO.

More details follow on the June 27th flow's early phases, as reported in the 27 June 2014 Daily Update. "Seismic tremor levels were low with a few dropouts (periods when spattering is absent in the lava lake and gas emissions are relatively low). Sixteen earthquakes were strong enough to be located beneath Kīlauea Volcano in the past 24 hours: 1 [centered on a fault system passing NNW of Kīlauea's summit] in the Ka'oiki Pali area, 1 beneath Halema`uma`u Crater, 4 beneath the area south of Halema`uma`u Crater, 6 on south flank faults, 3 within the upper East Rift Zone, and one within the middle East Rift Zone. GPS receivers spanning the summit caldera recorded almost +4 cm of extension since May 24; the long-term, cross-caldera measurements indicate continued extension at a rate averaging 10 cm/yr (4 in/yr) since March, 2010.

"Recent Observations at the middle East Rift Zone vents: The tiltmeter at Pu'u O'o cone recorded an abrupt drop, that is slowing, of more than 7 microradians. The lava flow from the northeast spatter cone continued to be active until midnight; early this morning, coincident with the rapid deflation, the crater floor started to slowly subside and new lava was erupted on the north flank of Pu'u O'o cone; in addition, the upper part of the south cone collapsed around 7 am. GPS receivers recorded 5 cm of contraction across the cone following this morning's deflation."

"Recent Observations of the Kahauale'a 2 flow: PNcam views yesterday showed active breakouts at the north base of Pu'u O'o cone and distant broad smoke plumes, with multiple glowing points visible at night from both near and distant breakouts. A satellite image from June 20 showed multiple active breakouts in the interior of the Kahauale'a 2 flow extending 7.1 km (4.4 mi) northeast from the Pu'u O'o vent (see map for June 17 flow details).

"In general, this slow-moving [Kahauale'a 2 ] lava flow has made erratic progress over the past few months and appears to be slowly weakening. Disruption of the flow front has occurred during strong DI deflation events when the lava supply abruptly decreased causing the flow front to stagnate. DI inflation and resumption of lava supply usually follow a few days later. Breakouts reappear well behind the stalled flow front and take some time to reach the front again. In this way, the flow front has not advanced more than 1.8 km (1.1 mi) since the first time it stalled in early November, 2013."

The 27 June breakout formed a lava shield high on the Pu'u O'o cone during 28-29 June. A set of HVO photos taken on 26 June and 6 July documented before and after shots of a broad prominent shield. Associated text said the shield made a "dramatic change to the skyline" at Pu'u O'o. The text attributed the growth to the process of successive flows stacked on top of each other in the near vent area. The caption also said that the shield hosted a lava pond.

Photos of Pu'u O'o taken on 18 July addressed a new crater at Pu'u O'o. Since the onset of the "June 27 breakout" flow, the central part of Pu'u O'o's crater had slowly collapsed within a bounding ring fracture. One photo showed the pit formed on the southern side of the crater floor, which contained a small lava pond roughly 10 m across. This pit sporadically overflowed sending lava toward the deeper central part of the crater.

During 16-22 July the lava flow followed an incipient lava tube from the vent to the gentle break in slope at the base of Pu'u O'o, and continued slowly moving in two main lobes that extended about 2 km NE. Two small lava ponds within cones were present within two southeastern pits in the crater floor, and glow above two other pits indicated lava near the surface.

On 23 July the SE wall of Overlook crater fell into the lava lake and triggered an explosive event that threw spatter bombs onto the rim of Halema'ama'u. Ejected material ranged from dust-sized particles to spatter bombs ~70 cm across. The HVO Photos and Video portion of their website featured some dramatic web camera videos of the event. This process repeated again in this middle to late2014 time frame with cases noted on 6 and 23 August, and on 24 September.

A photo of the Pu'u O'o vent area on 26 September appears in figure 232.

Figure (see Caption) Figure 232. Annotated photo taken 26 September 2014 showing Pu'u O'o and the vent and upper lava tube (orange dashed line at far right) for the June 27th lava flow. View is towards the E. Courtesy of HVO.

At 0115 on 19 October another explosion of spatter took place at the lava lake at Halema'ama'u from the lava lake in crater. . A collapse of wall rock fell into the lake, triggering a small explosion. The scar left by this collapse was visible as a light-colored area. The spatter fell around Halema'ama'u crater, which is within an area closed to the public due to hazards like this.

The summit lava lake has shown the usual fluctuations associated with changes in spattering behavior, which are also manifested as variations in tremor amplitudes and gas release. Small amounts of particulate material were carried aloft by the plume.

June 27th lava flow advance towards Pahoa. During the rest of this report, the advancing flow of note was the June 27th lava flow. As noted above, that flow ceased to advance rapidly but remained active near the distal end through the rest of 2014 (and months into 2015). That point is critical because the distal end began to encroach on the W margin of the town of Pahoa.

We present a series of HVO maps in this section, starting with one created to describe the June 27th lava flow (figure 233>).

Figure (see Caption) Figure 233. A map describing lava flows on 27 June 2014. Map showing the Kahauale?a 2 flow (pink) in relation to the E part of the Island of Hawai?i as of 17 June 2014. The most distant active breakout for Kahauale?a 2 lava flow was 7.1 km straight-line distance NE of Pu'u O'o. A new breakout of 27 June (shown in red) started on the NE flank of Pu'u O'o, sending new lava NE. Lava flows emitted since 1983 are labeled on the next figure. The Kahauale?a 2 flow contained an approximately located lava tube, shown with a yellow line (dashed where its position is less well known). Courtesy of HVO.

All of the following maps have several features in common. The yellow line depicts the approximate location of the feeding lava tube (dashed where less certain). When time is referred to, the times are in local (Hawaii Standard) time. Some of the maps contain more details than others on background information such as the age ranges of lava flows going back to the start of this eruption (1983). Figure 234 and its caption explain the color scheme, although some later maps generalize all the older lava flows as one color. A critical detail on figure 234 is that by 30 June, the Kahauale'a 2 lava flow had been declared inactive.

Figure (see Caption) Figure 234. A map describing Kīlauea E rift zone and the start of the June 27th lava flow ("breakout") on 30 June 2014. The area of the new flow as mapped on 27 June appears pink, while the extending portion mapped 30 June appears red. The 2013–2014 Kahauale?a 2 flow appears reddish orange. Older lava flows distinguished by color as labeled (episode 1-48b flows (1983–1986) are shown in gray; episodes 48c–49 flows (1986–1992), yellow; episodes 50-55 flows (1992-2007), tan; episodes 58-60 flows (2007-2011), pale orange, and episode 61 flows (2011-2013), very light tan). Courtesy of HVO.

Figures 235 to 237 portray the June 27th lava flow advance from 29 July to 6 September. HVO attributed the surprisingly narrow character of the flow as likely related to the numerous linear cracks and down-dropped structures (grabens) found in this area. In this regard, HVO noted that lava within a linear crack remained hidden for several days but over the day of 25 August lava returned to the surface at a point slightly farther along the crack. The emerging lava created a small island surrounded by thick forest. The farthest tip of the flow that day reached 11.4 km from Pu'u O'o, and 3.1 km from the eastern boundary of the Wao Kele o Puna forest reserve. On 28 August plumes of smoke from burning vegetation marked the farthest active lava on the surface (small, scattered lobes of pahoehoe). In addition, a pad of lava had emerged from the long ground crack that funneled it NE earlier this week. The lava was inactive at its surface but thermal imagery indicated it was still quite warm. East of this pad of lava, steaming appeared on 28 August, suggesting continuing lava advance below the surface along a ground crack. Direct views into the crack were not possible due to thick vegetation, but close views of the steaming areas with a thermal camera revealed temperatures up to 190°C, temperatures interpreted by HVO as evidence of lava moving along a crack. That was confirmed on the 29th when lava again emerged out of a steaming crack. On 1 September lava plunged into another ground crack. On 10 September, the most distal flow front had reached 14.5 km (straight-line distance) from its vent at Pu'u O'o.

Figure (see Caption) Figure 235. A map describing Kīlauea's June 27th lava flow on 29 July 2014. The pink area represents lava emplaced by 18 July. The red area represents lava emplaced after that and as late as 29 July. By this time the new flow had advanced while remaining much narrower than the adjacent Kahauale?a 2 flow. The new flow (pink and red zones) had a straight-line length of ~4.4 km. Courtesy of HVO.
Figure (see Caption) Figure 236. A map describing Kīlauea's June 27 lava flow on 3 September 2014. The area of the flow as mapped on September 1 is shown in pink, while widening and advancement of the flow as of September 3 is shown in red. On 2 September, lava welled up out of the crack it was filling and spilled out onto the ground to feed new surface flows. As of early afternoon on 3 September, lava on the surface was 13.2 km from the vent and 1.3 km from the E boundary of the Wao Kele o Puna Forest Reserve. All older lava flows (1983-2014) are shown in gray; the yellow line marks the lava tube. Courtesy of HVO.
Figure (see Caption) Figure 237. A map describing the state of Kīlauea's June 27th lava flow on 6 September 2014. The larger scale expands the area of coverage to see both the distal part of the lava flow and its relation to nearby Puna communities. This map also depicts the distal ends of the flow at various dates in time. The area of the flow on 3 September is shown in pink, while widening and advancement of the flow as mapped at ~1110 on 6 September is shown in red. The black dots mark the flow front on specific dates. The blue lines show the modeled steepest down-slope paths (see text). The narrowness of the flow was attributed to areas of linear down-dropped zones (grabens) and cracks along the E rift zone. Courtesy of HVO.

Kauahikaua (2007) discussed the use of an appropriate digital elevation model (DEM) to calculate the steepest path of descent along the East rift zone (blue lines in figure 237 and subsequent figures). The basis of that report was a 1983 digital elevation model (DEM). For the case at hand, Bulletin editors are uncertain about the exact dataset used to make the model. Whatever their source, the blue lines on the subsequent maps (below) can be used to infer the approximate directions of the flow's potential advance. These models are imperfect since, for example, the maps have only a finite resolution, and they may lack the updated distribution of lava flows, which themselves change the topography. Kauahikaua (2007) points out that seemingly subtle differences between actual topography and the model may lead to divergence from the modeled lines of steepest descent.

In early September the flow changed its direction of advance. The flow, initially headed almost N along one of the modeled paths of greatest descent (blue lines). By 10 September the direction of advance curved, shifting again more to the E (figure 238). On 3 September, HVO raised the Volcano Alert Level from Watch to Warning, where they both remained during the rest of 2014.

Figure (see Caption) Figure 238. A map describing the state of Kīlauea's lava flow on 10 September 2014, but also emphasizing points of farthest advance through August and early September. The distal end of the pink region shows the state of advance as late as 1245 on 8 September 2015. The red region shows advance from that time until about 1445 on 10 September. Blue lines show modeled steepest paths of descent (see text). Courtesy of HVO.

On 15 September, HVO noted that the flow entered a subdivision called the Kaohe Homesteads (figure 239). They said that at this stage the flow was still within the vacant, forested NW portion of subdivision.

Figure (see Caption) Figure 239. A map describing the state of advance for Kīlauea's lava flows on 15 September 2014. The area of the flow as of 12 September at 1230 appears in pink. The area of flow advance after that, and as late as 15 September at 1400, appears in red. The active flow reached 15.5 km from the vent and had crossed the Wao Kele o Puna Forest Reserve boundary progressing into the vacant NW corner of Kaohe Homesteads. At this stage, HVO noted, the flow front was situated 4.3 km upslope from Pahoa Village road. HVO also reported the flow length as measured along the curving path of the lava-tube (yellow line) as 17.7 km. The purple arrow shows HVO's short-term projection of flow direction based on topography and recent flow behavior. Blue lines depict the modeled steepest lines of descent (see text). Courtesy of HVO.

By 19 September the flow still progressed NE through Kaohe Homesteads, HVO noted. For the previous several weeks, the flow had been moving through thick forest but around this time the flow front reached the forest boundary (figure 240) and more open ground.

Figure (see Caption) Figure 240. A map (with key) describing the state of Kīlauea's lavas on 6 October 2014. Note the Forest Reserve and its boundary (a thin line crossing the flow a few hundred meters E of the 12 September flow front). HVO noted that vegetation density dropped after crossing that boundary. Blue lines depict the modeled steepest lines of descent (see text). Courtesy of HVO.

The flow advanced at an increased rate during 22-23 October, and at 1400 on 24 October the flow front pushed ahead as a narrow lobe reaching ~19 km from the Pu'u O'o vent. The front was 135 m from Cemetery Rd./Apa?a Street, two roads on the W outskirts of town. On 26 October the flow's leading tip advanced through Pahoa cemetery.

During 22-28 October HVO reported that the lava flow remained active. On 22 October a narrow lava flow (less than 50 m wide) that had overtaken the flow front during the previous few days moved into a small gully. It sometimes moved as fast as 300 m/day (many times faster than the typical). Another breakout upslope continued to advance at a slower rate. On 24 October, HVO scientists aboard an overflight measured the cross-sectional area of the lava tube feeding the flow at the vent. Their measurement suggested a slight increase in the lava supplied to the flow.

At approximately 0350 on 25 October lava crossed Apa'a Street and continued to advance towards the town of Pahoa. Throughout the morning the flow moved down the Pahoa cemetery driveway and then turned SE into adjoining pasture. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning. At 0900 on 26 October the flow was an estimated 140 m wide. The next day it had narrowed to 100 m wide and was about 570 m from Pahoa Village Road. At about 0200 on 28 October the flow had reached the first occupied residential property. The leading edge of the flow was less than 50 m wide but increased to 150 m upslope. At 1730 the lava flow was 310 m in a straight-line distance from Pahoa Village Road and about 900 meters in a straight-line distance from Highway 130. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning.

According to news articles, Pahoa is a town with 800-900 residents, and besides homes, contains small shops. A school and a few roads were closed. Crews were building temporary access roads and trying to build berms to divert lava away from the heavily traveled Highway 130, which passes through the town.

On 2 November, the lava flow front stalled, but scattered breakouts occurred upslope of the flow front. HVO documented in their online Photo and Video section that over the past several days leading up to 7 November, the flow had undergone inflation (thickening).

Although an earlier flow lobe had crossed Apa?a Street / Cemetery Road during October, on 9 November witnesses watched as fresh lava crossed asphalt pavement there, causing combustion with yellow flames and black sooty plumes. HVO cautioned that burning roads creates toxic fumes that can cause eye and respiratory tract irritation, as well as headaches, rashes, cough, and possibly cancer. On 25 October just a few hours after the flow crossed the road, the lava was only about 1 m thick. Ten days later, the flow grew to ~4 m thick.

The next map (figure 241) shows the lava's position as of 10 November 2014 with some earlier dated points of farthest advance indicated. On 10 November a breakout moved along Apa?a Street and onto private property setting an unoccupied home there on fire. According to news sources, this was the first home to be set on fire by the June 27th lava flow. Residents had long ago moved out of the wood frame structure, and had cleared out their belongings. The demise of the structure was widely seen in the news.

Around mid-November a solid-waste transfer station near that portion of the lava flow was the subject of numerous photos, including those documenting flow inflation, burning asphalt pavement, and how a strong cyclone (wire mesh) fence provided a an effective but short-lived barrier. HVO posted a photo disclosing how lava encroached close to the station on 13 November, crossing a fence and most of an access road that loops around the station.

Figure (see Caption) Figure 241. A map (with key) describing Kīlauea lava flows on 10 November 2014. On that day, surface activity was present along the N margin in the first few kilometers upslope (W) of the flow tip. For reference, Apa?a Street/Cemetery Road intersects the flow near the breakout farthest to the E. Blue lines depict the modeled steepest lines of descent (see text). Courtesy of HVO.

During an overflight on 1 December volcanologists measured a cross-sectional area of the lava stream within a tube near Pu'u 'O'o. They found a 25% reduction in area compared to the previous week. The result was consistent with less lava flowing through the tube due to summit deflation, which had been ongoing since 29 November.

A 21 December satellite image showed the flow moving towards Pahoa. The image came from the Advanced Land Imager instrument onboard NASA's Earth Observing 1 satellite. The image provided a view of active breakouts on this downslope (E) portion of the flow. Surface lava was active around the leading tip of the flow, but a short distance upslope (W) of the leading tip there was an absence of surface breakouts. About 1.5-2 km W and upslope of the leading tip of the flow, many scattered breakouts were indicated. Thus, HVO concluded, the image emphasizes that lava-flow movement was not limited to the flow front.

Figure 242 shows the lava flow one day before the end of 2014.

Figure (see Caption) Figure 242. A map describing lava flows on 30 December 2014. This large-scale map shows the distal part of Kīlauea's active E rift zone lava flow in relation to nearby Puna communities. The area of the flow on 22 December at 1500 is shown in pink; the areas that widened and advanced by 1430 on 30 December are shown in red. Most surface activity was within the leading 3 km of the flow's N lobe, but other small breakouts were scattered the flow in an area 7-8 km W of Pahoa (a region HVO described as just N of the True/Mid-Pacific geothermal well pad). One other breakout, outside the map area, was also active near Pu'u O'o. (As we will discuss in our next Bulletin report on Kīlauea, the June 27th flow remained active at least as late as April 2015.) Courtesy of HVO.

At the end of 2014, Kīlauea continued to erupt both at its summit and at Pu'u O'o along the East rift zone. An overflight on 1 January 2015 confirmed that the front of the 27 June lava flow remained stalled. However, HVO's Daily Update (issued at 0913 on 1 January) also noted a breakout along the S margin of the flow and 150 m up slope of the flow front, which had advanced ~20 m since the afternoon on the 31st. In addition to the aerial observations, farther back (upslope and W) from the flow front HVO noted that satellite data acquired on 31 December showed areas of activity 3 and 6 km W of the flow front .

Graphical approaches to scientific and hazards communication. The HVO website features a hazard map for Kīlauea (HVO, 1997). It shows the relative degree of hazard from lava flows for different areas of the volcano. The E rift zone is within Zone 1, which HVO (1997) states "is the most hazardous; it consists of the summit area and rift zones because Kīlauea's frequent eruptions originate in these areas."

As a result of the June 27th lava flow showing no signs of halting, on 3 December 2014, William P. Kenoi, the mayor of the County of Hawaii signed a proclamation that continued the state of emergency in the Puna district. This followed earlier proclamations signed on 4 September and 16 October 2014.

Figure 243 illustrates the advance of the June 27th lava flow from Pu'u O'o towards infrastructure such as Pahoa and the road through it (HI-130). The W-looking view has the advancing lava heading towards the reader. Figure 243 contains both a plot and an image of the June 27th lava flow, with four lobes identified by color coding (as defined on the right side of the figure). The illustration was posted on social media and serves to educate residents (it is not from a peer-reviewed publication). The same author has generated numerous other graphics associated with the advancing lavas and the geography of the Puna district, including relevant census and economic data, in what are often called infographics. Another example, focusing on roads, is figure 244.

Figure (see Caption) Figure 243. Diagram that shows both a plot (at left) and an oblique view of the land surface (at right) summarizing lava advance as of 23 December 2014. In the view at right the colored lines define some of the critical flow lobes. The plot shows position versus time (during 28 June 2014 to 12 January 2015 in 28-day increments). Pahoa (indicated) resides on route 130 (HI-130). Many of the labeled features (Hawaiian Beaches, Rail Road Avenue, and Government Beach Road) may also be seen in figure 239>. Courtesy of Mark Kimura (University of Hawaii at Hilo).
Figure (see Caption) Figure 244. An illustration of approximate drive times between various locations near the June 27th lava flow. The lava covered portion of the Chain of Craters road between Hawaii Volcanoes Nation Park at the W and Kalapana at the E is indicated as the yellow line with red dashes (the gray, lava covered portion, is ~13 km in length). Courtesy of Mark Kimura.

Work began on 24 October 2014 on the emergency access route between Hawai'i Volcanoes National Park and Kalapana along the historic portion of Chain of Craters Road-Kalapana alignment (yellow and red dashed line, figure 244). The lava-covered portion of that road is ~13-km long. According the National Park Service, the emergency route will assist residents of lower Puna district, whose access to the rest of the island would otherwise be cut off if E-flowing lava were to reach the ocean. According to a news article by Damon Tucker, bulldozers working inward from the E and W ends met in the middle on 6 November. The article noted that the roadbed was still considered 'rough grade' and when opened it will be ~6-m wide, 2 lane, and gravel surfaced. The road was intended chiefly for residents (and their agents and service provders) and, as planned, will not be open to the general public or park visitors. On the basis of several reports Bulletin editors found, the road's projected eventual cost varied within the range of 7-15.5 million dollars.

Lava lake heights in Overlook crater. At the summit, a lava lake resides in Overlook crater (see map of the Kīlauea summit caldera area in the previous report, figure 229). Overlook crater is a source of ash, spatter, pelee's hair, and this area also vents the bulk of the SO2; emissions (discussed in a subsection below). HVO Daily Updates describe Overlook crater as a pit or crater in the floor of the larger Halema`uma`u Crater. That crater resides, in turn, on the floor of the larger Kīlauea caldera or crater. The pit is about 160 m in diameter at the ground surface on the Halema`uma`u crater floor. At a depth of 200 m below the Halema`uma`u crater floor (the deepest point visible when the lake drains to those depths) the pit is ~50 m in diameter. HVO Daily Updates also said that a lava pond or lake in the pit has been in evidence since November 2009 and through 2014. The surface of the lake moved up and down and measurements reflect the depth below the crater floor.

Overall, from available data during 27 June to 31 December the lake surface ranged between 30 and 70 m below the pit's rim at the Halema'ama'u crater floor. During 27 June to 9 July 2014 the lake remained fairly stable at near 30 m depth below the floor. Starting a few days after that and until 19 September the lake was in the approximate range 30-60 m deep. On 20 September it reached ~65 m deep. During 21-24 September daily distances to the lake surface descended with attendant fluctuations to ~70 m deep. During 25 September to 3 November the lake remained in the range of 40-70 m through the end of the year, although the depths were not specifically given during much of November and December.

HVO Daily Updates contain the following general background explaining more about the lava lake. Overlook crater has been more-or-less continuously active since it opened during a small explosive event on 19 March 2008. Small collapses in the Overlook crater are common, and over time have resulted in a gradual enlargement of the Overlook crater. During 2013 and early 2014, the lava level has been typically between 30 m and 60 m below the floor of Halema`uma`u Crater. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation.

Geophysical monitoring. Geophysical monitoring, including seismicity at the summit was summarized in HVO Daily Updates during 27 June to 30 December. Located earthquakes in the summit area were most reliably reported only during 27 June through 7 August, an interval when they were often in the range 5 to 36 events per day. After that, the number of events was seldom reported although some comments noted an occasional number or a larger event (e.g., on 14 November, an M ~3.5 earthquake on Kīlauea's S flank) and many cases mentioned 'several' located earthquakes or commented on a lack of changes in seismicity without further quantification. Tremor and small seismic swarms were noted often. For example, a swarm of long-period earthquakes occurred during 20-21 August centered beneath the summit caldera at ~8 km depth. Epicenters were reported elsewhere (besides the summit), for example on the S flank and various parts of the E rift zone.

In multiple entries during the reporting interval, episodes of tremor were interpreted by HVO as linked to spatter on the surface of the lava lake.

The 19 October Daily Update made these comments about seismicity, tilt, and summit deformation measured by GPS. "A cluster of small seismic events occurred at a shallow level beneath Kīlauea's upper East Rift Zone at about the time that ground tilt switched from inflation to deflation. Such behavior is fairly common. Seismic tremor beneath the summit remained low and varied with changes in spattering on the surface of the lava lake. GPS receivers spanning the summit caldera recorded about 5 cm (2 in) of extension between early May and early July [2014]. Since then, little significant extension or contraction has occurred."

SO2 flux data. Table 12 contains SO2 flux data extracted from HVO Daily Updates for the interval 11 June 2014 through 13 January 2015. Near the start of that interval, during 25 June-1 July 2014, SO2 fluxes at Halema'uma'u yielded the highest values of the interval, 8,400 metric tons per day (t/d). This was about 10% higher than the largest value reported in the first half of 2014 (BGVN 39:09). Overall, SO2 fluxes for Pu'u 'O'o and associated E rift zone sources of degassing yielded somewhat elevated values. During the week of 25 June to 1 July 2014 scientists recorded fluxes of 900 t/d, about double the higher values HVO typically reported since July 2012.

Table 12. An overview of approximate and preliminary S02fluxes reported for Kīlauea and some associated comments during 11 June 2014 to 13 January 2015. The majority of these measurements were averages or ranges for a week-long interval recording plumes from gases vented at the summit caldera. "Minor ash" represents cases for summit measurements where HVO noted "a tiny amount of particulate material carried aloft by the plume." Note comment in text below table about the shift in measurement methodology, which resulted in higher values. The measurements in brackets, [ ], record flux estimates on the stated dates from all sources vented on the East Rift Zone (ERZ). For brevity, ERZ measurements during mid-July to mid-September were omitted from the table. All data and quoted text came from HVO Daily Updates (see link in the Information Contacts section).

Date (or range) SO2 flux (metric tons/day, t/d) at summit [East Rift Zone, ERZ]; Comments
11 Jun-17 Jun 2014 2,400-6,400 t/d
18 Jun-24 Jun 2014 2,800-5,200 t/d. [ERZ on 24th: 250 t/d (". . . emission rates typically ranged between 150 and 450 t/d since July 2012.")
25 Jun-01 Jul 2014 3,800-8,400 t/d. Highest value in table. [ERZ on 27th: 900 t/d; ". . . measured shortly after the new breakout started; emission rates have typically ranged between 150 and 450 t/d since July 2012."]
02 Jul-08 Jul 2014 5,800-6,900 t/d (minor ash) [ERZ on 3rd: 500 t/d]
09 Jul-15 Jul 2014 4,200-6,300 t/d (minor ash)
16 Jul-22 Jul 2014 4,500-5,700 t/d (minor ash)
23 Jul-29 Jul 2014 3,700-7,100 t/d (minor ash)
30 Jul-05 Aug 2014 3,600-6,100 t/d (minor ash)
06 Aug-12 Aug 2014 5,100 t/d (minor ash)
03 Aug-19 Aug 2014 2,400-5,000 t/d (minor ash)
20 Aug-26 Aug 2014 4,100-5,900 t/d (minor ash)
27 Aug-02 Sep 2014 3,300-6,700 t/d (minor ash)
03 Sep-09 Sep 2014 3,300-7,600 t/d (minor ash)
10 Sep-16 Sep 2014 4,300-6,800 t/d (minor ash)
17 Sep-23 Sep 2014 4,400-6,300 t/d (minor ash) [ERZ on 24th: 375 t/d]
24 Sep-30 Sep 2014 3,600-5,200 t/d (minor ash) [ERZ on 25th: 550 t/d]
08 Oct-14 Oct 2014 2,900-6,500 t/d [ERZ on 9th: 450 t/d]
15 Oct-21 Oct 2014 2,700-3,600 t/d
22 Oct-28 Oct 2014 4,250-7,000 t/d [ERZ on 23rd: 340 t/d]
29 Oct-04 Nov 2014 3,400-6,400 t/d [ERZ on 31st: 320 t/d]
05 Nov 2014 6,200 t/d (but winds thwarted later repeat measurements during week ending on 11th)
18 Nov 2014 4,400 t/d (another 1-day measurement like that above)
19 Nov-25 Nov 2014 6,900 t/d
27 Nov-02 Dec 2014 4,300 t/d [ERZ on 26th: 250 t/d]
03 Dec-09 Dec 2014 4,100 t/d
10 Dec-16 Dec 2014 3,100-6,500 t/d [ERZ on 11th: 300 t/d]
17 Dec-23 Dec 2014 5,500-7,700 t/d [ERZ on 19th: 250 t/d]
25 Dec-31 Dec 2014 6,000 t/d
31 Dec 2014-06 Jan 2015 5,400 t/d
07 Jan-13 Jan 2015 4,500 to 7,600 t/d [ERZ on 7th: ~200 t/d]

HVO emphasized the following caveat described in more detail in (BGVN 39:09). "Starting in 2014, [HVO began reporting] the emission rate estimated by a new, more accurate method. The numbers increase by a factor of 2-4 but the actual emission rate has not changed."

The gas plume from the summit area (Kīlauea caldera), sometimes included minor amounts of ash-sized tephra (sometimes noted in table 12). These included fresh spatter bits and Pele's hair from the circulating lava lake in Overlook crater. In general, the heaviest tephra deposited near the source; the finer tephra, several kilometers downwind.

References. Kauahikaua, J., 2007, Lava flow hazard assessment, as of August 2007, for Kīlauea East Rift Zone eruptions, Hawai'i Island: U.S. Geological Survey Open-File Report 2007-1264, 9 p., ( http://pubs.usgs.gov/of/2007/1264/ )

Kimura, Mark, 23 March 2015, Lower Puna infographics (https://www.facebook.com/lowerpuna) [Accessed in March 2015].

Poland, M.P., Takahashi, T.J., and Landowski, C.M., eds., 2014, Characteristics of Hawaiian volcanoes:

U.S. Geological Survey Professional Paper 1801, 428 p., http://dx.doi.org/10.3133/pp1801.

University of Hawaii at Hilo, 2015, UH Hilo Stories: Puna lava flow in graphics & maps, updated Feb. 22 (http://hilo.hawaii.edu/news/stories/2014/09/22/puna-lava-flow-in-graphics-maps/).

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai`i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/, Daily Updates, https://volcanoes.usgs.gov/observatories/hvo/activity/Kilaueastatus.php, and (weekly) Volcano Watch, https://volcanoes.usgs.gov/observatories/hvo/volcanowatch/); Recent maps, https://volcanoes.usgs.gov/observatories/hvo/maps); and Mark Kimura, Department of Geography and Environmental Sciences, University of Hawaii at Hilo, Geography Department, 200 W. Kawili St., Hilo, HI 96720-4091.


July 2015 (BGVN 40:07) Citation IconCite this Report

Lava lake in Halema'uma'u Crater overflows its rim; lava front from Pu'u 'O'o stalls near Pahoa village

Activity at Kīlauea during 27 June-31 December 2014 focused on lava flowing from fissures on Pu'u O'o's NE flank (the June 27th lava flow) and advancing toward Pahoa village (BGVN 39:12). Scattered breakouts upslope of the flow front continued into 2015. This report, taken primarily from Hawaiian Volcano Observatory (HVO) quarterly reports, covers activity of the ongoing eruption from 1 January through 30 June 2015.

Two noteworthy events occurred at Kīlauea during the first half of 2015. In late April, the lava lake in Halema'uma'u Crater overflowed from its vent onto the floor of the crater for the first time since the current eruption began, building up a new vent rim and sending explosions of small bombs and spatter onto the Overlook parking lot. The advancement of the June 27th flow toward the town of Pahoa ceased in early March and new flows initiated from several breakouts much closer to Pu'u 'O'o' crater, adding significant areas of coverage to the June 27th flow.

Activity at Halema'uma'u. The lava lake in Halema'uma'u rose and fell in its normal patterns during the first quarter of 2015, closely mimicking short-term changes in summit tilt. The lava level fluctuated about 40-50 m below the vent rim (the floor of Halema'uma'u) during January and February. A large DI (deflation-inflation) event during the first week of March, however, caused the lake to drop to a low of about 75 m below the vent rim. This drop saw the collapse of the inner ledge that has long bounded the southern edge of the lava lake. The lava level recovered thereafter and was back up to around 35-40 m below the rim by the end of March.

For the first three weeks of April, the lava lake behaved in typical fashion, with north-to-south circulation, and frequent transitions between periods of spattering and calm. The lava level rose early in the month as the summit recovered from a DI event, but then the volcano entered a period without DI events and the lava level remained steady (figure 245).

Figure (see Caption) Figure 245. Activity at the Halema'uma'u lava lake of Kīlauea, April-June 2015. (a) Summary plot of radial UWE (Uwekahuna tiltmeter, on the northwest rim of Kīlauea's caldera) tilt (blue) and lava level (red) at Halema'uma'u during the second quarter of 2015. The lava level rose above the field of view of the camera during late April-early May, resulting in no data for that period. Green dots show field measurements of lava level via laser rangefinder. Orange dots show VLF measurements of lava tube cross-sectional area near Pu'u 'O'o. Position along time series for images shown in panels b and c is indicated. (b) Thermal image showing the lava level on 8 May 2015, when near highest level. (c) Thermal image showing the lava level on 1 June 2015, when near lowest level; the solid white line shows the newly constructed vent rim; the dashed white line shows the original rim. Courtesy of HVO.

On 21 April the summit began to inflate continuously, and the level of the lava lake began to climb (see figure 245a). First spatter and then the actual lava lake surface came into view from HVO on 23 and 24 April, respectively. The rising level cooked the vent walls, causing a sharp increase in the frequency of loud pops and booms as the walls began to crack. This led to rockfalls into the lava lake, which triggered small explosive events at 0520 on 24 April, at 0157 and 0200 on 25 April, at 1020 on 28 April, and at 1320 on 3 May.

The 24 April event was a collapse of the NW vent rim that threw tephra onto the adjacent floor of Halema'uma'u. No significant amounts of tephra reached the rim. The back-to-back events on 25 April were caused by rockfalls from the S and E corners of the vent, where the crater floor meets the wall. Lapilli and bombs ~30 cm across were tossed onto the Halema'uma'u rim around the Overlook, and finer particles were carried downwind over the parking lot.

The Overlook was struck again on 28 April, when an explosion triggered by the collapse of the crater wall at the SE edge of the vent, threw small bombs and finer material into the parking lot and plastered the ground around and E of the Overlook with enormous, lacework gobs of spatter up to a few meters long. Lithic fragments up to 2 cm were embedded in the spatter, some of which were fairly glassy and quite heavy. The Overlook has been closed to visitors for some time.

Finally, the 3 May event was triggered by a rockfall from the underside and upper face of the overhanging S wall of the vent, below the Overlook. Fist-sized bombs were thrown as far as the Halema'uma'u parking lot, along with finer material.

The lava lake reached the vent rim early on 28 April and overflowed onto the floor of Halema'uma'u for the first time since appearing in 2008, late that night. The following days saw more overflows as the lava level continued to rise, with each overflow coating the vent rim and building it up layer by layer, adding 8 m to the rim's height (figure 246). The longer-lived overflows sent lava up to several hundred meters to the NNE and SW, eventually covering about 1.5 x 105 m2 at the SE edge of Halema'uma'u, or about 30% of the crater floor (not counting the area of the vent opening) (figure 246).

Figure (see Caption) Figure 246. Panoramic photo showing the Halema'uma'u lava lake on 15 May 2015. Note the dark, 8-m-thick layer of overflows that define the new vent rim, visible where the juvenile veneer has fallen away. Photo courtesy HVO.

The high lava level continued until 9 May, when it began to drop along with deflation related to the intrusion of magma beneath the S part of the caldera. Deflation rolled back into inflation on 13 May, but the lava level continued to fall until the 16th, reaching a depth of about 62 m below the new vent rim (54 m below the old rim).

The rest of May and June presented more typical behavior with frequent DI events and a lava lake level that fluctuated accordingly. The level dropped to as low as about 72 m below the new vent rim at the end of May and as high as about 39 m below the rim during the 3rd week of June. The low lava levels through this interval saw the shedding of the juvenile veneer from the walls of the vent as well as one larger collapse involving the E wall and rim of the vent at the end of June.

Activity along the East Rift Zone (ERZ). The June 27th flow remained active throughout this period (figure 247), with a widening of the flow field in several places, and the locus of activity changing substantially during this time. The most distant activity (~20 km NE of the Pu'u 'O'o vent) was scattered across the flow field within about 3.5 km of the Pahoa Marketplace through early March, when all surface flows near Pahoa shut down. The flow's farthest push downslope was in late January, when it reached to within about 500 m of Highway 130 (figure 248).

Figure (see Caption) Figure 247. Map of the NE flank of Kīlauea showing widening of the June 27th flow field from 6 January to 3 April 2015. Courtesy of HVO.
Figure (see Caption) Figure 248. Photo showing the Kīlauea lava flow immediately upslope from the Pahoa Marketplace on 13 March 2015, the day after the surface flow in that area shut down. The lobe near lower right is that which reached to within about 500 m of Highway 130. Courtesy of HVO.

In January and February, small breakouts occurred near the Kaohe Homesteads (figure 247). Beginning in late January through early March, a breakout north of Kahauale'a headed N reaching the forest on the N side of the Pu'u 'O'o flow in mid-February (figures 247, 249).

Figure (see Caption) Figure 249. Map showing changes to the June 27th flow field near Pu'u 'O'o between 10 March and 3 April 2015. Courtesy of HVO.

On 21 February a large breakout occurred (figure 249) near the head of the June 27th flow tube system, close to the fissure C vent, within a kilometer of Pu'u 'O'o Crater. The breakout sent lava N along the E side of the original June 27th tube and began to spread out at the base of Pu'u 'O'o in early March. Another large breakout near the S base of Kahauale'a was observed on 10 March (figure 249). This breakout was followed by the complete shutdown of the flow near Kaohe Homesteads and the Pahoa marketplace to the NE. Another breakout about 3 km downslope from Kahauale'a began on 13 March. The change in location of flowing lava from near the Pahoa marketplace, 20 km from Pu'u 'O'o Crater, to the sites within 9 km of the crater (the breakouts of 21 February, 9 March, and 13 March) is noticeable in MIROVA graphs (figure 250).

Figure (see Caption) Figure 250. Infrared MODIS data from MIROVA showing change in distance from summit of the Kīlauea thermal anomaly occurring at the end of March 2015. This is reflecting the cessation of lava flowing near Pahoa and the increases in flow from the 21 February, 9 March, and 13 March breakouts closer to the Pu'u 'O'o fissure C vent. Courtesy of MIROVA.

Surface activity associated with these new breakouts, extending over a broad area between about 1 and 8 km NE of Pu'u 'O'o, continued through the end of June and was joined by a few additional breakouts (figure 251) in the same area. With activity spread over such a large area, no single breakout was able to capture the majority of the discharge, and so the June 27th flow did not advance substantially in one direction. Pu'u Kahauale'a was repeatedly impacted by lava flows during this period, and by the end of June, little of it remained above the rising lava deposits.

Figure (see Caption) Figure 251. Map showing lava flow field changes between 1 April and 30 June 2015. Courtesy of HVO.

Activity at Pu'u 'O'o. Starting with the onset of the 21 February breakout, the floor and W wall of the current Pu'u 'O'o crater began to subside, presumably as the underlying storage body was partly emptied. Subsidence was accompanied by several small collapses within the crater, revealing small lava ponds at the crater's N and S pits. The subsidence ended in early March.

Small lava flows, fed from nearly all vents in the crater, erupted onto the crater floor during April and May. These flows occurred during the inflationary period, uninterrupted by DI events, leading up to the mid-May summit intrusion.

On 21 April, during the start of one of these periods of crater activity (21-23 April), the W end of the current crater dropped several meters. This period coincided roughly with the start of the rapid summit inflation which preceded the intrusion. The most vigorous period of eruptive activity occurred near the peak in the inflation, just before the intrusion, and resulted in lava filling the entire bottom of the crater.

The crater was relatively quiet after the summit intrusion, and only a few small, short-lived flows erupted into the crater in June. No further subsidence occurred after the April event.

In early April, a new collapse pit on the W side of the old crater floor was observed. The pit was about 27 m across at the rim and held a small lava pond about 24 m down. The pit widened over the following three months, and by 30 June was about 40 m across. Despite this widening, the pit was still overhung on its W end by about 20 m.

Seismicity. Seismicity at the summit and Southwest Rift Zone (SRZ) during the first quarter of 2015 was characterized by swarms of volcano-tectonic (VT) earthquakes and inflation within the rift zone, and long-period (LP) swarms at the summit.

Seismic activity in the SRZ was significantly above background in the first quarter of 2015. Seismicity began rising in early February with increases in rate generally tied to increases in tilt. Earthquake rates were dramatically higher between 10-17 February, with up to 45 located events/day. The maximum magnitude during this phase was M 2.6. Tilt initially recorded inflation until 14 February, corresponding with the peak in event rates, then recorded deflation until 17 February.

In the caldera, a swarm of moderate-depth long period earthquakes occurred beginning on 24 February and persisting into early March. On 10 March another shallow long-period (LP) swarm occurred in the caldera during two bursts from 0930 to 1319 UTC. A third swarm occurred a couple days later on 13 March.

The second quarter of 2015 was characterized by a surge in seismicity, deformation, and lava-lake activity within the summit region. Beginning in late April, earthquake activity throughout the summit region intensely increased and deformation data similarly reflected magma movement at the summit and upper rift zones.

At Halema'uma'u Crater, the lake-level drop in early May was accompanied by a change from inflation of the summit area to deflation centered near the crater. In addition, on 13 May, the focus of deformation changed to the S part of Kīlauea's summit caldera and upper Southwest Rift Zone (SWRZ), where rapid and localized inflationary tilt was recorded. Seismicity shifted from the summit and the upper East Rift Zone (ERZ) to the S part of the summit; seismicity at the upper SWRZ continued. The number of earthquakes increased on 15 May. The data suggest that magma had moved into a shallow area beneath the S part of the caldera and upper SWRZ. During 16-18 May, rates of tilting slowed and seismicity at the summit and SWRZ had decreased, although remaining above background levels. By 19 May seismicity rates at the summit were normal and the tilt had decreased slightly.

Deformation. Deformation of the summit area during the first quarter of 2015 was dominated by the episode of inflation in the S caldera area that started in early February and continued through the end of March. Tilt data at the summit show a similar number of short deflation-inflation (DI) events as in the recent past; a particularly large one occurred during the first week of March. General summit tilt trends were mimicked at Pu'u 'O'o.

During the second quarter, there was a series of events that culminated in an intrusion in the S caldera in mid-May. Strong inflation of the shallow reservoir near Halema`uma`u Crater was observed beginning on 22 April. Inflation was accompanied by elevated seismicity in the caldera and especially in the upper East Rift Zone. Sustained deflation of the reservoir started in the afternoon of 9 May. The rate increased two days later (11 May), as the lake level dropped and earthquakes in the S caldera increased in rate and magnitude. This was followed by rapid inflation in the S caldera which continued until 16 May. Preliminary modelling by HVO scientists suggested that the volume lost from the Halema`uma`u reservoir and lava lake was comparable to that gained in the S caldera. This was followed by slight deflation of the S caldera for about 10 days before it returned to normal short deflation-inflation (DI) events which were recorded by summit tiltmeters in May and June.

SO2 emission rates. During January through June 2015 East Rift SO2 emission rates ranged from 200 to 590 tons/day. A linear increase was observed from the beginning of the year until the summit intrusion activity. This is in contrast to the steady decline that was measured with the onset of the 27 June 2014 Pu'u 'O'o breakout. SO2 emissions at the summit crater did not change significantly during the overflow of the lava lake at Halema`uma`u Crater.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai`i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/)


February 2016 (BGVN 41:02) Citation IconCite this Report

Breakouts continue from the June 27th lava flow; new incandescent vent opens on the flank of Pu'u 'O'o cone.

The lava lake in the Overlook vent of Kīlauea, on the floor of Halema'uma'u crater, rose and fell in its regular pattern during July through December 2015, with a few episodes of spattering around the lake. East Rift Zone (ERZ) lava flows continued N and E of Pu'u 'O'o with new tube branches developing. Small lava flows continued within the Pu'u 'O'o crater, and a new incandescent vent appeared on the NE side of the cone in December. Seismicity was generally higher than normal in the Southwest Rift Zone and lower than average at the summit and in the East Rift Zone. SO2 emissions rates were varied but continued a long term decline. Information for this report is from the U.S. Geological Survey Hawaiian Volcano Observatory (HVO) quarterly reports.

Activity at Halema'uma'u. The lava lake at Halema'uma'u Crater was much less active since its overflow onto the crater floor on 28 April 2015. The only disruptions to the normal N-S circulation pattern were short-lived episodes of spattering around the lava lake edges which created local zones of downwelling, and some wall collapses. The lava surface rose and fell numerous times during DI (Deflation-Inflation) events associated with changes in summit pressure. The highest level the lake reached was 34.5 m below the crater rim in late December, and the lowest level was 84.5 m below the rim in mid-October. Thermal cracking sounds were common during high levels, and collapses of juvenile veneer from the vent walls were common during drops in level. An ashy plume was reported on 1 July 2015 when part of the rim and wall of the Overlook crater collapsed into the lake, causing a small explosion with intense spattering. A very-long-period earthquake at the summit on 24 November corresponded to the collapse of a large section of the N rim and wall of the summit vent. This caused increased lake spattering and turbulence.

Activity in the East Rift Zone (ERZ). Lava flows remained active in the ERZ from July through December 2015. During July-September three major branches of lava flowed N, NE, and E from Pu'u Kahauale'a. The N and NE branches were fed by a new tube branch. In addition small sporadic breakouts at the base of Pu?u ?O?o occurred during July and August (figure 252). The N and NE branches stopped advancing by October. Most activity shifted to the N and W sides of the flow field in late November from a new tube branch located about 300 m downslope from the June 27th fissure C vent (figure 253). Smaller breakouts along the S and E margin of the June 27th flow were also active into November.

Figure (see Caption) Figure 252. Flow field changes in the ERZ of Kīlauea between 30 June and 30 September 2015. Three active branches N and E of Kahauale'a added the most lava, fed from a new tube branch. Sporadic, smaller breakouts closer to Pu'u 'O'o occurred during July and August. Courtesy of HVO.
Figure (see Caption) Figure 253. Flow field changes in the ERZ of Kīlauea between 30 September 2015 and 5 January 2016. The flow fields moved to the N and W of the June 27th flow field during the last quarter of 2015 with flows coming from a new tube branch which developed closer to the main fissure at Pu?u ?O?o. Smaller breakouts on the E side of the flow ended by the end of November. Courtesy HVO.

Activity at Pu'u 'O'o. A number of small flows erupted from the three main incandescent vents within the crater during this period (figure 254). During 27-28 August 2015, coincident with the breakout from the upper tube on the ERZ (figure 252), a larger flow from the NE pit resurfaced the entire crater floor. Significant flows on 24 and 25 November from two of the pits were also confined to the crater floor. The small lava pond that formed in the W pit in April 2015 was still present. The pond surface was about 20 m below the pit rim. Stronger than usual fumes from the W wall of the north pit hindered access to the W pit by researchers. Sometime between 3 and 8 December, a new incandescent vent opened on the NE flank of the Pu'u 'O'o cone (figure 255).

Figure (see Caption) Figure 254. Oblique aerial photograph of Kīlauea showing crater and pits of Pu'u 'O'o. Red circles mark the approximate location of vents that erupted lava between July and December 2015. Courtesy of HVO.
Figure (see Caption) Figure 255. Photo of Kīlauea looking SW at Pu'u 'O'o on 17 December 2015, showing a new incandescent vent on the NE flank of cone. Courtesy of HVO; photo by T. Orr.

Seismicity. Seismicity between July and December 2015 was higher than normal in the Southwest Rift Zone, and relatively low in the summit and the ERZ areas. There were two notable periods of increased activity; for a few days in October following a slow-earthquake tectonic event where the S flank slipped about 3 cm southeastward, and during a period of a high lava stand in the summit in late December. The largest earthquake during this time was a M 3.9 event that occurred under Kīlauea's S flank.

Within the Southwest Rift Zone (SRZ), seismicity was focused at shallow depths (0-5 km) at the SW end of the rift; it generally occurred in clusters of several days of activity with little to no activity between those times. The seismic activity in the SRZ is interpreted by HVO seismologists to be tied to the transport of magma and volatiles into the zone. For three days in October, seismicity was also elevated in the deep mantle source area below the distal end of the SRZ.

Summit seismic activity was characterized by the typical cycles of tremor and non-tremor, associated with spattering in the overlook vent, and composite events at least a few times per month where rock-falls from the crater walls of the overlook vent generated very-long-period earthquakes in the conduit. An interesting swarm of earthquakes, at a rate of over one per minute at its peak, occurred in the Kīlauea caldera on 31 October 2015 between about 1830 and 2215 UTC; a burst of tremor interrupted the swarm from 2110 to 2123. At least 120 individual events, many were long-period earthquakes, were detectable on the summit spectrogram. The swarm occurred during a period of deflationary tilt, and tremor returned following the swarm. This swarm in the caldera occurred two days after the elevated seismicity in the deep mantle source area, and 15 days after the slow earthquake.

SO2 emission rates. Sulfur dioxide emission rates have been measured by multiple methods over time. The sulfur dioxide correlation spectrometer, or COSPEC, and differential optical absorption spectroscopy (DOAS), are two of these methods. Different digital processing techniques developed over time for the data also aid researchers in understanding the changes observed in SO2 values. Figure 256 shows Kīlauea summit SO2 emissions as recorded and processed by different methods since 2008. While the absolute values vary, the downward trend in SO2 emissions since the Halema'uma'u crater vent opened in 2008 is clear. To gather summit emissions data, the COSPEC instrument is driven at a constant speed around Kīlauea caldera on Crater Rim Drive, and the instrument records the total amount of SO2 overhead.

Figure (see Caption) Figure 256. Daily average summit SO2 emissions in tons per day at Kīlauea since 2008, as measured and processed by different methods. Black squares represent measurements from road-based traverse campaigns, using the single fit 305-315 nm window (SFW) processing technique with the COSPEC instrument. Blue squares represent the same data processed with a dual fit window (DFW) technique, and the pink triangles represent SRT-modeled values. HVO discontinued reprocessing data using the SRT-DOAS model at the end of 2014. Vertical bars represent the standard deviation of individual measurement values recorded on a single day. Image courtesy of HVO.

Values for SO2 emissions from the ERZ and Pu'u 'O'o are collected by taking a similar set of measurements down the Chain of Craters road. Data from 2014 and 2015 (figure 257) show the dramatic spike in emissions at the beginning of the June 27th 2014 breakout followed by gradual decline. A steady increase in emission rate was recorded from the beginning of 2015 until early May, when a sharp decline began coincident with the magma intrusion into the S caldera. The second half of 2015 is characterized by fairly low, relatively consistent emissions, with some notable outliers.

Figure (see Caption) Figure 257. 2014 and 2015 daily average SO2 emissions in tons per day for the East Rift Zone (ERZ), as measured along Chain of Craters Road under trade-wind conditions, with standard deviations of all traverses on a single day. Image courtesy of HVO.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai`i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/)


August 2016 (BGVN 41:08) Citation IconCite this Report

June 27th flow ceases; new flow from Pu'u 'O'o Crater's E flank heads SE

Hawaii's Kīlauea volcano continues the long-term eruptive activity that began in 1983 with lava flows from the East Rift Zone (ERZ) and convecting lava inside Halema'uma'u crater. The US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO) has been monitoring and researching the volcano for over a century since its founding in 1912. HVO provided quarterly reports of activity for January-June 2016, which are summarized below.

The lava lake at Halema'uma'u continued to rise and fall, with regular rockfalls and veneer collapses that sent spatter onto the Overlook on a number of occasions. The June 27th lava flow officially ended in early June 2016 after a new flow emerged from a side vent of Pu'u 'O'o in late May. That flow headed SE toward the ocean into areas where lava flows had not been active since 2013.

Activity at Halema'uma'u. Typical activity continued at Halema'uma'u for the first half of 2016. Rockfalls and veneer collapses from the crater wall caused short-lived (minutes to hours) spattering episodes around the lake margins, and the continuing north-to-south lava lake circulation led to intermittent spattering at the SE sink, (the SE corner of the lake where downwelling occurs).

Days-long oscillations in the lava lake level correlated with changes in summit pressure, as represented by the regular DI (Deflation-Inflation) events. At its lowest (20 February), the lava lake was ~50 m below the crater floor. The lake rose into view from the Jagger overlook multiple times throughout the period (28-29 February, 2 March, 3-4 April; 4 May, 16-17, 24, and 28 June). At its highest (4 April), the lava lake was ~22 m below the rim of the crater (i.e., the floor of Halema'uma'u).

Several vent rim collapses occurred during the period, including two (2 January at 1417 HST and 8 January at 0351 HST) that were large enough to trigger explosive events and very-long-period (VLP) seismicity. The 2 January event was caused by a collapse from the east wall, ejecting lapilli and small bombs onto the Halema'uma'u rim at the visitor's overlook. The 8 January event, triggered by a rockfall from the SE wall directly above the SE sink, was much larger, bombarding the overlook area with lapilli and bombs.

Other significant collapses occurred at 0318 on 4 January (NE rim), at 0023 on 14 February (NW rim), and at 0047 on 21 February (NNW rim). These were accompanied by VLPs and small explosions, but no material larger than ash reached the Halema'uma'u rim.

Activity at Pu'u 'O'o. There were several lava flows within the current crater at Pu'u 'O'o during the period. These flows were fed from the vent in the NE embayment and the two vents in the S embayment (figure 258), and added a few meters of fill to the crater. The larger flows erupted on 1 January, 8-9 February, 24 February, 29 February, 2-6 March, and 23-24 March. From 29 April to 14 May, flows again erupted intermittently onto the crater floor from those same vents. When measured on 9 May, the west side of the main crater floor was 12.5 m below the edge, which was the shallowest it had been since June 2014.

Figure (see Caption) Figure 258. Map showing configuration of crater and vents at Kīlauea's Pu'u 'O'o crater in March 2016. See text for details. Courtesy of HVO (2016 Q1 Quarterly Report).

In addition to filling by lava flows, the crater also shallowed through endogenous uplift. The thermal webcam recorded three instances (the first week of January, the last week of February, and late April through late May) of the crater floor gradually rising. These instances occurred during periods of relatively rapid inflation, as recorded on the nearby POC tiltmeter, which HVO interprets to be caused by pressurization of the underlying magma body.

The West Pit at Pu'u 'O'o continued to host an active lava pond ~27 m across, tucked partly back under the overhanging west edge of the pit. On 9 May the pond level was measured at ~11.5 m below the pit rim, its highest measured level to date, indicating that like the rest of the adjacent crater, it also filled during the period.

Important changes occurred on the upper flanks of Pu'u 'O'o cone during the first half of 2016. The vent that opened on the northeast spillway in early December (BGVN 41:02, figure 255) sealed shut between 19 January and 12 February. Two new flank vents opened up on the northeast spillway during the same time interval (figure 258, "February spillway vents"). These new openings were located higher on the cone, closer to the crater rim at the Northeast embayment.

The two new flank vents opened along a line extending from the outgassing source on the wall of the northeast embayment, through the December flank vent on the spillway, and to the vent for the June 27th lava flow. HVO speculated that this alignment traces the top of the dike that was the source of the June 27th lava flow.

The uppermost of the new openings ejected spatter at least twice: once between 12 February and 4 March, and again between 4 and 25 March. The second time, lapilli and oxidized lithic fragments from the vent walls were ejected to a greater distance (up to 40 m). A small lava flow also erupted from the middle of the three spillway vents between 4 and 25 March. A ~4-m-high spatter cone grew over the farthest downslope vent in mid-May, and aerial views into the upper vent in mid-June revealed that it was a window onto a 15–20 m deep cavity with two fast-moving lava streams that disappeared to the northeast (see below).

Activity along the East Rift Zone (ERZ). The June 27th lava flow (also now referred to as Episode 61e) widened into the forest towards the north of the East Rift Zone through late May 2016, although activity had slowed significantly in that area by the end of March (figure 259). Surface breakouts through late February were generally scattered across the flow field between about 1.5 and 6 km NE of the June 27th flow vent, except for a small breakout just under a kilometer from the vent in early January. In late February, a narrow lobe began to advance through forest along the north margin of the flow, eventually stalling 7.6 km from the vent at the end of March. This activity was fed by the November 25 breakout (see figure 259). Breakouts remained active along the forest boundary through late May. There was also a smaller breakout from the tube near the perched channel that sent flows to the east through the end of March, on the south side of the main Episode 61e flow field (figure 259).

Figure (see Caption) Figure 259. Map of the Episode 61e flow field (June 27th flow) at Kīlauea, showing changes between 30 December 2015 and 25 March 2016. Lava tubes are shown with yellow lines; dashed where abandoned during the report period. See text for the detailed description of flows. Courtesy of HVO (2016 Q1 Quarterly Report).

The distal part of the original June 27th tube NE of the perched channel also fed some minor breakouts through late January, when that section of tube was abandoned. HVO believes that this was probably the consequence of a reduced amount of lava reaching that part of the tube, with much of the lava supply being taken by the upper tube November 25 breakout.

This configuration of active lava flows from Pu'u 'O'o changed rapidly beginning on 24 May 2016 when gradual pressurization of the magma body culminated in two new breakouts from its flanks. The northern breakout (Episode 61f; ~820 m elevation) started at about 0650 from the same vent as the Episode 61e (June 27th) flow, sending a fast-moving channelized flow to the base of Pu'u 'O'o within minutes (figure 260). A second breakout (Episode 61g; ~790 m elevation) started about 40 minutes later on the E flank of the cone, about 500 m below the crater rim (figure 261), and was preceded by a migrating bulge of the ground surface that propagated from the general direction of the Episode 61e/f vent.

Figure (see Caption) Figure 260. View looking south of the northern breakout point (Episode 61f) at Kīlauea's Pu'u 'O'o cone on 24 May 2016 at approximately 0830 HST. This flow only lasted into early June. Courtesy of HVO (2016 Q2 Quarterly Report).
Figure (see Caption) Figure 261. Map showing flow field change on the East Rift Zone (ERZ) at Kīlauea from 25 March to 8 June 2016. Courtesy of HVO (2016 Q2 Quarterly Report).

The onset of episodes 61f and 61g was accompanied by a short-lived deflation at Pu'u 'O'o; the crater floor began a slow subsidence that continued into late June. When observed on 2 June, the lava pond in the West pit was ~24 m below the pit rim. The breakout at Pu'u 'O'o was followed by a slightly larger than usual DI event at Halema'uma'u crater. The summit then resumed gradual inflation overprinted by repeated DI events (figure 262).

Figure (see Caption) Figure 262. Radial tilt measured by borehole instruments at the summit of Kīlauea (UWE, in blue, on the NE rim of the caldera) and at Pu'u 'O'o (POC, in pink, on the N flank of the cone) from 1 April to 1 July 2016. "Radial" directions are chosen to maximize tilt signal during this time period, with positive change usually indicating inflation. The dramatic drop of POC corresponds to the 24 May 2016 opening of the 61f and g vents at Pu'u 'O'o. Image courtesy of HVO (2016 Q2 Quarterly Report).

The Episode 61f flow continued to feed channelized lava for several days after 24 May, but it began to wane as June approached. The 61e (June 27th) and 61f flows were both last definitively active on 4 June, with incandescence visible at night for a few more days, and both were found to be inactive by 8 June. Inactivity was confirmed by thermal camera on 10 June.

Like the 61f flow, the Episode 61g flow started with vigorous activity and rapid advancement, reaching several hundred meters from the vent within minutes. The rate of advance dropped quickly, but the flow remained active and continued to travel relatively steadily downslope SE at a rate of a few hundred meters per day. Generally advancing along the National Park boundary, the flow reached the top of the Pulama pali (cliff) just west of the Royal Gardens subdivision on 28 June (figure 263). The flow was at the base of the pali by the end of the month, giving it a total length of 7.7 km (figure 264). Webcams recorded bright incandescence from several skylights along the upper part of the tube system supplying lava to the front part of the flow.

Figure (see Caption) Figure 263. Aerial view of Episode 61g channelized ?a?a lava flow from Pu'u 'O'o crater at Kīlauea near the top of Pulama pali (cliff) on 28 June 2016. Courtesy of HVO (2016 Q2 Quarterly Report).
Figure (see Caption) Figure 264. Map showing change at the Episode 61g lava flow field from Pu'u 'O'o crater at Kīlauea between 8 and 30 June 2016. The total length of the flow by 30 June was 7.7 km. Courtesy of HVO (2016 Q2 Quarterly Report).

East Rift Zone thermal anomalies.The cessation of the Episode 61e flow field and the beginning of the 61f and 61g fields are clearly evident in the MODVOLC thermal alert pixel images from the MODIS data shown in four weekly views from late May and early June 2016 (figure 265). Prior to 24 May, the Episode 61e field showed strong thermal anomalies N and W of the ERZ. These anomalies immediately began tapering off on 24 May when the 61f and 61g fields appeared until they were no longer visible in satellite image by 8 June. The 61f and 61g fields grew stronger to the south and east after 24 May; after 61f ended in early June 61g anomalies progressed rapidly SE.

Figure (see Caption) Figure 265. Mosaic of four MODVOLC thermal alert pixel images from consecutive weeks in late May and early June 2016, showing the shutting down of active lava flows from the 61e flow field to the erupting of the 61f and 61g flow fields in the East Rift Zone at Kīlauea. A: 18-23 May, 61e (June 27th) flow field is active north of Pu'u 'O'o cone which is visible at bottom center of thermal anomalies. B: 24-30 May, 61f and 61g flows have emerged south of Episode 61e, obscuring the Pu'u 'O'o cone, and 61e anomalies have begun to diminish. C: 31 May-6 June, Episode 61e flow field has cooled considerably and the 61f and 61g fields are both actively showing infrared anomalies. D: 8-13 June, anomalies have ceased from Episode 61e and are now concentrated SE of the ERZ in the active 61g field. Courtesy of MODVOLC.

East Rift Zone SO2 measurements. Trends in East Rift Zone SO2 emissions can generally be correlated with notable summit and rift events. Elevated emissions were measured in 2014 when the June 27th flow began, in late April 2015 when the summit pond overflowed, as well as during the opening of the new vents on Pu'u 'O'o and start-up of the 61g flow in late May 2016 (figure 266).

Figure (see Caption) Figure 266. Daily average SO2 emissions, as measured along Chain of Craters Road under trade-wind conditions at Kīlauea, with standard deviations of all traverses on a single day. Significant events between 1 January 2014 and 1 July 2016 are highlighted with red arrows. Courtesy of HVO (2016 Q2 Quarterly Report).

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Hawai'i Institute of Geophysics and Planetology (HIGP), MODVOLC Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/).


August 2017 (BGVN 42:08) Citation IconCite this Report

New flow from Pu'u 'O'o reaches the sea on 26 July; Kamokuna delta collapses on 31 December 2016

Hawaii's Kīlauea volcano continues the long-term eruptive activity that began in 1983 with lava flows from the East Rift Zone (ERZ) and a convecting lava lake inside Halema'uma'u crater. The US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO) has been monitoring and researching the volcano for over a century since its founding in 1912. HVO provided quarterly reports of activity for July-December 2016, which are summarized below.

Summary of July-December 2016 activity. Activity at Kīlauea during the second half of 2016 was consistent with long-term trends of summit inflation punctuated by DI (Deflation-Inflation) events and a slowly rising average lava lake level inside Halema?uma?u crater. Two explosive events prompted by rockfalls into the lake sent spatter high enough to reach the Halema?uma?u rim; a small overflow at the crater occurred in October, the first since April-May 2015.

Pu'u 'O'o activity continued with little change except for the steady advance of the episode 61g lava flow towards the coast. The pahoehoe front reached the Emergency Access Road near the coast on 25 July and cascaded slowly over the seacliff into the ocean on 26 July just after midnight. It was the first time since August 2013 that lava from Pu'u 'O'o entered the sea. A growing lava delta of about 10 hectares (25 acres) at the Kamokuna entry was the focus of attention by visitors until most of it collapsed into the sea on 31 December 2016.

Activity at Halema'uma'u. Eruptive activity at Halema'uma'u crater was typical during July-December 2016, with a slightly elevated lake level for the last quarter of the year. The lava lake circulation pattern continued in the usual N-S direction, with occasional shifts due to short-lived spattering in areas other than the normal Southeast sink. The lake level rose and fell in concert with the regular summit DI events. On 7 September, the lake level rose to the level of the old rim prior to the April/May 2015 crater overflow, 8 m below the current rim (figure 267).

Figure (see Caption) Figure 267. Halema'uma'u lava lake at Kīlauea on 7 September 2016 at 1842 HST when the surface level was at the level of the old crater rim, 8 m below the current rim. Photo by M. Patrick, courtesy of Hawaiian Volcano Observatory (HVO) (Hawaiian Volcano Observatory Quarterly Report for July-September 2016).

The lowest lake level of the period was 55 m below the floor of Halema'uma'u on 6 October; the lake reached its highest level when it overflowed the rim on 15 October. This was the highest lake level since the overflows in late April to early May 2015, and it covered a small area of about 5,000 m² of the Halema'uma'u crater floor. The latest overflows consisted of two small lobes that spilled onto the crater floor on the SE and NW sides of the lake (figure 268).

Figure (see Caption) Figure 268. Aerial photo of Halema'uma'u crater and lava lake at Kīlauea, looking south, showing the two areas where the lake overflowed onto the crater floor on 15 October 2016. The first overflow is on the upper-left side of the lake; the later overflow at is at the lower right side. Photo by T. Orr, 3 November 2016, courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2016).

The lava lake surface or spatter from the lake was visible intermittently from the Jaggar Overlook on the NW rim of the caldera. During a few of the deflation phases of the DI events, newly exposed juvenile veneer on the crater walls detached and collapsed into the lake. Many of these collapses were too small to notice on the webcams or produce seismic events, but several events were noteworthy.

On 6 August there was a large collapse at the base of the Halema'uma'u crater wall (above the Southeast sink). The collapse produced a large explosive event, along with a composite seismic event, and vigorous spattering. The main explosive deposit blanketed the rim just east of the closed overlook, with tephra forming a continuous layer up to 20 cm thick. Bombs were deposited over an area 220 m wide (along the rim) and up to 90 m beyond the crater rim, with sparse lapilli thrown across the parking lot. HVO monitoring equipment and some of the remaining wooden fencing for the overlook were burned.

A second explosive event occurred on 19 September, also triggered by a collapse of the crater wall above the Southeast sink. Bombs and smaller scoria reached the Halema'uma'u crater rim and ash was deposited across the parking area and road. Large events also occurred on 4 October around 1100, and again at around noon. The first triggered a composite seismic event and spattering when veneer on the E wall fell into the lake, and the other triggered brief spattering when a large sheet of veneer fell from the SW wall. On 19 and 20 October, explosive events were triggered by rockfalls below the overlook (figure 269). The first, at 0745, deposited spatter and ribbon bombs up to 30 cm long on the rim of Halema'uma'u, and produced muted composite seismicity. The 20 October event occurred at 1225, producing a tephra deposit that extended across the road past the parking lot, and generated weak composite seismicity.

Figure (see Caption) Figure 269. Bombs and spatter from Halema'uma'u crater at Kīlauea during October and November 2016. Left: the 20 October explosive event from the HMcam (a webcam on the SE rim of the crater) taken at 1226, showing spatter bombarding the overlook, after the collapse of the crater wall below the webcam. Right: a large bomb thrown from the lava lake during the 28 November explosive event. The fluidity of the spatter allowed it to splat upon impact. Photo by M. Patrick, 28 November 2016, courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2016).

At 1159 on 28 November, another slice of crater wall below the HMcam (one of two Halema'uma'u webcams) fell and triggered an explosive event that again threw tephra onto the rim. The tephra deposit was sparse and confined to a narrow area 90-100 m wide along the rim between the two webcams on the SE rim. While most of the spatter bombs were less than 30 cm in size, the largest was about 160 cm long. The clasts were relatively fluidal in texture and most splatted upon impact (figure 269). The power and Ethernet cables for one of the webcams were damaged during this event. A similar event occurred on 2 December at 0658, when a large slab from the overlook crater wall directly below one of the webcams collapsed. This also triggered a small explosive event which bombarded the rim with spatter near the two cameras, and produced rare ribbon bombs close to a meter long. Another large veneer collapse occurred on 13 December at about 1355, when a slab fell from the N wall into the lake and triggered spattering.

Activity at Pu'u 'O'o and the East Rift Zone. There were few notable changes at Pu'u 'O'o cone from July through December. Very slight uplift was observed during 2-4 July that may have corresponded to inflationary tilt. The forked lava stream in the vent on the NE spillway was visible on a 15 July overflight. Subsequent overflights found the streams progressively more crusted over, and no lava was visible in the vent on the 19 August overflight. The W pit had a large collapse of its NE rim that was noticed on 1 September. A few meters had shaved off the rim of the pit, making a pile of rubble on the pit floor.

One of the two vents on the NE spillway re-opened at some point during the day on 2 November. Fieldwork on 3 November showed that the W-pit lava pond was 52 m across and 22 m below the pit rim, at an elevation of 848 m. The pond level was at 847 m when seen again on 29 November, with weak spattering at a few places around the pond perimeter.

The new flow (episode 61g), which began from the NE flank of Pu'u 'O'o cone on 24 May 2016, had reached the top of Pulama pali (cliff) on 28 June 2016 (BGVN 41:08, figure 263). It reached the base of the pali on the last day of June, and began to advance quickly across the coastal plain (figure 270). It was initially quite narrow, about 100 m across, possibly because of the flow high advance rate and confining topography in the area, according to HVO. The flow had slowed by 5 July; it was half way across the coastal plain, with the leading tip about 1.7 km from both the base of the pali and the ocean, and 1.6 km from the closest portion of the FEMA evacuation road that runs along the coast.

Figure (see Caption) Figure 270. Episode 61g lava flow at Kīlauea leaves the base of Pulama pali headed across the coastal plain on 2 July 2016. Several channelized 'a'a flows are visible coming down the slope. Location is at the eastern boundary of the National Park and western boundary of the Royal Gardens subdivision. Photo by Kirsten Stephens, courtesy of Hawaiian Volcano Observatory (HVO) (Hawaiian Volcano Observatory Quarterly Report for July-September 2016).

The flow front continued to advance slowly over the next few weeks and eventually stalled in mid-July. The stalled front was soon overtaken, however, by breakouts that had been steadily advancing downslope behind the front. These breakouts formed a new front that continued to advance rapidly at up to 170 m/day. By 24 July, the flow front had reached to within about 260 m of the FEMA emergency access road. The next day (25 July) at 1520 HST, the 61g flow crossed the FEMA road (figure 271), and at 0112 HST on 26 July lava spilled over the sea cliff and into the water, marking the start of the rapid growth of the Kamokuna ocean entry.

Figure (see Caption) Figure 271. Episode 61g lava flow of Kīlauea crosses the FEMA emergency access road. Left: the lava flow on 25 July 2016 at 1616 HST about 30 minutes after it crossed the road in a thin sheet, photo by L. DeSmither. Right: on 5 August (almost two weeks later), in the same general location as the first, note the amount of flow inflation (HVO geologist for scale), photo by M. Patrick. Both images courtesy of Hawaiian Volcano Observatory (HVO) (Hawaiian Volcano Observatory Quarterly Report for July-September 2016).

The flow field continued to widen over the next few months, as scattered breakouts crept down the flow (figure 272). One of these breakouts formed a second ocean entry point several hundred meters to the W of the initial entry. Other, smaller breakouts reached the ocean along the stretch of land between the two main entry points, forming short-lived entries (figure 273). Persistent breakouts near the base of the Pulama pali began to build a ramp, making the pali less steep.

Figure (see Caption) Figure 272. A breakout from the episode 61g flow on the coastal plain of Kīlauea on 20 September 2016. Burning vegetation on the pali from the recent flow is visible in the background. Photo by Matt Patrick, courtesy of Hawaiian Volcano Observatory (HVO) (Hawaiian Volcano Observatory Quarterly Report for July-September 2016).
Figure (see Caption) Figure 273. Lava flows into the sea at Kīlauea from one of the entry points along the Kamokuna ocean entry, as viewed from the sea, on 11 September 2016. Photo by Tom Pfeiffer, courtesy of Volcano Discovery.

Numerous small delta collapses on both the E and W deltas were reported during August and September, but the deltas overall continued to grow. By the end of September the E delta was about 5.2 hectares (12.9 acres), and had developed several large coast-parallel cracks that suggested it was becoming unstable (figure 274). Activity at the W delta was always subordinate to that at the E delta and was abandoned in late September, having reached about 2.6 ha in size.

Figure (see Caption) Figure 274. The E lava delta at the Kamokuna ocean entry at Kīlauea on 30 September 2016. Top: the E Kamokuna ocean entry and lava delta, showing large cracks parallel to the sea cliff. Photo by T. Orr. Bottom: thermal image of the delta showing heat in the cracks, and hot water plumes extending out from the ocean entry points. Courtesy of Hawaiian Volcano Observatory (HVO) (Hawaiian Volcano Observatory Quarterly Report for July-September 2016).

The only surface activity not on the lower half of the flow field (from the top of the pali to the coast) during July-September was a large breakout from the episode 61g vent on the east flank of Pu'u 'O'o cone that started 29 August. The breakout was active for only a few days and died during the first week of September. On 27 September a skylight abruptly opened a few hundred meters inland from the ocean entry, producing a strong glow at night. Very little surface activity was present on the coastal plain near the Kamokuna ocean entry during October-December. A small breakout started about a kilometer upslope from the park rope line on 24 November, and remained active until the evening of 28 November.

However, breakouts did continue near the Pulama pali during October-December, further building up the intermediate-sloped ramp at the base of the pali (figure 275). The first of these started on 1 October and continued until at least 23 October, having extended a short distance beyond the base of the pali. A breakout started near the bottom of the steepest part of the pali during 22-23 November, producing short-lived channelized flows. The breakout remained active until at least 30 November, but was apparently inactive by 6 December.

Figure (see Caption) Figure 275. Episode 61g eruption of Kīlauea on 13 November 2016, captured by the Advanced Land Imager (ALI) on NASA's Earth Observing-1 satellite. The lava first reached the ocean on 26 July, and most of the lava delta created at the Kamokuna entry collapsed into the sea on 31 December 2016. The gray areas in the image show lava that has accumulated since 1983. The 2016 active flow started at a vent just east of the Pu'u 'O'o crater. It moved SE and S through lava tubes below the surface. The signature of a recent surface breakout is the lighter gray area at the base of the Pulama pali (cliff). Courtesy of NASA Earth Observatory.

At the episode 61g vent near Pu'u 'O'o cone, a new breakout started between 0830 and 0840 on 21 November 2016. The ground surface over and just upslope from the vent was fractured and uplifted 3-4 m. The breakout consisted of two branches, one of which generally headed S and was short lived, stagnating during the day of 26 November. The other flowed NE and surrounded the nearby Pu?u Halulu cone before turning to the SE. The flow front of this second branch was about 2 km from the vent when mapped on 17 December (figure 276), but continued to advance through the end of the year. In addition to the 21 November breakout, other short-lived breakouts from the episode 61g vent were active during 1-3 December, 11-12 December, and 25-28 December.

Figure (see Caption) Figure 276. Changes to the flow field of the episode 61g flow between 20 September and 25 December 2016. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2016).

During an overflight on 3 November, HVO found that the W delta, which became inactive in late September, was approximately 2 ha after losing about 0.6 ha to wave erosion. The E delta at the Kamokuna ocean entry remained very active through December, reaching a relatively stable size of around 10 ha, kept in check by frequent small collapses. Large cracks on the delta parallel to the old sea cliff were apparent, and the delta on the seaward side of the cracks appeared to be tilted, indicating instability. The delta was about 9 ha in size in late December.

During mid-afternoon on 31 December 2016, the E delta began to collapse in pieces. Over the course of a few hours, most of the delta had disappeared into the water, leaving about 1 ha as narrow remnant ledges at the base of the sea cliff (figures 277 and 278). In addition to the delta collapse, roughly 1.6 ha of the older, post-1986 sea cliff also fell into the ocean, likely due to undercutting promoted by the delta collapse. This portion of the old sea cliff was partially above the E edge of the delta, but most of it was adjacent to the delta to the east (figure 278), and included part of the National Park viewing area. The sea cliff collapses produced thick, dusty plumes and large waves that splashed back onto the sea cliff, in some instances. In the days that followed, a few more small slices of unstable sea cliff collapsed into the water. The total area that collapsed, including the delta and the older sea cliff, was approximately 10 ha.

Figure (see Caption) Figure 277. Eastern Kamokuna lava delta (episode 61g flow) at Kīlauea, before and after the 31 December 2016 collapse. Left: The delta on 14 October when it was about 6 ha (15 acres) in size. Photo by L. DeSmither. Right: After the 31 December collapse, showing remnants of the delta. Photo by M. Patrick on 1 January 2017. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2016).
Figure (see Caption) Figure 278. Map of the Kamokuna ocean entry at Kīlauea as of 3 January 2017, showing areas of collapse, remaining delta, and other features. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2016).

Thermal anomaly data. Satellite-based thermal anomaly data from the MODIS instrument generates a strong continuous signal from Kīlauea that closely follows the distribution of the active lava flows. As the episode 61g flow emerged from Pu'u 'O'o and headed SE, the thermal signature was strong between Pu'u 'O'o and the Pulama pali during the last week of June as recorded by the University of Hawaii's MODVOLC thermal alert system. By mid-August, a few weeks after the flow had reached the sea, the thermal activity extended from the pali to the Kamokuna ocean entry site (figure 279).

Figure (see Caption) Figure 279. Thermal alerts from MODVOLC at Kīlauea during late June and August 2016. Pu'u 'O'o is beneath the pixel in the upper left of the top image. Top: Alerts during 26 June-1 July 2016. The Pulama pali shows as the shaded area underneath the leading SE edge of the flow. Bottom: Alerts during 12-19 August 2016. The lava was hottest between the Pulama pali on the N and the new Kamokuna ocean entry at the bottom of the image. Courtesy of HIGP MODVOLC Thermal Alerts System.

New breakouts from the Pulama pali area were recorded as thermal alerts during the second week of November along with the evidence for continued thermal alerts from the Kamokuna delta at the shoreline. At the vent area of episode 61g, near Pu'u 'O'o cone, new breakouts flowed NE of the cone and were captured as thermal alerts during early December (figure 280).

Figure (see Caption) Figure 280. Thermal alerts from MODVOLC at Kīlauea during November and December 2016. Top: New breakouts were reported from the Pulama pali area and were visible in the thermal data during 5-11 November along with the thermal alerts from the Kamokuna lava delta at the shoreline. Bottom: Alerts during 10-16 December 2016 show renewed breakout activity at the episode 61g vent near Pu'u 'O'o (upper left of image) as well as continued activity at the Kamokuna ocean entry on the shoreline. Courtesy of HIGP MODVOLC Thermal Alerts System.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); NASA Earth Observatory, EOS Project Science Office, NASA Goddard Space Flight Center, Goddard, Maryland, USA (URL: http://earthobservatory.nasa.gov/); Hawai'i Institute of Geophysics and Planetology (HIGP), MODVOLC Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/); Tom Pfeiffer, Volcano Discovery (URL: http://www.volcanodiscovery.com/).


November 2017 (BGVN 42:11) Citation IconCite this Report

Episode 61g lava flow continues with many breakouts; firehose enters the sea at Kamokuna ocean entry

Hawaii's Kīlauea volcano continues the long-term eruptive activity that began in 1983 with lava flows from the East Rift Zone (ERZ) and a convecting lava lake inside Halema'uma'u crater. The US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO) has been monitoring and researching the volcano for over a century, since 1912. HVO quarterly reports of activity for January-June 2017, by HVO scientists Lil DeSmither, Tim Orr, and Matt Patrick, form the basis of this report. MODVOLC, MIROVA, and NASA Goddard Space Flight Center (GSFC) provided additional satellite information of thermal anomalies and SO2 plumes.

The lava lake level inside Halema'uma'u crater continued to rise and fall periodically during January-June 2017. The lava continued to circulate, and periodic rockfalls and veneer collapses caused small explosions within the lake. A few pieces of lapilli and minor ash landed at the Jagger Overlook. There were no major changes at the Pu'u 'O'o crater during the period; only minor fluctuations occurred in the lava pond lake level, and periodic rockfalls briefly disturbed the pond surface. There were, however, many surface breakouts along almost the entire length of the episode 61g lava flow from near the base of Pu'u 'O'o all the way to the Kamokuna ocean entry, about 12 km S. After the collapse of a large part of the delta at the Kamokuna ocean entry on 31 December 2016, lava continued to pour into the sea, and a new submarine delta began to grow. Instability of the sea cliff led to fractures and additional collapses during January and February. By the end of March, a small new delta was again visible above sea-level. It collapsed into the sea on 3 May, but another new delta quickly began to grow and reappeared by the end of the month. The "firehose" solidified and formed a ramp to the delta; surface flows caused thickening of the delta through the end of June.

Activity at Halema'uma'u. The lava lake inside 1-km-wide Halema'uma'u crater at Kīlauea's summit was relatively quiet during the first half of 2017. It is located within the 200-m-wide "Overlook crater" at the SE edge of Halema'uma'u. The lava lake level rose and fell in reaction to typical summit pressure changes, as reflected in numerous deflation-inflation (DI) events. The rise and fall of the lake level generally took place over the course of several hours to days. At its highest level, the lake was 9 m below the floor of Halema?uma?u crater on 4 January 2017. Two weeks later, the lake dropped to its lowest level measured, 52.5 m, on 17 January. It was at a very similar height again, 52 m below the rim, on 23 June. There were two unusually large, fast drops in the lava lake level during June. The first, from 13 to 14 June, was a drop of 24 m in 24 hours. The second was a drop of 30 m over two days (21 to 23 June), which was the greatest single drop in lava level since mid-January.

The circulation pattern of the lava lake surface remained consistent, upwelling from the north end of the lake and migrating to the southern edge (and the southeast sink) where the crust descended. Short-lived spatter sources around the lake, generally caused by a disruption of the lake surface (e.g., rock falls), would temporarily (and sometimes only locally) redirect the lake surface towards the spatter source. Seismic tremor levels fluctuated along with spattering intensity. During much of the second quarter of 2017, spattering in the southeast sink was located inside of a large grotto with stalactites hanging from the roof.

The rockfalls and veneer collapses from January through June were not large enough to trigger any significant explosions, but there were several smaller events. The first, observed on 9 January at approximately 1320, occurred during Kona winds (stormy, rain-bearing winds that blow over the islands from the SW or SSW, in the opposite direction of the normal trade winds). It did not produce an explosive deposit or excessive amounts of tephra in the collection buckets near the Halema?uma?u Overlook and parking lot (500 m S of active lava lake), but did send ash and at least one 2-3 mm lapillus to the Jaggar Overlook and parking lot (about 1.8 km NW of the lava lake), and generated a composite seismic event. Composite events were also triggered on 14 January (2250) when a large piece of veneer collapsed off the northern crater wall, and on 16 January (1524) after a small rockfall from the southern inner edge of the Overlook crater (the smaller crater inside Halema?uma?u that contains the lava lake). On 23 March at 0036, a slice of the Overlook crater's southern ledge collapsed into the lake, triggering brief spattering and another composite event. On 26 May at 1114 HST, a piece of the northern Overlook crater wall collapsed into the lake (figure 281). This triggered a composite seismic event, lake surface agitation and spattering, and produced a dusting of ash on the cars in the HVO parking lot (at the Jaggar Overlook). Other veneer, grotto, and ledge failures often triggered brief spattering, localized subsidence of the crust, and composite seismic events.

Figure (see Caption) Figure 281. Webcam image from the HMcam on the rim of the Overlook crater at Kīlauea on 26 May 2017 at 1116 HST, less than two minutes after a collapse, showing the agitated lava lake surface. A large chunk from the northern crater wall, directly above the active spattering, fell into the lake, which triggered spattering and a composite seismic event. The area of the wall that collapsed is discernible above the spatter by the newly exposed wall rock that is lighter in color. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for April - June 2017).

Activity at Pu'u 'O'o. There were no major changes in Pu'u 'O'o crater during the first half of 2017, and there was still an active lava pond in the West pit at the end of June (see figure 258, BGVN 41:08 for detailed crater map). The pond level appeared to be relatively steady, ranging from 19 to 21 m below the pit rim (849-851 m elevation), and the pond diameter ranged from 43 m in March to 47 m at the end of May. A time-lapse camera looking into the West pit lava pond, which was installed on 16 March, revealed a few rockfalls and collapses. The pond surface was completely disturbed on 18 April at 0809 HST and again on 20 May at 2304; overnight on 4-5 May a talus deposit appeared on the pit floor, suggesting rockfalls. On 31 May a ledge just above the West pit lava pond surface, representing the pond level from a few months prior, had a pile of rubble from a portion of the east wall collapsing.

Summary of episode 61g breakouts. Throughout the first half of 2017, there were many active surface breakouts along almost the entire length of the episode 61g flow field (figure 282). Near the 61g vent, a new breakout started on 22 January, which traveled along the southern margin of the flow field before it stopped on the morning of 9 February. The breakout that had started on 21 November 2016, also ended on 9 February, possibly because the system was starved of supply after a week and a half of deflation. A new breakout began on the upper part of Pulama Pali on 10 February that lasted through early April. Two breakouts appeared in the Royal Gardens subdivision on 15 February and 1 March, each lasting a few weeks. During the day of 5 March, a breakout began approximately 1.3 km downslope of the vent that remained weakly active on the upper flow field through the end of June. Two new breakouts started in mid-June that were also active through the end of the month.

Figure (see Caption) Figure 282. Map of the episode 61g flow field at Kīlauea produced on 10 July 2017, showing the flow margin expansion (red) since 30 March 2017. During this time, the flow field expanded an additional 183 hectares from the previous 846 hectares (as of March 30), to a total of 1,029 hectares, increasing the flow field area by 22 percent. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for April - June 2017).

Details of episode 61g breakouts. On 10 February 2017 around 0710 a new breakout was reported on the steep part of Pulama Pali on the western flow field; by the next day pahoehoe surface flows were advancing across the coastal plain. Incandescence from the surface breakouts on the pali was only visible for the first few days, but the breakout continued to feed the surface flows on the coastal plain. By 14 February the flows had advanced approximately 2.3 km from the base of the pali (about 1.2 km from the coast), and by 25 February the flow was approximately 660 m from the ocean. These sluggish pahoehoe flows were largely outside the National Park boundary as they widened the eastern edge of the 61g flow margin. The flow advanced to within approximately 300 m of the road (500 m from the ocean) by 2 March. Breakouts then opened on the upper half of the coastal plain around 7 March, remaining weakly active through the end of March. On 8 April, tiny remnant surface flows from the breakout were found on the coastal plain. The spiny pahoehoe was 500 m out from the base of the pali and 2.8 km from the ocean, but the breakout was confirmed by thermal images to have ended by 10 April.

There were two breakouts that began near the top of Royal Gardens subdivision, on 15 February and 1 March 2017. The first started during the day, with glow visible in the R3cam at sundown. By 18 February the breakout was visible from the HPcam on the steep part of Pulama Pali, and remained active on the pali until the evening of 12 March. The 1 March breakout began higher upslope, with incandescence visible at sundown. This breakout slowly advanced and after a few days could not be seen from the webcam. Thermal images from 16 March indicated that the flow was no longer active.

During the day of 5 March 2017, a breakout began approximately 1.3 km downslope of the episode 61g vent (visible in the R3cam). By the middle of March, this was the most active breakout on the flow field, with surface activity expanding both sides of the flow field, and ranging between approximately 2 and 3.5 km from the vent. It was visible from the FEMA emergency road on 28 April on the upper pali. There was very little advancement over the next few weeks, until it reached the top of the steep part of the pali on 17 May. By 23 May, the sluggish pahoehoe flow front was approximately 400 m out from the base of the pali, and there were many small pahoehoe and aa channels on the steep pali face. Four days later (27 May), there were still breakouts on the pali, and the flow front had advanced another 100 m along the western margin of the 61g flow field. Satellite imagery from 2 June showed the breakout was still active, but by 13 June no activity was found on the coastal plain, and thermal imagery showed no active breakouts on 21 June. The 5 March breakout remained weakly active on the upper flow field (above the pali) through the end of June.

Two new breakouts started in June 2017, and remained active through the end of the month. The first started around 0600 HST on 13 June (figure 283), approximately 1.1 km from the episode 61g vent, located just upslope of the 5 March breakout point. These surface flows quickly became the most active along the 61g flow field. The second breakout originated from the upper pali (near the top of Royal Gardens subdivision) during the day of 26 June, and advanced down the pali east of the main flow field, reaching the base during the night of 4 July.

Figure (see Caption) Figure 283. The 13 June breakout point approximately 1.1 km from the 61g vent, along the tube system at Kīlauea. The breakout uplifted (about 2 m) and cracked the older flow (center) as it pushed its way to the surface and oozed through the cracks in multiple locations around the central uplifted area. Photo by L. DeSmither on 21 June 2017. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for April - June 2017).

Activity at Kamokuna ocean entry. After the ten hectare (25 acre) delta and sea cliff collapse on 31 December 2016, the ocean entry consisted of a single vigorous lava stream (informally called "the firehose") entering directly into the ocean from the episode 61g lava tube; it was located 21 m above the water (figure 284). Interactions between the lava and sea water produced a single robust plume and sporadic littoral explosions that threw spatter up to roughly 30 m above the top of the sea cliff. Spatter from these explosions fell on the cliff adjacent to the ocean entry, and began to build a littoral cone that was first noticed on 28 January on the cliff's edge. The sea cliff in the immediate area and downwind of the ocean entry was blanketed in a layer of Pele's hair and Limu o Pele (Pele's seaweed) which fell from the plume and added to the ground cover as the firehose continued.

Figure (see Caption) Figure 284. Lava pours into the ocean at the Kamokuna ocean entry at Kīlauea. Left: "The firehose" on 28 January 2017 exits the tube as a wide, thin sheet in this photo taken from the nearby observation point. Right: By 1 February, the lava stream changed to a cylindrical hose shape. Photos by M. Patrick, courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for January – March 2017).

A discolored water plume was visible at the ocean entry flanking an area of darker water directly out from the entry point, on either side. Thermal images taken in mid-March 2017 indicated that the discolored area was also heated, with the anomalous area extending out about one kilometer (figure 285).

Figure (see Caption) Figure 285. Photo and thermal images taken of the Kamokuna ocean entry at Kīlauea during a 30 March 2017 overflight. Left: Photo of the ocean entry and distinct plumes of steam and discolored water (photo by L. DeSmither). Right: A thermal image showing the heated water plume with the small area of cool water directly in front of the ocean entry. The hot material spread horizontally along the base of the sea cliff directly in front of the ocean entry, is the newly forming delta. On the 61g flow field (upper right), two small breakouts are visible on the coastal plain near the base of Pulama Pali, and the 5 March breakout (top-center), is discernable on the upper flow field near Pu'u 'O'o. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for January - March 2017).

Many large ground cracks were noticed in the sea cliff inland from the entry after the 31 December 2016 Kamokuna delta collapse, including a set of en echelon cracks at the edge of the old sea cliff where over 1.6 hectares (about 4 acres) had collapsed. On a 25 January 2017 overflight, thermal images revealed a hot crack parallel to the sea cliff and a corresponding collapse pit on the trace of the lava tube, suggesting major instability. A few days later (28 January) the crack was measured at 30 cm wide, up to 220°C, was visibly very deep, and the seaward side of the crack was sloping slightly towards the ocean (figure 286). HVO scientists could also occasionally feel slow ground shaking at an observation point 240 m east of the ocean entry. When measured again (in the same spot) on 1 February, the crack was 75 cm wide. Upon further examination, grinding noises were coming from the crack and the seaward side of the crack was visibly swaying about 1 cm.

Figure (see Caption) Figure 286. Photos of the large ground crack near the Kamokuna ocean entry at Kīlauea, with yellow arrows pointing out two distinctive flow edges for comparison. Left: A photo taken on 28 January 2017 (by M. Patrick), when the crack was measured at 30 cm wide (just above the lower arrow). Right: Photo taken on 2 February, after a large portion of the sea cliff collapsed into the ocean, the crack measured 100 cm (photo by T. Orr). Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for January - March 2017).

On the morning of 1 February around 0735, a small collapse of the sea cliff was reported near the firehose. The next day, the firehose was no longer visible from the observation point (possibly due to erosion of the sea cliff), but sporadic littoral explosions were still occurring. HVO personnel returned to the crack (which had begun steaming) for observations and to record video of the cliff oscillating. At 1255, about 30 seconds after the camera began to record, the seaward slab of the crack began to fall away. After the collapse only a small piece of the slab remained, and the crack measured 100 cm in width, 25 cm more than the previous day, most of which occurred during the collapse and in the few minutes following (figure 286). By 8 February, the remaining slab of cliff was gone, one piece collapsed at 1507 on 2 February, and the rest collapsed sometime between 6 and 8 February. The littoral cone that had been building on the edge of the cliff fell in with the collapse, but by 8 February, another had formed on the new sea cliff edge above the ocean entry.

During January, the firehose exited the tube as a thin broad sheet, but by the end of the month had changed into a cylindrical stream (figure 284). The output amount slowly began to wane, and on 8 March the ocean entry plume shut off for about 30 minutes between 1616 and 1646 with only a little puff of steam visible in between. The plume shut off briefly again several times on 18, 19, and 20 March for periods up to about 90 minutes in length.

From January through March 2017, the firehose continued with no sign of a delta forming, which suggested steep bathymetry below the ocean entry. By 22 March, the firehose was no longer visible from the public viewing area but incandescence was visible near the water surface, suggesting that the firehose was becoming encased in lava and a small delta was finally beginning to form. On 24 March, there were few, if any, littoral explosions, and the thick plume at the ocean entry made it impossible to see any signs of a delta, but time-lapse images verified the formation of one. There were many floating, steaming blocks in the water offshore of the entry. An overflight on 30 March showed a thick haze that was obscuring the small delta at the base of the cliff, where only brief tiny spots of incandescence could be seen near the water's surface. Images from a thermal camera indicated hot material from the delta extending approximately 60 m east along the cliffs base at the ocean entry.

By the end of March 2017, the firehose flow activity was no longer visible and a tiny new delta began to form. On 8 April, the delta was estimated to be extending roughly 25 m out from the base of the sea cliff (using cliff height for scale). A sparse field of dense angular blocks were deposited on 25 March between 0803 and 0808 HST on the sea cliff near the ocean entry, which covered an area of approximately 70 x 70 m (the largest block observed was 50 cm across).

During the first half of April the small delta was mostly obscured by the ocean entry plume. By the end of the month, the delta size was estimated to be 1.2 hectares (roughly 3 acres, using time-lapse images). On 3 May, nearly the entire delta collapsed between 0955 and 1000 HST, following a large steam plume and weak spattering from one of the cracks on the delta, along with delta subsidence in the preceding 20 minutes before the collapse. Many small pieces of the remnant delta fell off over the next few hours.

The delta quickly began to rebuild after the collapse, and on 23 May coast-parallel cracks were apparent on the new delta. The tubed-over firehose created a ramp-like feature near the cliff face where the 61g tube exited the older sea cliff (figure 287). This ramp was narrow at the point where the tube exits the cliff, and flared out as it reached the surface of the delta, insulating the 61g lava on its way to the delta. Near the top of the ramp there was an area of concentrated degassing, and evident cracks in the ramp revealed incandescence. On 16 June, surface flows on the delta covered a large portion of the surface, including the coast-parallel cracks so they were no longer visible.

Figure (see Caption) Figure 287. A view of the crusted over firehose ramp on 29 June 2017 at the Kamokuna ocean entry of Kīlauea where the 61g lava tube exits the sea cliff and feeds the ocean entry from an established tube on the delta. On the west (left) side of the ramp, there are cracks in the crusted surface where delta surface flows likely originated that show incandescence beneath. Photo by L. DeSmither, courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for April - June 2017).

Time-lapse images from 25 June revealed that firehose activity returned briefly between 1139 and 1149 HST, and produced channelized surface flows that continued into the following day (when a skylight was visible on the delta). The delta had grown to approximately 2.4 hectares (6 acres) by 29 June (figure 288), and had also thickened significantly from the recent surface flows on the delta. Much of the delta surface was covered by the repeated surface flows, but there was still a coast-parallel crack visible on the western side.

Figure (see Caption) Figure 288. The lava delta at Kamokuna ocean entry at Kīlauea on 23 May 2017 (left) and 13 July 2017 (right) showing the thickening of the delta near the cliff face caused by repeated small surface flows. These flows appear to have doubled the thickness of the delta and created a distinctly sloped surface from the base of the cliff to the sea. Photos by L. DeSmither, courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for April - June 2017).

Satellite thermal anomaly and SO2 data. Satellite thermal anomaly data for Kīlauea can be closely correlated with ground-based observations by HVO scientists, thus providing validation of remote-sensing data. The MODVOLC thermal alert system captured distinct anomalies during January-June 2017 from Halema?uma?u Crater, Pu'u 'O'o Cone, the episode 61g flow, and the Kamokuna ocean entry (figure 289). The changes from month to month in the locations of the hotspots, especially the locations of the breakouts of episode 61g flow, are readily apparent in the MODVOLC images, and match the descriptions of these events provided by HVO scientists.

Figure (see Caption) Figure 289. Thermal alerts identified by the MODVOLC system by month at Kīlauea, January-June 2017. The thermal anomaly signatures of the lava lakes at Halema'uma'u crater and Pu'u 'O'o crater persist throughout the period; while the changes in the locations of the thermal anomalies of the episode 61g flow and the Kamokuna ocean entry closely match ground observations by HVO staff, described in the text. Courtesy of HIGP - MODVOLC Thermal Alerts System .

The MIROVA thermal anomaly information, which plots Middle InfraRed Radiation from the MODIS data, also shows the locations and movements of the sources of heat at Kīlauea over time (figure 290), and this information correlates closely with ground observations by HVO staff. Note that the MIROVA center point for relative distances described here is about 10.5 km (0.1°) E of the summit on the western Halema'uma'u crater rim. The anomaly locations at about 10 km distance correspond to both the lava pond at Pu'u 'O'o crater and the Halema'uma'u crater lava lake. Those about 20 km away correspond to the Kamokuna ocean entry. Anomalies that migrate over time between 10 and 20 km distance trace the movement of the episode 61g flow breakouts between Pu'u 'O'o and the Kamokuna ocean entry.

Figure (see Caption) Figure 290. The MIROVA thermal anomaly data for Kīlauea tracks both radiative power and the distance of the radiative power from the assigned "summit" location (about 10.5 km E of the high point on the western Halema'uma'u crater rim). In this chart of the distance to the thermal anomalies during the year ending 17 August 2017, the variations in distance (y-axis) correspond closely to changes in the locations of the active lava flow sites. The Halema'uma'u and Pu'u 'O'o craters are located about 10 km away; the episode 61g flow field has anomalies that track between 10 and 20 km away; and the Kamokuna ocean entry is represented by the anomalies about 20 km distant. See additional discussion in the text. Courtesy of MIROVA.

Plumes of SO2 emissions visible in satellite data are common at Kīlauea (figure 291). The normal trade winds send most emissions to the SW, but occasional "Kona" winds blow in the opposite direction and disperse SO2 to the NE from the summit. Large lava breakouts and activity at the summit crater can produce substantial SO2 plumes.

Figure (see Caption) Figure 291. Sulfur dioxide emissions data from the OMI instrument on the Aura satellite for selected days at Kīlauea during January and March 2017. Top Left: uncommon "Kona winds" blowing from SW to NE over the island, opposite to the normal trade winds dispersed the SO2 plume to the NE on 5 January 2017. Top Right: The more common trade wind direction, to the SW, carried a typical size SO2 plume on 10 January 2017. Bottom: The significant breakout from episode 61g that began on 5 March likely produced the larger than normal SO2 plumes captured on 5 and 6 March 2017. Courtesy of NASA GSFC.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: https://volcanoes.usgs.gov/observatories/hvo/); Hawai'i Institute of Geophysics and Planetology (HIGP) - MODVOLC Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/); MIROVA (Middle InfraRed Observation of Volcanic Activity), a collaborative project between the Universities of Turin and Florence (Italy) supported by the Centre for Volcanic Risk of the Italian Civil Protection Department (URL: http://www.mirovaweb.it/); NASA Goddard Space Flight Center (NASA/GSFC), Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, 8800 Greenbelt Road, Goddard, Maryland, USA (URL: http://so2.gsfc.nasa.gov/index.html).


March 2018 (BGVN 43:03) Citation IconCite this Report

Activity continues at Halema'uma'u lava lake, and at the East Rift Zone 61g flow, July-December 2017

Hawaii's Kīlauea volcano continued its eruptive activity, intermittent for thousands of years and continuous since 1983, throughout 2017. The summit caldera formed about 500 years ago, and the East Rift Zone (ERZ) has been active for much longer. Lava lakes were intermittent in and around Halema'uma'u crater at the summit until 1982. Lava has been continuously flowing from points along the ERZ since 1983, and the episode 61g flow was still vigorous through the end of 2017. A large explosion within Halema'uma'u Crater in March 2008 resulted in a new vent with a lava lake that has been continuously active through 2017.

The US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO) has been monitoring and researching the volcano for over a century, since 1912. Quarterly Kīlauea reports for July-December 2017, written by HVO scientists Carolyn Parcheta and Lil DeSmither, form the basis of this report. MODVOLC, MIROVA, and NASA Goddard Space Flight Center (GSFC) provided additional satellite information about thermal anomalies and SO2 plumes.

The lava lake inside the Overlook vent at Halema'uma'u Crater continued to rise and fall during the second half of 2017 with no significant lake level changes and a few periods of spattering. The lake level overall was lower at the end of the year than during much of the year, reflecting long-term deflation of the summit. There were no major explosive events from rockfalls, but smaller sloughs of veneer (thin layers of recently cooled lava that adhere to the vent walls) without accompanying explosions were common. Ongoing subsidence at Pu'u 'O'o, especially around the West Pit prompted moves of monitoring equipment, but little else changed at the cone.

The episode 61g lava flow continued with numerous surface breakouts from areas near the vent all the way down over the pali and into the ocean at the Kamokuna delta during July-December 2017. Changes in the subsurface flow in lava tubes contributed to changing locations of surface breakouts, which were still active at the end of the year. The lava flowing into the ocean at Kamokuna slowed and finally ended in November with changes occurring on the delta in the final weeks of its activity.

Activity at Halema'uma'u. For the second half of 2017, activity at the lava lake inside the Overlook crater continued with little change from January-June. The lake's surface circulation pattern was typical, with upwelling in the N and subsidence of the crust along the southern lake margin, but also around the entire edge of the lake depending on the upwelling location (figure 292). There were often "sinks" a few tens of meters from the SW edge of the lake where the crust folds in on itself and sinks, pulling material away from the wall. A noticeable lava veneer buildup often occurred on the southern margin, where the surface crust was most consistently subducting. Short-term spattering events lasted minutes to hours and occasionally altered the surface crust motion by creating localized subsidence. Throughout the period, spattering was often confined to a grotto at the SE sink. On most days, two or more spattering sites were active simultaneously.

Figure (see Caption) Figure 292. Commonly referenced features and geographic nomenclature at the Halema'uma'u lava lake which is inside the Overlook vent at Kīlauea. Geographic directions are faded gray arrows inside the lake with white labels N, S, E, and W, and are distinct from nomenclature cardinal directions (black arrows) used in the text. Satellite image from DigitalGlobe taken on 20 October 2017. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2017).

The lava lake level generally rose and fell over periods of hours to days in response to gas-piston action and to inferred changes in summit lava pressure indicated by deflation-inflation (DI) events. There were a few periods with exceptions when the lake level remained constant for many days at a time, heating up the surrounding walls enough to produce thermal cracking and popping sounds. The total range of the lake level varied between 35 and 40 m during July-December 2017, with the highest level about 17 m below the rim in early September (elevation 1,020 m), and the lowest levels, about 57 m below the rim in late July and September (elevation 977 m) (figure 293).

Figure (see Caption) Figure 293. Halema'uma'u lava lake level measurements for 2017 in meters above sea level at Kīlauea. X-axis represents the count of the calendar days, 0 is 1 January 2017. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2017).

There were no significant explosive events triggered by rockfalls, but smaller collapses of veneer and the wall were common, particularly during deflationary phases when the lake level was low and exposed larger areas of the walls. A few larger collapses in September 2017 were big enough to change the geometry of the lake slightly (figure 294). The first, on 8 September at 1806 HST, was a collapse of the large ledge attached to the wall in the southern corner of the lake. This event produced a plume containing ash, a composite seismic event, and lake surface agitation. The following day, 9 September, there was another collapse at 0509. This involved an area of the E Overlook rim composed of mainly lithic deposits, directly above the Southeast sink, which produced a dusty plume, a composite seismic event, and lake surface agitation. On 12 September a thin slice of the southwest lake rim collapsed at 1420, producing a dusty plume, an agitated lake surface for about 10 minutes, and a composite seismic event.

Figure (see Caption) Figure 294. Small changes were visible in the geometry of the Overlook vent at Halema'uma'u from veneer and wall collapses in September 2017 at Kīlauea. Left image taken 31 May 2017 by T. Orr shows the areas where the largest collapses took place in September 2017. A large shelf collapsed on 8 September, and the other two dates highlight areas where portions of the lake's lithic wall collapsed. The right photo was taken on 21 September 2017 by L. DeSmither. The photo views are looking SE. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for July-September 2017).

An interesting effect observed on two veneer collapses occurred on 24 October 2017 at 1617 and 1623. Both were silent events but were noticed because they visually depressed the lake as they fell in and sent a small "wave" propagating outward before spattering began a few seconds later. The wave did not make it more than half way across the lake in either case, and both spattering events lasted only a few minutes. Several veneer ledges built up and subsequently collapsed around the lakes perimeter but were most notable on the SW corner of the lake. Three collapses, on 5 December at 0400 and 7 December at 1856 and 2024, enlarged the NNE edge of the lake towards true N, but did not produce a spatter deposit or explosion (figure 295). Another rockfall occurred on the N margin of the lake on 23 December 2017 at 1552 and triggered a large spattering event.

Figure (see Caption) Figure 295. View from the SW time-lapse camera at Kīlauea into the lava lake at Halema'uma'u showing the locations of two collapses in early December 2017 that expanded the Overlook vent towards the NNE. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2017).

Activity at Pu'u 'O'o. During July-December 2017, there were only minor changes in the main crater of Pu'u 'O'o as recorded by the PO webcam, PT webcam, and the West Pit time-lapse camera. Due to slight subsidence, altered ground, and widening cracks first noted in August, the West Pit time-lapse camera was relocated 20 m to the SE on 12 October, and roughly 25 m further back from the rim on 1 November after new crack expansion was observed.

During the month of August 2017 there was slight subsidence of the W portion of the crater floor, and around 20 August a crack opened up in the S embayment with three heat locations. There appeared to be slight subsidence of the E side of West Pit from the time-lapse imagery spanning 22 November to 12 December. This subsidence accelerated during 15-17 December, but then was slower through the end of the year. The deformation data confirmed subsidence at Pu'u 'O'o, but it seemed to be confined to the land bridge separating the main crater and the West Pit lava pond. The lava pond inside of the west pit rose slightly during the period from around an elevation of 847 m in early August to 849.5 m on 12 December when measured during site visits about every three weeks. A thick surface crust and sluggish plate motion was typical at the lava pond.

The time-lapse camera located on the E rim of the lava pond (through October) captured three rockfalls in July and two in August that disturbed the pond's surface. On 30 September 2017 a collapse of the west pit's SE rim also broke off a portion of the ledge below, as it was impacted by the falling rocks (figure 296). The collapse was large enough to agitate the pond surface for several tens of minutes, and produced a small step in the tilt at the POC tiltmeter.

Figure (see Caption) Figure 296. The West Pit lava pond time-lapse camera at Kīlauea's Pu'u 'O'o crater captured the area of the rim that collapsed (circled in upper left corner) at 0054 HST on 30 September 2017. The larger circle shows where the lower ledge broke off as a result of the impact. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for July-September 2017).

The pond surface was also disturbed from rockfalls on 22, 28, and 31 October 2017. The first two events were on the N side of the West Pit rim, and the events on 31 October were on the S side of the rim. A small rockfall that triggered minor spattering was witnessed during an overflight on 1 November (figure 297). After 1 November, when the camera was moved away from the rim, it no longer had direct views of the pond. One of the E spillway spatter cones collapsed into the lava tube that was feeding the 61g flow on 20 November and provided a skylight into the tube for a day before it crusted over. On 12 December, a large talus pile on the NNE side of West Pit was evidence of rock falls near the original time-lapse camera site. The talus, likely resulting from several rock falls, piled up onto the lava coated bench.

Figure (see Caption) Figure 297. A rockfall witnessed at Kīlauea's Pu'u 'O'o cone during a 1 November 2017 overflight. A small event on the W side of the pond triggered minor spattering. The surface of the pond had large plates with wide cracks. Left photo by L. DeSmither, right photo by C. Parcheta. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2017).

Activity at the East Rift Zone, episode 61g flow field. The 13 June 2017 breakout that had started on the upper flow field, approximately 1.1 km from the vent, was the largest area of active surface flows on the 61g flow during July-September. Ranging between 2.6–5.8 km from the vent, the breakout significantly expanded the upper flow fields western flow margin. This breakout remained active through the end of September (figure 298). On 26 June 2017 a breakout started near the top of Royal Gardens and quickly advanced down the pali, east of the main flow field. By 6 July the front of the breakout had extended 500 m beyond the pali base with fluid pahoehoe at the front, and a small a'a channel on the steep part of the pali. Slow advancement of the flow placed it approximately 1.5 km from the emergency road near the coast by 9 August before the flow front stalled. When mapped again on 15 August, the closest active flows were about 2.1 km uphill from the road. Intermittently during 1-20 September the breakout produced channelized flows on the steep part of the pali, sometimes as often as every 24 hours. By the end of September active surface flows had advanced to approximately 1.6 km from the emergency road (figure 298).

Figure (see Caption) Figure 298. Changes to the extent of Kīlauea's active episode 61g flow field between 2 July and 28 September 2017, showing the flow margin expansion in red. The yellow line indicates the active lava tube beneath the surface flow. During this time, the flow field expanded an additional 165 hectares from the previous 1,007 hectares (as of 2 July), to a total of 1,172 hectares, increasing the flow field area by 16 percent. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for July-September 2017).

Two other breakouts that started near the episode 61g vent were also active during July-September 2017. The 5 March breakout, which had advanced downslope during its 4 months of activity, was weakly active on 10 July, with two small lava pads observed approximately 4.8 km from the vent. By the time of the overflight on 9 August, the breakout was inactive. On 26 July around 1025 HST, a new breakout started about 1.1 km from the vent and remained active through the end of September with flow activity located 1.1-2.5 km from the vent. On 27 August at roughly 0945 a breakout began on the steep part of the pali originating from the main 61g tube. By 1 September the breakout was at the base of the pali and spreading onto the coastal plain. A few other channels were reported on this area of the pali, and activity continued through the end of September with very little advancement across the coastal plain (figure 299).

Figure (see Caption) Figure 299. A view looking NW at the breakouts on the Pulama Pali and the coastal plain of Kīlauea's East Rift Zone. The majority of the 61g surface flows that spread across the coastal plain were supplied by the 26 June 2017 breakout (right of the kipuka, green area, center right); the breakout that started on 27 August (left of the kipuka, steaming) supplied a smaller pad of flows closer to the base of the pali. A 'kipuka' is an Hawai'ian term for an "island" of land completely surrounded by one or more younger lava flows. Photo taken on 21 September 2017 by L. DeSmither. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for July-September 2017).

The 26 June 2017 breakout remained active and stable through the end of 2017, forming a tube from its breakout point to midway down the pali on the E side of the 61g flow. The area where breakouts from 5 March, 13 June, and 26 July occurred (1.1 km from vent) also remained intermittently active through the end of 2017 (figure 300).

Figure (see Caption) Figure 300. The lava flow field expansion for the 61g lava flow at Kīlauea between 1 October and 31 December 2017. In addition to continued activity from the longer-lived breakouts fueling the expansion shown in red, nearly 90 known shorter-lived surface breakouts occurred, based on observations from webcams, overflights, and satellite data. Changes in the breakout locations are seen in the progression of orange, red, and purple dots after the 61g tube became blocked by a graben collapse on the delta near the end of September (see discussion in next section). The yellow lines indicate lava tube locations underneath the surface flow. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2017).

Numerous overflows originating on the sea cliff began in early October 2017. These breakouts occurred within 310 m of the sea cliff and persisted for nearly a month. There were also approximately 20 short-lived breakouts in October above the sea cliff, each lasting 1-3 days. They were located mostly in clusters on the upper flow field at 1, 2, and 3.5 km from the vent, along the top and base of the pali, and from the coastal tube.

An estimated 35 tube breakouts occurred during November 2017; they typically lasted 2- 10 days, and were located inland of the October breakouts. Locations of activity were in the upper flow field almost entirely between 2 and 3.5 km from vent, with three closer breakouts at 0.5, 0.8, and 1 km from vent. The two active tubes on the pali continued to have breakouts at the top and base of the cliff, but also started breakouts midway downslope (figure 301). At 0805 on 7 November, a viscous breakout occurred approximately 500 m above the sea cliff. The small breakout came directly from the 61g tube and lasted for roughly four and a half days. Another viscous breakout from the tube occurred approximately 950 m upslope of the sea cliff from 18-23 November. A week after that, a third viscous breakout occurred about 2 km from the sea cliff. By the end of November, there was no further breakout activity on the delta or the distal half of the coastal plain.

Figure (see Caption) Figure 301. A pali breakout from the 61g lava tube observed during a 20 November 2017 overflight at Kīlauea. The photographer estimated the active breakout at tens of meters across. Photograph by C. Parcheta. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2017).

During December 2017, an estimated 30 breakouts were recorded from the 61g flow tube, however these were often longer, lasting up to a week on the upper flow field, and with near perpetual breakouts on the pali throughout the month, which made quantifying the exact number difficult. A new breakout occurred 500 m from the 61g vent on 1 December and lasted through 20 December. This breakout, and the whole area between 500-1,200 m from the vent, poured lava onto the eastern upper flow field (figure 300). Most of the upper flow field activity was focused very close to the vent, between 350-800 m; additional activity also occurred at the 1 km location and a few continued breakouts were noted from the 2-3.5 km region. The coastal flow field activity was sluggish and mostly a result of the near-constant pali tube breakouts reaching the base. On 9 December a new voluminous breakout began near the top of the pali that burned through the kipuka near the center of the flow field (figures 302 and 303). This major breakout lasted through the end of the year and produced mostly 'a'a channels on the pali with pahoehoe at the pali base. Pali tube breakouts occurred at nearly every elevation but seemed to move higher up the slope as the month came to a close. Activity did not advance more than 400 m from the base of the pali.

Figure (see Caption) Figure 302. A small channel of lava burned through the kipuka on Kīlauea's Pulama Pali on 21 December 2017. Figure 299 shows the kipuka on 21 September, still intact. Photograph by C. Parcheta. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2017).
Figure (see Caption) Figure 303. Close up of the 'a'a flow front near the base of the pali at Kīlauea, which burned the remaining trees within the kipuka. Photograph by M. Patrick on 21 December 2017. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2017).

Time series thermal maps of the 61g flow field overlaid on all of the tubes mapped from the field to date suggested to HVO scientists that some of the many breakouts during October-December 2017 may have come from reactivation of an earlier tube thought to be inactive since at least April 2017 (figure 304). Breakout locations coincided with the former tube trace, and happened at least five times between 21 September and 5 January 2018.

Figure (see Caption) Figure 304. A time series of thermal maps from overflights at Kīlauea with all 61g tubes overlaid. Solid white lines are tubes active as of the image date, indicated by a thermal trace. Long dashed white line is the main (western) tube that became blocked at the end of September 2017. Dotted lines are older tubes from 2016 that were active when the 61g flow first crossed the coastal plain. These tubes were no longer noted in public maps by April 2017. In all thermal maps from October-December 2017, there was activity (indicated by black arrows) located above the older tube down the center of the flow field suggesting to HVO scientists that this tube may have been still producing breakouts from backlogged lava in the system. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2017).

Activity at the East Rift Zone, Kamokuna ocean entry. By the end of June 2017, flows from multiple breakouts had resurfaced the delta of the Kamokuna ocean entry, covering earlier cracks, and building up and steepening the delta's landward side. These surface breakouts continued into early July, but by 10 July several new cracks had appeared, two of which visibly spanned the width of the delta (figure 305). Slumping of the seaward half of the delta and expansion of the cracks was visible in time-lapse camera images until the end of September.

Figure (see Caption) Figure 305. The Kamokuna ocean entry delta at Kīlauea with visible large coast-parallel cracks which span most of the delta's width. On the W (left) side of the delta, the largest crack has been partially buried by the 'a'a flow produced by the 19 August 2017 breakout which started on the sea cliff roughly 100 m inland (lighter in color). Photo taken on 1 September 2017 by L. DeSmither. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for July-September 2017).

On 19 August 2017 around 0405 HST a breakout started on the sea cliff approximately 100 m upslope of the ramp, and five minutes later lava was spilling over the sea cliff and onto the delta. The breakout point and the lava falls over the cliff were both on the W side of the 61g tube. The lava produced a small 'a'a flow on the delta (figure 305), during its short-lived activity that lasted roughly 9.5 hours. Late on 19 August, the time-lapse camera also captured two images of littoral explosions in the center of the delta that produced a large spatter deposit on the delta's surface.

Three more sea cliff breakouts started on 23 September 2017. The first was brief "firehose-like" activity that began in the early morning hours. Based on the delta surface flows it produced, activity lasted less than 24 hours. Later views of the cliff face revealed that the "firehose" came out of a narrow horizontal crack E of the ramp, that was less than a meter below the top of the cliff. Later that day, on the sea cliff near the ocean entry, two new breakouts started, one to the E and one to the W of the tube. The E breakout originated roughly 70 m upslope of the sea cliff, and the breakout point had been fractured and depressed. Its thin pahoehoe flow spread out behind the littoral cone and came close to the edge of the cliff but did not spill over. The W breakout was visible in the time-lapse camera images on 23 September from around noon until midnight, producing only a few small dribbles of lava over the sea cliff. The breakout point was roughly 100 m upslope of the sea cliff, and buried the breakout from 19 August with thick, viscous pahoehoe. By the end of September, surface flows again covered much of the delta until most of the cracks were obscured, and only the ramp and a small area of the eastern delta close to the sea cliff were still uncovered.

Beginning in late August 2017, the ocean entry plume started to fluctuate regularly, and the plume was often weak or would briefly shut down. A shatter ring (a raised rim depression that forms over active lava tubes) began forming near the front of the delta on 21 August. By 30 August, the repeated uplifting and subsidence of the delta had broken the surface flows and built up a large rubble pile. On 26 September 2017 a bulge formed on the back half of the delta where the slope was steepest (figure 306). This inflationary feature produced steam and a delta surface flow from a crack at its base.

Figure (see Caption) Figure 306. Changes at the Kamokuna ocean entry at Kīlauea between 26 June (left) and 26 September 2017 (right). The delta grew about 1.62 hectares (4 acres) in size, but also thickened from multiple breakouts resurfacing the delta. The delta cracks are not visible in either photo because the delta had been newly resurfaced in both images. Photos taken by L. DeSmither. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for July-September 2017).

HVO scientists concluded that the bulge observed on 26 September 2017 was the result of the formation of a spreading-induced graben in the middle of the delta that obstructed the 61g tube between 23 and 26 September 2017 (figure 307, top row). During the first part of October, additional breakouts from the tube above the sea cliff produced lava falls that poured down on the W side of the tube (figure 307, middle row). A few breakouts in the latter half of October flowed to the E side of the tube (figure 307, bottom row). The delta did not expand much in area during October-December 2017, but it thickened greatly due to the added volume from the lava falls breakouts and several small sluggish breakouts on the delta. The maximum extent that the delta reached was a little over 4 hectares in October, and then it began to shrink from waves crumbling its edges. By the end of December, the delta had lost about 0.4 hectares (1 acre) of land.

Figure (see Caption) Figure 307. Activity at the Kamokuna ocean entry of Kīlauea during September-October 2017. Top: before (left, 19 September 2017) and after (right, 26 September 2017) the graben formation induced by delta slumping. The yellow (left) and orange (right) lines indicate the topographic profile through the middle of the delta. Middle: Aerial photograph (left, C. Parcheta) and thermal image (right, M. Patrick) from a 12 October 2017 overflight showing the extent of lava falls both E and W of the tube. Once the tube became blocked, the whole delta was resurfaced by this outpouring of lava. Bottom: The last of the lava falls occurred on the E side of the tube. The western falls had solidified but were illuminated on the left in this image during the first activity of the eastern lava falls. Image taken by the Kamokuna time-lapse camera on 10 October 2017 at 1842. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2017).

The ocean entry was thought to have fully ceased activity shortly after 12 November 2017. The plume had its first pause in activity on 23 September, and quickly resumed but with decreasing vigor. By 26 September the plume was noticeably weaker and beginning to show intermittent pauses, which continued and became more prolonged through 4 November. The following day (5 November) was the first day with no plume visible in the HPcam, and 6 November was the last day an ocean entry plume was visible in the HP webcam. Ocean entry was active and observed during field visits between 6-11 November, but its weak, diffuse plume was not visible to the HP camera. The time-lapse camera stopped taking photos during the end of the Kamokuna delta activity in the late afternoon on 11 November (figure 308). This malfunction was discovered during a field visit on 12 November; the batteries were replaced a week later. The last photo of known lava activity on the delta was taken on 12 November, and the delta was likely completely inactive within a day or two.

Figure (see Caption) Figure 308. Kamokuna delta at Kīlauea on 11 November 2017 shortly before the edges began to crumble from the continuous wave action. Photograph by Kamokuna time-lapse camera. Courtesy of HVO (Hawaiian Volcano Observatory Quarterly Report for October-December 2017).

During a 12 December 2017 overflight, an HVO scientist witnessed a collapse of a small portion of the sea cliff east of the tube into a yellow talus pile on the back portion of the delta, removing the evidence of the lava falls.

Satellite thermal and SO2 data. In addition to field observations, satellite-based thermal and SO2 data provide important insights into the ongoing activity at Kīlauea. The many MODVOLC thermal alerts issued during July-December 2017 show the varying intensity and locations through time of the many breakouts along the episode 61g flow field from near the vent at the base of Pu'u 'O'o all the way down to the Kamokuna ocean entry delta (figure 309).

Figure (see Caption) Figure 309. MODVOLC thermal alert pixels for the episode 61g lava flow at Kīlauea during various weeks of July-December 2017. Green grid squares each represent 1 square km. Areas of activity discussed in the earlier text are labelled. Each image represents seven days of thermal alerts. Upper left: 2-8 July 2017, the 13 June breakout expands the upper flow field, and the front of the 26 June breakout has extended beyond the base of the pali. Upper right: 23-29 July 2017, the 26 July breakout appears about 1 km E of the vent, breakouts are active on the pali, and surface flows are active on the Kamokuna delta. Center left: 27 August-2 September 2017, extensive new breakouts along the base of the pali created multiple alerts in that area. Center right: 1-7 October 2017, abundant breakouts just above the delta create lava falls over the delta after the graben formed in late September. Lower left: 12-18 November 2017, many breakouts were observed near the vent and on the pali during November. Lower right: 17-23 December 2017, breakouts were focused on the upper slope and the pali where the kipukas burned up in December, and lava was no longer flowing into the ocean at the delta. Courtesy of HIGP, MODVOLC.

The MIROVA project thermal anomaly graph of distance from the summit also shows the multiple sources of heat at Kīlauea and the migration of those sources over time (figure 310). The MIROVA center point for relative distances described here is about 10 km (0.1°) E of Halema'uma'u crater. The anomaly locations at about 10 km distance from this point correspond to both the lava pond at Pu'u 'O'o crater and the Halema'uma'u crater lava lake. Those about 20 km away correspond to the Kamokuna ocean entry. Anomalies that migrate over time between 10 and 20 km distance trace the movement of the many episode 61g flow breakouts between Pu'u 'O'o and the Kamokuna ocean entry during July-December 2017.

Figure (see Caption) Figure 310. The MIROVA project thermal anomaly graph of distance from the summit shows the multiple sources of heat at Kīlauea and the migration of those sources from 1 June 2017-15 January 2018. The MIROVA center point for relative distances described here is about 10 km (0.1°) E of western Halema'uma'u crater. The anomaly locations at about 10 km distance (y-axis) correspond to both the lava pond at Pu'u 'O'o crater and the Halema'uma'u crater lava lake. Those about 20 km away correspond to the Kamokuna ocean entry. Anomalies that migrate over time between 10 and 20 km distance trace the movement of the many episode 61g flow breakouts between Pu'u 'O'o and the Kamokuna ocean entry during July-December 2017.

Kīlauea emits significant SO2 that is recorded by both ground-based and satellite instruments. Sulfur dioxide emissions exceeded density levels of two Dobson Units (DU) multiple times every month during the period (figure 311). Increases in SO2 flux are caused by many factors including increases in the number and size of surface lava breakouts as well as activity at the summit crater.

Figure (see Caption) Figure 311. Sulfur dioxide emissions generally exceeded density levels of two Dobson Units (DU) multiple times every month at Kīlauea and are recorded daily in satellite data. Increases in SO2 emissions are caused by many factors including increases in the number and size of surface lava breakouts as well as activity at the summit crater. A few of the SO2 plumes captured by the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite with DU greater than 2 during July-December 2017 are shown. The prevailing winds on Hawaii blow from NE to SW, so plumes generally drift SW. UR: 23 July 2017, UL: 12 September 2017, LR: 9 October 2017 and LL: 28 December 2017. Courtesy of NASA Goddard Space Flight Center.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: http://hvo.wr.usgs.gov/); MIROVA (Middle InfraRed Observation of Volcanic Activity), a collaborative project between the Universities of Turin and Florence (Italy) supported by the Centre for Volcanic Risk of the Italian Civil Protection Department (URL: http://www.mirovaweb.it/); Hawai'i Institute of Geophysics and Planetology (HIGP) - MODVOLC Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/); NASA Goddard Space Flight Center (NASA/GSFC), Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, 8800 Greenbelt Road, Goddard, Maryland, USA (URL: https://so2.gsfc.nasa.gov/).


July 2018 (BGVN 43:07) Citation IconCite this Report

Overflows of lava lake in Halema'uma'u crater; Pu'u 'O'o crater floor collapses 30 April 2018; inflation and increased seismicity

Open lava lakes at the Kīlauea summit caldera along with a lava lake and flows from the East Rift Zone (ERZ) have been almost continuous since the current eruption began in 1983, and the rift zone has been intermittently active for at least two thousand years. The period from January-April 2018 included the ending of activity in one part of the ERZ and the beginning of a new episode. March 2018 marked the tenth year of the active lava lake inside the Overlook vent at Halema'uma'u. Information for this report comes primarily from the US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO) which provides daily reports, volcanic activity notices, and photo and video data.

At the end of 2017, the lava lake inside the Overlook vent at Halema'uma'u crater maintained the typical activity it had exhibited throughout the year, with a consistent lava circulation pattern, and occasional spattering events from hardened lava falling into the lake from the pit walls. The lake level rose and fell by a few meters over periods of hours to days, ending the year about 30 m below its level at the beginning of the year. Longer-term subsidence of the Pu'u 'O'o cone on the East Rift Zone was also apparent during 2017, although there was little change in the elevation of the lava pond inside the west pit area of the crater; occasional rockfalls triggered minor spattering. At the end of 2017 the East Rift Zone episode 61g surface lava flow activity persisted on the upper portions of the flow field near Pu'u 'O'o, on the pali, and in scattered areas along the coastal plain. Changes in the subsurface flow in lava tubes contributed to frequent changes to surface breakout locations. The lava flowing into the ocean at Kamokuna slowed and finally ended in November 2017.

During January-April 2018, the lava lake level inside the Overlook vent of Halema'uma'u crater rose and fell daily with alternating periods of inflation and deflation, with a gradual overall inflationary trend. Inflation intensified at the end of April, and the lake overflowed onto the floor of the crater during 21-27 April. The lake level had dropped several meters below the rim of the vent by the last day of the month. Activity of the episode 61g lava flow decreased gradually throughout the period. The flow remained active at the base of the pali and on the upper flow field through February, but activity tapered off on the coastal plain. By the end of March, only the upper flow field was still active. Notable inflationary tilt began at Pu'u 'O'o on 12 March 2018. Lava flowed out of vents on the main crater floor and also created a perched lava pond in the west pit. In mid-April HVO noted that the inflation resulted from increased pressurization of the magma under Pu'u 'O'o and in the past this had led to the formation of new vents and lava flows along the East Rift Zone. A marked increase in seismicity and ground deformation at Pu'u 'O'o on the afternoon of 30 April was followed by the collapse of the crater floor, dispersing red ash a significant distance around the cone. Following the collapse, HVO seismometers and tiltmeters recorded a substantial increase in seismic activity and deformation from Kīlauea's summit to an area about 10-16 km downrift (east) of Pu'u 'O'o which propagated eastward overnight along the Lower East Rift Zone (LERZ), marking the beginning of a major new eruptive phase.

Activity during January 2018. Consistent activity continued into January 2018 with few notable changes. The lava lake inside the Overlook vent at Halema'uma'u crater rose and fell by a few meters over hours and days; on the East Rift Zone the lava pond persisted at Pu'u 'O'o cone, and scattered breakouts from the episode 61g lava flow continued. Early on 19 January two earthquakes of magnitude 2.4 and 2.5 occurred on the lower East Rift Zone near Leilani Estates. Also on 19 January, a rockfall from the wall of Halema?uma?u crater plunged into the lava lake producing a short-lived explosion of spatter and wallrock that blanketed an area around the former visitor overlook. Debris fell as far as the Halema'uma'u parking lot (figure 312).

Figure (see Caption) Figure 312. Spatter up to about 30 cm in size was thrown onto the rim of Halema'uma'u crater at Kīlauea during explosive events on 19 January 2018. Some fragments were thrown or blown farther downwind, reaching as far as the closed section of Crater Rim Drive in Hawai'i Volcanoes National Park. The boot of an HVO scientist, who entered the area to check on HVO's webcameras, is shown here for scale. Courtesy of HVO.

HVO noted that spattering from the lava lake at Halema'uma'u was visible from the visitor overlook overnight during 25-26 January. Spatter appeared again briefly the next day, and overnight during 29-30 January. Four spattering sites were visible on a clear 30 January day (figure 313). Webcam views overnight on 30-31 January showed that incandescence persisted from the small lava pond on the W side of the Pu'u 'O'o crater. On the morning of 26 January a new breakout from the episode 61g flow appeared on the pali. By the end of January, most of the breakouts from the episode 61g flow field were concentrated at the base of the pali and on the upper flow field, with little activity on the coastal plain.

Figure (see Caption) Figure 313. Clear views at the summit of Kīlauea on 30 January 2018 revealed four spattering sites visible on the surface of the Halema'uma'u lava lake inside the Overlook vent. Through the gas plume, a visible scar (light-colored wall rock) from the 19 January rockfall that triggered an explosive event, could be seen on the southern Overlook vent wall. Another, smaller scar on the northeastern lake wall (left), resulted from two small rock falls on 24 January. Courtesy of HVO.

Activity during February 2018. The lake level inside the Overlook vent continued with daily fluctuations of several meters, between 31 and 42 m below the Halema'uma'u crater floor, during February 2018. A small veneer collapse (rockfall) into the lava lake on 23 February was visible in lava lake webcam images. Throughout the month, persistent incandescence was observed in the webcam at the Pu'u 'O'o west pit lava pond (figure 314). On 10 February a large portion of the NE rim of the west pit collapsed. Prior to and during the rim collapse, the adjacent ground also subsided. The episode 61g flow remained active at the base of the pali (figure 315) and in the upper flow field. A new breakout on the upper flow field, 1-2 km from the vent, appeared early on 26 February. A small swarm of earthquakes occurred in the upper East Rift Zone on 21 February; the largest event was a M 2.3. Seismicity throughout the volcano was otherwise at normal rates throughout the month.

Figure (see Caption) Figure 314. Incandescence from the west pit at Kīlauea's Pu'u 'O'o cone on 19 February 2018 was typical of that observed during clear weather throughout the month. Courtesy of HVO.
Figure (see Caption) Figure 315. 'A'a flows at the base of Pulama pali at Kīlauea on 20 February 2018 produced shimmers of heat (top center) and incandescent fragments. Rubble from the flow rolled downhill, as the molten center slowly pushed forward. Courtesy of HVO.

Activity during March 2018. A brief swarm of small earthquakes occurred in the upper East Rift Zone on 2 March 2018. An ongoing long-period earthquake swarm at 5-10 km depth beneath the caldera began late on 6 March and continued into the next day. At the Halema'uma'u crater, the lava lake fluctuated daily, with levels ranging from a low of 40.5 m below the crater floor to a high of 20 m below it. Changes in levels of up to 10 m in a 24-hour period were common. Vigorous spattering was observed on 6 March (figure 316). On 16 March, the lava lake rose high enough (26 m below the crater floor) for active spattering to be visible in webcams mounted in the HVO tower, located across the crater from the vent. The 10th anniversary of the eruption within Halema'uma'u crater was marked on 19 March. When the vent first opened on 19 March 2008, it formed a small pit about 35 m wide. Over the following decade, the pit (informally called the "Overlook crater") grew to about 280 x 200 m in size (see figure 313).

Figure (see Caption) Figure 316. Within Kīlauea volcano's summit lava lake at the Halema'uma'u crater, vigorous spattering on 6 March 2018 was occurring on the southern margin where a ledge of solidified lava had built out from the vent wall. Courtesy of HVO.

Notable inflationary tilt at Pu'u 'O'o cone began on 12 March 2018; GPS stations also started recording extension across the cone on that date. A small increase in seismic events was observed at Pu'u 'O'o on the evening of 21 March. Increased views of spattering from the west pit lava pond were visible beginning the following day, likely due to subsidence over the previous months as reported by HVO. During the evening of 25 March lava flowed out of a vent in the SE part of the crater floor and continued to expand for the rest of the month (figure 317). Inflationary tilt slowed significantly on 27 March. Cracks along the ridge between the main crater and the west pit continued to grow throughout the month as the ridge continued to subside (figure 318).

Figure (see Caption) Figure 317. On 25 March 2018 a small lava flow began erupting onto the Pu'u 'O'o crater floor at Kīlauea for the first time since May 2016. In this thermal image, taken by the PTcam on 26 March 2018 at 1318, the flow (bright color) appears to be supplied by one of the small spatter cones in the crater's south embayment. The lava flow did not extend beyond the crater. This type of activity is not unusual for Pu'u 'O'o. Courtesy of HVO.
Figure (see Caption) Figure 318. At Pu'u 'O'o on Kīlauea's East Rift Zone, the ridge separating the main crater (top) from the west pit (bottom) had been subsiding over the previous several months due to small rockfalls and unstable ground when this image was taken on 27 March 2018. As the ground shifted, cracks along the ridge and on both sides of it continued to open. The lava pond within the west pit rose several meters during March and produced overflows (darker lava) onto the floor of the pit as it rose. A small lava flow also erupted onto the floor of the main crater on 25 March and remained active through 27 March, visible as the lava darker in color in the foreground of the main crater floor. Courtesy of HVO.

By 20 March surface lava flow activity from the episode 61g flow near the base of the pali appeared to have diminished, and only sparse lava flow activity on the coastal plains was noted after 23 March. Activity on the upper flow field, closer to Pu'u 'O'o, continued (figure 319). A 30 March overflight by HVO confirmed no flow activity on the coastal plain or the pali.

Figure (see Caption) Figure 319. Active lava breakouts were scarce across the episode 61g flow field on Kīlauea's East Rift Zone, with active flows confined to an area approximately 1-2 km from Pu'u 'O'o during March 2018. This breakout from the lava tube consisted of fluid pahoehoe and was photographed on 27 March 2018 during an overflight. The incandescent area is several meters across. Courtesy of HVO.

Activity during 1-16 April 2018. Constant spattering at the Overlook vent lava lake (figure 320) was intermittently visible from HVO and the Jagger Museum during April 2018 as the lake level rose and fell several meters on a daily basis. Its lowest level of the month was 32 m below the crater floor, and a general inflationary trend throughout the month resulted in significant overflows onto the floor of Halema'uma'u crater at the end of the month. A rockfall in the morning of 6 April triggered an explosion at the summit lava lake that damaged the power system to the Halema'uma'u crater rim webcams (figure 321). A moderate swarm of over 200 earthquakes occurred on 11 April at depths of 7-9 km below the summit; the largest event in the sequence was M 2.4. Seismicity returned to its background rate in the early morning of 12 April. Three minor ledge collapses, common while the lava lake level is lowering, occurred on 12 April.

Figure (see Caption) Figure 320. A clear view of Kīlauea's summit lava lake in the Overlook vent on 4 April 2018 revealed spattering on the N side and center of the lake surface, a departure from its more common location on the SE side of the lake; this occasionally happened when the surface flow direction reversed. Spattering is caused by gas bubbles bursting within the lava lake. Courtesy of HVO.
Figure (see Caption) Figure 321. On 6 April 2018 at 1028 HST a partial collapse of the southern Overlook crater wall triggered an explosive event at Kīlauea's summit lava lake. A large plume of gas, ash, and lava fragments rose from the lava lake and was visible from the Jaggar overlook. The explosion threw debris onto the Halema'uma'u crater rim at the old visitor overlook, which has been closed due to ongoing volcanic hazards such as this explosive event. Courtesy of HVO.

For the first half of April 2018, steady minor inflation continued at Pu'u 'O'o, interrupted by brief episodes of sharp deflation that appeared related to small lava flows on the crater floor. During an overflight on 13 April HVO geologists viewed a perched lava pond inside the west pit (figure 322). A slight increase in seismicity in the Upper East Rift Zone began overnight during 15-16 April; the largest event was a M 2.9 earthquake.

Figure (see Caption) Figure 322. During an overflight of Kīlauea on 13 April 2018 geologists from HVO observed that lava within the west pit at Pu'u 'O'o had formed a perched lava pond (center) contained within a levee. This levee, formed by an accumulation of hardened lava, confined molten lava to the perched pond, which allowed the lava surface to rise higher than the west pit floor. If the pond rises high enough, lava can spill over the levee, forming small flows around the margin of the perched pond. Courtesy of HVO.

At the beginning of April 2018 the episode 61g lava flow was active only above the Pulama pali. The areas of the upper flow field with active lava flows were located within the Kahauale'a Natural Area Reserve, which has been closed to the public since 2007 due to volcanic hazards. On 13 April 2018, geologists observed scattered breakouts from the 61g flow within about 2.2 km from Pu'u 'O'o and another sluggish breakout about 5 km from Pu'u 'O'o (figure 323).

Figure (see Caption) Figure 323. An HVO geologist photographed an active pahoehoe breakout on 13 April 2018 at Kīlauea after taking a lava sample nearby. This breakout was located approximately 0.4 km from the episode 61g vent. As the flow inflated, internal pressure cracked the rigid crust of the flow allowing molten lava to ooze out. Courtesy of HVO.

Activity during 17-30 April 2018. Beginning in mid-April 2018 seismometers recorded an increase in the number of small earthquakes beneath the summit and upper East Rift Zone reflecting increased pressurization. Kīlauea's summit and East Rift Zone magma systems are connected, with changes at one sometimes leading to changes at the other. Tiltmeters, GPS, web cameras, and field observations, continued to record inflation at the Halema'uma'u crater, at Pu'u 'O'o, and at the upper portion of the episode 61g lava tube system. HVO noted that this inflation could lead to the opening of a new vent on or near Pu'u 'O'o that could cause a significant drop in the summit lake level.

At the Halema'uma'u crater, inflation significantly outpaced deflation for the second half of April. In the afternoon of 18 April the lake level was at 25 m below the crater floor. A lengthy episode of inflation brought the lava to within 6 m of the floor on the afternoon of 21 April. As the level continued to rise, a small overflow along the S crater rim occurred about midnight overnight on 21-22 April (figure 324). The lava lake was below the rim again the next morning but spilled out several times over the next several days to the N, S, and SW. The flows, similar to those produced during the last significant overflow event in April-May 2015, consisted of lobate sheets of shelly pahoehoe traveling as far as 375 m across the floor of Halema'uma'u. A small overflow had also occurred in October 2016.

Figure (see Caption) Figure 324. The rising summit lava lake levels first peaked overnight on 21-22 April 2018, producing small overflows onto the floor of Halema'uma'u Crater at Kīlauea. The largest overflow, on the N side of the Overlook vent (shown here), reached about 80 m from the lake margin. Image taken on 22 April 2018, courtesy of HVO.

The summit lava lake spilled out of the Overlook crater rim multiple times during 22-27 April, caused by repeated inflation-deflation cycles (figures 325-327). Between overflows, the lava column receded below the crater rim. An overflight during the afternoon of 23 April showed that the overflows covered about 30% of the Halema'uma'u crater floor, approximately 16 ha. The height of the lava lake, on the floor of Halema'uma'u crater, was 79 m below the rim of the crater on 25 April. HVO estimated that only about one quarter of the floor of the crater remained uncovered by new flows as of 26 April. Summit tiltmeters continued to record an overall inflationary trend with brief periods of deflation until turning to more sustained deflation around midnight overnight on 26-27 April. A magnitude 3.2 earthquake occurred around 1308 HST on 26 April but did not cause any eruptive changes. Seismometers recorded a few small earthquakes in the upper East Rift Zone and south part of the caldera during 25-29 April.

Figure (see Caption) Figure 325. On 24 April 2018 between around 2030 and 2300, Kīlauea's summit lava lake overflowed again. The large overflow spread W (to the right) from the lava lake onto the floor of Halema'uma'u around 2230 in this image. The bright (yellow-white) spot is spattering along the S margin of the lava lake. USGS photo by M. Patrick, courtesy of HVO.
Figure (see Caption) Figure 326. Beginning at approximately 0615 on 26 April 2018 a new overflow began covering about 36 hectares (90 acres) of Kīlauea's Halema'uma'u crater floor with lava, continuing for about four hours and covering about two-thirds of crater floor. This was the largest overflow since the summit eruption began in 2008. In this view to the S taken later in the day, the gas plume was being produced by the lava lake in the SE crater floor (upper left). Courtesy of HVO.
Figure (see Caption) Figure 327. This thermal image (looking S) taken on 26 April 2018 at Kīlauea shows the active overflows from the lava lake (upper left) onto the Halema'uma'u crater floor. View is toward the south. Courtesy of HVO.

The summit lake level dropped 16 m during 27-28 April, ending the period of inflation that produced the overflows onto the crater floor. The lake level remained about 15 m below the floor when skies cleared on 30 April and permitted a view from the webcam (figure 328). Slight inflation returned later in the day and the lake level rose to just beneath the vent rim.

Figure (see Caption) Figure 328. A break in the weather on the morning of 30 April 2018 allowed HVO's webcam to capture this image of the lava lake within Halema'uma'u at the summit of Kīlauea. Following multiple overflows of the lava lake the previous week, the lake level dropped after summit deflation. Early that morning, the lava lake level was estimated to be about 15 m below the vent rim, but shortly thereafter, the summit switched to inflation, and the lake level rose to just below the vent rim. Courtesy of HVO.

HVO released a Volcanic Activity Notice, in addition to their regular daily report, midday on 17 April 2018. They noted that observations and measurements at Pu'u 'O'o during the previous month suggested that the magma system had become increasingly pressurized, raising the possibility that a new vent could form at any time, either on the Pu'u 'O'o cone or along adjacent areas. Since mid-March there had been uplift of the Pu'u 'O'o crater floor by several meters. Similar episodes of inflation and uplift at Pu'u 'O'o occurred in May-June 2014, prior to the start of the June 27th flow (active 2014-2016) and May 2016 before the start of the ongoing episode 61g flow.

When measured during a site visit on 18 April the pond level in the west pit at Pu'u 'O'o was 7 m higher than it had been in late March as a result of lava overflows building up the surrounding levee. An overflight on 23 April showed the perched lava pond with overflows slowly filling the pit (figure 329), and significant cracks on the NE part of the crater rim (figure 330). The pond had another overflow that remained in the pit on 24 April, and the floor continued to rise. Inflationary tilt continued at Pu'u 'O'o until it leveled off around midnight during 26-27 April, but the crater floor continued to rise for the next four days.

Figure (see Caption) Figure 329. On the East Rift Zone of Kīlauea, the perched lava pond in Pu'u 'O'o's west pit persisted during the second half of April, seen here on 23 April 2018. Overflows of the pond levees were slowly filling the bottom of the west pit and raising the floor. Courtesy of HVO.
Figure (see Caption) Figure 330. Ongoing uplift of the crater floor of Pu'u 'O'o at Kīlauea beginning in mid-March 2018 generated numerous cracks on the crater floor and around the rim. These cracks cut through both recent lava flows (darker color) and older flows on the crater floor. Image taken on 23 April 2018, courtesy of HVO.

Just after 1400 on 30 April 2018, a marked increase in seismicity and ground deformation began at Pu'u 'O'o. A few minutes later, a thermal webcam (PTcam) located on the crater rim showed the first of two episodes of floor collapse; the second collapse began at 1520 and lasted about an hour. Webcam views into the crater and surrounding area were frequently obscured by poor weather conditions. However, shortly after 1600 the PTcam recorded images that were likely the signature of small explosions from the western side of the crater as the floor collapsed.

Following the collapse there was an increase in seismicity and deformation from the summit to an area about 10-16 km downrift (east) of Pu'u 'O'o. Overnight, this activity continued to propagate eastward along the rift zone. The largest earthquake of this sequence was a magnitude 4.0 just offshore south of Pu'u 'O'o at 0239 on the morning of 1 May. HVO field crews were turned back the next morning by ash in the air above Pu'u 'O'o, likely due to continuing collapse within the crater and vigorous gas emissions. Reddish ash was also noted in abundance on the ground around Pu'u 'O'o.

Lava flow activity in the episode 61g flow continued on the upper flow field through the end of April 2018. Activity was focused above the pali and closer to Pu'u 'O'o, within 2 km of the vent. After the explosion and collapse of the crater floor at Pu'u 'O'o on 30 April, a large amount of red ash was deposited around the cone and covered over some of the active breakouts of the 61g flow (figure 331).

Figure (see Caption) Figure 331. The collapse of the Pu'u 'O'o crater floor at Kīlauea on 30 April 2018 produced a large amount of red ash that was deposited around Pu'u 'O'o, as well as blown farther downwind, with a thin dusting of ash reaching uprift (west) as far as Mauna Ulu. On 1 May 2018, a layer of red ash covered active 61g lava flow surface breakouts in an area between 1-2 km from the 61g vent. Courtesy of HVO.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: http://hvo.wr.usgs.gov/).


October 2018 (BGVN 43:10) Citation IconCite this Report

Twenty-four fissures open on the lower East Rift Zone in May 2018; at least 94 structures destroyed

Kīlauea's East Rift Zone (ERZ) has been intermittently active for at least two thousand years. Open lava lakes at the summit caldera, and a lava lake and flows from the East Rift Zone, have been almost continuously active since the current eruption began in 1983. A marked increase in seismicity and ground deformation at Pu'u 'O'o Cone on the upper East Rift Zone during the afternoon of 30 April 2018 and the subsequent collapse of its crater floor marked the beginning of the largest lower East Rift Zone eruptive episode in at least 200 years. The daily events of this episode underscored the nature of the interconnected components of the volcanic system. The lava lake level at Halema'uma'u began dropping on 1 May 2018, and fissures first opened on the lower East Rift Zone two days later. The eruptive events of May 2018 (figure 332), the first month of this episode, are described in this report with information provided primarily from the US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO) in the form of daily reports, volcanic activity notices, and abundant photo, map, and video data.

Figure (see Caption) Figure 332. A timeline of events at Kīlauea for 1-28 May 2018. Blue shaded region includes seismic events greater than M 4.0 and activity at Halema'uma'u crater at the summit. Green shaded area lists activity on the lower East Rift Zone.

Summary of events. During 1-11 May, seismicity propagated eastward from Pu'u 'O'o, indicating the intrusion of magma into the middle and lower East Rift Zone (LERZ). The first surface cracks appeared in the LERZ on 2 May, and the first eruptive fissure opened the next afternoon. Fissures were several hundred meters long and formed a NE-SW trending line near the axis of the LERZ that reached about 4 km in length by 8 May. Three large (greater than M 5) earthquakes shook the island on 4 May. New fissures opened daily, with activity consisting of spattering and lava flows; the largest effusion was a flow from fissure 8 that traveled N for a little over 1 km. By 9 May, 15 fissures had opened in the vicinity of the Leilani Estates subdivision; the residents had been evacuated and numerous structures were destroyed by the flows, spatter, and fissures. Active spattering paused on 10 and 11 May, although strong degassing continued, and many cracks within the fissure zone continued to widen.

The lava lake level in the Overlook vent at Halema'uma'u crater at the summit began to drop slowly on 1 May; the rate of deflationary tilt increased by late the next afternoon. The lake level had dropped about 128 m below the vent rim by 5 May, and satellite data indicated a 10 cm subsidence of the Halema'uma'u crater floor during that time. Rockfalls from the crater walls produced ash plumes above Halema'uma'u, resulting in light ashfall in the summit area. By 8 May the lake level was 295 m below the floor of Halema'uma'u crater. Larger rockfalls caused by the dropping lake level generated larger explosions and ash plumes on 9 May.

New fissures began opening again on 12 May in an area about 1.5 km NE of the previous activity on the LERZ, and over the following 11 days flow activity increased substantially, creating multiple flow channels. The fissure 17 flow reached 2.5 km in length on 15 May. A fast-moving flow from fissure 20 headed 4 km SE on 18 May, traveling over 300 m per hour. The two lobes of the flow reached the SE Puna coast overnight on 19-20 May and were joined by another adjacent flow to the west two days later. Fissures 16-23, all located in the NE half of the fissure zone, were active during 12-23 May.

Steam and ash emissions were persistent at Halema'uma'u crater during 12-23 May; they varied in intensity with abrupt increases associated with large rockfalls into the vent, and ashfall reported more than 50 km from the summit. Strong earthquakes at the summit continued in response to the deflation, causing frequent ground shaking and damage to roads and buildings. A large explosion on 17 May generated the highest ash plume for the period; it reached 9.1 km altitude and drifted NE. Intermittent explosive eruptions continued at the summit, and robust plumes of gas, ash, and steam periodically emerged from the Overlook vent.

Beginning on 24 May, activity on the LERZ shifted back towards the SW part of the fissure zone, again impacting the residents of the Leilani Estates subdivision with reactivation of fissures and new flows. While flows continued to reach the ocean on the SE coast, the volume of lava gradually decreased until the supply of lava ceased by 28 May. During 24-26 May fissures 7 and 21 were feeding a perched lava pond and flows that moved E and N within the subdivision. Overnight on 26-27 May activity increased substantially at fissure 7 with a 30-m-tall spatter rampart, and fountains that reached 70 m high feeding a flow moving N. Large cracks opened into fissure 24 adjacent to the reactivated fissure 8; fast-moving flows traveled W then N through the subdivision. By 28 May the eruptive activity was focused on vigorous fountaining at fissure 8, which supplied a voluminous flow that headed rapidly NE.

Intermittent explosions continued from the summit Overlook vent during 24-28 May as a result of the ongoing subsidence at Halema'uma'u. Ash clouds generally rose to about 3.1 km altitude and drifted SW. Earthquakes in the summit region continued as the summit area subsided and adjusted to the withdrawal of magma.

Activity during 1-11 May 2018. An intrusion of magma began overnight on 30 April-1 May into the lower East Rift Zone (LERZ), extending from the vicinity of Pu'u 'O'o eastward at least as far as Highway 130 (15 km E of Pu'u 'O'o). The intrusion began after the collapse of the Pu'u 'O'o crater floor on the afternoon of 30 April; about 250 located earthquakes were reported through the afternoon of 1 May, with the locations migrating eastward during the day. The seismicity consisted primarily of small-magnitude (less than M 3) earthquakes at depths of less than 10 km. During a helicopter overflight to Pu'u 'O'o on 1 May, HVO geologists observed a new fissure and crack extending about 1 km uprift (west) from the W flank of the Pu'u 'O'o cone (figures 333 and 334). A small amount of lava had erupted from the crack, apparently during the collapse of the Pu'u 'O'o crater floor. They also noted a few small, sluggish breakouts of the 61g lava flow, likely from lava still moving through the lava-tube system.

Figure (see Caption) Figure 333. HVO geologists observed a fracture on the W flank of Pu'u 'O'o at Kīlauea during an overflight on the afternoon of 1 May 2018. The 61g flow field as of 13 April 2018 is shown in pink. The crack that formed on the west side of Pu'u 'O'o on 30 April 2018, during or immediately after the crater floor collapse, is shown as a solid red line. Older Pu'u 'O'o lava flows (1983–2016) are shown in gray. The yellow line is the trace of the active lava tubes. The blue lines over the Pu'u 'O'o flow field are steepest-descent paths calculated from a 2013 digital elevation model (DEM), while the blue lines on the rest of the map are steepest-descent paths calculated from a 1983 DEM. Courtesy of HVO.
Figure (see Caption) Figure 334. A new fissure appeared on the W flank of Pu'u 'O'o at Kīlauea on 1 May 2018. Top: In this view to the NE, the fissure was visible as a line of white steam extending roughly 1.5 km W of Pu'u 'O'o Crater. Photo taken 3 May 2018. Bottom: A telephoto view of a small lava flow (lighter in color) and spatter (blue-gray) that were erupted from a section of the crack on the west flank of Pu'u 'O'o. Photo taken during overflight on 1 May 2018, courtesy of HVO.

Overnight on 1-2 May, earthquakes continued at a high rate in the area from Highway 130 eastward towards Kapoho (32 km NE of Pu'u 'O'o). Many events were felt by residents and there were reports of nearly constant ground vibration in some areas; seismicity generally migrated eastward (figure 335). During the morning of 2 May a GPS station located about 1.5 km SW of Nanawale Estates (24 km NE of Pu'u 'O'o ) began moving toward the north by several centimeters, indicating the approaching magma intrusion. A tiltmeter at Pu'u 'O'o recorded steady, deflationary tilt throughout the day, with several sharp inflation offsets. Some of these offsets corresponded to short-lived ashy plumes rising from the crater. New small ground cracks less than a few centimeters wide developed across some roads in and adjacent to Leilani Estates (23 km NE of Pu'u 'O'o).

Figure (see Caption) Figure 335. Starting on the afternoon of 30 April 2018, magma beneath Kīlauea's Pu'u 'O'o Cone drained and triggered the collapse of the crater floor. Within hours, earthquakes began migrating east of Pu'u 'O'o, signaling an intrusion of magma along the middle and lower East Rift Zone (ERZ). As of about noon on 2 May there were many reports of earthquakes felt by residents in nearby subdivisions. The orange oval marks the approximate area within which most of the earthquakes were located based on automatic earthquake locations and analysis by seismologists. A GPS device located in Nanawale Estates began moving towards the N on 2 May, and new, small ground cracks were reported in the Leilani Estates area. Courtesy of HVO.

The summit lake level showed very little change immediately after the collapse of the Pu'u 'O'o crater floor, but tiltmeters at the summit began recording deflationary tilt in the early morning of 1 May. The lava lake level had dropped about 20 m by the afternoon of 2 May when the rate of deflationary tilt increased. By the evening of 3 May, it had dropped an additional 37 m.

At 1030 HST on 3 May 2018 ground shaking from a M 5.0 earthquake south of Pu'u 'O'o caused rockfalls and possibly additional collapse into the Pu'u 'O'o crater (figure 336). A short-lived plume of ash produced by this event rose and dissipated as it drifted SW (figure 337).

Figure (see Caption) Figure 336. Clear weather on 3 May 2018 allowed good airborne observations of the collapse crater in Pu'u 'O'o. This view to the E shows the deep collapse crater that formed on 30 April when magma beneath Pu'u 'O'o drained. For scale, the crater is about 250 m wide. Courtesy of HVO.
Figure (see Caption) Figure 337. At 1030 HST on 3 May 2018 ground shaking from a preliminary M 5.0 earthquake south of Pu'u 'O'o caused rockfalls and possibly additional collapse into the Pu'u 'O'o crater on Kīlauea's East Rift Zone. A short-lived plume of ash produced by this event rose and dissipated as it drifted SW. USGS photo by Kevan Kamibayashi, courtesy of HVO.

New ground cracks were reported in Leilani Estates late in the afternoon of 3 May. Hot white vapor and blue fumes emanated from an area of cracking in the eastern part of the subdivision. Spatter began erupting from the cracks shortly before 1700 local time. The Hawaii County Civil Defense coordinated the evacuation of the subdivision. Lava spatter and gas bursts erupted from the fissure for about two hours; lava spread less than 10 m (figure 338).

Figure (see Caption) Figure 338. An eruption from fissure 1 began in the Leilani Estates subdivision at the lower East Rift Zone of Kīlauea during the afternoon of 3 May 2018. Hot white vapor and blue fumes emanated from an area of cracking in the eastern part of the subdivision. Spatter began erupting shortly before 1700 HST; lava was confirmed at the surface in the eastern end of the subdivision. According to the Hawai'i County Civil Defense update at 1740 all residents in Leilani Estates and Lanipuna Gardens subdivsions were required to evacuate. View is to the NE on 3 May, courtesy of HVO.

By the morning of 4 May 2018 three fissures had opened in the eastern portion of Leilani Estates; activity consisted primarily of vigorous lava spattering and development of short lava flows (figure 339). Additional eruptive fissures or vents opened during the day, each several hundred meters long (figure 340). Spatter and lava accumulated primarily within a few tens of meters of the vents. Fissure 6 opened on the eastern edge of the subdivision by the afternoon. Between 1130 and 1500 three large earthquakes (M 5.4, M 6.9, and M 5.3) shook the island along with numerous lower-magnitude events. The M 6.9 event at 1232 HST (the largest on the island in 43 years) produced a robust ash plume at Pu'u 'O'o (figure 341), and numerous rockfall events were triggered at both Pu'u 'O'o and Halema'uma'u craters.

Figure (see Caption) Figure 339. Fissure 3 was actively erupting at Leilani and Kaupili Streets in the Leilani Estates subdivision of the lower East Rift Zone at Kīlauea at 0807 HST on 4 May 2018. Lava on the road was approximately 2 m thick. Courtesy of HVO.
Figure (see Caption) Figure 340. Fissure 5 in the lower foreground was actively erupting at 1207 HST on 4 May 2018 in the Leilani Estates subdivision at Kīlauea. View is to the SW. Behind fissure 5 are fissures 1, 4, and 3 from front to back. Courtesy of HVO.
Figure (see Caption) Figure 341. At 1246 HST on 4 May 2018 a column of reddish-brown ash rose from Pu'u 'O'o crater at Kīlauea after a M 6.9 south flank earthquake shook the island. View is to the S with the steaming fissure on the SW flank of the cone visible behind to the right of the ash plume. Courtesy of HVO.

Fissures 7, 8, and 9 opened in the Leilani Estates subdivision on 5 May. Fissure 7 was only active until mid-afternoon (figure 342). Fissure 8 activity included fountaining and occasional bursts of spatter to 100 m as well as building a spatter cone (figure 343); the flow from fissure 9 migrated W. New ground cracks were reported on Highway 130 along the W edge of the subdivision.

Figure (see Caption) Figure 342. Fissure 7 began erupting around dawn on 5 May 2018 at Kīlauea and was active for several hours. At the peak of its activity, large bubble bursts occurred at one spot (lower left) in the fissure while spattering was present in other locations. A short lava flow was erupted from the fissure around 0800, moving NE and crossing Hookupu Street (left). View is to the S, emissions in upper right are from fissure 2. Image taken on 5 May 2018, courtesy of HVO.
Figure (see Caption) Figure 343. Fissure 8 erupted in the evening on 5 May 2018 at Kīlauea, located near fissures 2 and 7; it began with small amounts of lava spattering at about 2044 HST. By 2100, lava fountains as high as about 70 m (when this photo was taken) were erupting from the fissure. Courtesy of HVO.

Tiltmeters at the summit continued to record a deflationary trend. Satellite InSAR data showed that between 23 April and 5 May 2018 the summit caldera floor subsided about 10 cm. Corresponding to this deflation, the lava lake in the Overlook vent had dropped about 128 m below the crater rim during that same period. Rockfalls from the crater walls into the retreating lake produced ashy plumes above Halema'uma'u crater, resulting in light ashfall in the summit area. During 4 and 5 May about 152 M 2 and M 3 earthquakes occurred at depths less than 5 km beneath the summit area. These earthquakes were related to the ongoing subsidence of the summit area and south flank of the volcano.

Fissure 8 erupted lava fountains until about 1600 on 6 May. By early that afternoon, ten fissures had opened in the Leilani Estates subdivision, but not all were continuing to erupt (figure 344). A lava flow from fissure 8 advanced northward, reaching 1.1 km in length by early evening (figure 345). Deflation continued at the summit with the lava lake dropping at a rate of about 2 m per hour throughout the day, and by evening it had dropped a total of 220 m since 30 April (figure 346).

Figure (see Caption) Figure 344. Between 3 and 6 May 2018 ten fissures opened in the Leilani Estates area of the lower East Rift Zone at Kīlauea. This thermal map shows the ''a'a flow from fissure 8 spreading northward (top) during an overflight of the area on the afternoon of 6 May. The dark area is the extent of the thermal map. Temperature in the thermal image is displayed as gray-scale values, with the brightest pixels indicating the hottest areas (whitish areas show the active lava flow). The gray linear features are the other fissures (numbered in red). The thermal map was constructed by stitching overlapping oblique thermal images collected by a handheld thermal camera during a helicopter overflight of the flow field. The base is a copyrighted color satellite image (used with permission) provided by Digital Globe. Courtesy of HVO.
Figure (see Caption) Figure 345. A lava flow from fissure 8 flowed N on Makamae Street in Leilani Estates at Kīlauea at 0932 HST on 6 May 2018. Courtesy of HVO.
Figure (see Caption) Figure 346. The Kīlauea summit lava lake began dropping on 1 May 2018, and by the evening of 6 May when this image was taken it was roughly 220 m below the crater rim. This very wide-angle camera view captured the entire north portion of the Overlook crater. Courtesy of HVO.

Two new fissures broke ground in the morning on 7 May. The first (fissure 11) opened in a forested area SW of Leilani Estates and was active for only 3 hours. The second (fissure 12) opened around noon between fissures 10 and 11. By 1515 both new fissures were inactive but the west end of fissure 10 was steaming heavily. Cracks on Highway 130 widened from 7 to 8 cm over the course of the day and additional cracks were found just W of the highway on trend with the previous fissures (figure 347).

Figure (see Caption) Figure 347. Cracks several centimeters wide had opened along Highway 130 by 0930 HST on 7 May 2018. The highway runs N-S along the W edge of the Leilani Estates subdivision on Kīlauea's East Rift Zone, about 15 km E of Pu'u 'O'o. Orange paint was used to outline the cracks. Courtesy of HVO.

By the evening of 8 May 2018, the overall fissure zone was about 4 km long (figure 348), stretching SW-NE across most of the now-evacuated Leilani Estates subdivision; 14 distinct fissures had been mapped, and a lava flow starting from fissure 8 had traveled about 1 km NE from its source. Officials noted that 35 structures had been destroyed. Loud jetting and booming noises were heard from fissure 13 that evening. Rockfalls into the Overlook vent at the summit were intermittently producing small ash plumes that rose several hundred meters above the summit and traveled downwind as the lava lake continued to fall. Based on model data collected in the afternoon, the lake level was about 295 m below the floor of Halema'uma'u Crater by the end of the day on 8 May.

Figure (see Caption) Figure 348. The 4-km-long fissure zone that began erupting on 3 May 2018 at Kīlauea's lower East Rift zone had crossed most of the Leilani Estates subdivision by 1900 on 8 May with 14 distinct fissures within the zone. An ''a'a flow from fissure 8 had traveled about 1 km NE since it emerged on the evening of 5 May. Inset shows numbered locations of each fissure in red. The purple areas are lava flows erupted in 1840, 1955, 1960, and 2014-2015. Courtesy of HVO.

At 0832 HST on 9 May 2018, a large rockfall from the steep crater walls into the summit lava lake triggered an explosion that generated an ash column above Halema'uma'u crater; the ash was blown SSW (figure 349). During the day on 9 May fissure 15 broke ground at the NE edge of the LERZ fissure area and generated a pahoehoe flow about 20 m long. Severe ground cracks associated with fissure 14 were steaming vigorously in the morning (figure 350). During an overflight around 1500 in the afternoon HVO geologists also noticed an area of steaming uprift (west) of Highway 130 at the SW edge of the fissure area. Rates of motion increased late in the morning at a GPS station located 1.5 km SE of Nanawale Estates (about 2 km N of Leilani Estates). The direction of motion was consistent with renewed movement of magma in the downrift direction (to the NE).

Figure (see Caption) Figure 349. An ash plume rose from Halema'uma'u crater at the summit of Kīlauea around 0830 on 9 May 2018. HVO's interpretation was that the explosion was triggered by a rockfall from the steep walls of the Overlook vent. The photograph was taken at 0829 HST from the Jaggar Museum overlook. Geologists examining the ash deposits on the rim of Halema'uma'u crater found fresh lava fragments ejected from the lava lake. Courtesy of HVO.
Figure (see Caption) Figure 350. Severe ground cracks associated with fissure 14 in Leilani Estates at Kīlauea were steaming vigorously at 0953 on 9 May 2018. Courtesy of HVO.

Strong degassing continued from existing fissures on 10 and 11 May; although active spatter and lava had paused, several cracks within the fissure zone continued to widen (figure 351). A 3D model constructed of thermal images of Pu'u 'O'o crater taken on 11 May indicated that the deepest part of the crater was 350 m below the rim (figure 352). Hawai'i Volcanoes National Park closed to the public on 11 May due to heightened (daily) earthquake activity at the summit, and concerns about a potentially larger summit explosion.

Figure (see Caption) Figure 351. Ground cracks continued to widen near Leilani Estates subdivision at Kīlauea on 10 May 2018 even though active spatter and lava flows had paused. At 1354 a geologist inspected a crack that widened considerably during the previous day on Old Kalapana Road. In other areas, new cracks appeared along sections of Highway 130, some with visible escaping fumes. Courtesy of HVO.
Figure (see Caption) Figure 352. A clear view into Pu'u 'O'o crater of Kīlauea was possible on 11 May 2018. The upper part of the crater had a flared geometry, which narrowed to a deep circular shaft. The deepest part of the crater was about 350 m below the crater rim according to a 3D model constructed from thermal images. The crater is about 250 m wide, and N is to the left. Courtesy of HVO.

Activity during 12-23 May 2018. Minor spattering resumed from a new fissure (16) that opened about 0645 on 12 May around 1.5 km NE of fissure 15, at the NE end of the existing vent system (figure 353). It produced a lava flow that traveled about 230 m before stalling in the early afternoon. A steady, vigorous plume of steam and variable amounts of ash rose from the Overlook vent and drifted SW. Over the course of the day, rockfalls from the steep enclosing crater walls at the summit crater periodically generated small ash clouds mixed with water vapor. These ash clouds rose only about a hundred meters above the ground, a few generating very localized ashfall downwind.

Figure (see Caption) Figure 353. Fissure 16 opened in the morning on 12 May 2018 at around 0830 HST; it was located about 1.3 km NE of fissure 15, visible at the top left. The fissure is also located 500 m NE of the Puna Geothermal Venture (PGV) site (green piping, top right). View is uprift to the SW. Photograph courtesy of Hawai`i County Fire Department and HVO.

A plume of steam and volcanic gas, occasionally mixed with ash, rose from the Overlook vent within Halema'uma'u for much of the day on 13 May 2018. That morning, a new outbreak was reported about 0.5 km NE of fissure 16. Aerial observations of this new fissure (17) indicated it was at least several hundred meters long and produced spatter rising tens of meters into the air. By late in the day, activity was dominated by lava fountaining, explosions of spatter bombs, and several advancing lava flow lobes moving generally NE at the downrift (NE) end of the new fissure system. As of about 1900 on 13 May, one lobe was 2 m thick and advancing roughly parallel to Highway 132 (figure 354). A smaller fissure 18, a few hundred meters S of 17, was weakly active late in the day. A new fissure (19) was spotted early on 14 May producing a sluggish lava flow. By 1430 on 14 May, fissure 17 was producing a lava flow extending about 1.7 km from the fissure (figure 355).

Figure (see Caption) Figure 354. Fissures 15-19 opened along the fissure zone NE of Leilani Estates between 9 and 14 May 2018 on Kīlauea's East Rift Zone. As of the early morning on 14 May, lava from fissure 17 had traveled about 1.2 km, roughly ESE parallel to the rift zone, and was turning slightly S; at 0830 HST, the flow was about 0.9 km S of Highway 132. Fissure 18, which became active late on 13 May, and fissure 19, which opened early on 14 May, were both weakly active. Updated at 1430 on 14 May, this map shows the location of the front of the fissure 17 flow at that time. The flow is following a path of steepest descent (blue line), immediately south of the 1955 ''a'a flow boundary. Shaded purple areas indicate lava flows erupted in 1840, 1955, 1960, and 2014-2015. Courtesy of HVO.
Figure (see Caption) Figure 355. A thermal map of the NE end of the fissure system on the lower East Rift Zone of Kīlauea as of 1430 on 14 May 2018 shows the active fissure 17 flow extending about 1.7 km from the fissure. The black and white area is the extent of the thermal map. Temperature in the thermal image is displayed as gray-scale values, with the brightest pixels indicating the hottest areas. The thermal map was constructed by stitching many overlapping oblique thermal images collected by a handheld thermal camera during a helicopter overflight of the flow field. The base is a copyrighted color satellite image (used with permission) provided by Digital Globe. Courtesy of HVO.

Activity on the LERZ on 15 May 2018 was concentrated at fissure 17 with intermittent spattering at fissure 18; the fissure 17 flow continued to slowly advance ESE reaching a length of nearly 2.5 km in the early morning (figures 356 and 357). A new fissure (20) opened up SW of fissure 18 and produced two small pads of lava. During the morning, ash emissions from the Overlook vent inside Halema'uma'u varied greatly in intensity with abrupt increases likely associated with large rockfalls deep into the vent (figure 358). Ashfall was reported as far away as Discovery Harbor (55 km SW), Pahala (30 km SW), at locations along Highway 11 from Pahala to Volcano, and in the Ka'u Desert section of Hawaii Volcanoes National Park near the summit. NWS radar and pilot reports indicated the top of the ash cloud ranged from 3.0 to 3.7 km altitude.

Figure (see Caption) Figure 356. The 2.5-km-long fissure 17 lava flow on Kīlauea's lower East Rift Zone at 0844 on 15 May 2018 was an active ''a'a flow moving ESE from fissure 17, which was visible as low lava fountains in the middle of the photo. Highway 132 appears on the right side of the photograph; the view is toward the W. Photograph courtesy of the Hawai`i County Fire Department and HVO.
Figure (see Caption) Figure 357. Highly viscous (sticky) lava oozed from the edge of the ''a'a flow spreading slowly ESE from fissure 17 at Kīlauea's lower East Rift Zone on 15 May 2018. Courtesy of HVO.
Figure (see Caption) Figure 358. Activity at Halema'uma'u crater at Kīlauea increased in the morning of 15 May 2018 to include the nearly continuous emission of ash with intermittent stronger pulses that formed occasional higher plumes 1-2 km above the summit. At about 0900 HST the plume was drifting SW with the tradewinds toward the Ka`u Desert. The dark area to the right of the ash column rising from the Overlook vent is ash falling from the cloud. Courtesy of HVO.

On the morning of 16 May dense ballistic blocks up to 60 cm across were found in the parking lot a few hundred meters from Halema'uma'u crater, reflecting the most energetic explosions to date. Strong earthquakes within the summit continued in response to ongoing deflation and lava column drop. By the afternoon of 16 May the floor of the larger Kīlauea Caldera had dropped 90 cm from the ongoing deflation, stressing faults around the caldera and causing multiple earthquakes. Employees at the Hawaiian Volcano Observatory, Hawai`i Volcanoes National Park, and nearby residents reported frequent ground shaking and damage to roads and buildings. The decision was made to evacuate HVO's office building on Uekahuna Bluff overlooking Halema'uma'u Crater. Low-level eruption of lava continued from multiple points along the NE end of the active fissure system on the lower East Rift Zone, but spattering generally decreased in vigor throughout the day.

At about 0415 on 17 May an explosion from the Overlook vent produced a volcanic cloud that reached 9.1 km altitude and drifted NE. Traces of ash fell with rain on the Volcano Golf Course, in Volcano Village, and in other areas immediately around the summit (figure 359). Subsequent continued emissions reached 3.7 km altitude; vog or volcanic air pollution produced by volcanic gas was reported in Pahala. After the explosion, seismic levels increased gradually throughout the day.

Figure (see Caption) Figure 359. At 0745 on 17 May 2018 the view of Halema'uma'u crater at Kīlauea from the visitor viewing area in front of the Jaggar Muesum at Hawai'i Volcanoes National Park included a light coating of ash on the Park's interpretative sign caused by ashfall after significant explosive events the previous day. Note the contrast of the mostly-steam plume rising from the Overlook vent in the background with the eruption column that emerged during explosive activity in May 1924 (shown in the middle photograph on the sign). Courtesy of HVO.

At the LERZ, fissures 18, 19, and 20 reactivated during the afternoon of 17 May, and a new fissure opened (21) between fissures 7 and 3 (figure 360). Ground cracks continued to open and widen around Leilani Estates, several with both horizontal and vertical offsets (figures 361 and 362). An area 50-90 m wide, parallel to and N of the line of fissures between Highway 130 and Lanipuna Gardens, dropped slightly, forming a depression that pahoehoe flows from fissures 20 and 21 began filling. Fissure 22 opened just downrift of fissure 19.

Figure (see Caption) Figure 360. Fissure 21 opened between fissures 3 and 7 on 17 May 2018 on the lower East Rift Zone at Kīlauea. Around 1500 an aerial view of the fissure showed fountaining and a lava flow expanding outward from the fissure. View is toward the west. Courtesy of HVO.
Figure (see Caption) Figure 361. SW-trending en-echelon ground cracks dissected and offset NW-trending Pohoiki Road around 0700 on 17 May 2018 as seen during an overflight by HVO of the eruptive fissure area at Kīlauea's East Rift Zone. Cracks continued to open and widen, many with both horizontal and vertical offsets. These cracks were caused by the underlying intrusion of magma into the lower East Rift Zone. Courtesy of HVO.
Figure (see Caption) Figure 362. HVO geologists examined widening cracks on Nohea Street in Leilani Estates at Kīlauea's lower East Rift Zone on 17 May 2018. These cracks had expanded significantly during the previous day. Courtesy of HVO.

Spattering continued on 18 May 2018 from fissures 15, 17, 18, 20, 21, and new fissure 22. Pahoehoe lava flows were also erupted from fissures 17, 18, and 20 (figure 363). During the afternoon, fissure 17 was actively spattering fragments as high as 100 m, and the flow was active but had not covered new ground (figure 364). A flow from fissure 18 had traveled approximately 1 km SE. The graben area N of the fissures was still being filled by pahoehoe flows from fissures 20 and 21; fissure 15 produced a flow that crossed Pohoiki Road. Later in the afternoon a fast-moving pahoehoe flow emerged from fissure 20 and traveled SE, moving over 300 m per hour. By late that evening, the flow had three main lobes; the easternmost was E of Pohoiki Road moving about 200 m per hour while the westernmost was near Malamaki Road and moving about 40 m per hour. At the summit, for much of the day, a steady steam plume rose from the Overlook vent. Several minor emissions of ash were observed in web cameras; no significant explosions and no earthquakes greater than M 3.5 had occurred in the previous 24 hours. At 2358 local time, however, a short-lived explosion from Halema'uma'u created an ash cloud that reached up to 3.1 km altitude and was carried SW by the wind.

Figure (see Caption) Figure 363. By the early afternoon of 18 May 2018, fissures 21, 4, 15, 22, 20, 18, and 17 (SW to NE) were all erupting with either pahoehoe flows, fountaining, or spatter on Kīlauea's lower East Rift Zone. Shaded purple areas indicate lava flows erupted in 1840, 1955, 1960, and 2014-2015. Courtesy of HVO.
Figure (see Caption) Figure 364. The line of fountains on fissure 17 coalesced into a large fountain sending lava fragments 50 m into the air in the morning on 18 May 2018 at the lower East Rift Zone of Kīlauea; small bits of spatter reached 100 m high. Courtesy of HVO.

The rate of lava eruption increased overnight on 18-19 May; fountaining continued at fissure 17, and fissures 16 and 20 merged into a continuous line of spatter and fountaining. Two flows from this consolidated fissure complex were wide, very active, and advancing southward at rates up to 300 m per hour (figures 365 and 366). Flows from fissures 17 and 18 were also still active but advancing slowly, and fissure 18 had stalled by the end of the day. By mid-afternoon on 19 May the two fast-moving flows had joined about a kilometer from the coast and continued to flow southward (figure 367). The GPS instrument located on the NE side of Leilani Estates was no longer moving. While earthquake activity continued, it had not moved farther downrift in the previous few days.

Figure (see Caption) Figure 365. Channelized lava flows originating from a merged, elongated fountaining source between fissures 16 and 20 in Kīlauea's lower East Rift Zone split into two flows that both traveled rapidly S as seen at 0737 on 19 May 2018. This view to the SW also showed the steaming line of fissures on the lower East Rift Zone that continued SW of the fountaining source. Courtesy of HVO.
Figure (see Caption) Figure 366. 'A'a lava flows emerged from the elongated fissure 16-20 at Kīlauea to form several channels. The flow direction is from upper center to the lower left of image. Incandescence from the second flow is visible in the upper left. Image taken around 0818 on 19 May 2018 during a helicopter overflight of Kīlauea's lower East Rift zone by HVO geoscientists. Courtesy of HVO.
Figure (see Caption) Figure 367. Around 1215 on 19 May 2018 the two primary lava-flow fronts originating from the fissure 20-22 area on Kīlauea's lower East Rift Zone were about to merge as they flowed SE. The flow front position based on a later update at 1840 is shown by the red circle. The black and white area is the extent of the thermal map. Temperature in the thermal image is displayed as gray-scale values, with the brightest pixels indicating the hottest areas. The thermal map was constructed by stitching many overlapping oblique thermal images collected by a handheld thermal camera during a helicopter overflight of the flow field. The base is a copyrighted color satellite image (used with permission) provided by Digital Globe. Courtesy of HVO.

The two flows from the fissure 20 complex entered the ocean at two points along the SE Puna coast overnight on 19-20 May (figure 368). Soon after, a crack opened under the E lava channel diverting some of the lava into underground voids (figure 369) and reducing the amount of lava flowing into the ocean. Spattering continued from fissures 6 and 17 during the day on 20 May. Fissure 23 first appeared at 1100 on 20 May, at the NE corner of the Leilani Estates subdivision near fissures 4 and 14, about 2 km SW of fissure 20; it was only active during 19-20 May. Volcanic gas emissions tripled as a result of the voluminous eruptions from the fissure 20 complex; satellite instruments measured a major increase in SO2 emissions on 19 May (figure 370). Intermittent explosive eruptions continued at the summit, and plumes of gas and steam periodically emerged from the Overlook vent and drifted SW.

Figure (see Caption) Figure 368. The fissure 20 complex flows from Kīlauea's lower East Rift Zone reached the ocean overnight during 19-20 May 2018, as seen in this image from an HVO overflight in the early morning on 20 May. Dense white plumes of "laze" (short for "lava haze") formed as lava entered the ocean. Laze is formed as lava boils seawater. The process leads to a series of chemical reactions that result in the formation of a billowing white cloud composed of a mixture of condensed seawater steam, hydrochloric acid gas, and tiny shards of volcanic glass. This mixture has the stinging and corrosive properties of dilute battery acid and is hazardous to breathe. Because laze can be blown downwind, its corrosive effects can extend far beyond the actual ocean entry area. Courtesy of HVO.
Figure (see Caption) Figure 369. Lava from the eastern channel of the fissure 20 complex flowed into a crack in the ground that opened on the morning of 20 May 2018. The resulting decrease in lava volume caused the easternmost channel of lava and the eastern ocean entry to be less vigorous than the western entry point. Courtesy of HVO.
Figure (see Caption) Figure 370. SO2 emissions increased substantially at Kīlauea when the rate of lava emission increased significantly on 19 May 2018 on the lower East Rift Zone. The OMI instrument on the Aura satellite measured 8.2 Dobson Units (DU) of atmospheric SO2 on 3 May, the day fissure 1 opened, and 18.11 DU on 19 May when the flow rates increased at the fissure 20 complex. Courtesy of NASA Goddard Space Flight Center.

The most vigorous eruptive activity during 21-23 May in the lower East Rift Zone, was concentrated in the middle portion of the system of fissures, primarily between fissure 20 on the NE and fissure 23 on the SW (figure 371). Fountaining 50 m high from fissure 22 was feeding the channelized flow reaching the coast (figure 372). Fissure 6 reactivated with spattering and a short flow on 21 May. Fissure 17, at the NE end of the fissure system was only weakly active. On 22 May lava fountains continued from fissures 6 and 22, with fissures 19 and 5 also active; a new area of fountaining also appeared near fissure 23. Fountaining from fissures 5 and 23 fed flows in the eastern part of Leilani Estates and blue methane was observed burning in road cracks overnight on 22-23 May (figure 373). Observers noted that the height of the perched lava pond forming on the NW side of fissures 5 and 6 had reached 11 m above the ground level.

Figure (see Caption) Figure 371. By 20 May 2018, two lava flows from fissures 20 and 22 in the lower East Rift Zone at Kīlauea had coalesced and reached the ocean. Activity at the fissure 17 flow had diminished significantly. The most vigorous eruptive activity during 21-23 May 2018 was concentrated in the middle portion of the system of fissures, primarily between fissure 20 on the NE and fissure 23 on the SW. Courtesy of HVO.
Figure (see Caption) Figure 372. HVO geologists reported fountaining from fissure 22 as 50 m high on 21 May 2018 at Kīlauea's lower East Rift Zone. Courtesy of HVO.
Figure (see Caption) Figure 373. Blue flames of methane emerged from ground and road cracks on 22 May 2018. This early morning photo was taken on Kahukai Street in the Leilani Estates subdivision at Kīlauea looking SE, with an active lava flow from fissure 13 behind the blue flames. Photo by L. DeSmither, courtesy of HVO.

By 23 May, fountains from fissures 5, 6 (figure 374), 13, and 19 were feeding a flow advancing to the S, roughly parallel to the western flow from fissure 22 (figure 375); it reached the ocean late in the afternoon, creating multiple entry points that produced occasional small explosions. Small ash emissions from the Overlook vent occurred frequently during 21-23 May (figure 376). Fissure 8 reactivated briefly in the morning of 23 May and erupted two small pahoehoe flows over the initial `a`a flow.

Figure (see Caption) Figure 374. Fissure 6 in the lower East Rift Zone at Kīlauea built a lava berm across Pohoiki Road as seen on 23 May 2018. Flows from fissure 6 and adjacent fissures formed a flow parallel to an earlier flow that traveled SE reaching the coast that afternoon. Courtesy of HVO.
Figure (see Caption) Figure 375. Multiple channels of lava flowed SE from the fissure zone at Kīlauea's lower East Rift Zone to the sea on 23 May 2018. Overflows from the channels spread out over existing, older flows; note the large agriculture buildings as indicators of the scale of the flows. The visible haze is sulfur dioxide gas from the fissures. Photo taken by J. Ozbolt, Hilo Civil Air Patrol, courtesy of HVO.
Figure (see Caption) Figure 376. A pulse of ash rose from Halema'uma'u on 23 May 2018 as part of semi-continuous emissions at Kīlauea's summit. Ash could be seen falling from the plume as it was blown downwind around 1528 HST on 23 May. USGS photo by I. Johanson, courtesy of HVO.

Activity during 24-28 May 2018. Overnight on 23-24 May field crews observed that fissure areas 2, 7, 8, 3, 14, and 21 had reactivated and were spattering (figure 377). Fissure 22 continued to erupt lava flowing SE to the coast (figure 378). Fissures 7 and 21 were feeding a perched lava pond and pahoehoe flow that advanced eastward later that afternoon. An explosion from the summit Overlook vent just after 1800 on 24 May produced an ash cloud that rose to 3.1 km altitude and had more ash than most recent explosions (figure 379). The National Weather Service Nexrad radar tracked the cloud for 15-20 minutes; moderate trade winds were blowing to the SW.

Figure (see Caption) Figure 377. Reactivation of fissures 2, 7, 8, 3, 14, and 21 was noted on 24 May 2018 at the lower East Rift Zone at Kīlauea. Fissures 7 and 21 were feeding a perched lava pond and pahoehoe flow. Several ocean entries were also active from the channelized flow down the SE flank sourced from the region of fissures 6-20. Courtesy of HVO.
Figure (see Caption) Figure 378. During HVO's overflight in the morning of 24 May 2018, the fissure 22 fountain was not as high as several days earlier, but was still erupting significant lava that was flowing to the SE Puna coast at Kīlauea. USGS photo by M. Patrick, courtesy of HVO.
Figure (see Caption) Figure 379. An explosion was detected from the summit Overlook Crater at Kīlauea just after 1800 on 24 May 2018 that produced an ash cloud that rose to 3.1 km altitude, carrying more ash than most recent explosions. This view to the SW is from the caldera rim near Volcano House where USGS scientists were stationed to track the ongoing summit explosions. Courtesy of HVO.

By 25 May, the two flows from fissure 22 and fissures 6 and 13 were still reaching the ocean with two entry points (figure 380); fissures 7 and 21 were feeding a flow that continued to slowly advance NE, covering several streets in Leilani Estates (figure 381). By the next day, the flow front of fissure 21 had become an 'a'a flow and was continuing to move NE (figure 382), reaching the PGV (Puna Geothermal Venture) property by late afternoon on 26 May. Fissure 7 was feeding a flow that had turned S toward the coast, and at dusk the lava was cascading into the Pawaii crater, adjacent to the western margin of the fissure 6 flow that fed one of the ocean entries. On the W side of fissure 7 a perched pahoehoe flow broke out around 0400 on 26 May, feeding short flows to the W. Multiple small eruptions continued to occur at the summit, most ejecting ash to under 3.1 km altitude. One of the largest occurred about 1617 on 25 May sending ash as high as 3.7 km altitude.

Figure (see Caption) Figure 380. Fissures 6 (left) and 13 (right) at midday on 25 May 2018 on Kīlauea's lower East Rift Zone, with lava flows merging into one channel that flows SE into the ocean. Note plume in distance at the ocean entries (top left). Courtesy of HVO.
Figure (see Caption) Figure 381. Reactivated fissures 7 and 21 within the Leilani Estates subdivision at Kīlauea were feeding new flows moving NE towards the Puna Geothermal Venture (PGV) property during 25 and 26 May 2018. Courtesy of HVO.
Figure (see Caption) Figure 382. An 'a'a flow, erupted from fissure 21 at Kīlauea was approximately 3-4 m high at the flow front and slowly advancing to the NE in the Leilani Estates subdivision around 1030 HST on 26 May 2018. Courtesy of HVO.

Overnight during 26-27 May fissure 17 was the source of multiple booming gas emissions. Fissure 7 activity increased overnight, producing a large spatter rampart over 30 m tall from fountains reaching 50-70 m high (figure 383). The fountains fed two perched channels, the N channel, 8-15 m thick, fed a lava flow that advanced toward pad E of the PGV property; the S channel was a flow advanced SE. Large cracks were observed overnight near fissure 9 which developed into fissure 24. Fissure 8 had three vents active overnight on 26-27 May that were spattering and flaming; they had doubled in size over the previous 24 hours.

Figure (see Caption) Figure 383. Pahoehoe lava advanced rapidly W from fissure 7 on Leilani Avenue in Kīlauea's lower East Rift Zone on 27 May 2018. Activity had increased overnight, with lava fountains reaching 50 to 60 m high. Courtesy of HVO.

The fissure 21 'a'a flow continued to advance NE onto PGV property but at a slower pace on 27 May. By the end of the day, fissures 7 and 8 were the most active, fountaining and feeding lava flows that advanced NE onto PGV property. At about 1900 HST a fast-moving lava flow broke from this area and advanced rapidly to the N and W through the eastern portion of Leilani Estates, causing additional evacuations. Activity had noticeably diminished from fissures 22 and 13, and the supply of lava to the channel flowing to the sea had ceased by the next day, 28 May. Ash continued to erupt intermittently from the Overlook vent at the summit. Observations from the ground and by UAV during the previous week documented retreat of the Overlook vent wall due to collapse of the steep enclosing walls and rim. Trade winds carried the ash clouds primarily SW.

Fissure 8 fed a fast-moving flow early on 28 May that moved N along the margin of the existing fissure 7 flow before turning E and crossing out of Leilani Estates (figure 384). Flow activity from fissure 8 diminished abruptly midday and a few other fissures reactivated briefly with fissure 7/21 having the tallest fountains. Vigorous fountaining resumed at fissure 8 late in the afternoon, spawning a flow that traveled an estimated 20 m per hour to the NE over the flow of the previous day; fountains were 50-60 m tall (figure 385). During the evening, fissures 16, 18, 22, 13, and 20 were also active, with flows moving S from fissures 16/18. Pele's hair from vigorous fountaining of fissure 8 was being transported downwind, and there were reports of some strands falling in Pahoa. Residents were warned to minimize exposure to Pele's hair, which could cause skin and eye irritation similar to exposure to volcanic ash. Ash continued to erupt intermittently from the vent within Halema'uma'u crater. A magnitude 4.1 earthquake occurred at 1739 HST on the Koa'e fault zone south of the caldera. Earthquakes in the summit region continued as the area subsided and adjusted to the withdrawal of magma.

Figure (see Caption) Figure 384. A fast-moving flow from fissure 8 moved N and then E out of Leilani Estates on 28 May 2018 marking a new phase in the 2018 Kīlauea eruption. Courtesy of HVO.
Figure (see Caption) Figure 385. Fissure 8 on Kīlauea's lower East Rift Zone reactivated after a brief pause on the afternoon of 28 May 2018 with lava fountains that reached heights of 60 m and fed a lava flow that advanced rapidly to the NE. Courtesy of HVO.

By 26 May 2018, flows on the lower East Rift Zone had destroyed at least 82 structures including 41 homes since the beginning of May. Twelve more were destroyed on 27 and 28 May as flows continued to move across the region, according to USA Today. By 29 May, activity on the lower East Rift Zone was focused on the vigorous eruption of lava from fissure 8 advancing rapidly downslope towards the NE and Highway 132.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: http://hvo.wr.usgs.gov/); NASA Goddard Space Flight Center (NASA/GSFC), Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, 8800 Greenbelt Road, Goddard, Maryland, USA (URL: https://so2.gsfc.nasa.gov/); USA Today (URL: https://www.kiiitv.com/article/news/nation-now/hawaii-lava-flow-destroys-12-more-homes-as-Kilauea -volcano-continues-exploding/465-afd62fc3-91d2-4764-9eb9-c3dee473033d).


December 2018 (BGVN 43:12) Citation IconCite this Report

Lava fountains on the Lower East Rift Zone build 50-m-high pyroclastic cone and 13-km-long lava flow that engulfs Kapoho Bay during June 2018; 533 homes destroyed since 1 May

Kīlauea's East Rift Zone (ERZ) has been intermittently active for at least two thousand years. Open lava lakes and flows from the summit caldera and East Rift Zone have been almost continuously active since the current eruption began in 1983. A marked increase in seismicity and ground deformation at Pu'u 'O'o Cone on the upper East Rift Zone on 30 April 2018 and the subsequent collapse of its crater floor marked the beginning of the largest lower East Rift Zone eruptive episode in at least 200 years.

During the month of May 2018 there were 24 fissures that opened along a 6-km-long NE-trending fracture zone on the lower East Rift Zone spawning lava flows in multiple directions, including several that traveled about 5 km SE to the coast; at least 94 structures were destroyed in the Leilani Estates subdivision and adjacent areas (BGVN 43:10). As lava emerged from the fissures, the lava lake at Halema'uma'u drained and explosions produced plumes that spread minor amounts of ash to downwind communities. At the end of May eruptive activity refocused around fissure 8, which began fountaining lava tens of meters into the air and creating a voluminous incandescent flow that headed downslope to the NE. The eruptive events of June 2018 (figure 386), the second month of this episode, are described below with information provided primarily from the US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO) in the form of daily reports, volcanic activity notices, and abundant photo, map, and video data.

Figure (see Caption) Figure 386. A timeline of events at Kīlauea for 28 May-30 June 2018. Blue shaded region denotes activity at Halema'uma'u crater at the summit. Green shaded area describes activity on the lower East Rift Zone (LERZ). HST is Hawaii Standard Time. Black summit symbols indicate earthquakes (diamonds) and ash plumes (stars); red LERZ symbols indicate lava fountains (stars), lava flows (triangles) and lava ocean entry.

Summary of events during June 2018. Lava fountains from fissure 8 were reaching 60 m in height on 29 May 2018 and producing a vigorous stream of lava that traveled rapidly downslope. Several lobes of lava advanced ENE, some at rates of several hundred meters per hour. Fissure 18 was also generating a narrow flow that headed SE for 3 km before stopping. A spatter cone began growing at fissure 8 and reached 30 m in height in just a few days. On the morning of 2 June the fissure 8 flow covered the Four Corners Intersection of Highways 132 and 137, and continued E and then SE around Kapoho Crater; lava flowed into the crater and evaporated the fresh water lake inside. Traveling at a rate of about 75 m per hour, the flow moved towards the shore and reached Kapoho Bay late on 3 June, where it began building a delta. In just a few days the delta was a kilometer in width, and lava was entering the ocean in many streams along the flow front, generating dense plumes of steam and laze.

By 15 June the fissure 8 cone had reached just over 50 m in height. Fissure 8 lava fountains persisted at 40-70 m high for all of June, feeding the 13-km-long channel to Kapoho Bay. Periodic overflows along the channel built up the levees on either side of the fast-moving river of lava; they were short-lived and traveled only a few meters. Flow speeds slowed as the lava spread out over the delta, which reached 150 hectares (380 acres) in size by 20 June. The ocean-entry points migrated north and south along the delta over the course of the month, expanding the width of the ocean entry area to over 3 km. Towards the end of June, lava was crusted over in the delta up to 1 km back from the ocean, and molten material was traveling within the interior of the earlier flows to the ocean. Minor oozing of lava was reported from a few other fissures during the month, but no other significant flow activity was observed.

Within Halema`uma`u crater at the summit a near-daily pattern of collapse explosion events was due to the subsidence caused by the magma withdrawal. As the crater subsided, its rim and walls slumped inward and large blocks dropped down along growing fractures around the caldera with seismic energy releases greater than M 5.0 almost every day. The deepest part of the crater had reached 400 m below the caldera floor by late June.

Activity at the Lower East Rift Zone during 29 May-4 June 2018. By 29 May, activity on Kīlauea's lower East Rift Zone was focused on the vigorous eruption of lava from fissure 8 advancing rapidly downslope towards Highway 132. Lava fountains from fissure 8 reached 60 m in height on 29 May, feeding a flow that advanced NE over a flow from a few days earlier. The first lobe of the flow crossed Highway 132 just before 1400 that afternoon and continued NE. Most of the flow remained on the S side of the highway as it moved downslope. Visual observations in the early afternoon also confirmed continued weak activity at fissures 18 and 16. Fissure 18 had produced channelized flows which advanced about 2.6 km toward the coast during the previous day. At the ocean entry on the SE coast, only a few small channels of lava were still entering the ocean. Fissure 8 maintained high fountains throughout the day and into the overnight of 29-30 May with sustained heights exceeding 60 m and multiple secondary fountains that reached 20 m. As the flow moved downslope along the highway, the advance rates accelerated overnight, reaching approximately 550 m/hour. Overnight, sporadic bursts of activity were also observed from fissures 7 and 15.

Fissure 8 maintained fountains that rose 60-75 m high on 30 May. The flow split into three lobes; the two easternmost lobes advanced in a more ENE direction while the westernmost lobe advanced in a NE direction (figure 387). The flow rate had dropped to around 90 m/hour by late afternoon and slowed further to 45 m/hour by late evening. The fissure 18 flow also remained active, moving downslope toward Highway 137 at rates of less than 90 m/hour. By late afternoon, the front of the fissure 18 flow was about 1 km from Highway 137 and was spreading and slowing (figure 388). In the late afternoon, a new flow lobe began branching from the S side of the fissure 18 flow approximately 2 km upslope from the flow front. Throughout the day, sporadic bursts of activity were also observed from fissures 22, 6, and 13.

Figure (see Caption) Figure 387. A major lava flow that first emerged from Kīlauea's fissure 8 on 28 May was moving rapidly downslope to the NE when photographed during HVO's early morning overflight on 30 May 2018. The lava channel was estimated to be about 35 m wide; 60-m-high fountains from the fissure are visible in the upper right. Courtesy of HVO.
Figure (see Caption) Figure 388. Kīlauea's Lower East Rift Zone had many active flow fronts as of 1500 HST on 30 May 2018. Active fissures and flows are shown in dark red. Shaded purple areas indicate lava flows erupted in 1840, 1955, and 1960. Courtesy of HVO.

Four lobes of the fissure 8 flow advanced on 31 May (figure 389), fed by persistent fountaining that reached heights up to 80 m. A spatter cone was forming on the downwind side of the fountain and was approximately 30 m high. The fountains were feeding the flow to the NE, and minor overflows from the growing fissure 8 channel were occurring along its length, covering several of the remaining roads in Leilani Estates. The front of the flow advanced at about 90 m/hour through agricultural lands and was within 1.7 km of the Four Corners area (the intersection of Highways 132 and 137) by the evening. The fissure 18 flow that had advanced to within 1 km of Highway 137 had stalled. The new flow that branched from the fissure 18 channel 2 km upslope appeared to have captured most of the lava output from fissure 18. It descended downslope just to the S of the previous flow. Lava was pooling around the vent of fissure 22 throughout the day.

Figure (see Caption) Figure 389. Four advancing lobes from Kīlauea's LERZ fissure 8 were moving 75 m per hour to the NE on the morning of 31 May 2018 in this view to the E. The flow moved north of Highway 132 in the vicinity of Noni Farms and Halekamahina roads, from which the two easternmost lobes advanced in a more ENE direction while the westernmost lobe advanced in a NE direction. Courtesy of HVO.

The advance rates of the distal part of the fissure 8 flow were low overnight on 31 May-1 June as lava ponded in a flat area, but flow continued throughout the day to within 0.5 km of the Four Corners intersection of Highways 132 and 137 by evening; fissures 18 and 22 were inactive. By 0645 on 2 June it was about 100 m from the intersection (figure 390). Around 0930 on 2 June a broad front over 275 m in width extending both north and south of Highway 132 (figures 391) crossed the intersection and continued advancing into Kapoho Crater (sometimes called Green Lake Crater) and Kapoho Beach Lots. It entered Green Lake within the crater, creating a large steam plume that was visible until 1330. The Hawaii County Fire Department reported around 1500, after an overflight, that lava had filled the lake and apparently boiled away all the water.

Figure (see Caption) Figure 390. This thermal map of Kīlauea's LERZ fissure 8 flow shows the location of the lava front as of 0645 on 2 June 2018 shortly before it reached the Four Corners intersection. At that point it was roughly 10 km from the vent. The black and white area is the extent of the thermal map. Temperature is displayed as gray-scale values, with the brightest pixels indicating the hottest areas. The map was constructed by stitching many overlapping oblique images collected by a handheld thermal camera during a helicopter overflight of the flow field. The base is a copyrighted color satellite image (used with permission) provided by Digital Globe. Courtesy of HVO.
Figure (see Caption) Figure 391. Around 0715 on 2 June 2018 Kīlauea's LERZ fissure 8 flow was a 275-m-wide lava front advancing on both sides of Highway 132 (left); the flow front was approximately 90 m west of the Four Corners Intersection when USGS scientists on HVO's morning overflight captured this image. Note trees and highway for scale. Courtesy of HVO.

The flow continued to advance overnight on 2-3 June along an 800-m-wide front towards the ocean at Kapoho Bay between Kapoho Beach Road and Kapoho Kai Drive. As of 0700 on 3 June, the lava flow was around 450 m from the ocean (figures 392 and 393) traveling at a rate of about 75 m/hour. By 1745 it had advanced to within 225 m of the ocean at its closest approach point. The other branches of the fissure 8 lava flow were inactive, and all other fissures were inactive, although observers on the late afternoon overflight noted abundant gas emission from fissures 9 and 10 and incandescence without fountaining at fissures 16 and 18.

Figure (see Caption) Figure 392. At 0700 HST on 3 June 2018 Kīlauea's LERZ fissure 8 flow front was about 450 m from the ocean, advancing at about 75 m/hour. View is to the W looking up the flow front. Nearly all of the front was active and advancing. Courtesy of HVO.
Figure (see Caption) Figure 393. The flow front of Kīlauea's LERZ fissure 8 on the morning of 3 June 2018 was advancing around 75 m/hour along a broad front towards Kapoho Bay. Dark red areas are active flow expansion, shaded purple areas indicate lava flows erupted in 1840, 1955, and 1960. Courtesy of HVO.

Fountaining lava 45-75 m high at fissure 8 continued overnight on 3-4 June, feeding the growing lava channel flowing NE along Highway 132 to the Kapoho area. Throughout 30 May-3 June tephra landing downwind from the fountaining produced a growing pyroclastic cone at fissure 8 (figure 394). Local videographers reported that lava entered the ocean at Kapoho Bay at about 2230 HST on 3 June and began constructing a delta (figure 395); by late afternoon the next day the delta extended about 640 m into the bay. A laze plume (a corrosive seawater steam plume laden with hydrochloric acid and fine volcanic particles) was blowing inland from the ocean entry but dissipating quickly. The lava flow front was about 800 m wide. A lava breakout was also occurring upslope (N) of the Kapoho cone cinder pit. A lava breakout from the S margin of the flow near the intersection of Highway 132 and Railroad Avenue had completely encircled Kapoho Cone by the end of the day.

Figure (see Caption) Figure 394. A comparison of thermal images of the fountains and fast-growing pyroclastic cone at Kīlauea's LERZ fissure 8 from 30 May to 3 June 2018 indicated the increase in height of the lava fountains from 45 to over 75 m, as well as the growth of a cone (pu'u) downwind to about 30 m height. HVO reported the lava fountain temperatures were reaching up to about 1,115°C (2,040°F). The composition of the lava erupted had high MgO (magnesium oxide) values, which came from olivine crystals that were being pulled from deep within the rift zone. Courtesy of HVO.
Figure (see Caption) Figure 395. The flow front of Kīlauea's LERZ fissure 8 flow reached the ocean at Kapoho Bay late in the evening of 3 June; by 0613 HST on 4 June 2018 when this image was taken during an HVO overflight, the lava was creating a large laze plume and beginning to form a delta into the bay. Courtesy of HVO.

Activity at the Lower East Rift Zone during 5-12 June 2018. The intensity of the fountaining at fissure 8 declined overnight on 4-5 June to between 40-50 m in height, not far above the top of the cone formed during the previous several days (figure 396). By the early morning of 5 June the fissure 8 flow had completely filled Kapoho Bay, extending 1.1 km from the former coastline (figure 397). On the south side of the ocean entry, lava was entering the water at the Vacationland tidepools, having inundated most of that subdivision. To the north, lava had covered all but the northern part of Kapoho Beach Lots. The northernmost lobe of the fissure 8 flow, in the Noni Farms Road area, advanced downslope about 180 m overnight (figure 398) and continued to slowly advance during the day on 5 June.

Figure (see Caption) Figure 396. Lava fountains continued at Kīlauea's LERZ fissure 8, although overnight on 4-5 June 2018 USGS field crews reported reduced fountain heights. The lava fountain had built a 35 m (115 ft) high spatter cone, and an actively-growing spatter rampart on its eastern side. The lava channel leading from the cone was filled to the top of its levees at the time of this photo. The white objects in the upper left are the roofs of houses adjacent to the edge of the flow levee. Courtesy of HVO.
Figure (see Caption) Figure 397. Kapoho Bay was filled with lava from Kīlauea's LERZ fissure 8 flow by the morning of 5 June 2018, as seen in this view looking S during the morning HVO overflight. Hundreds of homes around the bay were buried within the lava flow. Courtesy of HVO.
Figure (see Caption) Figure 398. By 1000 HST on 5 June 2018 there were two growing areas of active ocean entry on the delta at the front of Kīlauea's LERZ fissure 8 lava flow. Dark red areas are active flows and shaded purple areas indicate lava flows erupted in 1840, 1955, 1960, and 2014-2015. Courtesy of HVO.

By the morning of 6 June 2018, the lava fountaining at fissure 8 continued to reach heights of 45-55 m and feed a stable channel to the NE and E (figure 399) to the ocean entry in the Kapoho Bay area. The lava delta that formed at the bay had also extended slightly outward overnight; during the day on 6 June a lateral lobe of the flow pushed slowly N through what remained of the Kapaho Beach Lots subdivision. Overnight on 6-7 June and throughout the following day the fountain heights from fissure 8 fluctuated between 58 and 70 m feeding the channel with vigorous flow (figure 400). The delta was about 1.9 km wide in the Vacationland/Waopae area and the flow was expanding northward (figure 401). By the late afternoon overflight on 8 June, two vigorous steam plumes were rising from the ocean flow front and being blown inland. Strong thermal upwelling was noted in the ocean extending up to 900 m out to sea from the visible lava front. Heavy gas and steam emissions were noted at fissures 9 and 10, but lava emission was occurring only at fissure 8.

Figure (see Caption) Figure 399. HVO used drones, referred to as Unmanned Aircraft Systems (UAS), to gather high-resolution video and images throughout the eruption on Kīlauea's lower East Rift Zone. On 6 June 2018 a UAS flight collected video of flowing lava in the upper lava channel of fissure 8. The view is to the S towards the fissure 8 cone in the upper left. The houses on the right provide a sense of scale for the fissure 8 flow. Scientists used the video to assess lava flow velocities, which are measured by tracking surface features in the stationary video view. This still image was taken from video captured by the U.S. Geological Survey and Office of Aviation Services, Department of the Interior, with support from the Hawaiian Volcano Observatory. Courtesy of HVO.
Figure (see Caption) Figure 400. In this early morning view to the E on 7 June 2018, fountains of lava rise 50 m from Kīlauea's LERZ fissure 8 and the lava channel travels NE to the ocean, a distance of about 12.5 km. Steam plumes in the distance rise from inactive fissures that opened during May. Courtesy of HVO.
Figure (see Caption) Figure 401. By 8 June 2018, Kīlauea's LERZ fissure 8 flow had created a lava delta approximately 77 hectares (190 acres) in size, filling Kapoho Bay and shallow reefs along the nearby coastline. Dark red areas are active flows, shaded purple areas indicate lava flows erupted in 1840, 1955, 1960, and 2014-2015. Courtesy of HVO.

Overnight on 8-9 July the fountains at fissure 8 were slightly lower, reaching heights of 40-55 m. Fissure 22 was incandescent and there was minor lava activity at fissures 16/18 while the fuming from fissures 24, 9, and 10 had decreased from the previous day. The fissure 8 flow had created a lava delta approximately 80 hectares (200 acres) in size by the morning of 9 June, filling Kapoho Bay and covering shallow reefs along the nearby coastline (figure 402); observers that night also noted vigorous convection taking place up to 1.5 km offshore from the entry points. Minor levee overflows along the upper part of the channel occurred on 10 June from the strong channelized flow (figure 403). Near the Four Corners region the channel was incandescent and flowing vigorously.

Figure (see Caption) Figure 402. A view from offshore of the Kapoho ocean entry of Kīlauea's LERZ fissure 8 flow as of 0630 HST on 9 June 2018 shows the extent of the lava delta, about 80 hectares (200 acres) in size, that formed over the previous six days. Across the front of the delta plumes of laze, created by molten lava interacting with seawater, appeared diminished that morning, but this was probably due to a change in atmospheric conditions rather than a change in the amount of fissure 8 lava reaching the ocean. Courtesy of HVO.
Figure (see Caption) Figure 403. Overflows of the upper channel at Kīlauea's LERZ fissure 8 lava flow on 10 June 2018 sent small flows of lava down the levee walls. These overflows did not extend far from the channel, so they posed no immediate threat to nearby areas. Channel overflows, like the ones shown here, add layers of lava to the channel levees, increasing their height and thickness. In the lower right of the photo, a paved road and power lines provide a scale for the size of the flow channel and levees. Courtesy of HVO.

By the evening on 10 June, three closely spaced lava fountains at fissure 8 were erupting with maximum heights reaching 35-40 m (figure 404), feeding the fast moving channelized and braided flow that now traveled 13 km to the ocean at Kapoho Bay (figure 405). A strong steam plume was observed on the S end of the ocean entry with frequent steam explosions at the flow front. Weak lava activity continued during 10-12 June at fissures 16/18 as it had for the previous several days (figure 406). Incandescence was noted at fissures 15 and 22 on 12 June. Lava was entering the ocean over a broader area than before with several minor incandescent points and small plumes, and two larger entries and corresponding plumes. The fissure 8 cinder cone had reached about 43 m in height by the evening of 12 June.

Figure (see Caption) Figure 404. The three closely spaced lava fountains at Kīlauea's LERZ fissure 8 reached maximum heights of 35-40 m overnight 10-11 June 2018. Lava fragments falling from the fountains were building a substantial cinder-and-spatter cone around the erupting vent, with the bulk of the fragments falling on the downwind side of the cone. The cone had reached 43 m in height by 12 June. Courtesy of HVO.
Figure (see Caption) Figure 405. Braided channels of lava from Kīlauea's LERZ fissure 8 covered a wide swath of the NW side of the LERZ in the morning on 12 June 2018. Incandescence from the fountain feeding the flow is visible several kilometers in the distance in this image looking upstream. The 13-km-long flow traveled NE then E and flowed into Kapho Bay. Courtesy of HVO.
Figure (see Caption) Figure 406. The fountains at Kīlauea's LERZ fissure 8 remained active as of 1400 HST on 12 June 2018, with the 13-km-long lava flow entering the ocean at Kapoho Bay along a growing delta. Very small, weak lava flows were also active near the fissure 18 area (center). The black and white area is the extent of the thermal map. Temperature in the thermal image is displayed as gray-scale values, with the brightest pixels indicating the hottest areas. The map was constructed by stitching many overlapping oblique images collected by a handheld thermal camera during a helicopter overflight of the flow field. The base is a copyrighted color satellite image (used with permission) provided by Digital Globe. Courtesy of HVO.

Activity on the Lower East Rift Zone during 13-19 June 2018. Lava fountaining at fissure 8 during 13-19 June generally rose 30-50 m with intermittent bursts as high as 60 m. The growing cone was 52 m at its highest point on 15 June (figure 407). From fissure 8, lava flowed freely over small cascades (rapids) into a well-established channel (figure 408). Near the vent, channel lava was traveling about 24 km/hour; it slowed as it traveled the 13 km-long-channel (figure 409) to about 2 km/hour near the ocean entry at Kapoho Bay. Minor amounts of lava periodically spilled over the channel levees.

Figure (see Caption) Figure 407. Lava fountains were still rising higher than the 52-m-high cone at Kīlauea's LERZ fissure 8 on 15 June 2018. Courtesy of HVO.
Figure (see Caption) Figure 408. Cascades of lava from 50-m-high fountains flowed over rapids into the channel of Kīlauea's LERZ fissure 8 lava flow on 17 June 2018. Near the vent, lava was traveling about 24 km per hour; lava slowed to about 2 km per hour near the ocean entry at Kapoho.
Figure (see Caption) Figure 409. Lava flowed in an open channel 13 km long to the ocean from Kīlauea's LERZ fissure 8 on 18 June 2018. Kapoho Crater, which partly filled with lava on 2 June, is the vegetated hill on the right side of the photograph. The lava evaporated Green Lake inside the crater. The ocean entry plume can be seen in the distance on the left. The small white objects on either side of the flow are large buildings about 75 m long. Highway 137 emerges from underneath the flow and heads S into the distance in the upper center of the image. Courtesy of HVO.

Several laze plumes rose along the ocean entry margin as break outs fed many small and large flows during mid-June. The largest pahoehoe breakout area was on the northern margin of the flow (figure 410). A small amount of expansion continued at the southern boundary of the flow near the coast and south of Vacationland. By 17 June, lava flowing into the ocean had built a delta of flows, rock rubble, and black sand, which was over 121 hectares (320 acres) in size. The flow front at the coast was about 2.4 km wide by 18 June. Limited spattering and small flows were also observed at fissures 16 and 18 during 13-19 June; mild spattering from fissure 15 was observed late in the day on 16 June, and incandescence and mild spattering were observed from fissure 6 on 17 June.

Figure (see Caption) Figure 410. A large breakout of lava created several laze plumes as it entered the ocean along the northern ocean entry margin of Kīlauea's LERZ fissure 8 flow delta on 14 June 2018. Courtesy of HVO.

Fissure 8 lava fountains 52-70 m tall showered spatter onto the cone overnight into 19 June (figure 411). Small overflows were observed on the N side of the channel near Pohoiki Road overnight and in the morning, with one breakout spreading slowly beyond the flow boundary. Field crews on the ground near fissure 8 midday on 19 June observed a still-vigorous channelized lava flow being fed by fountains at the vent. Standing waves were visible within the channel and cascades/rapids were visible near the base of the 50-m-high cone. The maximum flow velocity in the channel was measured at 28 km/hour. During the morning overflight, several small overflows could be seen along the channel margins. The flow of lava was faster in the center of the channel and decreased in speed toward the margins where friction with the channel walls increased. A small, sluggish overflow along a section of Luana Street was advancing NW. Fissures 6, 15, 16 were still oozing lava and fuming.

Figure (see Caption) Figure 411. Kīlauea's LERZ fissure 8 vigor increased overnight on 18-19 June 2019 with lava fountains reaching up to 60 m. Spatter continued to build up on the E flank of cone and lava flowed into the channel. Courtesy of HVO.

Activity at Halema'uma'u crater during June 2018. Throughout June intermittent explosions and earthquakes continued at Halema'uma'u crater as the summit area subsided and adjusted to the withdrawal of magma from below. Inward slumping of the rim and walls of Halema`uma`u continued in response to the persistent subsidence. A near-daily pattern of explosive events was characterized by seismicity at the summit that would gradually increase to tens of events per hour, culminating with a larger explosion, often with an energy release equivalent magnitude greater than M 5.0. Seismicity would usually then drop significantly before gradually rising until the next explosion. Ash plumes from the explosions often rose to altitudes of 2.4-4.6 km. With each explosion, Halema'uma'u crater subsided, generating fractures and down-dropped blocks within and around the crater floor, dramatically reshaping the morphology of the summit caldera in just a few weeks (figures 412 and 413).

Figure (see Caption) Figure 412. HVO scientists captured this aerial view of a much-changed Halema'uma'u during their overflight of Kīlauea's summit on the afternoon of 5 June 2018. Explosions and collapses had enlarged the crater (foreground) that previously hosted a lava lake, and the far rim of Halema'uma'u had also dropped with continued summit deflation. The parking area for the former overlook (closed since early 2008 due to volcanic hazards) is to the left of the crater with small fractures trending across it. Courtesy of HVO.
Figure (see Caption) Figure 413. Explosions and collapses continued throughout June 2018, enlarging Halema'uma'u crater almost daily. In this view on 12 June (one week after the previous image (figure 412)), the scale and rate of change at the summit of Kīlauea was clear. The obvious flat surface (center) was the former Halema'uma'u crater floor, which had subsided at least 100 m during the previous two weeks. Large ground cracks circumferential to the crater rim can be seen cutting across the parking lot (left) for the former Halema'uma'u visitor overlook, which is beginning to fall into the crater. The deepest part of Halema'uma'u (foreground) was about 300 m below the crater rim. Courtesy of HVO.

Overnight on 10-11 June there were two explosions at the summit separated by about four hours, followed by a decrease in seismicity. Video recorded during a UAS (Unmanned Aircraft Systems) flight HVO on 24 June 2018 revealed details of the extensive changes occurring within Halema'uma'u crater since explosive eruptions of ash and gas and ongoing wall collapse had begun in mid-May. Clearly visible were the steep crater walls that continued to slump inward and downward with ongoing subsidence. The deepest part of Halema'uma'u had dropped over 400 m below the caldera floor. There were two obvious flat surfaces within the crater that had slumped downward as nearly intact blocks; the shallower one was the former caldera floor and the deeper one was the former Halema'uma'u crater floor. HVO reduced the Aviation Color code from Red to Orange on 24 June, citing the fact that the episodic plumes from the summit rarely exceeded 3 km altitude where the might pose a risk to aviation.

Activity on the Lower East Rift Zone during 20-30 June 2018. For the remainder of June, vigorous fountaining nearly 60 m high from fissure 8 fed the established channel that transported incandescent lava to the ocean at the Kapoho coastline where several entries were active (figure 414). The largest entry area was at the S end of the flow front, but the locations of the ocean entry points migrated back and forth along the delta over time. Periodic overflows from the channel were short-lived and produced sluggish pahoehoe flows that only traveled a few meters (figure 415). Minor effusion of lava was observed from fissures 6, 15, and 16. Activity ceased at fissure 6 by 22 June. During an overflight in the early morning of 23 June, only incandescence was noted at fissure 22.

Figure (see Caption) Figure 414. Lava from Kīlauea's LERZ fissure 8 remained incandescent on its 13-km-long journey to the ocean in an open channel during the last part of June 2018. Plumes of steam and laze at the ocean entry were visible in the upper right of the left image on 20 June 2018. Small streams of lava entered the ocean across a broad area the same day, shown by the multiple white steam and laze plumes. Lava had added about 155 hectares (380 acres) of new land by 20 June 2018. Courtesy of HVO.
Figure (see Caption) Figure 415. Sluggish pahoehoe briefly spilled over a section the levee along the well-established channel of Kīlauea's LERZ fissure 8 lava flow on 20 June 2018. The overflows generally traveled short distances measured in meters. Geologists tracked the extent of overflows and looked for potential areas of weakness and seepages along the sides of the perched channel in order to assess potential breakouts from the channel. The small blades of grass in the lower left suggest the scale of this photo is about one meter across. Courtesy of HVO.

The spatter cone grew to 55 m tall by 24 June, after which the lava fountains only occasionally rose above its highest point. Geologists measured lava entering the channel traveling as fast as 30 km/hour. By 25 June, most of the lava was entering the sea on the southern side of the flow front along a 1-km wide area marked by billowing laze plumes, although the lava front extended for more than 3 km along the coast (figure 416). Beginning on 27 June geologists observed fresh lava oozing at several points along the northern margin of the flow field in the area of the Kapoho Beach Lots. By then, the lava channel had crusted over about 0.8 km inland of the ocean entry; lava was moving beneath the crust and into the still-molten interior of earlier flows before it entered the sea (figure 417). The same day, small overflows on both sides of the channel occurred in the uppermost part of channel, but none of these overflows extended past the existing flow field (figure 418).

Figure (see Caption) Figure 416. Most of the lava from Kīlauea's LERZ fissure 8 flow was entering the ocean at the southern edge of the delta flow field on 25 June 2018, although the whole delta extended for more than 3 km along the coast. Dark red areas were active flows, shaded purple areas indicate lava flows erupted in 1840, 1955, 1960, and 2014-2015. Courtesy of HVO.
Figure (see Caption) Figure 417. At Kīlauea's LERZ fissure 8 delta, small breakouts were observed in the morning of 27 June 2018 in the area of Kapoho Beach Lots on the N flank of the flow delta near the ocean. The lava channel had crusted over about 0.8 km inland of the ocean entry; lava was moving beneath the crust and into the still-molten interior of earlier flows before it entered the sea. This thermal map shows the fissure system and lava flows as of 0600 on 27 June 2018. The fountain at fissure 8 remained active, with the lava flow entering the ocean at Kapoho. Very small, short flows were observed near fissure 22. The black and white area is the extent of the thermal map. Temperature in the image is displayed as gray-scale values, with the brightest pixels indicating the hottest areas. The map was constructed by stitching many overlapping oblique images collected by a handheld thermal camera during a helicopter overflight of the flow field. The base is a copyrighted color satellite image (used with permission) provided by Digital Globe. Courtesy of HVO.
Figure (see Caption) Figure 418. A small overflow from the lava channel of Kīlauea's LERZ fissure 8 flow, visible on the left, was recorded by an Unmanned Aircraft System (UAS) flight. Small overflows on both sides of the channel occurred shortly after midnight on 27 June 2018 in the uppermost part of channel. None of these overflows extended past the existing flow field. The 'arm' is likely about 10 m long. Image by the U.S. Geological Survey and Office of Aviation Services, Department of the Interior. Courtesy of HVO.

The northern margin of the ocean entry flow field was the most active during the last few days of the month with lava entering the sea over a broad area (figure 419). A few burning areas were also observed on the S side of the flow and W of Highway 137. Field crews were able to make rough estimates of the velocity of the flow in the channel by timing the large blocks in the flow as they passed by islands within the channel and known points along the edges (figure 420). Volcanic gas emissions were very high from fissure 8 eruptions throughout June 2018 causing trade winds to bring Vog (volcanic air pollution, a hazy mixture of SO2 gas and aerosols) to the central, south, and western parts of the Island of Hawaii on many occasions. Substantial SO2 plumes were recorded daily (figure 421).

Figure (see Caption) Figure 419. At the Kapoho coast, lava from Kīlauea's LERZ fissure 8 entered the ocean over a broad area along the northern margin of the flow field on 30 June 2018. Courtesy of HVO.
Figure (see Caption) Figure 420. Lava flowed rapidly around islands in the lava channel of Kīlauea's LERZ fissure 8 flow on 30 June 2018. The direction of flow was from the upper right to lower left. Field crews were able to make a rough calculation of velocity by timing large blocks as they passed between two landmarks that were a known distance apart. Courtesy of HVO.
Figure (see Caption) Figure 421. Volcanic gas emissions were very high from Kīlauea's LERZ fissure 8 eruptions throughout June 2018 causing trade winds to bring VOG to the central, south, and western parts of the Island of Hawaii on many occasions. Large plumes of SO2 were identified with satellite instruments on numerous days of the month; 4, 13, 20, and 22 June, shown here, were just a few of the days where large SO2 plumes drifted SW on trade winds across the southern and western margins of the island of Hawaii. The island of Hawaii is 150 km from the N tip to the S tip. Courtesy of NASA Goddard Space Flight Center.

Thermal observations during May-June 2018. The MODVOLC thermal alert system captures infrared data from satellite instruments (MODIS) that indicate the location of hot-spots around the planet. The data collected for Kīlauea for May and June 2018 clearly indicated the size and scope of the eruptive episode (figures 422 and 423). At the end of April, infrared data indicated strong activity at Halema'uma'u and weak activity from the episode 61g flow that originated on the flank of Pu'u 'O'o (figure 422). The first MODVOLC thermal alert of activity on the LERZ appeared 6 May; even though the lava lake had begun to drop, there was still a strong thermal signal at Halema'uma'u that day as well. As the eruption progressed during May, the increasing size of the effusive activity that included lava flows reaching the SE coast was apparent.

Figure (see Caption) Figure 422. Selected maps showing MODVOLC thermal alert pixels at Kīlauea for May 2018. An overflowing lava lake at Halema'uma'u and the episode 61g flow that originated on the flank of Pu'u 'O'o were captured in the infrared data in late April. The first MODVOLC alert on the LERZ appeared in the first week of May, and continued to grow throughout the month; the signal at Halema'uma'u was gone by mid-May. Courtesy of MODVOLC.

By early June, just a few days after the flow-volume increase on the LERZ from the channel emerging from fissure 8, the new pattern of heat flow to the N and NE around Kapoho Cone was recorded in the satellite data. The growing delta filling Kapoho Bay generated a strong infrared signal throughout the month. Although the fissure 8 flow was essentially unchanged in its thermal output on 22 and 23 June based on ground observations, the infrared data for those two days was significantly different, likely reflecting atmospheric conditions that blocked satellite views. In spite of this, the general nature of the flow activity is still clear in the data. By the end of June, the extent of the MODVOLC thermal alert pixels clearly indicated the robust nature of the continuing eruption.

Figure (see Caption) Figure 423. In early June 2018 the new pattern of heat flow to the N and NE around Kapoho Cone was recorded in satellite thermal data. The growing delta filling Kapoho Bay generated a strong infrared signal throughout the month. A change in meteoric conditions, not a change in flow activity, was likely responsible for the change in signal on 22 and 23 June. By the end of June, the extent of the MODVOLC thermal alert pixels clearly indicated the robust nature of the continuing eruption.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: http://hvo.wr.usgs.gov/); NASA Goddard Space Flight Center (NASA/GSFC), Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, 8800 Greenbelt Road, Goddard, Maryland, USA (URL: https://so2.gsfc.nasa.gov/); Hawai'i Institute of Geophysics and Planetology (HIGP) - MODVOLC Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://modis.higp.hawaii.edu/).


January 2019 (BGVN 44:01) Citation IconCite this Report

Fissure 8 lava flow continues vigorously until 4 August, ocean entry ends in late August, last activity at fissure 8 cone on 5 September 2018

Kīlauea's East Rift Zone (ERZ) has been intermittently active for at least two thousand years. Since the current eruptive period began in 1983 there have been open lava lakes and flows from the summit caldera and the East Rift Zone. A marked increase in seismicity and ground deformation at Pu'u 'O'o Cone on the upper East Rift Zone on 30 April 2018, and the subsequent collapse of its crater floor, marked the beginning of the largest lower East Rift Zone eruptive episode in at least 200 years; the ending of this episode in early September 2018 marked the end of 36 years of continuous activity.

During May 2018, lava moving into the Lower East Rift Zone opened 24 fissures along a 6-km-long NE-trending fracture zone, sending lava flows in multiple directions. As lava emerged from the fissures, the lava lake at Halema'uma'u drained and explosions sent ash plumes to several kilometer's altitude (BGVN 43:10). At the end of May, eruptive activity focused on 60-m-high fountains of lava from fissure 8 that created a rapidly moving flow that progressed 13 km in just five days, entering the ocean at Kapoho Bay and destroying over 500 homes. Throughout June vigorous effusion from fissure 8 created a 50-m-tall cone and a massive lava channel that carried lava to a growing 3-km-wide delta area which spread out into the ocean along the coast (BGVN 43:12). At Halema'uma'u crater, regular collapse explosion events were the response of the crater to the subsidence caused by the magma withdrawal on the lower East Rift Zone. The deepest part of the crater had reached 400 m below the caldera floor by late June. The eruptive events of July-September 2018 (figure 424), the last three months of this episode, are described in this report with information provided primarily from the US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO) in the form of daily reports, volcanic activity notices, and abundant photo, map, and video data.

Figure (see Caption) Figure 424. Timeline of Activity at Kīlauea, 1 July through 14 September 2018. Blue shaded region denotes activity at Halema'uma'u crater at the summit. Green shaded area describes activity on the lower East Rift Zone (LERZ). HST is Hawaii Standard Time. Black summit symbols indicate earthquakes; red LERZ symbols indicate lava fountains (stars), lava flows (triangles) and lava ocean entry.

Summary of activity, July-September 2018. The lava flow emerging from the fissure 8 cone on the Lower East Rift Zone continued unabated throughout July 2018. Overflows from the open channel were common, and often occurred a few hours after summit collapse events. There were multiple active ocean entry areas along the north, central, and southern portions of the coastal flow front of the fissure 8 flow at various times throughout the month. As the flow approached the delta area, lava spread out over the flow field and was no longer flowing on the surface but continued on the interior of the delta; numerous ocean entry points spanned the growing delta. In mid-July, an overflow diverted the channel W of Kapoho Crater, causing a new channel to the S of the delta that destroyed a park and a school, and increased the width of the delta to 6 km. The near-daily collapse events at Halema'uma'u crater continued until 2 August, transforming the geomorphology of the summit caldera.

Lower lava levels at the fissure 8 channel flow were first reported in early August; a reduced output from the cone was reported on 4 August and the lava level in the cone fell below the spillway the next day, shutting off the lava supply to the channel. The lava channel drained and crusted over during the next few days, but lava continued to enter the ocean at a decreasing rate for the rest of the month; the last ocean entry point had ceased by 29 August. A minor burst of spatter from gas jets inside the cone was noted on 20 August. The last activity was a small flow that covered the floor of the fissure 8 cone and created a small spatter cone during 1-5 September. Incandescence at the crater subsided during the next week until only steam activity was reported on the Lower East Rift Zone by the second half of September 2018.

Activity on the Lower East Rift Zone during 1-12 July 2018. The lava flow emerging from the fissure 8 cone on the Lower East Rift Zone continued unabated during July 2018 (figure 425). Overflows from the open channel were common, sending multiple short streams of lava down the built-up flanks of the channel (figure 426). The fissure 8 lava flow was the most significant activity at the Lower East Rift Zone during July 2018, but it was not the only activity observed by HVO scientists. Fissure 22 was also spattering tephra 50-80 m above a small spatter cone and feeding a short lava flow that was moving slowly NE along the edge of earlier flows during 1-11 July (figures 427 and 428). There were multiple active ocean entry areas along the north, central, and southern portions of the coastal flow front of the fissure 8 flow at various times throughout the month.

Figure (see Caption) Figure 425. The lava flow emerging from the fissure 8 cone on Kīlauea's Lower East Rift Zone continued unabated on 3 July 2018, as viewed from the early morning HVO helicopter overflight. Recent heavy rains had soaked into the still-warm tephra causing the moisture to rise as steam around the channel. Note house and road in lower right for scale. Courtesy of HVO.
Figure (see Caption) Figure 426. Numerous overflows were visible from Kīlauea's LERZ fissure 8 lava channel during the HVO morning overflight on 2 July 2018. They appear as lighter gray to silver areas on the margins of the channel. Note road and Puna Geothermal Venture (PGV) for scale on top. Courtesy of HVO.
Figure (see Caption) Figure 427. Ocean entries were active on the northern and central parts of the ocean entry delta of Kīlauea's LERZ fissure 8 flow on 2 July 2018. Flows and overflows were also active along the W side of the delta area. Dark red areas are active flow zones, shaded purple areas indicate lava flows erupted in 1840, 1955, 1960, and 2014-2015. Courtesy of HVO.
Figure (see Caption) Figure 428. This thermal map shows the fissure system and lava flows as of 0600 HST on 2 July 2018. The fountain at fissure 8 remained active, with the lava flow entering the ocean at Kapoho, although the active channel on the surface ended about 0.8 km from the coast. Fissure 22 was also spattering tephra 50-80 m above a small spatter cone and feeding a short lava flow that was moving slowly NE along the edge of earlier flows. The black and white area is the extent of the thermal map. Temperature in the image is displayed as gray-scale values, with the brightest pixels indicating the hottest areas. The map was constructed by stitching many overlapping oblique images collected by a handheld thermal camera during a helicopter overflight of the flow field. The base is a copyrighted color satellite image (used with permission) provided by Digital Globe. Courtesy of HVO.

The lava channel had begun crusting over near the coast late in June, and the lava was streaming from the flow's molten interior into the ocean at many points along its broad front during the first half of July. The crusted-over area was 0.8 km from the coast on 2 July and had increased to 2 km from the coast on 6 July (figure 429). Temporary channel blockages of the flow caused minor overflows north of Kapoho Crater during 4-6 July. Multiple breakouts fed flows on the N and the SW edge of the main `a`a flow. HVO captured images during an overflight on 8 July of the area where the open channel ended and turned into the broad flow area of the delta (figure 430).

Figure (see Caption) Figure 429. This thermal map shows the fissure system and lava flows as of 0600 on 6 July 2018. The fountain at fissure 8 remained active, with the lava flow entering the ocean in several places at Kapoho; the northern delta area was especially active. The crusted over area had increased to 2 km from the coast (compare with figure 428). Small flows were still observed near fissure 22. The black and white area is the extent of the thermal map. Temperature in the image is displayed as gray-scale values, with the brightest pixels indicating the hottest areas. The map was constructed by stitching many overlapping oblique images collected by a handheld thermal camera during a helicopter overflight of the flow field. The base is a copyrighted color satellite image (used with permission) provided by Digital Globe. Courtesy of HVO.
Figure (see Caption) Figure 430. The end of the surface channel in Kīlauea's LERZ fissure 8 was near Kapoho Crater on 8 July 2018. Top: The partially filled Kapoho Crater (center) is next to the open lava channel where it makes a 90-degree turn around the crater. Lava flows freely through the channel only to the southern edge of the crater (left side of image). Lava then moves into and through the molten core of the thick 'a'a flow across a broad area. Bottom: Close up view of the "end" of the open lava channel where lava moves beneath the crusted 'a'a flow. Courtesy of HVO.

By 9 July the main lava channel had reorganized and was nearly continuous to the ocean on the S side of the flow, expanding the south margin by several hundred meters (figure 431). Lava was also entering the ocean along a 4-km-long line of small entry points across the delta. Early that afternoon observers reported multiple overflows along both sides of the main lava channel in an area just W of Kapoho Crater; small brushfires were reported along the margins. Another flow lobe farther down the channel was moving NE from the main channel. The channel near Four Corners was mostly crusted over, and plumes from the ocean entry were significantly reduced. The dramatic difference in landscapes on the northern and southern sides of the fissure 8 lava channel was readily apparent during a 10 July overflight (figure 432). With dominant trade winds blowing heat and volcanic gases to the SW, the N side of the lava channel remained verdant, while vegetation on the S side was severely impacted and appeared brown and yellow.

Figure (see Caption) Figure 431. By 9 July 2018 the lower part of Kīlauea's LERZ fissure 8 flow had reorganized and was nearly continuous to the ocean on the south side of the flow, expanding the south margin by several hundred meters. Dark red areas denote active flow expansion and shaded purple areas indicate lava flows erupted in 1840, 1955, 1960, and 2014-2015. Courtesy of HVO.
Figure (see Caption) Figure 432. During HVO's morning overflight on 10 July 2018, the dramatic difference in landscapes on the northern and southern sides of Kīlauea's LERZ fissure 8 lava channel was readily apparent. With dominant trade winds blowing heat and volcanic gases to the SW, the N side of the lava channel remains verdant, while vegetation on the S side has been severely impacted and appears brown and yellow. The fissure 8 cone is obscured by a cloud of steam (top center), but a small speck of incandescence rises at the center. The width of the channel and levee in the narrowest place at lower left is about 500 m. Note houses and trees for scale. Courtesy of HVO.

A channel blockage just W of Kapoho Crater overnight on 10-11 July sent most of the channel S along the W edge of previous flows on the W side of the crater. By mid-morning this channelized ?a?a flow had advanced to within 0.5 km of the coast at Ahalanui Beach Park. A few houses were also threatened by overflows along the upper channel on 11 July (figure 433). The broad ocean entry area widened as a result and covered nearly 6 km by 12 July (figure 434).

Figure (see Caption) Figure 433. A pahoehoe flow fed by overflows from Kīlauea's LERZ fissure 8 lava channel was active and threatening homes along Nohea Street in the Leilani Estates subdivision on 11 July 2018. Courtesy of HVO.
Figure (see Caption) Figure 434. An aerial view to the SW of the ocean entry at Kapoho from Kīlauea's LERZ fissure 8 on 11 July 2018 shows Cape Kumukahi (with lighthouse) in the foreground surrounded by lava flows that formed in 1960. The northern edge of the new fissure 8 flow is close to the steam plume closest to the lighthouse. Kapoho Crater in the upper right is surrounded by new lava from fissure 8. See figure 431 for additional location details. Courtesy of HVO.

HVO first mentioned a connection between the lava levels in the upper channel of the fissure 8 flow and the collapse-explosion events at the summit on 12 July. They observed a rise in the lava level shortly after each collapse event at the summit for most of the rest of July. Overnight into 12 July, the diverted channelized ?a?a flow W of Kapoho Crater advanced to the ocean destroying the Kua O Ka La Charter School and Ahalanui Count Beach Park and established a robust ocean entry area (figure 435). Despite no visible surface connection to the fissure 8 channel, lava continued to stream out at several points on the 6-km-wide flow front into the ocean. A small island of lava also appeared offshore of the northernmost part of the ocean entry on 12 July (figure 436).

Figure (see Caption) Figure 435. The channel overflow during 9-10 July from Kīlauea's LERZ fissure 8 flow created a new lobe that reached the ocean on 12 July 2018 destroying Ahalanui Park and the nearby charter school. The lava flow was also still entering the ocean at numerous points along the coast. The black and white area is the extent of the thermal map. Temperature in the image is displayed as gray-scale values, with the brightest pixels indicating the hottest areas. The map was constructed by stitching many overlapping oblique thermal images collected by a handheld camera during a helicopter overflight of the flow field. The base is a copyrighted color satellite image (used with permission) provided by Digital Globe. Courtesy of HVO.
Figure (see Caption) Figure 436. A small new island of lava from Kīlauea's LERZ fissure 8 flow formed on the northernmost part of the ocean entry; it was visible during the morning overflight on 13 July 2018. HVO's field crew noticed the island was effusing lava similar to the lava streaming from the broad flow front along the coastline. The freshest lava in the delta has a silvery sheen and is adjacent to older flows. Courtesy of HVO.

Activity on the LERZ during 13-31 July 2018. As the southern margin of the flow continued to advance slowly south, it reached to within 1 km of the Isaac Hale Park on 14 July and within 750 m on 17 July. An increase in lava supply overnight into 18 July produced several channel overflows threatening homes on Nohea street and also additional overflows downstream on both sides of the channel. The overflows had stalled by mid-morning. South of Kapoho Crater, the surge produced an ?a?a flow that rode over the active southern flow that was still entering the ocean. The southern margin was 500 m from the boat ramp at Isaac Hale Park on 19 July (figure 437).

Figure (see Caption) Figure 437. The southern margin of Kīlauea's LERZ fissure 8 flow was 500 m N of Isaac Hale Park on 19 July 2018. Active flow expansion is shown in dark red, shaded purple areas indicate lava flows erupted in 1840, 1955, 1960, and 2014-2015. Courtesy of HVO.

During the HVO morning overflight on 20 July scientists noted that the channel was incandescent along its entire length from the vent to the ocean entry (figure 438, top). The most vigorous ocean entry was located a few hundred meters NE of the southern flow boundary; a few small pahoehoe flows were also entering the ocean on either side of the channel's main entry point (figure 438, bottom). On 23 July there were overflows just NW of Kapoho Crater following a collapse event at the summit the previous evening. During the day, small breakouts along the edge of the lava flow in the Ahalanui area caused the flow to expand westward. The flow margin was about 175 m from the Pohoiki boat ramp in Isaac Hale Park by the end of 24 July, and the active ocean entry was still a few hundred meters to the E of the lava flow margin. The numerous ocean entry points were concentrated along the southern half of the 6-km-long delta (figure 439).

Figure (see Caption) Figure 438. HVO scientists noted that Kīlauea's LERZ fissure 8 flow was incandescent all the way from the vent to the ocean the day before these 21 July 2018 images of the flow. Top: Fissure 8, source of the white gas plume in the distance, continued to erupt lava into the channel heading NE from the vent. Near Kapoho Crater (lower left), the channel turned S on the W side of the crater, sending lava toward the coast, where it entered the ocean in the Ahalanui area (bottom image). Channel overflows are visible in the lower right. Bottom: The most vigorous ocean entry of the fissure 8 flow was located a few hundred meters NE of the southern flow margin in the Ahalanui area. Courtesy of HVO.
Figure (see Caption) Figure 439. Kīlauea's LERZ fissure 8 flow at 0600 on 24 July 2018. The dominant ocean entry points were on the section of coastline near Ahalanui and Pohoiki. The flow margin was about 175 m from the Pohoiki boat ramp in Isaac Hale Park by the end of 24 July. The black and white area is the extent of the thermal map. Temperature in the image is displayed as gray-scale values, with the brightest pixels indicating the hottest areas. The map was constructed by stitching many overlapping oblique images collected by a handheld thermal camera during a helicopter overflight of the flow field. The base is a copyrighted color satellite image (used with permission) provided by Digital Globe. Courtesy of HVO.

On 26 July, lava movement in the channel appeared sluggish and levels had dropped in the lower part of the channel compared to previous days. Pulses of lava were recorded every few minutes at the fissure 8 vent (figure 440). HVO suggested that overflows on 28 July may have resulted from a channel surge following a summit collapse event in the morning (figures 441 and 442). Lava was actively entering the ocean along a broad 2 km flow front centered near the former Ahalanui Beach Park, but the edge of the flow remained about 175 m from the Pohoiki boat ramp at Isaac Hale park for the rest of the month. There were a few breakouts to the W that were distant from the coast and not directly threatening Pohoiki. A more minor entry was building a pointed delta near the south edge of the flow. At 2202 on 29 July an earthquake on Kīlauea's south flank was felt as far north as Hilo by a few people. The M 4.1 (NEIC) earthquake was weaker than recent summit earthquakes but it was felt more widely, possibly due to its greater depth of 7 km (compared with 2 km for summit earthquakes).

Figure (see Caption) Figure 440. Pulses of lava from Kīlauea's LERZ fissure 8 vent occurred intermittently every few minutes on 26 July 2018. These photographs, taken over a period of about 4 minutes, showed the changes that occurred during these pulses. Initially, lava within the channel was almost out of sight. A pulse in the system then created a banked lava flow that threw spatter (fragments of molten lava) onto the channel margin. After the bottom photo was taken, the lava level again dropped nearly out of sight. Courtesy of HVO.
Figure (see Caption) Figure 441. Incandescent lava covering the 'a'a flow between Kīlauea's LERZ fissure 8 lava channel and Kapoho Crater (lower left) is from an overflow that may have resulted from a channel surge following the morning summit collapse event on 28 July 2018. The active ocean entry can be seen in the far distance (upper left). Courtesy of HVO.
Figure (see Caption) Figure 442. Overflows from Kīlauea's LERZ fissure 8 lava channel on 28 July 2018 may have ignited this fire (producing dark brown smoke) on Halekamahina, an older cinder-and-spatter cone to the west of Kapoho Crater. Courtesy of HVO.

Activity at Halema'uma'u during July and August 2018. Periodic collapse explosion events with energy equivalents to a M 5.2 or 5.3 earthquake continued on a near daily basis throughout July at Halema'uma'u, enlarging the crater floor inside the Kīlauea caldera and creating large down-dropped blocks and fractures across the caldera (figure 443). Ash-poor plumes occasionally rose a few hundred meters above the caldera floor. Summit seismicity would drop dramatically after each explosion and then gradually increase to 25-35 earthquakes (mostly in the M 2-3 range) prior to the next collapse explosion. The periodicity of the explosion events was consistent until 24 July when a gap of 53 hours occurred until the next event on 26 July, the longest break since early June.

Figure (see Caption) Figure 443. The WorldView-3 satellite acquired this view of Kīlauea's summit on 3 July 2018. Despite a few clouds, the area of heaviest fractures in the caldera is clear. Views into the expanding Halema'uma'u crater revealed a pit floored by rubble. The now-evacuated Jaggar Museum and Hawaiian Volcano Observatory (HVO) is labelled on the NW caldera rim. Remains of the Crater Rim Drive are visible along the bottom of the image; the overlook parking lot was completely removed by the growing S rim of the crater. Courtesy of HVO.

Images of the caldera on 13 July and 1 August demonstrated the unprecedented magnitude of change that affected Kīlauea during the month (figures 444 and 445). The last collapse explosion event, at 1155 HST on 2 August, was reported as a M 5.4 seismic event (figure 446). Seismicity increased after the event as it had after previous events, but after reaching about 30 earthquakes per hour on 4 August, seismicity decreased without a collapse-explosion event occurring. The rate of deformation at the summit as measured by tiltmeter and GPS was also much reduced after 4 August.

Figure (see Caption) Figure 444. USGS scientists acquired this aerial photo of Halema'uma'u and part of the Kīlauea caldera floor during a helicopter overflight of the summit on 13 July 2018. In the lower third of the image are the buildings that housed the USGS Hawaiian Volcano Observatory and Hawai'i Volcanoes National Park's Jaggar Museum, the museum parking area, and a section of the Park's Crater Rim Drive. Although recent summit explosions had produced little ash, the gray landscape was a result of multiple thin layers of ash that blanketed the summit area during the ongoing explosions. Courtesy of HVO.
Figure (see Caption) Figure 445. This aerial view of Kīlauea's summit taken on 1 August 2018 shows the continued growth of the crater. Compare with the previous image (figure 444) taken a few weeks earlier; a section of Hawai'i Volcanoes National Park's Crater Rim Drive and the road leading to the Kīlauea Overlook parking area are visible at lower right. HVO, Jaggar Museum, and the museum parking area are visible at far middle right. On the far rim of the caldera, layers that are downdropped significantly more than on 13 July are clearly exposed. On the caldera rim (upper right) light-colored ash deposits from explosions in May were stirred up by brisk winds, creating a dust cloud dispersing downwind. Courtesy of HVO.
Figure (see Caption) Figure 446. Rockfalls along Kīlauea's caldera walls were common during summit collapse events. This image, taken just after the 1155 HST collapse on 2 August 2018, shows dust rising from rockfalls along Uekahuna Bluff. This was the last collapse explosion event at Halema'uma'u during the current eruption.

Activity on the Lower East Rift Zone during August 2018. Activity continued essentially unchanged on the fissure 8 flow during 1-4 August, although there were reports of somewhat lower lava levels in the channel. Multiple overflows were reported late on 2 August, one of which started a small fire near Noni Farms Road. Other overflows were concentrated in the wide lava field W and SSW of Kapoho Crater, also igniting small fires in adjacent vegetation (figure 447). The south edge of the flow did not advance any closer to the boat ramp in Isaac Hale Park (figure 448). The channel was incandescent at its surface to approximately 4.5 km from the vent (figure 449); lava was still flowing farther beneath the crust to the vicinity of Kapoho Crater where it was seeping out of both sides of the channel. The lower lava channel adjacent to Kapoho Crater shifted W about 0.25 km early on 4 August and was feeding lava into the SW sector of the lower flow field.

Figure (see Caption) Figure 447. Overflows formed a pool of lava at the channel bend just west of Kapoho Crater (vegetated cone at left) on 1 and 2 August 2018 as seen in this view toward the SE on 1 August 2018 at Kīlauea's LERZ fissure 8 flow. Courtesy of HVO.
Figure (see Caption) Figure 448. During the morning overflight on 2 August 2018, HVO geologists observed the ocean entry laze plume was being blown offshore, allowing this fairly clear view (looking NE) of the Pohoiki boat ramp at Isaac Hale Beach Park (structure, lower left). Incandescent spots of lava can be seen within the flow field beyond the boat ramp. HVO geologists also observed some lava escaping on or near the western flow margin. The southern margin of the flow front was still more than 100 m from the boat ramp. Courtesy of HVO.
Figure (see Caption) Figure 449. Kīlauea's LERZ fissure 8 channel was incandescent for about 4.5 km from the vent in the early morning on 2 August 2018. Downstream of the vent, the channel split to form a "braided" section in the lava channel, and the north (right) arm of the braided section appeared to be partially abandoned. Lava was still visible in part of the northern braid, but the lower section was only weakly incandescent. The lava within the channel generally appeared to be at a lower level than in previous days. Courtesy of HVO.

The NE half of the flow's ocean-front was inactive with no evidence of effusion into the ocean by 4 August. Field observations and UAS overflight images indicated a reduced output of lava from fissure 8 during the day on 4 August. During the morning helicopter overflight on 5 August geologists confirmed a significant reduction in lava output from fissure 8 that began the previous day. HVO field geologists observed low levels of fountaining within the fissure 8 spatter cone and largely crusted lava in the spillway and channel system downstream (figure 450). The lava level in the channel near Kapoho Crater had dropped substantially on 5 August. (figure 451).

Figure (see Caption) Figure 450. HVO field geologists observed low levels of fountaining within Kīlauea's LERZ fissure 8 spatter cone and largely crusted lava in the spillway and channel system downstream (left) during the morning overflight on 5 August 2018. The inner walls of the cone and lava surface were exposed and a dark crust had formed on the lava with the spillway. Courtesy of HVO.
Figure (see Caption) Figure 451. Incandescent lava remained visible in a section of Kīlauea's LERZ fissure 8 channel W of Kapoho Crater (just visible at far left) on 5 August 2018 after a large drop in the flow rate during the previous day. This view is looking S toward the ocean; the laze plume rising from the ocean entry can be seen in the far distance. Courtesy of HVO.

Lava continued to slowly enter the ocean along a broad flow front generally near Pohoiki, but remained about 70 m SE of the boat ramp on 5 August. The next morning's overflight crew saw a weak to moderately active bubbling lava lake within the fissure 8 cone, a weak gas plume, and a completely crusted lava channel. Later in the morning ground crews found the upper channel largely devoid of lava, confirming that the channel was empty to at least the vicinity of Kapoho Crater where a short section of spiny active lava in a channel was present. There were small active breakouts near the coast on the Kapoho Bay and Ahalanui lobes, but the laze plume was greatly diminished. Active lava was close to the Pohoiki boat ramp but had not advanced significantly toward it. A major change in the heat flow recorded by satellite instruments was apparent by the end of the first week in August (figure 452). The MIROVA signal, which had shown a persistent high-intensity thermal signal for several years, recorded an abrupt drop in activity early in May that coincided with the opening of the fissures on the LERZ, and the dropping of the lava lake at Halema'uma'u. The lower levels of heat flow fluctuated from May through early August, and then ended abruptly after the first week of August.

Figure (see Caption) Figure 452. The MIROVA plot of thermal activity at Kīlauea changed abruptly after the first week of August 2018 after many years of registering high heat flow from numerous sources at Kīlauea. Compare with figure 310 (BGVN 43:03) and figure 290 (BGVN 42:11). Courtesy of MIROVA.

On 7 August the surface of the lava lake was about 5-10 m below the spillway entrance (figure 453) and the upper part of the channel was crusted over (figure 454). There were a diminishing number of small active flow points near the coast on the Kapoho Bay and Ahalanui lobes. By 9 August the overflight crew observed a crusted lava pond deep inside the steaming cone at a level significantly below that seen on 7 August. Up-rift of fissure 8, fissures 9, 10, and 24, and down-rift fissures 13, 23, 3, 21 and 7, continued to steam, but no new activity was observed. Lava was streaming at several points along the Kapoho Bay and Ahalanui coastline, causing wispy laze plumes on 10 August, and only minor areas of incandescence were visible in the lava pond inside the fissure 8 cone (figure 455). The next day the overflight crew noted two small ponds of lava inside the cone; one was crusted over and stagnant, and the other was incandescent and sluggishly convecting. A gas plumed billowed up from fissure 8 and low-level steaming was intermittent from a few of the otherwise inactive fissures.

Figure (see Caption) Figure 453. On 7 August 2018 Hawaii County's Civil Air Patrol got a closer view of Kīlauea's LERZ fissure 8 cone and the small pond of lava within the vent. The lava was below the level of the spillway that fed the fissure 8 channel from May 27 to August 4, 2018. Courtesy of HVO.
Figure (see Caption) Figure 454. Lava in Kīlauea's LERZ fissure 8 channel near the vent was crusted over by 7 August 2018. Fissure 8 and other inactive fissures were steaming in the background. Courtesy of HVO.
Figure (see Caption) Figure 455. The Unmanned Aircraft Systems (UAS) team flew over Kīlauea's LERZ fissure 8 on 10 August 2018 and provided this aerial view into the cinder cone. The pond of lava within the vent had receded significantly from a few days earlier (see figure 453), and was about 40 m below the highest point on the cone's rim. Courtesy of HVO.

By 12 August the only incandescent lava visible on the flow field was that entering the ocean between Kapoho Bay and the Ahalanui area. Fresh black sand, created as molten lava is chilled and shattered by the surf, was being transported SW by longshore currents and accumulating in the Pohoiki small boat harbor (figure 456). A sandbar blocked the entrance to the harbor the following day. The westernmost ocean entry of lava was about 1 km from the harbor on 13 August.

Figure (see Caption) Figure 456. The Pohoiki boat ramp at Isaac Hale Park at Kīlauea on 11 August 2018 was blocked in by a black sand bar forming from the longshore currents carrying material SW from the edge of the fissure 8 flow delta even though the southern-most flow margin had not advanced significantly toward the Pohoiki boat ramp. Geologists observed several small lava streams trickling into the sea along the southern portion of the lava delta, producing weak laze plumes. Courtesy of HVO.

By 14 August only a small, crusted over pond of lava deep inside the fissure 8 cone and a few scattered ocean entries were active; there had been no new lava actively flowing in the lower East Rift Zone since 6 August. No collapse events had occurred at the summit since 2 August. Earthquake and deformation data showed no net changes suggesting movement of subsurface magma or pressurization. Sulfur dioxide emission rates at both the summit and LERZ were drastically reduced; the combined rate was lower than at any time since late 2007. As a result of the reduced activity, HVO lowered the Alert Level for ground-based hazards from WARNING to WATCH on 17 August. By 18 August, the only incandescence visible was at the coast near Ahalanui, where there were a few ocean entries and minor laze plumes (figure 457).

Figure (see Caption) Figure 457. Lava was still entering the ocean at scattered entry points, mainly near Ahalanui (shown here), but also at Kapoho from Kīlauea's LERZ fissure 8 flow on 17 August 2018 even though no new lava had entered the system since 6 August. Courtesy of HVO.

Gas jets were throwing spatter, fragments of glassy lava, from small incandescent areas deep within the fissure 8 cone on 20 August (figure 458). The last day that the small lava pond deep within the fissure 8 cone was visible during an overflight was on 25 August; a few ocean entries were still active. A single small lava stream from the Kapoho Bay lobe was the only moving lava noted during an HVO overflight on 27 August (figure 459). Two days later, on 29 August, no lava was entering the ocean.

Figure (see Caption) Figure 458. Gas jets were throwing spatter (fragments of glassy lava) from small incandescent areas deep within Kīlauea's LERZ fissure 8 cone on 20 August 2018. The spatter is the light gray material around the two incandescent points at the center. Courtesy of HVO.
Figure (see Caption) Figure 459. Only one small ocean entry near Ahalanui was visible on 27 August 2018 at Kīlauea's LERZ fissure 8 flow delta. Courtesy of HVO.

The fissure 8 lava flow entering the ocean had built a lava delta over 354 hectares (875 acres) in size by the end of August 2018 (figure 460). A sand bar, comprised of black sand and lava fragments carried by longshore currents from the lava delta, completely blocked the boat ramp at Isaac Hale Beach Park on 31 August 2018 (figure 461).

Figure (see Caption) Figure 460. Kīlauea's LERZ fissure 8 lava flows had built a lava delta over 354 hectares (875 acres) in size, but no active ocean entries were observed by HVO geologists on 30 August 2018. View is to the SW. Courtesy of HVO.
Figure (see Caption) Figure 461. A sand bar, comprised of black sand and lava fragments carried by longshore currents from Kīlauea's LERZ fissure 8 lava delta, blocked access to the boat ramp at Isaac Hale Beach Park on 31 August 2018. The white cement ramp leads down to a small pool of brackish water surrounded by black sand. The S edge of the ocean-entry delta is at lower left. Courtesy of HVO.

Activity during September 2018. A brief resurgence of minor activity during the first few days of September was the last observed from LERZ fissure 8. Incandescence was noted in the fissure 8 cone on 1 September. There was a persistent spot of spattering, and lava slowly covered the 15 x 65 m crater floor by evening (figure 462). Webcam views showed weak incandescence occasionally reflected on the eastern spillway wall from the crater overnight, suggesting that the lava in the crater remained active. A UAS oblique image the next afternoon showed that the new lava was mostly confined to the crater floor within the cone, although a small amount extended a short distance into the spillway (figure 463). Weak lava activity continued inside the fissure 8 cone for several days; lava filled the small footprint-shaped crater inside the cone as sluggish pahoehoe flows crept across the crater floor but did not flow down the spillway. A small spatter cone ejecting material every few seconds was noted on the floor of the crater on 4 September; observations the next day showed that it had reached an estimated height of around 3-4 m (figure 464). Only a small amount of incandescence was visible overnight on 5-6 September at fissure 8.

Figure (see Caption) Figure 462. An Unmanned Aircraft Systems overflight of Kīlauea's LERZ fissure 8 on 1 September 2018 showed incandescence within the cinder cone, with reports that lava had covered the 15 x 65 m foot-print shaped crater floor by evening. Courtesy of HVO.
Figure (see Caption) Figure 463. This 2 September 2018 UAS oblique image of Kīlauea's LERZ fissure 8 cone showed that the new lava was mostly confined to the crater floor within the cone, although a small amount extended a short distance into the spillway. HVO geologists noted that the lava activity was at a low level by the evening, with only minimal (if any) incandescence emanating from the cone. Gas emissions from the vent were nearly nonexistent. Courtesy of HVO.
Figure (see Caption) Figure 464. A close-up view of the small cone that formed on the floor of the crater within Kīlauea's LERZ fissure 8 on 5 September 2018. Bits of spatter emitted from the cone every few seconds had built it up to an estimated height of around 3-4 m. See video of spatter on HVO website. Courtesy of HVO.

 Pu'u O'o crater experienced a series of small collapses on 8 September. These produced episodes of visible brown plumes throughout the day and generated small tilt offsets and seismic energy recorded by nearby geophysical instruments. The collapses had no discernable effect on other parts of the rift and continued for several days at a decreasing frequency. Minor amounts of incandescence and fuming continued to be observed on 9 September at the fissure 8 cone. A small collapse pit formed in the cone on 10 September exposing hot material underneath and producing a short-lived increase in incandescence. Minor fuming was visible the next day from the small spatter cone. Incandescence at the collapse pit decreased over the next few days, but a glowing spot just west of the pit appeared on 11 September and grew slowly for a few days before diminishing. HVO interpreted it to be a layer of incandescence exposed in the slowly subsiding lava surface within the fissure 8 cone. Minimal incandescence was visible overnight on 14-15 September. After this, only minor fuming was visible during the day; incandescence was no longer observed for the remainder of the month.

HVO determined that the 2018 Lower East Rift Zone eruptive episode ended on 5 September 2018, bringing with it an end to the lava lake at Halema'uma'u crater and the eruptive activity that had been continuous at either Pu'u O'o or Halema'uma'u since 3 January 1983; a period of more than 36 years. Satellite imagery from early September 2018 demonstrated some of the impact of this last eruptive episode on the region around Kīlauea's lower East Rift Zone since the first fissure opened at the beginning of May 2018 (figures 465 and 466).

Figure (see Caption) Figure 465. This comparison shows satellite images of Leilani Estates subdivision before (2014) and after the LERZ eruptive episode of May-September 2018 at Kīlauea. The image on the right, collected in early September 2018, shows that the eastern portion of the subdivision was covered by new lava. The fissure 8 lava channel runs NE from the fissure 8 cone at the start of the channel. Note also the brown areas of dead vegetation S of the lava flow. Highway 130 runs N-S along the left side of the images. Courtesy of HVO.
Figure (see Caption) Figure 466. This comparison of satellite imagery from before (2014) and after the May-September 2018 LERZ eruptive episode at Kīlauea shows the area of Kapoho before and after the event. Kapoho Crater is in the left portion of the image. Lava filled much of the crater, including the small nested crater that contained Green Lake. The Kapoho Beach Lots subdivision is on the right side of the image, north of Kapoho Bay, and was completely covered by the fissure 8 lava flow. Vacationland Hawai'i, in the lower right corner of the image, was also completely covered, along with the adjacent tide pools. Kapoho Farm Lots, near the center of the image, is also beneath the flow. Courtesy of HVO.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: http://hvo.wr.usgs.gov/); MIROVA (Middle InfraRed Observation of Volcanic Activity), a collaborative project between the Universities of Turin and Florence (Italy) supported by the Centre for Volcanic Risk of the Italian Civil Protection Department (URL: http://www.mirovaweb.it/).


March 2021 (BGVN 46:03) Citation IconCite this Report

New eruption in December 2020 with an active lava lake, lava flows, spattering, and a dome fountain

Kīlauea, which overlaps the E flank of the Mauna Loa shield volcano, is the southeastern-most volcano in Hawaii. It’s East Rift Zone (ERZ) has been intermittently active for at least 2,000 years; the most recent eruption period began in January 1983 and was characterized by open lava lakes and lava flows from the summit caldera and the East Rift Zone. During May 2018 lava migrated into the Lower East Rift Zone (LERZ) and opened 24 fissures along a 6-km-long NE-trending fracture zone that produced lava flows traveling in multiple directions. Lava fountaining was reported in these fissures and the lava lake in the Halema’uma’u crater drained (BGVN 43:10).

September 2018 marked the end of the previous eruption period after 36 years of continuous activity. A new eruption began during December 2020 in the Halema’uma’u crater, characterized by a new lava lake, lava flows, lava fountaining, and gas-and-steam emissions. This report covers the activity from December 2020 through January 2021 using information provided from the US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO) in the form of daily reports, volcanic activity notices, and abundant photo, map, and video data.

Monitoring through mid-December 2020. Monitoring data from HVO since the end of the previous eruption in September 2018 included variable rates of seismicity and ground deformation, low rates of sulfur dioxide emissions, and minor morphological changes. Areas of elevated ground temperatures and minor gas emissions persisted in the vicinity of the 2018 LERZ fissures. Since March 2019, GPS stations and tiltmeters at the summit had detected deformation consistent with slow magma accumulation approximately 1-2 km below ground level. In addition, GPS stations in the upper ERZ recorded increased rates of uplift beginning in September. The HVO seismic network recorded 1,450 earthquakes in September, a significant increase over previous months, followed by another increase to 2,100 events in October. The pond at the bottom of the Halema’uma’u crater, which appeared on 25 July 2019, continued to collect water over time, slowly expanding and deepening from 23 m in early January 2020 to 48 m by 3 November 2020 (figure 467).

Figure (see Caption) Figure 467. Photos comparing the growth of the water lake in the Halema’uma’u crater at Kīlauea on 18 December 2019 (left) and 23 September 2020 (right). During this time, the lake had risen approximately 25 m and had a surface area of 0.033 km2, compared to December 2019 (0.011 km2). Photos taken from the E rim of Halema’uma’u by K. Mulliken and M. Patrick; courtesy of USGS HVO.

The number of earthquakes detected in November was 1,350, less than what was recorded in October. By late November seismic stations recorded an average of at least 480 shallow, small-magnitude, earthquakes per week underneath the summit and upper ERZ; during 29-30 November HVO recorded over 80 earthquakes beneath the summit, beginning at 2300 on 29 November and continuing for 11 hours. On 2 December, spikes in seismicity were reported, consistent with a small dike intrusion under the S part of the caldera; tiltmeters at the summit detected about 8 cm of caldera floor uplift. At 1745 earthquakes intensified and another spike occurred after 0000 to an average rate of 10-12 earthquakes per hour. Within 24 hours, up to 220 earthquakes were recorded, occurring in clusters under the caldera and upper ERZ, according to HVO. By the afternoon of 3 December, seismicity and ground deformation rates at the summit had decreased and returned to near background levels. On 17 December, the number and duration of long-period seismic signals increased.

Eruptive activity during 20-21 December 2020. On the evening of 20 December at 2030 an earthquake swarm was recorded, accompanied by ground deformation detected by tiltmeters. Shortly after 2130 HVO reported an orange glow within the Halema’uma’u crater at Kīlauea’s summit caldera, observed on an infrared monitoring camera, as well as a vigorous gas-and-steam plume, which marked the beginning of the eruption. At 2236 an M 4.4 earthquake was detected below the S flank. The Volcano Alert Level (VAL) was raised to Warning and the Aviation Color Code was raised to Red.

An HVO Volcanic Activity Notice issued on 21 December at 1014 stated that the water lake in the summit crater had boiled away due to new effusive activity, producing a large gas-and-steam emission (figure 468). Three vents in the N, NW, and W walls of the Halema’uma’u crater generated lava flows that fed a growing lava lake at the base of the crater (figure 469). Minor lava fountaining at these vents rose 25 m high; the highest fountain reached 50 m high in the N fissure. The lava lake began rising several meters per hour since the start of the eruption and exhibited a circulating perimeter, but a stagnant center (figure 470). Occasional blasts originated from the ponded lava in the crater. The eruption was confined to the Halema’uma’u crater. On 21 December the VAL was lowered to Warning and the Aviation Color Code decreased to Orange. Sulfur dioxide emission rates remained high at around 30,000 tons/day. In comparison, the emission rates from the pre-2018 lava lake ranged between 3,000-6,500 tons/day.

Figure (see Caption) Figure 468. Webcam image of the summit of Kīlauea at 0630 on 21 December 2020. The water lake had been replaced by a lava lake as fissure vents in the wall of Halema’uma’u effused lava into the crater. Strong gas-and-steam emissions were visible. Courtesy of HVO.
Figure (see Caption) Figure 469. Map of the Halema’uma’u crater at Kīlauea showing the location of volcanic activity shortly after 2130 on 20 December 2020. The red spots are the approximate locations of the three initial fissure vents effusing lava into the bottom of the Halema’uma’u crater. The water lake at the base of the crater had been replaced with a growing lava lake. The lava is deeper by at least 10 m compared to the water lake in this base map. The base map is from imagery collected on 23 September 2020. The eastern-most vent was characterized by lava fountains up to 50 m high with minor fountaining on the W side. Courtesy of HVO.
Figure (see Caption) Figure 470. Aerial view of the summit of Kīlauea during an overflight at 1120 on 21 December 2020 showing two active fissure vents that effused lava into the growing lava lake in the Halema’uma’u crater. The N fissure (right-most) is the dominant stream of lava. The fresh cooling lava appears black, surrounding the center of the lake, which was described as stagnant. Courtesy of HVO.

Activity during 22-25 December 2020. The effusive eruption continued on 22 December from at least two vents on the N and W sides of Halema’uma’u; the third vent between the N and W vents paused between 0730 and 0800. The middle and W vents became inundated by the growing lava lake, while the northern-most vent remained vigorous. As of 1151 the crater lake had grown to 487 m below the crater rim, which suggests that the lake had filled 134 m from the crater floor; the rate at which the lake rose was more than 1 m per hour. Measurements made on 22 December showed that approximately 10-12 million cubic meters of lava had been erupted to that point, with a surface area of about 0.13-0.22km2 (figure 471). Another measurement made during the afternoon showed that the volume of the lava lake grew an additional two million cubic meters. The dimensions of the lake were 690 m E-W and 410 m N-S. Overflights were made on 21 and 22 December to obtain natural color and thermal infrared images of the growing lava lake (figure 472).

Figure (see Caption) Figure 471. Location map showing the activity from the new eruption at the summit of Kīlauea in the Halema’uma’u crater updated on 22 December 2020 at 1400. Two active fissure vents (orange dots) on the N and W side of the crater fed lava into the growing lava lake (red). The blue dashed line represents the extent of the former water lake (July 2019 to December 2020) that was present in the crater before the eruption and the black dashed line represents the extent of the lava lake that was present during 2008-2018. The current lava lake is larger than both the previous lakes and has formed slightly more N compared to the former lava lake. Map created by M. Zoeller; courtesy of USGS HVO.
Figure (see Caption) Figure 472. Comparison of thermal images taken on 21 December at 1120 (top) and 22 December 2020 at 1130 (bottom) showing the rise and infilling of the lava lake from wall vents in the Halema’uma’u crater at Kīlauea’s summit. Images by M. Patrick; courtesy of HVO.

By 23 December the lava lake had deepened to 155 m (figure 473). Two fissure vents on the N and W walls remained active; the W vent fed two narrow channels into the lake and the N vent remained the most vigorous. An island of cooler, solidified, lava within the lava lake that measured 115 x 260 m was drifting slowly eastward, based on a thermal map. During an overflight made later in the day, the approximate surface area was 0.25 km2, with dimensions of 460 x 715 m. High SO2 emissions were an estimated 30,000-40,000 tons/day, based on measurements made on 21 and 23 December.

Figure (see Caption) Figure 473. Plot showing the increasing depth in Kīlauea’s summit lava lake since the beginning of the eruption on 20 December 2020 at 2130. A laser rangefinder was used to take measurements of the lava lake surface about 2-3 times per day. The depth of the lake was about 155 m on 23 December at 0630 (top right) compared to 87 m on 21 December at 0630 (bottom right). In comparison, the water lake that was observed in Halema’uma’u before the start of the eruption was 51 m at its deepest. Plot by H. Dietterich; courtesy of HVO.

Measurements taken on 24 and 25 December showed a continuously growing lava lake that was 169 and 176 m deep, respectively, and the volume of the lake had reached 21 million cubic meters. By 25 December the vigorously erupting N fissure vent was starting to become inundated and the W vent displayed intermittent spattering (figure 474). Around 1400 the lake level had dropped by 2 m to reveal a narrow black ledge around the N edge of the crater. The rate of SO2 emissions decreased to 16,000-20,000 tons/day during 25 December.

Figure (see Caption) Figure 474. Photo of the Halema’uma’u crater at the summit of Kīlauea at 0230 on 25 December 2020 showing lava flows and lava fountaining feeding the lake. The main N vent started to become inundated by the growing lava lake. Intermittent activity continued at the W vent. Photo taken from the S rim of the crater by J. Schmith and C. Parcheta; courtesy of HVO.

Activity during 26-31 December 2020. During the morning of 26 December, at 0240, the N vent continued to erupt lava into the lake while the W vent began to effuse more vigorously with up to three narrow lava flows feeding the lake (figure 475). The depth and volume of the lake remained the same as on 25 December: 176 m deep and 21 million cubic meters. Lava fountaining was visible up to 10 m high above the W vent. After 0300, the N vent declined in activity and started to drain lava from the lake. Summit tiltmeters continued to record some deformation. Effusive activity remained confined to Halema’uma’u; the lava lake was 177 m deep as of 0700 m on 27 December. The SO2 emissions continued to decrease to about 3,300-5,500 tons/day during 27-28 December. Summit tiltmeters continued to record weak inflation.

Figure (see Caption) Figure 475. Photo of the W vent in Halema’uma’u at Kīlauea’s summit shows the effusive activity increased on 26 December 2020. Some lava fountaining in this vent was visible while lava flows continued to feed the lake from the N vent. The lava fountaining in the W vent rose at least 10 m high. Photo was taken at 0515 by H. Dietterich; courtesy of HVO.

On 28 December the volume of the lava lake had grown to 21.5 million cubic meters and a thermal map updated on 26 December showed the new dimensions of the lava lake were 520 x 790 m, covering a surface area of 0.29 km2. The narrow black ledge visible above the N edge of the crater was about 1-2 m above the lake surface. During 27-28 December the main central island of cooler, solidified, lava drifted slowly W and measured about 110 x 225 m. The island surface was about 6 m above the lake surface and was covered in tephra, possibly remnants of explosive activity generated when lava first reached the water lake. Reduced, but still elevated, SO2 emissions were 3,300 tons/day; the emission plume carried Pele’s Hair and Pele’s Tears SW, depositing the tephra in areas downwind.

Effusive activity continued, with the lava lake measuring 179-180 m deep with a narrow black ledge around it as of 0400 on 29 December. Multiple narrow lava channels from the W vent fed into the crater. The lava lake volume was slightly more than 22 million cubic meters. The central 135 x 250 m island of solidified lava had drifted slowly W until 2200 on 28 December, then during the morning of 29 December it stalled and began rotating. There were about 10 smaller islands to the E.

On the morning of 30 December, at 0345, the lava lake was 181 m deep with the narrow black ledge around it; the lava lake was an estimated volume of 23 million cubic meters. A spatter cone built around the W vent, while lava effused through crusted-over channels. The main central island was about 6-8 m above the surface of the lake. The rate of SO2 emissions were 3,800 tons/day.

Similar observations were made during 31 December; the lava lake continued to grow, with the depth of the lake measuring 181-186 m and dimensions of 530 x 800 m, based on thermal mapping. The total surface area was 0.33 km2. Spattering continued in the W vent while lava flowed through crusted-over channels into the lake (figure 476). The main island in the lake continued to drift slowly W while roughly 10 smaller islands were observed around the E end of the crater (figure 477). The SO2 emission rate increased to 4,500-6,300 tons/day, compared to the previous day.

Figure (see Caption) Figure 476. Photo of the active W vent in Halema’uma’u at the summit of Kīlauea, viewed from the W crater rim on 31 December 2020 with incandescence, spattering, and a prominent spatter cone; the lava lake is visible in the right background. Photo by B. Carr; courtesy of HVO.
Figure (see Caption) Figure 477. Annotated photo taken from the S rim of Halema’uma’u at the summit of Kīlauea at 1700 on 30 December 2020 showing the location of the main central island and the smaller islands located on the eastern part of the crater. The W vent continued to effuse lava, as well as some spattering, while the N vent was inactive. Photo by K. Lynn; courtesy of HVO.

Activity during January 2021. Effusive activity continued within Halema’uma’u during January 2021. Lava originated from the NW side of the crater, with the W vents exhibiting spattering and lava effusions through crusted-over channels into the lava lake. A levee had also begun to develop around the perimeter of the lake (figure 478), creating what is known as a “perched” lake. According to HVO, this is common in lava lakes at Kīlauea, and is due to repeated small overflows and the rafting and piling of surface crust that fuses together to form a barrier. During 31 December and 1 January the main island of solidified lava (135 x 250 m) had moved W while the other 10 smaller islands remained near the E side of the lake. Summit tiltmeters recorded weak deflation during 1-2 January. Both SO2 emission rates and seismicity remained elevated; the SO2 emission rate was 4,400 tons/day on 1 January.

Figure (see Caption) Figure 478. Photo of the lava lake in Halema’uma’u at Kīlauea on 1 January 2021 that has developed a levee (darker black) around the perimeter, allowing the lake to be slightly perched above its base. Photo by M. Patrick; courtesy of HVO.

During 2-3 January the depth of the lake had grown to 189-190 m, had a volume of 26 million cubic meters, and still maintained the narrow black ledge around its perimeter. Measurements on 3 January showed that the lake was perched about a meter above its E and W edges, and discontinuously on the N edge. A thermal webcam showed spatter originating from two places in the W vents and a small dome fountain above the lake crust in front of the W vents (figure 479). The dome fountain had formed where lava was entering the lake from a submerged inlet at the base of the W vent. The height of the dome fountain reached 5 m and the width was an estimated 10 m. The main island, about 6 m above the lake surface, continued to drift W in front of the W vents while the 10 smaller islands remained relatively stationary near the E end of the lake.

Figure (see Caption) Figure 479. Video data showed the lava at Kīlauea’s summit crater formed a dome fountain at the inlet to the lava lake in Halema’uma’u during 2-3 January 2021. The fountain is located near the base of the W vents where the inlet had become partially submerged. The 5-m-high dome fountain was about 10 m wide. Video by H. Dietterich; courtesy of HVO.

Lava effusion continued during 4-5 January from vents on the NW side of the crater. The lava lake was perched 1-2 m above its edge and had deepened to 191-192 m (figure 480). A thermal map from 5 January showed the perched lake dimensions had slightly decreased in size to 520 x 760 m, with a volume of about 27 million cubic meters. Summit tiltmeters continued to record weak deflation. Spatter in the W vents was visible from the top of a small cone on the NW wall of Halema’uma’u; the dome fountain persisted in front of the W vents (figure 481). The main island was rotating counterclockwise in front of the W vent while the now 11 smaller islands had generally stayed in the E side of the crater. Measurements on 4 January showed that the island was 7-8 m above the lake surface.

Figure (see Caption) Figure 480. A comparison of the Digital Elevation Model (DEM) and topographic profiles of the Halema’uma’u crater at Kīlauea created from aerial imagery collected during helicopter overflights, showing the change in depth and elevation of the lava lake between 26 December 2020 (left) and 5 January 2021 (right). The N vent remained inactive as it became inundated by the rising lava. The central island had migrated W and rotated by 5 January. The depth of the lava lake was 192 m on 5 January. DEMs created by B. Carr, graphic created by K. Mulliken; courtesy of USGS HVO.
Figure (see Caption) Figure 481. Photo of the Halema’uma’u crater at Kīlauea at 0545 on 5 January 2021 showing ongoing activity at the W vent, generating a lava flow that feeds both the lake and the dome fountain. Photo by K. Lynn; courtesy of USGS HVO.

HVO continued to monitor the changes in the active lava lake on 6 January, which was 194 m deep and remained perched 1-2 m above its edge. At 1500 rapid deflationary tilt was recorded overnight into 7 January. Lava from the W vents continued to feed the dome fountain through crusted-over channels on the W side of the crater. During the morning of 7 January the dome fountain weakened giving way to spattering at the top of the vent and the formation of a second cone. A thermal map on 7 January showed that the lake size had decreased to 470 x 760 m, covering 0.28 km2; more of the E part appeared to be stagnant while solidified lava was being progressively pulled beneath the molten surface (figure 482). SO2 emissions were still elevated at 3,400 tons/day on 6 January, but had decreased to 2,700 tons/day the next day. During 7-8 January incandescence was visible from two small cones on the NW wall of Halema’uma’u while lava flowed into the lake through a crusted channel. The main island remained 135 x 250 m; it had moved slightly E while the 11 smaller islands remained stationary.

Figure (see Caption) Figure 482. Thermal image (top) and photo (bottom) of the lava lake at Kīlauea showing the larger central island on the W side of the Halema’uma’u crater and 11 smaller islands on the E side of the crater, taken on 7 and 9 January 2021, respectively. The lake is slightly perched and surrounded by a lower ledge of cooler lava along the perimeter (appears pink-purple in the thermal image along the perimeter). The lava effusion at the W vent has become less intense and much of the E half of the lake has stagnated completely, likely because the lake level has not changed significantly in the last three days. Image by M. Patrick (top) and photo by H. Dietterich (bottom); courtesy of HVO.

Incandescence and spatter continued on 9 January at the two W vents as lava descended through a crusted channel into the lake. Summit tiltmeters recorded weak deflation since 1 January, but on the evening of 9 January weak inflation was detected. A newly installed instrument during 9-10 January showed that the lake had risen about a meter since the switch to inflationary tilt. The depth of the lake slightly increased to 196 m below the W vents on the morning of 10 January. The W vents exhibited strong lava flows during the afternoon with spattering and spatter-fed lava flows from the top of the small cones on the NW wall of Halema’uma’u; lava also flowed through crusted-over channels into the lake. Low lava fountaining was also visible during 10-11 January. The SO2 emission rates were 2,300 tons/day and 2,500 tons/day on 10 and 11 January, respectively.

During the morning of 12 January the lava lake remained at a depth of 196 m below the W vents; the stagnant E half of the lake was about 4 m shallower and had subsided below its perched rims. Low lava fountaining and flows through channels from the top of the small cones were visible. Measurements of the main island on 12 January showed that it was 8 m above the surface, with the highest point at 23 m. By 13 January, the depth of the lake had increased to 198 m. On 13 January a small portion of the active cone had collapsed, causing a second vent to open adjacent to the main vent and effuse lava for less than 20 minutes.

Activity continued in Halema’uma’u with low fountaining, lava flows, and spattering from the W vent through 22 January (figure 483). The depth of the lake continued to increase slowly to 204 m on 22 January. The entire lake was perched 1-2 m above the crust between the levees along the perimeter and the crater wall. All of the islands of solidified lava within the lake were stagnant; the dimensions of the main island were unchanged since 10 January. On 14 January the SO2 emissions increased to 4,700 tons/day, then decreased to 2,500 tons/day on 16 January. On 19 January at 1746 field crews observed a minor collapse event from the spatter cone on its N rim and open channel margins at the W vent (figure 484). Summit tiltmeters began to detect some deflation on 20 January; the rate of which began to slow by 21 January. Measurements on 22 January showed that the S end of the main island was 12 m above the lava lake surface, with the highest point still around 23 m.

Figure (see Caption) Figure 483. Photo of low fountaining and an accompanying lava flow at the W vent of Halema’uma’u at Kīlauea on 15 January 2021. The vent formed a spatter cone around the fountaining as the flow moved through an open channel into the lake. Photo by M. Patrick; courtesy of HVO.
Figure (see Caption) Figure 484. Series of photos showing the W vent at Kīlauea (seen from the S rim looking NW) that continued to feed the growing lava lake in Halema’uma’u through an open channel. At 1746 on 19 January field crews observed a minor collapse on the N rim of the spatter cone and channel margins. The photo at 1731 (top left) shows the vent just before the collapse; the photo at 1746 (top right) shows just after the collapse; the photos at 1749 (bottom left) and at 1811 (bottom right) show the destabilization and movement of the portion of the remaining cone flank surrounded by incandescence. Photos by H. Dietterich; courtesy of HVO.

During the morning of 23-25 January the lava lake was about 205 m deep; the W half remained active with low fountaining and a lava flow while the E half was stagnant (figure 485). The E side of the lake was elevated about 1-2 m and the W half was elevated about 4 m above the solidified lava adjacent to the crater wall. HVO reported that summit tiltmeters continued to record variable inflation and deflation. On 23 January SO2 emission rates were 2,200 tons/day.

Figure (see Caption) Figure 485. Map of the Halema’uma’u crater at the summit of Kīlauea on 25 January 2021 showing the locations of the active lava lake (red), the extent of the lava lake (light red), the major islands of solidified lava (yellow), the active W vent (orange), and the inactive N vent (maroon). The depth of the lake is 205 m, the size of the lake is 0.1 km2, and the total lake volume is 31 million cubic meters. In comparison, the dashed blue line represents the final extent of the water lake that evaporated on 20 December 2020 and the dashed black line represents the extent of the 2008-2018 lava lake. Courtesy of USGS HVO.

The depth of the lava lake continued to deepen, and by the evening of 27 January it was 209 m, while the stagnant E half remained up to 5 m lower. The active lake surface no longer extended around the E side of the central island; surface circulation was limited to the W, N, and S sides of the island. Activity in the W vents consisted of slow surface movements at the base of the lava flow and overturning of the crust near its margins. The E side of the lake was elevated approximately 1 m while the W was 3 m above the solidified lava adjacent to the crater wall. All the islands within the lake were stationary. By 28 January only the W part of the lava lake was active. On 29 January, measurements made on the main island showed its edges were 7-8 m above the lake surface.

On the morning of 30 and 31 January, the active W part of the lava lake was 211 and 212 m deep, respectively; the W vent had crusted over except for a single (possibly two) openings that were mostly obscured by degassing, though several incandescent areas on the cone were visible. Surface lava continued to effuse into the central part of Halema’uma’u from the base of the cone (figure 486). A series of surface cracks separated the active and stagnant parts of the lake. During 30-31 January tiltmeters recorded inflation at the summit.

Figure (see Caption) Figure 486. Photo showing the leading edge of an active lava lobe moving S into the central part of Halema’uma’u at Kīlauea on 31 January 2021. Photo by M. Patrick; courtesy of HVO.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: http://hvo.wr.usgs.gov/).


June 2021 (BGVN 46:06) Citation IconCite this Report

Active lava lake, lava flows, and spattering during February-May 2021

Kīlauea is the southeastern-most volcano in Hawaii and overlaps the E flank of the Mauna Loa shield volcano. It’s East Rift Zone (ERZ) has been intermittently active for at least 2,000 years; an extended eruption period began in January 1983 and was characterized by open lava lakes and lava flows from the summit caldera and the East Rift Zone. During May 2018 lava migrated into the Lower East Rift Zone (LERZ) and opened 24 fissures along a 6-km-long NE-trending fracture zone that produced lava flows traveling in multiple directions. Lava fountaining was reported in these fissures and the lava lake in the Halema’uma’u crater drained (BGVN 43:10).

September 2018 marked the end of the previous eruption period after 36 years of continuous activity. A new eruption began during December 2020 in the Halema’uma’u crater, with a new lava lake, lava flows, fountaining, and gas-and-steam emissions. During January 2021 a levee developed around the perimeter of the lake, creating what is known as a “perched” lake with the center elevated above a moat near the crater wall. In addition, the E half of the lake became stagnant and crusted over with cooled lava, allowing the active W half of the lake to rise slightly higher. This report updates activity during February through May 2021 using daily reports, volcanic activity notices, and abundant photo, map, and video data from the US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO).

Activity during February 2021. The effusive eruption continued from the base of the vent on the NW side of Halema’uma’u crater, maintaining an active lava lake in the W half of the crater (figures 487 and 488). During February, the depth of the lava lake increased to 219 m relative to the bottom of the crater; only the W part of the lake was active. The W fissure had a few incandescent vents, but there was no open lava channel and no signs of spattering. The stagnant E part of the lake was 5-8 m lower than the perched, active W part of the crater. The lake surface actively overturned at “plate” boundaries. The small islands that had formed in the E side of the crater remained stationary; the dimensions of the main, largest island in the W perched area remained unchanged and was 9 m above the lake, with the highest point at 21 m, based on measurements taken on 12 February. A series of surface cracks separated the active and inactive sections of the crater. Sulfur dioxide emission rates remained elevated; measurements of a high of 2,200 tons/day were taken on 1 February. Seismicity was also elevated, but stable, which included a few minor earthquakes.

Figure (see Caption) Figure 487. Close-up photo of the active W vent in Halema’uma’u at Kīlauea on 5 February 2021. The W side of the lava lake had numerous surface breakouts while lava effusion fed the lake from the base of the vent (left). White gas-and-steam plumes were observed from the W vent. Photo by K. Lynn; courtesy of USGS HVO.
Figure (see Caption) Figure 488. Photo of the lava lake in Halema’uma’u at Kīlauea taken on 10 February 2021 from the S rim and looking N showing the active western (left) part of the lake that has hot incandescent lava and the inactive (right) eastern part of the lake that appears dark. A white gas-and-steam plume accompanied the W active vent. Photo by N. Deligne; courtesy of USGS HVO.

On 2 February HVO scientists observed that the intensity of the lava flow into the crater varied, with cycles lasting 5-6 minutes. During the morning of 8 February, a small dome fountain became active; by 13 February lava rapidly developed a thin crust from this upwelling that flows to the E (figure 489). Observations showed gas jetting at two locations above the W vents and two bursts of spatter during 9-10 February. Sulfur dioxide measurements taken on three consecutive days in February showed a gradual decrease from 1,600 tons/day on the 10th, 1,200 tons/day on the 11th, and 1,100 tons/day on the 12th. During 14-15 February some lava overflows N of the inlet site flowed around the NW margin of the perched lake. A few lava flows were noted along the N and E margins of the stagnant E portion of the lake during 15-16 February. HVO reported on 21 February that there was circulation in the active W part of the lake due to lava effusions. The E part of the lake remained stagnant with a solidified surface crust that slowly grew W around the main island; minor amounts of debris accumulated around one or two of the smaller islands as their edges began to cool and collapse. Lava effusion at the W vent slowed during 22 February, allowing a thin crust to develop. A thin surface crust also started to form around three small pieces of the spatter cone that had been in the lake and close to the vent. On 22 and 23 February SO2 measurements continued to show a gradual drop in flux to 600 tons/day and 800 tons/day, respectively.

Figure (see Caption) Figure 489. Close-up photo of the small dome fountain at Kīlauea effusing from the active W vent in Halema’uma’u on 11 February 2021. Lava from this upwelling cooled rapidly and began to form a thin crust by 13 February, moving E. Photo by M. Patrick; courtesy of USGS HVO.

On 24 February the W vent was 28 m tall, feeding a submerged inlet to the lava lake in addition to a slow-moving flow that was several tens of meters long onto the crusted-over NW margin of the lake. The S end of the island was 10 m above the lava lake surface, with the highest point at 23 m. SO2 emissions had increased briefly to 1,100 tons/day on 25 February before declining again to 700 tons/day on the 26th. A map of the summit area updated on 26 February showed the lava lake surface was 65 m below the Halema’uma’u rim, 218 m deep, and had a total volume of 36 million cubic meters (figure 490).

Figure (see Caption) Figure 490. Map of the summit area at Kīlauea updated on 26 February 2021 noting that the lava lake was 65 m below the Halema’uma’u rim and 218 m deep relative to the bottom of the crater when the eruption began on 20 December 2020. The contour lines highlighted in green, purple, and blue mark the rim of the crater, the edge of the E down-dropped block, and the rim of the 2018 collapse, respectively. The total lava lake volume was 36 million cubic meters. The red color represents the active lava lake; the light red color represents the extent of the lava flows; the yellow color represents the active W eruptive vent; the maroon color represents the inactive eruptive vent; the orange color marks the location of the central island. The dashed blue line marks the formed water lake, and the dashed black line marks the 2008-2018 lava lake. The contour lines are in 20 m intervals. Courtesy of USGS HVO.

Activity during March 2021. Similar activity continued during March and remained confined to Halema’uma’u where the main section of the W vent effused lava through one or two crusted-over channels and submerged lake inlets on the NW side of the crater. Another section of the W vent less than 100 m to the NE occasionally fed short lava flows (less than 100 m) onto the crusted margins of the lake, one of which was lasted an hour during the morning of 4 March. One of these flows stretched to 150 m long by 5 March. Several shifting inlets were active, but some lava was also accumulating on the lake margin within 50 m of the vent. Circulation continued in the active W part of the lake as lava effused into it through several new inlets. The E part of the lake remained stagnant with a solidified surface crust that slowly grew W around the main island. Lava continued to develop a thin crust while expanding E. Minor debris continued to accumulate on the lava surface around one or two of the islands as their edges cooled, cracked, and broke off. The active W half of the lava lake was approximately 224 m deep, as measured by a remote laser rangefinder (figure 491). SO2 emissions rates varied during the month but remained elevated to 1,100 tons/day based on measurements on 19 March. By 29 March the SO2 flux had declined to 600 tons/day.

Figure (see Caption) Figure 491. Data taken from a Kīlauea summit helicopter overflight on 4 March 2021 was used to calculate the depth of the lava lake in Halema’uma’u. The deepest parts of the lake (darkest red) exceed 200 m. The different colored lines show the perimeter of the lake and the vents. The rise of the lava lake had slowed as the rate of the eruption decreased and the crater extent increased. The base map is a pre-eruption DEM from 2019. Courtesy of USGS HVO.

By midday on 7 March the lava flows had built a perched lava pond on the NW lake margin, but it abruptly collapsed just after 1300; the ongoing lava flow stabilized into a second relatively steady inlet to the lake. Rangefinder measurements and visual observations made on 15 March indicated that the E part of the lake was 5 m lower than the active W part of the lake. Lava effusions continued to flow from both the main vent and a newer one several meters NE into the lake through submerged inlets. On 16 March at 0220 the NE section of the W vent complex, located several meters away from the submerged inlets, fed another lava flow from approximately halfway up the cone structure.

Activity during April 2021. During April lava continued to erupt at a low rate through a crusted-over channel and submerged inlet on the NW side of the crater; the lake reached 227 m depth and the E half remained stagnant with a solidified crust. SO2 emission rates were consistent with previous measurements of 1,200 tons/day on 1 April. Lava circulation continued in the W part of the lake, with lava flowing out sporadically along the perimeter of the lake through 26 April (figure 492). During 1-2 April HVO scientists noted occasional weak spatter from two areas on the W vent (figure 493). Thermal mapping done on 16 April showed that the stagnant and solidified crust covered 93% of the lake surface (figure 494). HVO reported that SO2 emission rates during 21, 22, 23, 24, and 25 April were among the lowest recorded during the current eruption period: 350 tons/day, 550 tons/day, 300 tons/day, 350 tons/day, and 375 tons/day respectively, though they were still considered elevated compared to rates in the month before the start of the eruption in late December 2020. This drop in emissions occurred when summit tilt was slowly increasing, which also suggested that the effusion rate had also decreased.

Figure (see Caption) Figure 492. Photo of the E side of Halema’uma’u at Kīlauea on 2 April 2021 showing lava extruding between the crusted surface of the lava lake and the crater wall. Photo by L. DeSmither; courtesy of USGS HVO.
Figure (see Caption) Figure 493. Photo from the S crater rim of Halema’uma’u at the summit of Kīlauea showing lava on 2 April 2021 continuing to enter the lake through an inlet near the base of the W vent cone (right). An incandescent opening near the top of the cone (upper center) ejected occasional spatter accompanied by white gas-and-steam emissions. Photo by L. DeSmither; courtesy of USGS HVO.
Figure (see Caption) Figure 494. Composite view using a basemap of aerial photos and satellite images of Halema’uma’u crater at the summit of Kīlauea overlayed with a thermal image of the active surface lava lake taken from a helicopter at 1200 on 16 April 2021. The active surface lava is limited to the W side of the lake (yellow-orange) while the E part of the lake has stagnated and is mostly composed of cooling, solidified crust (blue). The scale of the thermal map ranges from blue to red with blue colors representing cooler temperatures and red colors representing warmer temperatures. Map by M. Patrick; courtesy of USGS HVO.

Activity during May 2021. Effusive activity continued through 23 May at the Halema’uma’u crater where lava erupted from a vent on the NW side of the crater through a submerged inlet. The lava lake was 229 m deep, based on data from a laser rangefinder; the E half of which remained stagnant. Sulfur dioxide emission rates were elevated to 475 tons/day on 2 May but were significantly lower than rates that averaged over 800 tons/day during mid-February to mid-April. Lava circulation continued in a smaller W part of the lava lake, though effusions have not been observed around the perimeter since 26 April. Measurements of the surface showed that it was no longer rising, which suggested that between 11 and 13 May lava had stopped flowing into the lake. The decrease in lava supply over the previous month caused the lake to shrink to two small ponds by 11 May. After 11 May some weak inflation was recorded and an increase in shallow volcano tectonic earthquakes at the summit. SO2 emission rates continued to gradually decline to a less than 100 tons/day after 18 May, which was comparable to levels associated with the non-eruptive period from late 2018 to late 2020 (less than 100 tons/day). By 13 May lava circulation was confined to two small pools that had occasional overflows; effusions had not been observed along the perimeter of the lake since early May (figure 495). Stagnant and solidified lava crust covered 99% of the lake surface, based on thermal mapping done on 13 May. A series of thermal images taken on 13 and 28 April, and 10 and 19 May, showed a decreasing area of active surface lava between the two months (figure 496). By 19 May the small lava pond was visible in thermal imagery and measured 20 m long near the W fissure.

Figure (see Caption) Figure 495. Photo of the fluid surface of the lava lake at Kīlauea on 13 May 2021. Two areas of ponded lava were visible (one pictured here). Photo taken from the S ponded area at 1415 by K. Mulliken; courtesy of USGS HVO.
Figure (see Caption) Figure 496. Comparison of thermal images taken from the S rim of Halema’uma’u at the summit of Kīlauea showing the decreasing area of the active lava on the surface on 13 April (top left) 2021, 28 April (top right), 10 May (bottom left), and 19 May (bottom right). By 19 May 2021 the active lava was limited to a small pond about 20 m long near the W fissure. Images by M. Patrick; courtesy of USGS HVO.

According to HVO, no active lava was observed after 23 May, based on webcam images. In addition, there was a decrease in the volume of gas emissions to close to pre-eruption background levels. Seismicity, though weaker, persisted, which indicated some shallow magmatic activity. Field crews on 24 May observed two small points of incandescence in the lava lake and a faint glow from the W vent but reported no signs of surface activity. The location of the incandescence was also noted in thermal webcams (figure 497). Summit tiltmeters recorded inflation until 2100 on 24 May and recorded deflation afterward. The total volume of the lake was approximately 41.2 million cubic meters. Field crews on 25 May did not observe any sign of lake activity, incandescence, nor surface activity. As a result, on 26 May HVO lowered the Volcano Alert Level (VAL) to Advisory and the Aviation Color Code to Yellow (the third highest on a four-color scale).

Figure (see Caption) Figure 497. Zoomed-in view of the W vent in Halema’uma’u at Kīlauea showing a weak incandescent glow on 24 May 2021. Photo by B. Carr; courtesy of USGS HVO.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: http://hvo.wr.usgs.gov/).


January 2022 (BGVN 47:01) Citation IconCite this Report

New eruption in the lava lake at Halema’uma’u during September-December 2021

Kīlauea is the southeastern-most volcano in Hawaii and overlaps the E flank of the Mauna Loa shield volcano. Its East Rift Zone (ERZ) has been intermittently active for at least 2,000 years. An extended eruption period began in January 1983 and was characterized by open lava lakes and lava flows from the summit caldera and the East Rift Zone. During May 2018 lava migrated into the Lower East Rift Zone (LERZ) and opened 24 fissures along a 6-km-long NE-trending fracture zone that produced lava flows traveling in multiple directions. Lava fountaining was reported in these fissures and the lava lake in Halema’uma’u crater drained (BGVN 43:10).

The previous eruption period, during December 2020-May 2021 in Halema’uma’u crater, included a lava lake, lava flows, fountaining, and gas-and-steam emissions (BGVN 46:06). During January 2021 a levee developed around the perimeter of the lake, creating what is known as a “perched” lake with the center elevated above a moat near the crater wall. The E half of the lake became stagnant and crusted over with cooled lava, allowing the active W half of the lake to rise slightly higher. A new eruption period with similar activity that started in September is described here through December using daily reports, volcanic activity notices, and abundant photo, map, and video data from the US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO).

Activity during June-August 2021. Activity during June through August was relatively low and consisted primarily of low sulfur dioxide emissions and an increase in the number of earthquakes during August. On 12 August the sulfur dioxide emission rate was 50 tons/day (t/d), which was close to levels associated with the non-eruptive period from late 2018 to late 2020 (less than 50 t/d) and significantly lower compared to the 800 t/d measured during mid-February to mid-April. An earthquake swarm was recorded beneath the S part of the caldera at 1630 on 23 August and continued into the early morning of 25 August. The swarm increased in intensity at 0130 on 24 August and was accompanied by an increase in the rate of ground deformation to the W, as recorded by the Sandhill tiltmeter. Over 275 earthquakes were recorded during this swarm, the largest of which was Mw 3.3; the majority were less than Mw 1. Small earthquakes continued at a rate of at least 10 per hour and peaked at 28 events between 1900 and 2000 on 24 August. The rate of earthquakes decreased to 5-12 during 25 August, and by 26 August ground deformation levels had also decreased. HVO reported that ground deformation beneath the S part of the caldera had stopped on 30 August and the earthquake rate decreased during 30-31 August.

Activity during September 2021. No significant activity was reported through most of September until the 29th, when HVO detected an increase in earthquakes activity and a change in ground deformation. At approximately 1520 that day incandescence appeared in the summit webcam images, in addition to new fissures on the floor of Halema’uma’u crater that generated lava flows (figure 498). A photo taken at 1615 showed a large plume comprised of steam, carbon dioxide, and sulfur dioxide rising from the fissures. Measurements taken just after the eruption began showed that the rate of the sulfur dioxide emissions was high at around 85,000 t/d. At about 1640 another fissure with several vents opened on the inner W wall of the crater and produced low lava fountains and flows that descended to the crater floor (figure 499). Lava from both fissures pooled on the solidified lava lake surface that quickly began to overturn and form a lava lake. Tephra was deposited in areas SW of the crater. The tallest fountain was near the S end of the lava lake and rose 20-25 m during the night of 29-30 September. Scientists on a helicopter overflight at 0730 on 30 September determined that the lake was about 980 m E-W and 710 m N-S, covering an estimated 52 hectares (figure 500). The W wall was visible, and several fountains rose from the fissure in the center of the lake. Sulfur dioxide rates remained high at around 20,000 t/d. Overnight during 30 September-1 October the fountains rose as high as 15 m above the dominant vent on the W wall, based on reports from field crews (figure 501). In total, the surface of the lava lake had risen 24 m by the morning of 1 October since the eruption began. Cooled and crusted parts of the lake’s surface overturned, also referred to as “overfoundered.” Sulfur dioxide emissions remained high, though had decreased slightly to 12,900 t/d.

Figure (see Caption) Figure 498. An aerial photo of Halema’uma’u crater at Kīlauea’s summit crater on 29 September 2021. Webcam imagery showed fissures at the base of the crater (highlighted with the red circle). Aerial image was taken prior to the reactivation of the lake. Cooler temperatures are blue and warmer are shown in red. Aerial imagery copyright 2018 DigitalGlobe Nextview license. Annotated image courtesy of M. Patrick, USGS.
Figure (see Caption) Figure 499. Telephoto image of one of the low lava fountains near the center of Halema’uma’u crater lava lake at the Kīlauea summit crater taken on 29 September 2021. Courtesy of M. Patrick, USGS.
Figure (see Caption) Figure 500. Thermal map of the Halema’uma’u crater at the summit of Kīlauea based on aerial visual and thermal imagery taken from a helicopter at 0730 on 30 September 2021. Cooler temperatures are blue and warmer are shown in red; the red spots indicate where lava fountains had emerged through the lava lake surface, and the active W vent area. The dimensions of the lava lake are 980 m E-W and 710 m N-S, an area of about 52 hectares. Annotated image courtesy of M. Patrick, USGS.
Figure (see Caption) Figure 501. Photo of Halema’uma’u crater at the summit of Kīlauea at 1800 on 30 September 2021 showing vigorous fountaining activity at the new vent on the western crater wall. This view is from the south caldera rim looking to the W. The fountain here is approximately 15 m high, measured over a five-minute interval. Courtesy of K. Lynn, USGS.

Activity during October 2021. The lake had risen another 2 m by the morning of 2 October for a total of 26 m since the start of the eruption, though the rate of the rise in the lava lake surface has slowed (figure 502); fountains were 7 m tall at the main W wall vent and rose 1-2 m at the S vents, based on observations from field crews. A burst of fountain spattering on the morning of 2 October rose 50-60 m high. On 3 October the sulfur dioxide rate was 14,750 t/d and the lava lake had risen 27 m, partially submerging the fountaining fissures and building a cone around the W vent. The W vent remained the most vigorous during 3-4 October; lava fountains rose 10-15 m with occasional bursts to 20 m and a 12-m-high spatter cone had formed. In the S and central parts of the lake, including along a fissure 35-42 m long, fountains rose 5-10 m. The W end of the lava lake was 1-2 m higher than the E part and the S end was approximately 2-3 m higher than the N end. The active lava lake surface was perched 1-2 m above a 20-m-wide ledge that extended outward to the Halema’uma’u crater wall.

Figure (see Caption) Figure 502. Webcam image of Halema’uma’u crater at the summit of Kīlauea taken at 0600 on 2 October 2021 showing the active lava lake that is slowly filling the crater. The W vent in the crater is located to the bottom right. Courtesy of USGS, HVO.

A VONA report on 4 October described vigorous fountaining up to 50-60 m high that produced significant amounts of pumice, Pele’s hair, and fragments of volcanic glass that were deposited downwind along the rim and beyond the crater. Sulfur dioxide emissions decreased from 85,000 to 7,000-9,000 t/d by 4 October. The central island and several of the smaller eastern islets from the 2020 lava lake were also visible on the lake surface; the smaller islets were covered at the beginning of the eruption but have since re-emerged. A dark ring of cooled lava around the central island was from the partial submersion at the beginning of the eruption.

The surface of the lava lake continued to rise each day by about 1 m, and the depth of lava filling in the lake was 256 m with a surface elevation of 774 m by 6 October. The W vent remained the most vigorous source of lava effusion, where fountains were rising 12-16 m high and bursts to 20 m. The cone building around the W vent had an opening to the E that effused lava to the lake (figure 503). The active vent in the S part of the lake sustained fountains that rose 1-5 m but was no longer active by 8 October. Overturning of the lake’s surface was mainly focused on the W part of the lake. The lava fountain height at the W vent was variable; on 11 October it ranged from 4 to 35 m. The total lava volume erupted since the start of the eruption was an estimated 19.9 million cubic meters on 15 October. Fountains during late October were typically less than 12 m high, according to field crews. The spatter cone that built up around the W vent was approximately 10 m wide. On 29 October field crews reported that fountaining had been replaced by low roiling in the lake and spatter from the W vent. The sulfur dioxide emissions were as high as 6,800 t/d on 12 October but continued to fluctuate up to 1,600 t/d on 16 October.

Figure (see Caption) Figure 503. Photo of the W vent at Kīlauea showing lava fountaining rising 12 m high on 6 October 2021. A spatter cone had built up around the vent and has an opening to the E. Photo taken from the NW rim looking S. Courtesy of K. Lynn, USGS.

Activity during November 2021. Lava continued to erupt from a vent in the W wall of Halema’uma’u crater, though it was described as roiling and spatter activity that fed the lake rather than fountaining (figure 504). The W end of the crater had a maximum elevation of 795 m, based on data from HVO’s laser rangefinder on 1 November; the lake had risen roughly 51 m since 29 September and continued to rise by roughly 1 m/day. The lava lake continued to have about 7-8 m of elevation difference between the active W vent and the stagnant E part. On 3 November the spatter reached 6 m high, and lava was frequently thrown over the edge on the vent cone. The total volume of lava erupted as of 3 November was about 28.2 million cubic meters. The short channel from the vent to the lake crusted over on 4 November. HVO reported that the E edge of the lake was level with the lowest down-dropped blocks from the 2018 collapse event. Activity briefly decreased on 8 November; SO2 emissions decreased to 250 t/d and webcams showed minimal spatter in the W vent. Activity resumed at normal levels the next day; webcam images showed spatter and ponded lava in the W vent and an increase in the active lava surface area. Lava sporadically oozed out along the cooler outer lake margins (figure 505). By 16 November the total erupted volume was roughly 30 million cubic meters (figure 506). A brief increase in effusion on 22 November lasted a few hours. According to HVO, the area of the lava lake decreased greatly in size for about 9 hours during the late afternoon on 24 November but recovered by the early morning on 25 November. Webcams showed spatter and ponded lava within the W vent and an overflow on the S side of the cone. Sulfur dioxide emissions varied, ranging from 1,200 t/d on 29 November to 6,400 t/d on 23 November; the average rate was 3,000 t/d during the month.

Figure (see Caption) Figure 504. Telephoto image of the W vent of Halema’uma’u crater at the summit of Kīlauea taken on 9 November 2021 where spatter bursts in triggered movement on the lava surface. Spattering rose 6-9 m and occasional ejecta fell onto the rim of the cone. Courtesy of USGS, HVO.
Figure (see Caption) Figure 505. Telephoto image of the W lava lake at Halema’uma’u crater at the summit of Kīlauea taken at 1000 on 9 November 2021. The active lava lake (right) is flowing onto an area of cooled solidified crust (left). The inactive part of the lake surface is about 4 m lower than the active one. Courtesy of J. Schmith, USGS.
Figure (see Caption) Figure 506. Aerial and thermal image of Halema’uma’u crater at the summit of Kīlauea based on observations made during a helicopter overflight on 16 November 2021 at 0830. A crater within the W vent cone contained a small spattering lava pond that was notably warmer. The thermal image shows the extent of the new lava extruded into the lake since the start of the eruption. The active lava lake in the W part of the crater is about 300 m in diameter. The E part of the lake is solidified at the surface, though some lava extrusions can be observed along the perimeter of the lake as the surface continues to rise. The new lava flow due to the new breakouts on the down-dropped block N and E of Halema’uma’u is visibly warmer. Cooler temperatures are blue and warmer are shown in red. Courtesy of HVO, USGS.

Activity during December 2021. Eruptive activity continued during December in Halema’uma’u crater, where lava effused from the W wall vent. The E end of the lake continued to advance onto the down-dropped block on the caldera floor while the W end stood at an elevation of 809 m, based on data from HVO’s permanent laser rangefinder; the total increase in elevation was about 65 m since 29 September. Spatter and ponded lava within the W vent persisted (figure 507), in addition to occasional oozes of lava along the outer lake margins, according to webcam data. HVO reported that between 1600 and 1800 on 3 December the rate of lava effusion sharply decreased, and around 1700 a small portion of the vent cone collapsed. Only a few small hotspots were visible around the vent area. Lava re-entered the vent and resumed erupting between 1730 and 1800 on 6 December. The rate sulfur dioxide emissions varied from 3,500 t/d on 9 December to 125 t/d on 13 December.

Figure (see Caption) Figure 507. Photo of lava erupting from the W vent in Halema’uma’u crater at the summit of Kīlauea, including large spatter bursts on 15 December 2021. Courtesy of B. Carr, USGS.

On 20 December the lava effusion rate began to decrease following a strong deflationary event. By 21 December lava had stopped erupting from the W vent, though incandescence was still visible. The surface of the lake had mostly crusted over, except for a section N of the vent that was less than 50 m in diameter, following a sequence of partial overturning on 20 December; the lake had risen 69 m since the start of the eruption. Measurements from a helicopter overflight during the morning of 21 December indicated that the total lava volume erupted was 38 million cubic meters (figure 508).

Figure (see Caption) Figure 508. Aerial photo of the W part of Halema’uma’u crater at the summit of Kīlauea taken during a helicopter overflight on 21 December 2021. Activity at the lake has paused and only a weak gas-and-steam plume was observed from the W vent (center right). Just N of the vent (toward the bottom of the photo) a small lava pond remained weakly active. The general N direction points to the bottom of the image. Courtesy of D. Downs, USGS.

Around 2000 on 22 December new breakouts were observed from the W vent in the lava lake following strong volcanic tremor at 1930; 30 minutes later the summit began to deflate. This renewed activity began to overflow and feed substantial lava flows to the SE onto inactive, crusted-over portions of the lake against the crater wall until midnight. On 24 December the rate of sulfur dioxide emissions rose to 5,300 t/d in the summit region. Lava was detected oozing out from the margins along the crusted-over E part of the lake, including one onto the lowermost down-dropped block from the 2018 caldera collapse. Another strong deflationary event was reported on 25 December, followed by another decrease in lava effusion; the W vent had stopped erupting.

New breakouts were reported around 1910 on 27 December, following a strong volcanic tremor around 1850. Lava began to overflow and feed lava flows that moved N and S onto the inactive, crusted-over parts of the lake surface. The sulfur dioxide rate was approximately 5,000 t/d in the summit region on 28 December. Due to the decreased rate of lava effusion, HVO reported a cooler crust on the outer half of the lake. No overflows from the active lake were observed during 28-29 December, but several lava breakouts occurred along the margins of the N and E part of the lake. There was also occasional minor activity at the vent on the N side of the spatter cone during the morning of 30 December. Activity picked up again at 1445 on 30 December, which included several large overflows onto older lava lake crust in the evening. Strong incandescence was also visible at night. The surface of the lake had risen a total of 70 m since the start of the eruption.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: http://hvo.wr.usgs.gov/).


August 2022 (BGVN 47:08) Citation IconCite this Report

Lava effusions persisted in the lava lake at Halema’uma’u during January-June 2022

Kīlauea is the southeastern-most volcano in Hawaii and overlaps the E flank of the Mauna Loa shield volcano. Its East Rift Zone (ERZ) has been intermittently active for at least 2,000 years. An extended eruption period began in January 1983 and was characterized by open lava lakes and lava flows from the summit caldera and the East Rift Zone. During May 2018 lava migrated into the Lower East Rift Zone (LERZ) and opened 24 fissures along a 6-km-long NE-trending fracture zone that produced lava flows traveling in multiple directions. Lava fountaining was reported in these fissures and the lava lake in Halema’uma’u crater drained (BGVN 43:10).

The current eruption period started during September 2021 and has included seismicity, new fissures on the Halema’uma’u crater that generated lava flows, lava fountaining, and an active lava lake (BGVN 47:01). Similar activity with intermittent pauses continued during this reporting period of January through June 2022 using daily reports, volcanic activity notices, and abundant photo, map, and video data from the US Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO).

Summary of activity during January-June 2022. Activity at Kīlauea consisted of intermittent lava effusions from the western vent in the Halema’uma’u crater and ooze-outs along margins of the crusted over eastern side of the lake (figure 509). The lake had risen about 70 m since lava was first detected on 29 September 2021 and measurements from a helicopter overflight on 30 December 2021 indicated that the total erupted volume of lava since September was approximately 40 million cubic meters. Activity remained confined to the crater. Summit tiltmeters and nearby seismometers detected inflation and deflation events and volcanic tremors that rose and declined in frequency, reflective of pauses in the eruption. Sulfur dioxide emissions were frequently measured, reaching as much as 4,500 t/d on 1 February.

Figure (see Caption) Figure 509. Reference map of the summit eruption at Kīlauea on 7 January 2022. One eruptive vent (orange color) is intermittently active in the Halema’uma’u crater along the western edge of the lava lake, which frequently effuses lava that moves into the active portion of the lake (red color). During eruptive pauses, the only active lava is within a pond just N of the vent (purple color). The eruption statistics listed at the bottom of the map were updated on 30 December 2021. Courtesy of USGS, HVO.

Activity during January 2022. The lava lake at the Halema’uma’u crater remained active during January, showing several large overflows onto older ones and strong crater incandescence. Lava was visible at the western vent of the crater at 1445 on 31 December and remained confined to the crater. Seismicity in the summit region remained below background levels, and the sulfur dioxide emission rate was approximately 5,000 tons/day (t/d), based on measurements from 28 December. Pause events occurred throughout much of the reporting period and were characterized by lower effusion rates, deflation events, and lower volcanic tremor events. HVO issued a notice on 2 January at 0914 stating that the eruption was entering a pause, meaning that lava effusions continued, but at a much lower rate. Summit tiltmeters tracked rapid deflation during the early morning of 2 January. In addition, volcanic tremor associated with the eruption and recorded by nearby seismometers, also rapidly decreased. The lava lake began to cool at the same time. A large breakout along the northern margin of the crusted-over lava lake was observed during the morning; no effusions were reported from the western vent.

At approximately 0400 on 5 January the summit eruption at Halema’uma’u crater resumed, beginning with volcanic tremors detected at 0340 and then lava erupting from the western vent. On 6 January the sulfur dioxide emission rate was 3,300 t/d. Following another short pause, lava effused from the western vent at 1840 on 11 January, and lava ooze-outs were observed along the margins of the crusted over eastern side of the lake. The lava lake rose approximately 13 m, which was then followed by decreases in the summit tilt, tremor, and lake level. The total volume of lava erupted measured on 14 January was 45 million cubic meters. On 16 January HVO reported that lava had stopped erupting from the western vent and the level of the lake surface had dropped about 10 m. Occasional minor activity was reported at the vent on the N side of the spatter cone, as well as small lava ooze-outs along the margins of the crusted over eastern side of the lake.

After another multi-day pause, lava returned to the western vent at 1045 on 18 January and by 1630 the lava lake level had increased by about 12 m (figure 510). There were also several ooze-outs along the SE and NW margins of the lake. The active lava lake was confined to a small pond north of the western vent overnight during 20 January. Just after 0400 on the morning of 21 January the rate of effusion had increased, and the lava lake remained confined to the western half of the crater. Two overflow events were reported during the night of 21 January, with lava flowing NW, SW, and SE out of the lava lake. In addition, several ooze-out events occurred along the NW, N, SE, and S margins of the lake. By this time, the lava lake level had increased about 83 m since the beginning of the eruption period in late September 2021. Again, activity was confined to a small pond N of the western vent and several long-lived ooze-outs occurred along the margins of the E and NW side of the crater. Lava effusions into the pond were intermittent, with several hours in between short-lived periods of lava input. On 19 January the rate of sulfur dioxide emissions was 2,100 t/d and another measurement taken on 24 January showed that the rate had decreased to 58 t/d.

Figure (see Caption) Figure 510. Comparison of two images of the active lava lake at Kīlauea on 18 January 2022 at 1230 (top) and 1345 (bottom). The two photos compare the active portion of the lava lake shortly after the eruption restarted when the lake level was lower (top) to when it had refilled with lava (bottom). The white arrows point to approximately the same spot on both images, the level of which is different by about one meter. Courtesy of K. Mulliken, USGS.

During the morning of 25 January at 0552 a lava flow from the top of the western vent was observed that traveled W and N along the crater margin. The lava lake began to rise around 0630 and by 0820, it had risen 11 m. Overflows from the lava lake and the small pond N of the western vent, the largest of which were on the W and S margins, continued until the afternoon. A small lava flow was noted along the N margin of the larger inactive lava lake surface during the early morning of 27 January, and a small spatter zone that was active in the E section of the crater had produced a small and steep cone. Field crews working in the caldera on 27 January noted loud gas-jetting from the new cone that had developed earlier that morning. The sulfur dioxide emission rate was measured at 2,800 t/d on 25 January, during which time lava was being erupted from the western vent.

HVO reported that on at 0800 on 29 January there was no active lava visible in the Halema’uma’u crater, which indicated a pause in activity. The lava lake depth had very gradually decreased less than one meter. Some overturning during the afternoon was observed in the eastern part of the crater, which briefly exposed surficial lava, and circulating lava was occasionally visible in the small pond N of the western vent. Then, just before 2130 on 30 January, a lava overflow in the western vent occurred, moving NW. The small pond also began to quickly fill with lava, which flowed into the lava lake and occupied the W part of the crater by 2200. The lake began to rise and was overflowing by midnight. Lava flows travel to the S and then E along the margin of the crater. Lava also began to ooze out along the N margin of the larger inactive lava lake surface just after 0500 on 31 January.

Activity during February 2022. Lava continued to intermittently erupt from the western vent in the Halema’uma’u crater during February, with overflows feeding a lava flow to the SE along the S margin of the crater until 1100 on 31 January. Multiple ooze-outs occurred intermittently along the N, E, and S margins of the crater, some of which remained weakly active, with substantial portions of the inactive E lava lake being resurfaced by these flows. A small pond to the N of the western vent also fed the active part of the lava lake via a small lava flow (figure 511). The level of the lava lake continued to fluctuate, depending on the lava supply and summit inflation or deflation. The small spatter cone near the E end of the crater was less than 6 m tall and was erupting lava fountains up to approximately 10 m high for several hours during the night of 1 February and into early the next morning. These fountains fed a short lava flow that was contained near the E margin of the crater. The sulfur dioxide emission rate was approximately 4,500 t/d measured on 1 February and during an eruptive pause they were around 330 t/d on 8 February. A particularly vigorous ooze-out was observed at the far E side of the crater during 4-5 February. Heavy rain at the summit occurred between 1320 and 1800 on 13 February, which triggered spattering in the lava lake. As a result, there were brief decreases in the level of the lake during 1330 and 1557; the lake level returned to its pre-spatter measurement within an hour of each spattering episode. The sulfur dioxide emission rate was 2,800 t/d measured on 14 February.

Figure (see Caption) Figure 511. Photo of the small 20-m-wide pond to the N of the western vent in Kīlauea’s Halema’uma’u crater taken at 0930 on 1 February 2022. A small lava flow is shown feeding the active part of the lava lake. Photo was taken from the western rim of the crater. Courtesy of D. Downs, USGS.

Short-lived overflows of the active western lava lake to the W started around 1000 on 20 February, and were followed by lava flows coming from the western vent and flowing to the S and W an hour later, at 1100. Minor ooze-outs also continued intermittently along the crater floor margins. Lava continued to erupt from the western vent and move to the S, W, and into the western lava lake through the rest of the month. The sulfur dioxide emission rate was 2,500 t/d on 25 February. The Halema’uma’u crater floor had risen about 96 m since the eruption began in September 2021.

Activity during March 2022. Activity continued to fluctuate at the summit crater during March. Throughout February, the main western cone had broken down and by 4 March, lava effused from multiple vents, including the tallest cone (19 m high). The eruption was paused at 0130 on 1 March, meaning that the effusions from the western vent into the lava lake had diminished, though short-lived minor flows continued to be observed. These flows moved S, W, and into the western part of the lake, although they had stopped by the morning. Little to no ooze-outs along the crater margins were also reported. At 0100 on 2 March the eruption resumed, consisting of increased tremor that began 30 minutes earlier and continuous flows from the western vent moved to the S, W, and into the western lava lake (figure 512). During 4-5 March several ooze-outs were reported along the E and N margins of the crater floor. Spatter was also observed from the western vents on 4 March (figure 513). The total measured volume of the effusions since the start of the eruption was 53.6 million cubic meters on 4 March. During the early morning of 9 March, a small lava flow breakout began on the SE margin of the crater floor, but was already crusting over by 0900. The sulfur dioxide emission rate was approximately 2,200 t/d on 8 March and 1,900 t/d on 10 March. A sustained breakout from the NE edge of the crater began at around 1700 on 10 March and lasted until about 0630 the next day. On 11 March, HVO reported that lava was supplied from an embayment just N of the tallest cone in the western part of the crater, which had since grown to 27 m high (figure 514). Another small breakout occurred on the NW side of the crater floor from about 1700 on 12 March to 0500 the next day. Minor and slow crustal overturning occurred on the NW side of the crater floor during 13-14 March and began on the SE side of the crater floor edge, lasting for several hours.

Figure (see Caption) Figure 512. A helicopter overflight on 2 March 2022 allowed for aerial visual and thermal imagery to be taken of the Halema’uma’u crater at Kīlauea’s summit crater. The active part of the lava lake is confined to the western part of the crater. The scale of the thermal map ranges from blue to red, with blue colors indicative of cooler temperatures and red colors indicative of warmer temperatures. Courtesy of USGS, HVO.
Figure (see Caption) Figure 513. Photo of spatter erupting from the western vents in the Halema’uma’u crater at Kīlauea, near where the main cone used to be. On 4 March the tallest of these vents, at 19 m high, was seen characterized by spattering activity. Courtesy of L. Gallant, USGS.
Figure (see Caption) Figure 514. Telephoto view looking east of the active lava lake in the Halema’uma’u crater at Kīlauea on 11 March 2022. The broken down remains of the main western vent cone is visible in the lower right (through the volcanic gas plume). Lava supplies the lake through a small embayment and spillway (bottom center) just N of the western vent area. Some lava spills over a narrow divide into a second smaller lake to the SE (upper right). Courtesy of N. Deligne, USGS.

At around 0700 on 16 March a lava flow that originated from the N part of the western vent area started to advance NW onto the crater floor and remained active for several hours into the early afternoon. At least one ooze-out occurred on the E crater floor. A lava flow advanced onto the NW crater floor from during noon to midnight on 18 March and 2100 to 0700 during 19-20 March. Measurements taken on 17 March showed that the total volume of lava erupted since the eruption began was 57.7 million cubic meters and the lava lake level had risen 89 m. HVO reported a notable ooze-out along the N margin of the crater floor at 0345 on 21 March and continued into the next day. Some ooze-outs were also observed along the N and S crater margins during 23-24 March. The sulfur dioxide emission rate measured on 23 March as approximately 1,400 t/d, which increased to 3,100 t/d on 29 March. Numerous and sustained ooze-outs along the margins of the crater floor continued but showed decreasing activity; by 29 March the volume of the lava effused measured 64 million cubic meters. During 30-31 March a hornito forming on the E side of the lake had a few periods of spattering throughout the day (figure 515).

Figure (see Caption) Figure 515. Telephoto view looking north of the active lava lake in the Halema’uma’u crater at Kīlauea on 30 March 2022. Minor spattering is shown on the eastern margin (left) of the lava lake while circulation in the lake primarily moves from west to east (left to right). Sometimes lava can spatter up when it encounters the active lake margin, as shown in this image (right). Courtesy of N. Deligne, USGS.

Activity during April 2022. Intermittent activity continued during April with numerous and sustained ooze-outs along the NW, NE, and E half of the crater floor, occasional crustal overturning on the NW margin, and lava effusions from the western vent into the lava lake. On 6 April ooze-outs were observed along the NW margin of the crater floor, as well as the E half. The active part of the lava lake showed continuous surface activity and had risen about 1 m. The sulfur dioxide emission rate was 3,400 t/d on 5 April and 3,200 t/d on 6 April. The crater floor had risen about 99 m since the beginning of the eruption, and approximately 66 million cubic meters of lava had been erupted. Overnight on 8 April a small breakout from the active western part of the lava lake was observed, in addition to a small ooze-out along the E lake margin. Small ooze-outs were also detected during 9-10 April along the NW, E, and SE lake margins. Shortly after 2315 on 10 April a surface flow emerged from the S side of the western vent. The flow traveled S on the crater floor and covered the SW and W lake margin and remained active through 14 April. The sulfur dioxide emission rate measured 1,300 t/d on 8 April. Sporadic lava breakouts also occurred along the E, NE, S, and N lake margins. By 17 April lava flowed from the breakouts along the margins of the crater: N to the NE, and a smaller one to the S. During the morning of 27 April and into the next day, HVO reported increased roiling and spattering in the SE portion of the lake, particularly to the E. Sporadic breakouts also continued along the crater margins, particularly to the E. On 27 April the sulfur dioxide emission rate increased to 4,300 t/d, but dropped to 1,800 t/d by the next day.

Activity during May 2022. Lava continued to effuse into the lava lake and onto the crater floor during May; the active part of the lake showed continuous surface activity. The level of the lake fluctuated as a result of inflation, sporadic to continuous breakouts along the margins of the crater, and lava effusions. A particularly vigorous and expansive ooze-out began along the NW margin after 0200 on 5 May, accompanying relatively sluggish lava ooze-outs along the NE and S margins of the crater floor. Around 0700 on 7 May a new lava flow effused from the western vent onto the crater floor, but had stalled an hour later. The sulfur dioxide emission rate was 2,600 t/d on 4 May and 2,800 t/d on 12 May. Overflight measurements taken on 10 May indicated that the crater floor had risen about 106 m and 77 million cubic meters of lava had been effused since the September 2021. On 18 May HVO reported that the lake was draining into a small pond while spatter occurred along the margins of the crater (figure 516). This activity was also accompanied by loud whooshing and roiling noises, sometimes audible from the Keanakako‘i public overlook. On 31 May the sulfur dioxide emissions rate was 3,900 t/d.

Figure (see Caption) Figure 516. Photo of the active lava lake in the Halema’uma’u crater at Kīlauea during the morning of 18 May 2022. The active lake is shown draining into a small pond to the right while spattering along the margins occurred (top center). Courtesy of L. Gallant, USGS.

Activity during June 2022. During June, lava effusions persisted from the Halema’uma’u western vent into the active lava lake, in addition to frequent ooze-outs along the E, NE, NW, W, S, and N crater floor margins and some spattering activity at the margins. Minor fluctuations in the lava lake level were also recorded throughout the month due to consistent surface activity. The sulfur dioxide emission rate was approximately 2,500 t/d on 2 June and 1,350 t/d on 10 June. On 10 June an overflow from the western vent produced a lava flow that moved onto the W side of the crater floor. Overflight measurements made on 17 June indicated that the crater floor had risen about 120 m and that 93 million cubic meters of lava had been effused since the start of the eruption (figure 517). On 24 June there was a small zone of weak ooze-outs effusing from the crater floor (figure 518). The sulfur dioxide emission rates were measured again on 23 and 29 June that were 3,000 t/d and 1,200 t/d, respectively.

Figure (see Caption) Figure 517. Reference map of the summit eruption at Kīlauea on 17 June 2022. One eruptive vent (orange color) was active in the Halema’uma’u crater along the western edge of the lava lake, which frequently effused lava that moved into the active portion of the lake (red color). An adjacent pond (purple color) fed lava to a larger lake (light red), though at times the lava level declined and circulation decreased. Lava was visible from three public visitor overlooks in Hawai‘i Volcanoes National Park: Keanakako‘i Overlook and Kupina‘i Pali (Waldron Ledge) can see the eruptive vent and lava lake, while Kīlauea Overlook occasionally saw lava ooze-outs in the southeast part of the crater. The eruption statistics listed at the bottom of the map were updated on 21 June 2022. Courtesy of USGS, HVO.
Figure (see Caption) Figure 518. Photo looking just north of the main lava lake in Halema’uma’u crater at Kīlauea showing a small zone of weak ooze-outs effusing from the crater floor on 24 June 2022. Courtesy of M. Patrick, USGS.

Information Contacts: Hawaiian Volcano Observatory (HVO), U.S. Geological Survey, PO Box 51, Hawai'i National Park, HI 96718, USA (URL: http://hvo.wr.usgs.gov/).

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History

There is data available for 72 confirmed Holocene eruptive periods.

2021 Sep 29 - 2023 Sep 16 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halema`uma`u Crater.
2021 Sep 29 - 2022 Dec 9 Evidence from Observations: Reported

List of 3 Events for Episode 1 at Halema`uma`u Crater.

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
2021 Sep 29    - - - - Lava lake
2021 Sep 29    - - - - VEI (Explosivity Index) VEI 0
Episode 2 | Eruption Episode Halema`uma`u Crater
2023 Jan 5 - 2023 Mar 7 Evidence from Observations: Reported

List of 2 Events for Episode 2 at Halema`uma`u Crater

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
Episode 3 | Eruption Episode Halema`uma`u Crater
2023 Jun 7 - 2023 Jun 19 Evidence from Observations: Reported
Episode 4 | Eruption Episode Halema`uma`u Crater
2023 Sep 10 - 2023 Sep 16 Evidence from Observations: Reported

2020 Dec 20 - 2021 May 23 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode
2020 Dec 20 - 2021 May 23 Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
2020 Dec 20    - - - - Lava lake
2020 Dec 20    - - - - VEI (Explosivity Index) VEI 0

1983 Jan 3 - 2018 Sep 5 Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode East rift zone (Puu O'o), Halemaumau
1983 Jan 3 - 2018 Sep 5 Evidence from Observations: Reported

List of 36 Events for Episode 1 at East rift zone (Puu O'o), Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow Entered water.
   - - - -    - - - - Tephra
   - - - -    - - - - Scoria
1983 Jan 2    - - - - Seismicity (volcanic) At 0030 the seismicity developed into a swarm of small shallow (depth < 5 km) earthquakes and weak harmonic tremor. The swarm started in the upper E rift near Mauna Ulu, increased in the early hours and migrated downrift about 9 km to Napau Crater. Tiny earthquakes were recorded at a rate of 3-5/minute; seismic intensity peaked between 0040 and 0110, when several earthquakes, magnitude 2.5 to 3.0, were felt in the Hawaii Volcanoes National Park area. From 0300 to 1300, the seismic zone spread farther downrift to beyond Pu'u Kamoamoa. From then until the eruptive outbreak, small earthquakes accompanied by harmonic tremor occurred at a nearly constant rate, mainly along a zone between Napau Crater and Pu'u Kamoamoa.
1983 Jan 2 1983 Jan 8 Deformation (deflation) Broken only by temporary inflation during the non-eruptive interval between 3 and 5 January, almost all of the summit deflation occurred at a high rate from early on 2 January to early on 8 January. When the eruption was sighted at Napau Crater by a ground crew at 0031 on 3 January, [instruments] started to record increasing harmonic tremor amplitudes and constant summit deflation. The summit subsidence and the period of intense shallow seismic activity were coincident. Tiltmeters in the Uwekahuna Vault recorded a summit collapse of about 125 µrad, which represents an estimated volume loss of 50 x 106 m3 from the summit region. Approximately 3/4 of the volume of extruded lava was erupted during the same period. Minor, very slow deflation of the summit continued until about 18 January. Gradual recovery of about 4 µrad of tilt occurred during the remainder of the month.
1983 Jan 3    - - - - Fissure An eruption in the E rift zone began at 0031 on 3 January. The outbreak began at Napau Crater, 14 km SE of the caldera rim, and extended progressively NE. By 0740, the line of eruptive fissures was 6 km long and its E end was about 0.7 km SE of Pu'u Kahaualea.
1983 Jan 3    - - - - Seismicity (tremor) When the eruption was sighted at Napau Crater by a ground crew at 0031 on 3 January, [instruments] started to record increasing harmonic tremor amplitudes and constant summit deflation.
1983 Jan 3    - - - - Lava fountains Fountaining and production of SE-moving lava flows of local extent continued until 1002. During this first day's activity, fountains up to 80 m high produced an estimated 2-3 x 106 m3 of lava.
1983 Jan 3    - - - - Lava flow Fountaining and production of SE-moving lava flows of local extent continued until 1002.
1983 Jan 3    - - - - Fissure After a 4.5 hour pause, the eruption resumed at 1425 along a 100-m fissure at the NE (downrift) end of the vent system (about 600 m S of Pu'u Kahaualea). This eruption lasted until 1535.
1983 Jan 3 1983 Jan 5 Deformation (inflation) Temporary inflation occurred during the non-eruptive interval between 3 and 5 January.
1983 Jan 3    - - - - VEI (Explosivity Index) VEI 0 P2
1983 Jan 5 1983 Jan 6 Fissure The volcano remained quiet for nearly 2 days. Eruptive activity resumed at 1123 on 5 January and continued with only brief interruptions until 2049 on 6 January. The eruptive activity jumped from one segment to another of a kilometer-long section of the vent system S of Pu'u Kahaualea (including, at its E end, the easternmost vent of 3 January). A large amount of the lava poured into an open crack, parallel to the eruptive vents and about 0.1 km SE of their E ends. The crack was along a bounding fault at the NW edge of a prominent older graben.
1983 Jan 5    - - - - Lava flow A large amount of the lava poured into an open crack, parallel to the eruptive vents and about 0.1 km SE of their E ends. The crack was along a bounding fault at the NW edge of a prominent older graben. Minor additional fountaining and flow production also occurred at, and within 1.5 km SW of, Pu'u Kamoamoa, along vents established on 3 January.
1983 Jan 7    - - - - Fissure In the morning, the main eruptive center shifted temporarily still farther NE to a 1 km-long line of vents approximately 1.4 km ESE of Pu'u Kahaualea. After a brief introductory emission from 0957-0959, these vents erupted strongly from 1030-1557.
1983 Jan 7    - - - - Lava fountains During this period, the vents produced the highest fountains of the eruption; maximum sustained fountain heights of 80-100 m were estimated, with bursts sending fragmented spatter higher.
1983 Jan 7 1983 Jan 8 Lava flow This episode also fed a lava flow nearly 6 km long that extended E toward Kalalua then turned SE toward the coast. The flow, with an estimated volume of about 4 x 106 m3, converted to aa as its front passed near Kalalua and stopped nearly 5 km from the coast. A second eruption from the same vents, from 1625 on 7 January to 0430 on 8 January, produced a smaller lava flow that overrode the near end of the first flow from the vents E of Pu'u Kahaualea.
1983 Jan 8 1983 Jan 15 Fissure Seven episodes of lava production ranging in duration from 8 minutes to 11 hours occurred from a group of vents S and SW of Pu'u Kahaualea that were active 5-6 January. The first and briefest of these (from 1446-1454 on 8 January) was from the E end of this group of vents. The remainder erupted from the W half of the kilometer-long line. Six of the seven extrusive episodes occurred 8-11 January, the latest on 15 January.
1983 Jan 8 1983 Jan 15 Lava flow Seven episodes of lava production ranging in duration from 8 minutes to 11 hours occurred from a group of vents S and SW of Pu'u Kahaualea that were active 5-6 January. New lava covered an area of approximately 4.4 x 106 m3. The erupted volume is estimated to be on the order of 10 x 106 m3.
1983 Jan 23    - - - - Lava flow One additional extrusion occurred during the evening, when approximately 7000-8000 m3 of lava were erupted about 0.25 km E of Pu'u Kamoamoa following a magnitude 4.2 earthquake on the S flank.
1983 Feb 10 1983 Mar 4 Fissure The E rift zone eruption of Kīlauea that began on 3 January resumed on 10 February, and lava production continued until 4 March along eruptive fissures established during the initial outbreak on 3 January.
1983 Feb 10 1983 Feb 24 Incandescent ejecta Increased spatter production was first recognized on 10 February; a small (6 m-high) spatter cone had formed at the E vents (0.7 km S of Pu'u Kahaulea). By 12 February, a second small spatter cone had formed, and a glowing crack extended tens of meters NE of the 2 cones. Subsequent intermittent production of low fountains and small lava flows through 24 February led to growth of a flat-topped shield estimated to be about 200 m long, 100 m wide, and 10 m thick. The shield was capped by a 170 m-long line of juxtaposed spatter cones ranging up to about 15 m high. Lava production during the 2-week shield-building period is estimated at 0.5 x 106 m3. In addition, a short (probably 10-minute) episode of spatter production occurred at a vent just E of Pu'u Kamoamoa at about 2220 on 19 February.
1983 Feb 25 1983 Mar 4 Lava fountains Beginning at 0145 on 25 February, fountaining and lava flow production increased in the W and central parts of the shield and a flow about a kilometer long extended NE. Thirteen hours later, at about 1440 on 25 February, the main eruptive locus shifted about 100 m uprift and eruption from the shield vents soon terminated, at 1518. Fountains played continuously at this new locus until the end of the eruptive episode on 4 March. During its week of sustained activity, the main fountain, about 0.75 km SSW of Pu'u Kahaualea, was commonly 40-80 m high. Estimated to be about 30 m wide at its base, the fountain arose from a lava pond about 60 m in diameter.
1983 Feb 25    - - - - Lava flow Beginning at 0145 on 25 February, fountaining and lava flow production increased in the W and central parts of the shield and a flow about a kilometer long extended NE.
1983 Feb 25 1983 Mar 4 Lava flow Thirteen hours later, at about 1440 on 25 February, the main eruptive locus shifted about 100 m uprift. During its week of sustained activity, the main fountain, about 0.75 km SSW of Pu'u Kahaualea, was commonly 40-80 m high. Estimated to be about 30 m wide at its base, the fountain arose from a lava pond about 60 m in diameter. By the evening of 25 February, the S rim of the levee containing the lava pond had developed a spillway through which 2 major flows were supplied during the ensuing week. One of these moved NE 25-26 February within the same graben that contained the upper part of the 7 January flow. Following the path of that earlier flow, the new flow turned SE about 0.5 km W of Kalalua and stopped about 3 km from its source. By the morning of 27 February, the active lava river leading from the pond had been diverted SE, producing a flow that eventually extended more than 7 km from the vent to its terminus, about 3.8 km from the coast. This latest flow, parallel to and a kilometer SW of the 7 January flow, advanced slowly through the rain forest until 4 March, when lava production stopped. In the half nearest the vent, where the feeding channel was largely pahoehoe, the average velocity of the advancing flow front was about 90 m/hour. In the lower half, where the flow was dominantly aa, the front advanced episodically, but at an average rate of about 30 m/hour, even on the steepest (about 7°) slopes.
1983 Feb 25    - - - - Lava lake Estimated to be about 30 m wide at its base, the fountain arose from a lava pond about 60 m in diameter. By the evening of 25 February, the S rim of the levee containing the lava pond had developed a spillway through which 2 major flows were supplied during the ensuing week.
1983 Mar 2 1983 Mar 4 Property Damage In the early evening of 2 March, the advancing aa front, locally up to 10 m thick, entered the NE part of a sparsely populated subdivision on the S flank, just E of Hawaii Volcanoes National Park. Two dwellings were destroyed before lava production at the vent stopped at about 1500 on 4 March.
1984 Sep 19    - - - - VEI (Explosivity Index) P3
1985 Jan    - - - - Evacuations
1985 Jan 3    - - - - VEI (Explosivity Index) P4
1993 Apr 19    - - - - Fatalities
1998 Apr 28    - - - - Fatalities
2000 Nov 3    - - - - Fatalities
2009 Apr    - - - - Evacuations
2018 May 17    - - - - VEI (Explosivity Index) P1

1982 Sep 25 - 1982 Sep 26 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Kilauea Caldera (SSE of Halemaumau)
1982 Sep 25 - 1982 Sep 26 Evidence from Observations: Reported

List of 11 Events for Episode 1 at Kilauea Caldera (SSE of Halemaumau)

Start Date End Date Event Type Event Remarks
1982 Sep 25    - - - - Seismicity (volcanic) Nearly 100 earthquakes were located from the pre-eruption swarm, which started at 1650 when small earthquakes and weak harmonic tremor began to record on the summit seismographs. The seismic activity intensified rapidly so that within a few minutes stations 50 km away registered the signals and the number of recorded earthquakes reached 2-5/minute. For the first 3/4 hr, the onset of earthquake activity migrated from SW to NE at a rate of about 4 km/hour. Moderate-sized earthquakes continued repeatedly along the entire epicentral zone until the eruption began, when earthquake activity in the S caldera region virtually ceased and strong harmonic tremor started.
1982 Sep 25    - - - - Deformation (inflation) A rapid increase in summit tilt, probably related at least in part to emplacement of the feeding dike, coincided closely with the pre-eruption earthquake swarm. Uplift had reactivated old cracks by the time (1715) the first observer arrived near the site of the eventual outbreak. The recorded change in tilt on the upper NW flank was about 30 µrad, down to the NNW. Termination of the rapid increase in tilt coincided approximately with the onset of strong harmonic tremor and the first appearance of lava.
1982 Sep 25 1982 Sep 26 Seismicity (tremor) Moderate-sized earthquakes continued repeatedly along the entire epicentral zone until the eruption began, when earthquake activity in the S caldera region virtually ceased and strong harmonic tremor started. Tremor intensity remained fairly steady through most of the eruption, but declined sharply between 0400 and 0500 on 26 September. By 0500, the tremor amplitude had declined almost to threshold level.
1982 Sep 25 1982 Sep 26 Fissure An eruption in the S part of the caldera began at 1844:40, following nearly 2 hours of a premonitory seismic swarm and an abrupt increase in summit tilt. The eruption continued for 15 hours. Lava erupted from a kilometer-long set of left-stepping enechelon fissures in the the southernmost part of the caldera. The E and central parts of the vent system were oriented in the usual ENE direction, nearly parallel to the nearby caldera wall. In the W part, however, the fissure turned NW, as if to follow the arcuate circumcaldera fault system. At the NW end of this dogleg, the fissure intersected a circumcaldera fault, and a small isolated vent erupted weakly at the top of the fault scarp. The NW-trending vent segment was first recognized at about 1900. It extended NW to the caldera wall, which it reached at about 1945. The northwesternmost vent, on a segment of the caldera rim, opened at about 2100, and a small graben about 7 m wide and 20-40 cm deep extended E and W from the vent. The NW part of this line of vents had largely ceased erupting by 2300, but all other vents erupted with unchanged vigor until about 0500 on 26 September. At that time, the color changed from the normal yellow to an orange cast, and by 0600 most of the vents had shut down. For the remainder of the eruption the only active vent was one in the central or S part of the NW-trending vent alignment. By 0830, eruption of new lava was about over, but loud explosive gas bursts continued until 0940.
1982 Sep 25 1982 Sep 26 Lava fountains The ENE-trending vents were fully active within about 3 minutes of the onset of the eruption and fountained vigorously and steadily through the night. General fountain height was estimated at 20-40 m, with Strombolian bursts that occasionally went as high as 50-70 m. The main, ENE-trending, vents fountained more vigorously, almost certainly erupted much more lava, were hotter, and emitted far more gas than the vents on the NW alignment. By 0600 on 26 September most of the vents had shut down. Diminution of fountaining closely followed a marked decrease in tremor amplitude and a change in summit tilt from slow decrease to slow increase.
1982 Sep 25 1982 Sep 27 Lava flow Lava, fed primarily by the ENE-trending vents, rapidly filled a broad graben. At about 1930 the lava spilled southward through a gap in the caldera wall and fed an actively flowing channel that eventually extended more than 1.5 km to the S. Between 2100 and 2200, NE-flowing lava spilled into the interior of the caldera. After the eruption was over, lava from the interior of the extensive pond surrounding the main vents drained back into the vents until 1800 on 27 September. The resulting collapse of the pond surface left a bathtub `ring' on the order of 2-4 m high on the enclosing escarpments. An early estimate suggests that perhaps as much as 3-4 x 106 m3 of pahoehoe lava was erupted. Of this, possibly as much as 1-2 x 106 m3 drained back into the vent system.
1982 Sep 25    - - - - Deformation (deflation) Most of the vigorous phase of the eruption was marked by gradual summit deflation. Intermittent swarms accompanied minor surges of inflation indicated by summit tiltmeters.
1982 Sep 25    - - - - VEI (Explosivity Index) VEI 0
1982 Sep 26 1982 Sep 30 Seismicity (volcanic) As the eruptive activity waned during the morning of 26 September, earthquake activity renewed in the NE part of the seismic zone. Intermittent swarms accompanied minor surges of inflation indicated by summit tiltmeters. Post-eruption earthquakes occurred vigorously for much of 26 September and activity decreased slowly over the next 2 days. As of the end of September, the number of microearthquakes beneath the summit and upper E rift remained higher than average.
1982 Sep 26 1982 Sep 27 Lava lake After the eruption was over, lava from the interior of the extensive pond surrounding the main vents drained back into the vents until 1800 on 27 September. The resulting collapse of the pond surface left a bathtub `ring' on the order of 2-4 m high on the enclosing escarpments.
1982 Sep 26 1982 Sep 30 Deformation (inflation) Tilt reversed at about 0450 on 26 September and the waning phase of the eruption was accompanied by gradual to moderate inflation that continued intermittently.

1982 Apr 30 - 1982 May 1 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Kilauea Caldera (NE of Halemaumau)
1982 Apr 30 - 1982 May 1 Evidence from Observations: Reported

List of 8 Events for Episode 1 at Kilauea Caldera (NE of Halemaumau)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor) Before eruption.
   - - - -    - - - - Deformation (deflation)
1982 Apr 30    - - - - Seismicity (volcanic) A summit eruption began at 1137 on 30 April and lasted about 19 hours, preceded by a microearthquake swarm about 3 hours long. Earthquakes at 1-3 km depth and magnitudes of less than 3 occurred in the S part of the caldera.
1982 Apr 30    - - - - Deformation (inflation) Rapid inflation of 5.5 µrad was recorded at the Uwekahuna tiltmeter, on the NW rim of the caldera, during the earthquake swarm.
1982 Apr 30    - - - - Fissure A summit eruption began at 1137 and lasted about 19 hours. Lava was erupted from an ENE-trending fissure approximately 1 km long. The fissure, on the S flank of the 1954 spatter ramparts, first opened near its E end about 2 minutes before spatter appeared. Steam emission closely followed opening of the crack as it extended in length both to the E and W. Preliminary data indicate that the line of vents propagated both E and W from the initial vent. Eastward propagation occurred at about 1-2 m/second. The entire line of vents, including its westernmost part (in Halemaumau pit crater), was active within 25 minutes of the eruption's start, forming a nearly continuous and steady curtain of spatter on the order of 5-10 m high with bursts to 25-50 m. A decrease in eruption rates near the ends of the line of vents was first recognized at approximately 1630, about 5 hours from the beginning of the eruption. About an hour later (at 1740) the westernmost vents, except for those in Halemaumau, had shut off, and drainback was occurring in the area of the central vents, from which the relatively extensive flows to the N and S were fed. By 2100, only the central 150-200 m of the fissure system was active. At this group of vents, activity continued steadily until about midnight, after which the rate of fountaining decreased and the length of the active fissure system gradually diminished.
1982 Apr 30 1982 May 1 Lava fountains Lava was erupted from an ENE-trending fissure approximately 1 km long. The entire line of vents, including its westernmost part (in Halemaumau pit crater), was active within 25 minutes of the eruption's start, forming a nearly continuous and steady curtain of spatter on the order of 5-10 m high with bursts to 25-50 m. At the central vents, activity continued steadily until about midnight, after which the rate of fountaining decreased and the length of the active fissure system gradually diminished. Minimal fume production, relatively high density of spatter, and low fountain heights suggest that the gas content of the lava was low. However, gas bursting increased in the last hours of the eruption as the rate of fountain activity waned at the remaining centrally located vents. Frothy pumiceous lapilli were ejected during this phase.
1982 Apr 30 1982 May 1 Lava flow Lava was erupted from an ENE-trending fissure approximately 1 km long. Lava flows to the N, E, and S, which eventually formed prominent lobes, were under way within minutes of the beginning of the eruption. The central vents fed the relatively extensive flows to the N and S. A preliminary estimate suggests that the volume of new lava is about 0.5 x 106 m3, primarily pahoehoe flows. A quick hand-lens inspection suggests that it is aphyric, or has at most rare olivine microphenocrysts.
1982 Apr 30    - - - - VEI (Explosivity Index) VEI 0

1980 Mar 11 - 1980 Mar 11 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode East rift zone (near Mauna Ulu)
1980 Mar 11 - 1980 Mar 11 Evidence from Observations: Reported

List of 5 Events for Episode 1 at East rift zone (near Mauna Ulu)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow weak or small
1980 Mar 10    - - - - Seismicity (volcanic) Earthquakes began beneath Mauna Ulu on 10 March at 2157, summit deflation at 2206, and volcanic tremor at 2310.
1980 Mar 10 1980 Mar 12 Deformation (deflation) Earthquakes began beneath Mauna Ulu on 10 March at 2157, summit deflation at 2206, and volcanic tremor at 2310. Eight centimeters of deflation, representing the draining of 8 x 106 m3 of magma from the summit chamber, occurred before the end of summit deformation on 12 March at 1630.
1980 Mar 10 1980 Mar 13 Seismicity (tremor) Earthquakes began beneath Mauna Ulu on 10 March at 2157, summit deflation at 2206, and volcanic tremor at 2310. Volcanic tremor around Mauna Ulu waned slowly and had almost ceased by 13 March.
1980 Mar 11    - - - - VEI (Explosivity Index) VEI 0

1979 Nov 16 - 1979 Nov 17 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode East rift zone (Pauahi Crater)
1979 Nov 16 - 1979 Nov 17 Evidence from Observations: Reported

List of 14 Events for Episode 1 at East rift zone (Pauahi Crater)

Start Date End Date Event Type Event Remarks
1979 Nov 15    - - - - Seismicity (volcanic) A shallow seismic swarm began at 2100 hours near Pauahi Crater, 7-8 km SE of the central caldera region, and within a half an hour the summit tiltmeter indicated the onset of deflation. Simultaneously, two borehole tiltmeters detected inflation in the upper part of the E rift zone.
1979 Nov 15    - - - - Deformation (deflation) A shallow seismic swarm began at 2100 hours near Pauahi Crater, 7-8 km SE of the central caldera region, and within a half an hour the summit tiltmeter indicated the onset of deflation.
1979 Nov 15    - - - - Deformation (inflation) Simultaneous with deflation at the summit, two borehole tiltmeters detected inflation in the upper part of the E rift zone.
1979 Nov 16    - - - - Seismicity (tremor) Shallow volcanic tremor very local to Pauahi Crater became strong at about 0700 as the number of earthquakes gradually decreased.
1979 Nov 16    - - - - Fissure At 0805 copious steam and fume emission began from fissures E of Pauahi Crater. The fissures occupied an old spatter rampart and never emitted lava, but the emitted gases were hot enough to ignite adjacent vegetation. Observers arriving at Road's End parking lot around 0836 found fissures already erupting a low (5-10 m) curtain of fire (E1) about 100 m long, 230 m E of the copiously fuming area noted at 0805. Fissuring migrated E, eventually producing a separate lava pad (E2). New fissures east of the E2 vent occupied the center of an old spatter rampart.
1979 Nov 16    - - - - Lava fountains Observers arriving at Road's End parking lot at 0836 found fissures already erupting a low (5-10 m) curtain of fire (E1) about 100 m long, 230 m E of the copiously fuming area noted at 0805. Fissuring migrated E, eventually producing a separate lava pad (E2). Eruptive activity on E1 and E2 fissures ceased at 0925. A brief eruption (time uncertain) from a fissure (EN) N of the main E vents took place around 1135.
1979 Nov 16    - - - - Fissure A sharp cracking sound at 0821 accompanied the opening of a vent (P1) on the NE wall of the NW lobe of Pauahi Crater; initial fountain heights were less than 1 m. At 1130 a fissure opened about 70 m W of the still active P1 vent in Pauahi Crater, and almost immediately began to fountain to heights of 2-10 m on its W end. A few seconds later, three smaller vents began activity between the new fountain (P2) and P1. These vents collectively are labeled P3. At 1140 an eruptive fissure (P4) opened 20 m W of P2.
1979 Nov 16 1979 Nov 17 Lava fountains Initial fountain heights at P1 at 0821 were less than 1 m. At 1130 a fissure opened about 70 m W of the still active P1 vent in Pauahi Crater, and almost immediately began to fountain to heights of 2-10 m on its W end. A few seconds later, three smaller vents began activity between the new fountain (P2) and P1. At 1140 an eruptive fissure (P4) opened 20 m W of P2. At 1150 activity at P1 vent abruptly decreased with concurrent increase of activity at P2, P3, P4. At 1214 when activity increased at the W vents, there was a temporary decrease in activity of vents P2-4 in Pauahi crater. At 1716 there was an increase in activity of P2, P3, and P4 vents; the approximately constant combined effusion rate of P2-4 was 15,000-20,000 m3/hour for the next 6 hours. At 1845 activity of P4 vent decreased; it ceased by 2030. Activity at P2 and P3 decreased early on 17 November, and all but gas activity had ceased in Pauahi crater vents by 0630.
1979 Nov 16 1979 Nov 17 Lava flow Around 1155-1200 flows produced by the now-inactive P1 began to cascade down the mezzanine into the SE crater of Pauahi, followed by flows from P2-4. During 1547-1555 the Chain of Craters road was cut by small flow lobes from the W vents. By 0809 the next day, surface movement of red lava in channels in Pauahi crater had ceased, followed over the next 2 hours by collapse of crust and levees and formation of slab pahoehoe.
1979 Nov 16    - - - - Fissure At 1203 fissures migrating W of Pauahi Crater cut the overlook parking lot and the Chain of Craters Road. At 1214 eruption began from E to W on three fissures (W1, W2, and W3) beginning just W of the Chain of Craters Road.
1979 Nov 16    - - - - Property Damage At 1203 fissures migrating W of Pauahi Crater cut the overlook parking lot and the Chain of Craters Road. During 1547-1555 the Chain of Craters road was cut by small flow lobes.
1979 Nov 16    - - - - Lava fountains At 1214 eruption began from E to W on three fissures (W1, W2, and W3) beginning just W of the Chain of Craters Road; concurrently there was a temporary decrease in activity of vents P2-4 in Pauahi. Curtains of fire to 10 m high with spatter ejected to 30-40 m were soon established on two of the new vents (W2 and W3); weak spattering occurred at W1 vent. At 1239 eruption began at W4 vent. Activity at W1, W2, and W3 vents decreased abruptly at the onset of this activity. At 1255 eruption began from W5 vent, followed by roughly constant rates of effusion (about 50,000 m3/hour) from all the W vents over the next 3.5 hours. At 1542 an abrupt brief decrease in fountain height of all W vents was followed by cessation of activity at W5 vent and slight decrease in activity of vents P2-4. During 1543-1631 activity ceased at W4 vent. There was a decrease in the activity of W2 and W3 vents; the total emission from W1 was less than 15 m3. During 1631-1648 activity of W2 and W3 vents declined to sporadic spatter emission and had ceased at all W vents by 1651.
1979 Nov 16    - - - - Seismicity (tremor) At 1445 tremor amplitude at seismic stations 6 km from the eruption site reached a peak. The earthquake rate dropped by an order of magnitude from its peak values at 0005.
1979 Nov 16    - - - - VEI (Explosivity Index) VEI 0

1977 Sep 13 - 1977 Oct 1 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode East rift zone (near Kalalua Crater)
1977 Sep 13 - 1977 Oct 1 Evidence from Observations: Reported

List of 19 Events for Episode 1 at East rift zone (near Kalalua Crater)

Start Date End Date Event Type Event Remarks
1977 Sep 12    - - - - Seismicity (volcanic) A swarm of earthquakes began at 2130 on the upper E rift, near the young satellite shield, Mauna Ulu, and Makaopuhi crater.
1977 Sep 12 1977 Sep 15 Seismicity (tremor) These earthquakes were accompanied by harmonic tremor and rapid summit deflation, indicating that magma was moving into the E rift in the subsurface. Harmonic tremor ends at 2400 on 15 September.
1977 Sep 12 1977 Sep 19 Deformation (deflation) These earthquakes were accompanied by harmonic tremor and rapid summit deflation, indicating that magma was moving into the E rift in the subsurface. The deflation continued strongly for about a week and then tapered off gradually. A total of 90 µrad of tilt change was measured on the tiltmeters at Uwekahuna vault. Levelling later showed maximum summit subsidence of 44 cm."
1977 Sep 13    - - - - Seismicity (volcanic) Earthquake hypocenters began to migrate E along the E rift mid-morning.
1977 Sep 13    - - - - Fissure Fountaining began at newly opened fissures at 1930 extending 3 km E from Kalalua Crater, accompanied by heavy harmonic tremor. The initial active section of rift was approximately 5.5 km long, but fountaining at all times and locations was restricted to a few hundred meters of this length. The remainder of the rifted zone opened as a series of en echelon fractures and were sites of profuse steaming.
1977 Sep 13    - - - - Lava fountains Fountaining began at newly opened fissures at 1930 extending 3 km E from Kalalua Crater, accompanied by heavy harmonic tremor. Maximum fountain heights reached during the early phases of the eruption did not exceed 70-80 m.
1977 Sep 13    - - - - VEI (Explosivity Index) VEI 0
1977 Sep 14    - - - - Lava fountains Fountaining was confined to the E one-third of the new fissures, feeding a lava flow moving S.
1977 Sep 14 1977 Sep 15 Lava flow Fountaining was confined to the E one-third of the new fissures, feeding a lava flow moving S. Flows consisted chiefly of aa, with a maximum rate of advance of about 170 m/hour. By dawn on 15 September these flows had slowed to 65 m/hour. They came to rest late afternoon about 2.5 km from their source fountains, close to a papaya field and ranch.
1977 Sep 15    - - - - Lava fountains Two areas of fountains, about 60 m high were active at 0200. Activity along remainder of the fissure was confined to low spattering.
1977 Sep 18    - - - - Lava fountains Renewed fountaining (phase 2), feeding a small flow parallel to the first flow began at 0400. Fountains were discontinuous, rising to about 50 m from a vent area about 200 m long, slightly W of the earlier vents.
1977 Sep 18 1977 Sep 20 Lava flow Renewed fountaining (phase 2), feeding a small flow parallel to the first flow began at 0400. By late afternoon on 19 September this activity had decayed and flow movement was scarcely perceptible, but by midnight fountaining resumed. By 0900 hours on 20 September this phase of the eruption had ended. The new flow had stopped less than 0.5 km from the vent.
1977 Sep 23    - - - - Lava fountains Strombolian activity began at a small, new cone downrift in the afternoon. The lava was highly viscous and was ejected sporadically in a series of taffy-like, irregular sheets and long clots. Minor fountaining (to 15 m) fed small flows, and ended by nightfall (Phase 3).
1977 Sep 23    - - - - Cinder Cone Strombolian activity began at a small, new cone downrift in the afternoon.
1977 Sep 23    - - - - Lava flow Minor fountaining (to 15 m) fed small flows, and ended by nightfall (Phase 3). The lava was highly viscous and was ejected sporadically in a series of taffy-like, irregular sheets and long clots. All lava to this point in the eruption was tholeiite rich in plagioclase microphenocrysts, presumably old and highly differentiated lava.
1977 Sep 25 1977 Oct 1 Lava fountains Phase 4 began around 2350 from a vent W of the earlier ones. During the next 24 hours, fountains rose 100 m, and discharge rates briefly reached an estimated 5-7 x 105 m3/hour. Except for a 2-hour lull in the early afternoon of 26 September this fountaining continued until mid-afternoon on 1 October. Fountains played from heights of 20 m to as much as 300 m, lava production was copious at all times.
1977 Sep 25 1977 Oct 1 Lava flow Phase 4 began about 2350 from a vent W of the earlier ones. Discharge rates briefly reached an estimated 5-7 x 105 m3/hour. Lava advanced SE at up to 300 m/hour. New flows ran NE, ENE, and SE, but only the ENE flow eventually threatened populated areas. In the early hours of 28 September it turned away from the rift down which it had flowed for 1.5 km and started toward the village of Kalapana. On 29 September the flow front, several thousand meters from the village, was advancing toward it about 150 m/hour down a steep slope. A transition from pahoehoe to aa flow types occurred at the edge of the steep slope. By 1 October the flow advance had stopped 400 m from the nearest house in Kalapana. The pahoehoe to aa transition had retreated to the vent area. The flow front had thickened from 4.5 to 12 m and had widened from 300 to 900 m.
1977 Sep 25    - - - - Cinder Cone The source cone, named Pu'u Kia'i (Hill of the Guardian) is 250 m long, 140 m wide, and 35 m high.
1977 Sep 30    - - - - Evacuations Evacuation of Kalapana began at dawn and was completed by evening. Evacuees returned 3 October, 38 hours after cessation of fountaining.

1975 Nov 29 - 1975 Nov 29 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Kilauea Caldera, Halemaumau
1975 Nov 29 - 1975 Nov 29 Evidence from Observations: Reported

List of 6 Events for Episode 1 at Kilauea Caldera, Halemaumau

Start Date End Date Event Type Event Remarks
1975 Nov 29    - - - - Earthquake (tectonic) The Kalapana earthquake occurred at 0448. The epicenter of the M 7.2 quake was 30 km ESE of Kīlauea Caldera, located at a depth of 5-8 km. The earthquake was the strongest in Hawaii since at least 1868, and extensive damage was reported. On the SE shore, at Punaluu, a 6-m tsunami was observed. The coastal area at Halape, the area of maximum subsidence, was permanently lowered 3 m. The tide gauge at Hilo recorded a 2.5 m wave.
1975 Nov 29    - - - - Fatalities At Halape, two people died when a wave in excess of 7 m high [swept inland] and reached 16 m up a fault scarp perpendicular to the coast after the M7.2 earthquake.
1975 Nov 29    - - - - Fissure At 0532 on 29 November, 44 minutes after a severe earthquake beneath Hawaii's SE coast, lava erupted from a N85°E-trending fissure on the floor of Kīlauea caldera.
1975 Nov 29    - - - - Lava fountains Lava fountains were 50 m high for the first 15 minutes but decreased to 5-10 m heights for the next 75 minutes before stopping.
1975 Nov 29
(in or after)
   - - - - Lava flow Eruptive activity resumed at about 0830 in Halemaumau pit crater and continued intermittently before ceasing around 2200, after 16 hours of activity. Lava drained into the SW rift zone for days after the end of visible activity.
1975 Nov 29    - - - - VEI (Explosivity Index) VEI 0

1974 Dec 31 - 1974 Dec 31 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Southwest Rift Zone (1,095 m)
1974 Dec 31 - 1974 Dec 31 Evidence from Observations: Reported

List of 10 Events for Episode 1 at Southwest Rift Zone (1,095 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Earthquakes (undefined) Before.
   - - - -    - - - - Earthquakes (undefined) After.
1974 Sep 1
(in or after)
1974 Dec 31 Deformation (inflation) Kīlauea erupted for six hours on 31 December 1974, after a four-month period of continuous inflation monitored by ground deformation measurements.
1974 Dec 31 1974 Dec 31 Fissure The eruption began at 0255 HST (1255 GMT) from a fissure 2.5 km S of Halemaumau. Fissures opened progressively both to the NE and SW, and ultimately the total span of erupting fountains reached about 3 km in length. The individual eruptive fissures trend N80°E, but separate segments are en-echelon and form a zone that trends N60°E. The eruption began to decline in vigor about 0530 and stopped about 0850.
1974 Dec 31    - - - - Lava fountains Fissures opened progressively both to the NE and SW, and ultimately the total span of erupting fountains reached about 3 km in length. Maximum height of fountains was about 100 m.
1974 Dec 31    - - - - Lava flow Tholeiitic basaltic lava flows covered an area of ~7.5 km2, and their volume is estimated at 15 x 106m3. The flows traveled chiefly southwestward and southward, and have a total length of about 12 km.
1974 Dec 31    - - - - Deformation (deflation) The eruption was accompanied and followed by an unusually large deflation of Kīlauea's summit region and extensive ground cracking and deformation along the southwest rift zone.
1974 Dec 31 1975 Jan 4 Seismicity (volcanic) An intense seismic swarm along the southwest rift zone lasted from 31 December to 4 January that included about 120 earthquakes stronger than M 3 and five earthquakes exceeding M 5.
1974 Dec 31    - - - - VEI (Explosivity Index) VEI 0

1969 Feb 22 - 1974 Sep 19 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode East rift zone (885-945 m), Alae Crater
1969 Feb 22 - 1969 Feb 28 Evidence from Observations: Reported

List of 13 Events for Episode 1 at East rift zone (885-945 m), Alae Crater

Start Date End Date Event Type Event Remarks
1969 Feb 22    - - - - Seismicity (tremor) The swarm of short tremors burst and small earthquakes started at 0627. By 0900 tremors were constant.
1969 Feb 22    - - - - Seismicity (volcanic) The swarm of short tremors burst and small earthquakes started at 0627.
1969 Feb 22    - - - - Lava flow Earthquakes had diminished and lava appeared about 0950.
1969 Feb 22    - - - - Fissure Kīlauea erupted three miles of fissure in the upper east rift beginning at 1000 HST. Within the next two hours the erupting fissure extended eastward across the north flank of Kane Nui O Hamo, westward across the mezzanine of Alae, across the chain of crater roads, and to a point south of west edge of Alae.
1969 Feb 22    - - - - Lava flow The first crack extended to the base of Kane Nui O Hamo and produced two flows that rapidly moved south across the chain of crater roads.
1969 Feb 22    - - - - VEI (Explosivity Index) VEI 0
1969 Feb 23    - - - - Lava fountains Fountains from Alae Mezzanine were forming a new lava lake in Alae Crater that was more than 150 feet deep as of the afternoon.
1969 Feb 23    - - - - Lava flow A sluggish aa-flow from the eastern fissure was moving down the highway and reached more than one and a half miles by the afternoon.
1969 Feb 23    - - - - Lava lake Fountains from Alae Mezzanine were forming a new lava lake in Alae Crater that was more than 150 feet deep as of the afternoon.
1969 Feb 25    - - - - Fissure Late afternoon, fountaining resumed on a quarter mile fissure half way between Alae Crater and Kane Nui O Hamo. This fissure is either the same or very close to the original fissure that started the activity on the morning of 22 February.
1969 Feb 25 1969 Feb 27 Lava fountains Late afternoon, fountaining resumed on a quarter mile fissure half way between Alae Crater and Kane Nui O Hamo. Fountaining was not too strong during 24 hours, and was localized in three main fountains. The effluent lava pooled and built a confining levee that reproduced a miniature Halemaumau lake. This localized activity built up on [the night of 26 February] and the vigor of tremor increased. On [the morning of 27 February] the three fountains in the "lake" had become one vigorous fountain, playing up to 200 feet, and the levee had burst permitting a strong lava flow to cascade into Alae Crater. A small fountain had resumed at the base of the northwest slope of Kane Nui O Hamo and sent a sluggish small flow northward into the forest. A third small fountain had resumed in Alae.
1969 Feb 27    - - - - Lava flow On [the morning of 27 February] the three fountains in the "lake" had become one vigorous fountain, playing up to 200 feet, and the levee had burst permitting a strong lava flow to cascade into Alae Crater. A small fountain had resumed at the base of the northwest slope of Kane Nui O Hamo and sent a sluggish small flow northward into the forest.
1969 Feb 27    - - - - Property Damage New lava has covered the new highway for a mile and a half south from Makaopuhi.
Episode 2 | Eruption Episode East Rift Zone (Mauna Ulu, 960 m)
1969 May 24 - 1974 Jul 22 Evidence from Observations: Reported

List of 50 Events for Episode 2 at East Rift Zone (Mauna Ulu, 960 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic)
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Property Damage
1969 May 24    - - - - Fissure Kīlauea erupted along a one-mile-long segment of the East Rift in the morning, local time. The location of the activity is approximately one mile nearer to Kīlauea Summit than the 22 February 1969 eruption.
1969 May 24 1969 May 25 Lava flow Lava flows moved south into Aloi Crater and back into Alae Crater.
1969 May 24    - - - - VEI (Explosivity Index) VEI 0
1969 Jun 12 1969 Jun 13 Lava fountains Lava fountains were active.
1969 Jun 12 1969 Jun 13 Lava flow Lava flows traveled a path down toward the beach.
1969 Jun 24 1969 Jun 25 Lava fountains Exactly the same fountain trough opened up as was active on 12-13 June, and we had very strong fountaining starting about 2100 GMT on 24 June and it stopped at 1755 GMT the next morning (25 June). It went for a little over nine hours. The fountaining was quite strong and steady.
1969 Jun 24 1969 Jun 25 Lava flow Lots of lava was produced and the flow from the fountaining followed practically the same path that the flow had taken down toward the beach, on 12 and 13 June and this flow reached within 75 yards of the beach while the fountain was still active. Then, when the fountain ceased activity, there was still lava in the system along the channel that was still hot enough to be mobile, so there was some extension of the flow at the end. . . the lava did reach the beach and a little bit of it flowed into the water at about 0835 (more than 1.5 hours after the fountain stopped).
1969 Jul 15    - - - - Lava flow There was an eruption on the island of Hawaii (same area as 24-25 April 1969 eruption) that began at 0400 and ceased at 1228 the same day.
1969 Aug 3 1969 Aug 4 Lava flow An eruption from the same vent started [at 1715 on 3 August]. It stopped at 0008 [on] 4 August. The flow nearly filled the Alae [pit crater]. Nothing flowed toward the ocean.
1969 Aug 3
(in or before)
   - - - - Lava lake The last eruptive phase which took place on 3 August at the same site was followed on 4 August by the down-dropping of a graben extending from Alae Crater to Kane Nui O Hamo and the almost complete draining of lava from Alae Crater. Alae had been almost completely filled by lava several hundred feet deep that erupted during previous phases in February, May, June, July and August.
1969 Aug 4    - - - - Fissure Concurrently with the draining of Alae, lava oozed from a mile long fissure on the rift zone below Napau Crater.
1969 Aug 5    - - - - Lava fountains Another phase of the current Kīlauean eruption started at 2200 when lava started pouring into Alae Crater from a nearby fountain.
1969 Aug 5 1969 Aug 6 Lava flow Another phase of the current Kīlauean eruption started at 2200 when lava started pouring into Alae Crater from a nearby fountain. The concurrent eruptive phase ended at 6pm 6 August, and left a new lake of lava more than a hundred feet deep in Alae Crater.
1969 Aug 5 1969 Aug 6 Lava lake The concurrent eruptive phase ended at 6pm 6 August, and left a new lake of lava more than a hundred feet deep in Alae Crater.
1969 Aug 6
(in or after)
1969 Aug 22
(in or before)
Lava fountains The volcano went into a very active phase about midnight Hawaiian Time on 22 August. In the last few weeks the volcano has been continuously active in between violent stages; the fountaining being very low, only 25-50 feet high, and the lava flowing only a short distance until flowing down a fissure.
1969 Aug 6
(in or after)
1969 Aug 22
(in or before)
Lava flow The volcano went into a very active phase about midnight Hawaiian Time on 22 August. In the last few weeks the volcano has been continuously active in between violent stages; the fountaining being very low, only 25-50 feet high, and the lava flowing only a short distance until flowing down a fissure.
1969 Aug 22 1969 Sep 6 Seismicity (tremor) Starting at midnight Hawaiian Time (1000 GMT 22 August) the fountaining rapidly increased and a volcanic tremor recorded on the seismograph, increased. On 6 September, at noon, the tremor and fuming stopped and a periodic rise and fall of the lava surface in the vent began.
1969 Aug 22    - - - - Lava fountains Starting at midnight Hawaiian Time (1000 GMT 22 August) the fountaining rapidly increased and a volcanic tremor recorded on the seismograph, increased. This vent was in strong eruption between midnight and 0440. When Dr. Powers called, the fountaining had reached 1500 feet in height. Over the last several months in a number of eruptions, there have been two fountains, one of which feeds a stream of lava flowing down due south to the shoreline and the other feeding a flow that poured into Alae Crater. During this current phase, only the eastern fountain, feeding the flow into Alae, is active.
1969 Sep 6    - - - - Lava lake At noon, the tremor and fuming stopped and a periodic rise and fall of the lava surface in the vent began. The surface rose nearly to the lip of the fissure and then dropped 100 feet deep in surges lasting short of an hour.
1969 Sep 6 1969 Sep 7 Lava fountains A sustained and strong eruption began about 2000. Fountains attained heights of 1,800 feet maximum and held steady at over 1,000 feet for several hours. Activity suddenly stopped at 0430, 7 September.
1969 Sep 6 1969 Sep 7 Lava flow Two small flows extended southward to within a couple of miles of the coast.
1969 Sep 6 1969 Sep 7 Lava lake Alae pit crater filled.
1969 Sep 6 1969 Sep 7 Cinder Cone Pumice and spatter cones was increased to a height of more than a hundred feet.
1969 Sep 7    - - - - Deformation (inflation) Summit swelling resumed immediately and the strong fuming started up right after the last fountain died.
1969 Oct 10 1969 Oct 11 Lava fountains Phase end, or a very vigorous episode of interphase activity, began 10 October at 0900 and is continuing as of 1930, 11 October. Fountains have been very low (50-125 feet) but they have been continuous so they have put out a fair amount of lava.
1969 Oct 10 1969 Oct 11 Lava flow Phase end, or a very vigorous episode of interphase activity, began 10 October at 0900 and is continuing as of 1930, 11 October. Nearly all the lava has gone into Alae Crater which was refilled by 1400, 10 October, and is now overflowing along its SE side. Flows apparently fed through tubes beneath the stable crust from Alae Lake are covering a fairly extensive area south of Alae and east of the area covered previously since 24 May.'"
1969 Oct 10 1969 Oct 11 Lava lake Phase end, or a very vigorous episode of interphase activity, began 10 October at 0900 and is continuing as of 1930, 11 October. Nearly all the lava has gone into Alae Crater which was refilled by 1400, 10 October, and is now overflowing along its SE side.
1969 Oct 20    - - - - Lava fountains High fountaining and significant lava output from the same vent area as before marked the 11th phase of the eruption.
1969 Oct 20    - - - - Lava flow High fountaining and significant lava output from the same vent area as before marked the 11th phase of the eruption.
1970 Jan 29 1970 Jan 30 Deformation (deflation) At about 2100 29 January the summit recording tiltmeter showed the start of slow, steady deflation and sometime thereafter the vent between Aloi and Alae began a moderate welling of lava with very little fountaining.
1970 Jan 29 1970 Jan 30 Lava flow At about 2100 29 January the summit recording tiltmeter showed the start of slow, steady deflation and sometime thereafter the vent between Aloi and Alae began a moderate welling of lava with very little fountaining. This mild activity continued until about 1530 to 1600 on 30 January when overflow ceased and drainback took place.
1970 Jan 30 1970 Jan 31 Deformation (inflation) The summit tiltmeter showed the resumption of inflation about 1530 that continued at least until 1000 31 January. The lava has risen again in the vent but is not overflowing at this time."
1970 Apr 9 1970 May 1 Fissure Kīlauea erupted from its east rift zone shortly before 0800, 9 April 1970, when lava began welling out of a fissure crossing the bottom of Aloi Crater. The fissure cut the SW flank of Mauna Ulu, and it spread westward across Aloi Crater and for 800 m beyond. Lava erupted from this fissure filled the crater, but activity died out by 1 May.
1970 Apr 9    - - - - Lava lake Within a few hours, the crater was filled and lava began pouring southward toward the coast.
1970 Apr 9 1970 Apr 10 Lava flow Within a few hours, the crater was filled and lava began pouring southward toward the coast.
1970 Apr 9 1970 Apr 10 Lava dome Aloi Crater is on the SW side of a new lava dome named Mauna Ulu, built by repeated phases of the continuing eruption that started 24 May 1969. Surprisingly, the summit crater of the dome, which has been continuously active during both quiet and violent phases of the eruption, did no more than fume during this latest activity.
1970 Apr 10    - - - - Deformation (deflation) By 0500, 10 April, deflation of the summit (10-15 µrad during the eruption) had ceased and the eruption was presumed to be over.
1970 Jul 1
(in or after)
1970 Dec 22
(in or before)
Lava dome The main fissure atop Mauna Ulu is about 140 m long. It was largely roofed over until July, but vents in the roof were sources of many small flows that built the bulk of the shield. The roof collapsed in early July, nearly coincident with resumption of vigorous activity of Mauna Ulu's east flank. Since July, the summit fissure has been widening by the caving of its walls until it is now nearly circular in plan view.
1970 Jul 1
(in or after)
1970 Dec 22
(in or before)
Lava lake Lava can always be seen in a pool 8-30 m below the rim, and lava in the pool nearly always has a circulation pattern from west to east. The level of lava in the pool rises and falls periodically but not as regularly as described by card 814, 3 November 1969. Moderately violent spattering and degassing take place nearly constantly from one or more locations in the fissure.
1970 Jul 6 1970 Dec 22
(in or after)
Fissure The fissure on the NE flank of Mauna Ulu was active periodically in the fall and winter of 1969, but it remained quiet in 1970 until 6 July, when low fountains burst from it. Since then, eruptive activity from this fissure has been more or less constant, although most erupted lava has been fed away from the fissure by underground lava tubes. This fissure extends discontinuously down the northeast flank of the shield, recently named Mauna Ulu ("Growing Mountain" in Hawaii), and lava flows and spatter are commonly erupted from several vents along this extension.
1970 Jul 6    - - - - Lava fountains The fissure on the NE flank of Mauna Ulu was active periodically in the fall and winter of 1969, but it remained quiet in 1970 until 6 July, when low fountains burst from it.
1970 Jul 6 1970 Dec 22
(in or after)
Lava flow Eruptive activity from the NE flank Mauna Ulu fissure has been more or less constant, although most erupted lava has been fed away from the fissure by underground lava tubes. Many flows have advanced as far as 11 km S, cascading over fault scarps of the Hilini fault system and pooling near and even entering the sea.
1970 Jul 6
(in or after)
1970 Dec 22
(in or before)
Crater Several small pit craters have developed along the fissure. These pit craters are collapse features several tens of meters in diameter which have formed over sections of the fissure that had shown rather persistent activity before becoming roofed over by spatter and small flows. The craters are elongate along the fissure when they first form, but they become more nearly circular in plan view as the sheer walls collapse.
1970 Jul 6
(in or after)
1970 Dec 22
(in or before)
Lava lake A pool of gently circulating (W to E) lava normally fills each crater to within 2-20 m of the rim. The lava in the pool commonly rises slowly upward as gases within the lava expand. Suddenly gases begin to escape with vigorous low fountaining, and the level drops several meters. Sometimes the rising lava reaches the crater rim and spills out; overflows generated by such activity last from a few minutes to several hours before ending with an episode of degassing and fountaining.
1970 Aug 1
(in or after)
1970 Dec 22
(in or before)
Lava flow Since early August 1970, lava has almost constantly been erupting from the fissure northwest of Alae Crater at an average rate of more than 105m3 per day. This lava flows through a large tube which enters Alae beneath the solidified crust of the lava lake that fills the crater. The lava then leaves the crater in another tube and continues its subsurface flow for several kilometers toward the sea. The lava finally emerges from the tube as fluid but relatively degassed pahoehoe, not aa, doubtless because the insulation of the tube allows the lava to remain hot despite the long distance of travel and small volume of lava. Much of the lava changes to aa after flowing on the surface for some distance, however.
1971 Mar 8 ± 2 days 1971 Apr 19 Lava flow A team of five divers from the US Geological Survey, the University of Hawaii, and the Lockheed Aircraft Company dived on the lava flow from Kīlauea Volcano on the south coast of the Island of Hawaii on 19 April. This is the lava flow that has been going on for six weeks and is presently flowing into the sea. The flow is advancing under water as a wall of rubble which is some 300 to 500 feet seaward of the new sea cliff. The front of the rubble wall is at the angle of repose of about 45°, and the base of it is covering over the old ocean floor to a depth of about 100 feet. Tongues of lava, circular in cross section, extend down the front of the rubble of this rubble slope. Some of these are as long as 200 feet and they are three to four feet in diameter, generally. Budding off of them are typical pillows. We could approach one of these elongate lava tongues, in which lava was actually flowing inside and whose surface was too hot to touch on the outside. Generally, the surface was dark, but periodically it would crack and bright incandescence could be seen inside for a few seconds until the crack solidified and then it would crack in some other place. There was a continuous loud mixture of noises: hissing, cracking, small explosions, and rumbling noise as the lava went down through these tubes.
1971 Aug 14    - - - - Lava flow During the summit eruption volcanic activity continued at a low level at Mauna Ulu about 12 km distant on Kīlauea's east rift zone.
Episode 3 | Eruption Episode Kilauea Caldera
1971 Aug 14 - 1971 Aug 14 Evidence from Observations: Reported

List of 6 Events for Episode 3 at Kilauea Caldera

Start Date End Date Event Type Event Remarks
1971 Aug 11 1971 Aug 14 Deformation (inflation) A measurement of ground deformation showed that the Kīlauea's summit region was gradually inflating for several weeks and that the rate of inflation increased rapidly for about three days just preceding the eruption.
1971 Aug 14    - - - - Seismicity (tremor) Strong seismic harmonic tremor began about an hour before the eruption started.
1971 Aug 14    - - - - Fissure A summit eruption lasted from 0855 to about 1900 Hawaiian Standard Time. Basaltic lava erupted from four en echelon fissures that trended from N60°E to N75°E and had a combined length of about 1.9 km. The two fissures on the floor of Kīlauea caldera extended East-northeast from a point a few hundred meters east of the south rim of Halemaumau for about 1.2 km to a point NW of Keanakakoi Crater and were roughly parallel to the caldera rim. Two other fissures about 0.7 km in length extended along the upper rim of the caldera on the N side of Keanakakoi.
1971 Aug 14    - - - - Lava fountains Lava fountains reached a maximum height of about 65 m. Fountains from the upper fissure lasted for about two hours; the lava descended the caldera walls in spectacular cascades. Fountains from the lower fissure continued for about ten hours.
1971 Aug 14    - - - - Lava flow Lava flowed E from the fissures along the S edge of the caldera floor in a counterclockwise direction, and it ultimately reached the NE part of the caldera. Preliminary determinations indicate that new lava has covered about 2.1 million square meters, which is about one-fifth the area of the caldera floor, and that the total volume erupted was approximately 13 million cubic meters.
1971 Aug 14    - - - - VEI (Explosivity Index) VEI 0
Episode 4 | Eruption Episode Halemaumau and upper SW rift zone
1971 Sep 24 - 1971 Sep 29 Evidence from Observations: Reported

List of 8 Events for Episode 4 at Halemaumau and upper SW rift zone

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic) Before eruption.
   - - - -    - - - - Property Damage
1971 Sep 24 1971 Sep 25 Lava fountains Fountains of basaltic lava began at 1920 HST, on the caldera floor between Halemaumau and the SW caldera wall, and reached about 80 m high. Fountains spread into Halemaumau crater, and about a quarter of its floor was covered by new lava. At 2059 fountains began on the upper SW caldera rim, and then progressively advanced down the SW rift zone for about 1 km. This advancing line of fountains was about 100 m long, and averaged 15-30 m high. The fountains on the rift zone and caldera floor began to decline about 2300 and ended by 2400, but light activity continued in Halemaumau until late 25 September.
1971 Sep 24    - - - - Lava flow At the SW side of the caldera, a tongue of lava breached the low point in the rim and flowed SE for 2.5 km.
1971 Sep 24    - - - - VEI (Explosivity Index) VEI 0
1971 Sep 25 1971 Sep 29 Lava fountains At 0945 new fountains broke out on the SW rift zone about 5 km from Halemaumau. This was the beginning of sporadic fountaining on this rift that persisted through 29 September. Fountains were active at many places along a line spanning about 8 km; they migrated both up and down the rift. As many as five localities at a time had activity, but most of the time only one or two places were fountaining.
1971 Sep 25 1971 Sep 29 Lava flow Rows of spatter cones were built, and lava flows covered many thousands of square meters. Activity ended the evening of 29 September.
1971 Sep 25    - - - - Deformation (inflation) By the morning of 25 September, the floor of Halemaumau had dropped like a piston a distance of 45 m, so its depth is now about 100 m.
Episode 5 | Eruption Episode East rift zone, Pauahi, Hiiaka
1973 May 5 - 1973 May 5 Evidence from Observations: Reported

List of 7 Events for Episode 5 at East rift zone, Pauahi, Hiiaka

Start Date End Date Event Type Event Remarks
1973 May 5    - - - - Lava fountains The Kīlauea volcano erupted spectacularly, with lava fountains reaching a height of 100 feet.
1973 May 5    - - - - Fissure The eruption ripped open a fissure 600 feet wide, and caused several forest fires to suddenly break out. The eruption was only the second time in 60 years that an eruption went up a rift zone instead of down.
1973 May 5    - - - - Seismicity (tremor) The eruption occurred amidst hundreds of volcanic tremors, ten days after a 6.2 Richter magnitude earthquake shook the island.
1973 May 5 1973 May 6 Deformation (deflation) By 6 May the volcano was in a deflated condition.
1973 May 5    - - - - Lava flow The Chain of Craters Highway and the Hilina Pali Road were damaged by the lava flow.
1973 May 5    - - - - Property Damage The Chain of Craters Highway and the Hilina Pali Road were damaged by the lava flow.
1973 May 5    - - - - VEI (Explosivity Index) VEI 0
Episode 6 | Eruption Episode East rift zone, Pauahi
1973 Nov 10 - 1973 Dec 9 Evidence from Observations: Reported

List of 6 Events for Episode 6 at East rift zone, Pauahi

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava lake Small
1973 Nov 10    - - - - Seismicity (tremor) At 1730 HST, strong harmonic tremor began to be recorded by Hawaiian Volcano Observatory seismographs.
1973 Nov 10    - - - - Fissure At 2417, lava fountains began as a fissure opened in Pauahi Crater, 6 km SE of Kīlauea caldera and 2 km W of Mauna Ulu. Additional fissures opened both east and west of Pauahi, trending from N65°E to N70°E, and lying en-echelon along a belt 2 km long.
1973 Nov 10 1973 Nov 12 Lava fountains At 2417, lava fountains began as a fissure opened in Pauahi Crater, 6 km SE of Kīlauea caldera and 2 km W of Mauna Ulu. Lava fountains reached heights of 75 m. At about 0400, 11 November, eruptive intensity began to decline, and by 0600 all fountains outside Pauahi had stopped. Fountains 10-30 m high continued in Pauahi through 12 November, after which activity has gradually declined.
1973 Nov 10 1973 Nov 18
(in or after)
Lava flow Sluggish outflow continued on 16 November, and summit inflation had resumed. Approximately 100 hectares of land was covered by new lava during the Pauahi episode, and approximately three million cubic meters of lava was erupted during the eight hours of strongest activity.
1973 Nov 10    - - - - VEI (Explosivity Index) VEI 0
Episode 7 | Eruption Episode Kilauea Caldera, Keanakakoi
1974 Jul 19 - 1974 Jul 22 Evidence from Observations: Reported

List of 7 Events for Episode 7 at Kilauea Caldera, Keanakakoi

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor) Before eruption.
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Earthquakes (undefined) Before.
   - - - -    - - - - Deformation (undefined)
   - - - -    - - - - Property Damage
1974 Jul 19    - - - - VEI (Explosivity Index)
Episode 8 | Eruption Episode Kilauea Caldera (Halemaumau and to SW)
1974 Sep 19 - 1974 Sep 19 Evidence from Observations: Reported

List of 8 Events for Episode 8 at Kilauea Caldera (Halemaumau and to SW)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor) Before eruption.
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow violent, strong, or large
   - - - -    - - - - Earthquakes (undefined) Before.
   - - - -    - - - - Deformation (inflation)
   - - - -    - - - - Deformation (deflation)
   - - - -    - - - - Property Damage
1974 Sep 19    - - - - VEI (Explosivity Index)

1967 Nov 5 - 1968 Oct 22 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1967 Nov 5 - 1968 Jul 13 Evidence from Observations: Reported

List of 6 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor) Before eruption.
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
1967 Nov 5    - - - - VEI (Explosivity Index)
Episode 2 | Eruption Episode East rift zone (580-885 m), Hiiaka Crater
1968 Aug 22 - 1968 Aug 26 Evidence from Observations: Reported

List of 9 Events for Episode 2 at East rift zone (580-885 m), Hiiaka Crater

Start Date End Date Event Type Event Remarks
1968 Aug 22    - - - - Seismicity (volcanic) An eruption along the upper east rift of Kīlauea started with a swarm of earthquakes at 0249.
1968 Aug 22 1968 Aug 25 Deformation (deflation) Collapse of the summit began recording on the Uwekahuna tiltmeters almost simultaneously. Collapse at the caldera totaled about 60 µrad on the rim stations during the first 36 hours, and reversed to a steady but moderate inflation Sunday and Monday. Level stations on the floor of the caldera dropped a little more than half a foot during this period.
1968 Aug 22    - - - - Fissure By daylight, 0530, clouds of fumes were issuing from a line of new cracks that intercepted the Chain of Craters Road, crossed through Hiiaka pit and half-way across the Old Keauhou Wagon Road at B.M. 3270.
1968 Aug 22    - - - - Lava fountains Kīlauea erupted with fountains up to 75 feet in height. Activity broke out in Hiiaka Crater about 0645.
1968 Aug 22    - - - - Lava lake Lava vents appeared in the bottom of Hiiaka Crater about 0645 and rapidly fed a lake that deepened to about 100 feet and reached a diameter at "shore line" of about 300 feet. Drainback started conspicuously while some continued another half hour leaving only a thin plaster of new lava covering the funnel-shaped bottom walls of Talus.
1968 Aug 22    - - - - Lava flow During the early part of the Hiiaka eruption, another small flow was erupted from one fissure a mile east of Hiiaka.
1968 Aug 22 1968 Aug 25 Seismicity (tremor) The earthquake swarm ceased within about six hours, and strong harmonic tremor was recorded on all the near-summit seismometers for more than 24 hours. It then diminished rapidly under the caldera but remained strong under the upper east rift until there also it died out rapidly during the early hours of 25 August.
1968 Aug 22    - - - - VEI (Explosivity Index) VEI 0
1968 Aug 23 1968 Aug 26 Fissure During the next four days (through 26 August 1968) cracks opened progressively eastward as far as about 13.5 miles from Hiiaka; first at three miles, next at 12 miles, and finally at 13.5 miles, somewhat E of Kalalua Crater. Violent emission of hot gas with no outpouring of lava took place from the western set of cracks; small amounts of rampart spatter and short, stubby, listless flows issued from the more distant groups of cracks.
Episode 3 | Eruption Episode East rift zone (730-915 m), Napau Crater
1968 Oct 7 - 1968 Oct 22 Evidence from Observations: Reported

List of 11 Events for Episode 3 at East rift zone (730-915 m), Napau Crater

Start Date End Date Event Type Event Remarks
1968 Oct 7    - - - - Seismicity (tremor) Kīlauea volcano erupted at 1435 HDT after 3.5 hours of harmonic tremors and abundant earthquakes.
1968 Oct 7    - - - - Fissure The eruption is from a fissure between two and three miles in length crossing Napau Crater on the east rift zone, nine miles southeast of the summit. The fissure is located approximately four-and-a-half miles northeast of the Makaopuhi Road and the lava is disappearing in another fissure which is located approximately one mile to the northeast of the fountaining activity.
1968 Oct 7    - - - - Lava flow Quite a bit of lava came out of the fissure and covered the floor of Napau Crater. Another small lava flow from the same fissure blocked the trail into the crater. The greatest advance of the lava was about 5.5 miles NE of the road and within two miles of the Puaialua Crater.
1968 Oct 7 1968 Oct 9 Lava fountains There was lava fountaining throughout the night of 7-8 October all along the three-and-a-half mile fissure that initially opened up. The fountaining continued until 0400 on 8 October. At 0700, the lava fountaining was still continuing in the northeasterly section of the fissure. The fountains on 8 October were 200 feet high, on 9 October they were 50-100 feet high.
1968 Oct 7    - - - - VEI (Explosivity Index) VEI 0
1968 Oct 10    - - - - Lava fountains Fountain activity was limited to 200 yard stretches approximately one to two miles from Napau Crater rim.
1968 Oct 10    - - - - Lava flow Napau Crater lava extrusion extended three miles from the crater but activity was decreasing.
1968 Oct 10    - - - - Lava lake Napau Crater flooded with lava. Flooding stopped by midday.
1968 Oct 12 1968 Oct 14 Seismicity (tremor) Weak tremors were recorded.
1968 Oct 12 1968 Oct 14 Lava fountains As of 12 October at 0200Z one area was still fountaining approximately one mile from Napau Crater rim. As of 14 October 0200Z there was slight bubbling in the previous fountaining area one mile from Napau Crater rim.
1968 Oct 21 1968 Oct 22 Lava fountains On the afternoon of 21 October, minor fountaining activity, perhaps 15 feet high, had resumed, in a small area of the rift east of Napau Crater. Though it is uncertain when the activity started, it seems likely that it began in the early morning hours of 21 October. By 22 October, the activity ceased.

1965 Dec 24 - 1965 Dec 25 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode East rift zone (915-960 m)
1965 Dec 24 - 1965 Dec 25 Evidence from Observations: Reported

List of 9 Events for Episode 1 at East rift zone (915-960 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic) Before eruption.
   - - - -    - - - - Seismicity (tremor) Before eruption.
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Seismicity (tremor) After eruption.
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Incandescence Event was "Glow"
   - - - -    - - - - Deformation (undefined)
1965 Dec 24    - - - - VEI (Explosivity Index)

1965 Mar 5 - 1965 Mar 15 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode East rift zone (700-915 m)
1965 Mar 5 - 1965 Mar 15 Evidence from Observations: Reported

List of 8 Events for Episode 1 at East rift zone (700-915 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic) weak or small
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
   - - - -    - - - - Deformation (inflation)
   - - - -    - - - - Collapse Event was "Partial collapse at end of eruption"
1965 Mar 5    - - - - VEI (Explosivity Index)

1963 Aug 21 - 1963 Oct 6 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode East rift zone (825-960 m)
1963 Aug 21 - 1963 Aug 23 Evidence from Observations: Reported

List of 3 Events for Episode 1 at East rift zone (825-960 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
1963 Aug 21    - - - - VEI (Explosivity Index)
Episode 2 | Eruption Episode East rift zone (700-840 m)
1963 Oct 5 - 1963 Oct 6 Evidence from Observations: Reported

List of 11 Events for Episode 2 at East rift zone (700-840 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic) Before eruption.
   - - - -    - - - - Seismicity (volcanic)
   - - - -    - - - - Seismicity (tremor) Before eruption.
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Seismicity (tremor) After eruption.
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
   - - - -    - - - - Incandescence Event was "Glow"
   - - - -    - - - - Deformation (undefined)
1963 Oct 5    - - - - VEI (Explosivity Index)

1962 Dec 7 - 1962 Dec 9 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode East rift zone (945-990 m)
1962 Dec 7 - 1962 Dec 9 Evidence from Observations: Reported

List of 9 Events for Episode 1 at East rift zone (945-990 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic) Before eruption.
   - - - -    - - - - Seismicity (volcanic)
   - - - -    - - - - Seismicity (tremor) Before eruption.
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow weak or small
   - - - -    - - - - Lava lake
   - - - -    - - - - Deformation (undefined)
1962 Dec 7    - - - - VEI (Explosivity Index)

1961 Jul 10 - 1961 Sep 24 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Halemaumau
1961 Jul 10 - 1961 Jul 17 Evidence from Observations: Reported

List of 3 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
1961 Jul 10    - - - - VEI (Explosivity Index)
Episode 2 | Eruption Episode East rift zone (395-790 m)
1961 Sep 22 - 1961 Sep 24 Evidence from Observations: Reported

List of 3 Events for Episode 2 at East rift zone (395-790 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
1961 Sep 22    - - - - VEI (Explosivity Index)

1961 Feb 24 - 1961 Mar 25 Confirmed Eruption Max VEI: 1

Episode 1 | Eruption Episode Halemaumau
1961 Feb 24 - 1961 Feb 24 Evidence from Observations: Reported

List of 3 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
1961 Feb 24    - - - - VEI (Explosivity Index)
Episode 2 | Eruption Episode Halemaumau
1961 Mar 3 - 1961 Mar 25 Evidence from Observations: Reported

List of 3 Events for Episode 2 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
1961 Mar 3    - - - - VEI (Explosivity Index)

1959 Nov 14 - 1960 Feb 19 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Kilauea Iki
1959 Nov 14 - 1959 Dec 19 Evidence from Observations: Reported

List of 9 Events for Episode 1 at Kilauea Iki

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic) Before eruption.
   - - - -    - - - - Seismicity (tremor) Before eruption.
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
   - - - -    - - - - Pumice
   - - - -    - - - - Deformation (undefined)
1959 Nov 14    - - - - VEI (Explosivity Index)
Episode 2 | Eruption Episode East Rift Zone (near Kapoho, 30 m)
1960 Jan 13 - 1960 Feb 19 Evidence from Observations: Reported

List of 14 Events for Episode 2 at East Rift Zone (near Kapoho, 30 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor) Before eruption.
   - - - -    - - - - Explosion weak or small
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava flow Entered water.
   - - - -    - - - - Cinder Cone
   - - - -    - - - - Ash
   - - - -    - - - - Bombs weak or small
   - - - -    - - - - Pumice
   - - - -    - - - - Earthquakes (undefined) Before.
   - - - -    - - - - Property Damage
   - - - -    - - - - Evacuations
1960 Jan 13    - - - - VEI (Explosivity Index)

1955 Feb 28 - 1955 May 26 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Lower east rift zone (50-400 m)
1955 Feb 28 - 1955 May 26 Evidence from Observations: Reported

List of 17 Events for Episode 1 at Lower east rift zone (50-400 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic) Before eruption.
   - - - -    - - - - Seismicity (volcanic)
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow Entered water.
   - - - -    - - - - Lava flow
   - - - -    - - - - Ash weak or small
   - - - -    - - - - Lapilli weak or small
   - - - -    - - - - Bombs weak or small
   - - - -    - - - - Pumice
   - - - -    - - - - Flames
   - - - -    - - - - Incandescence Event was "Glow"
   - - - -    - - - - Audible Sounds
   - - - -    - - - - Deformation (undefined)
   - - - -    - - - - Property Damage
   - - - -    - - - - Evacuations
1955 Feb 28    - - - - VEI (Explosivity Index)

1954 May 31 - 1954 Jun 3 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau and Kilauea caldera
1954 May 31 - 1954 Jun 3 Evidence from Observations: Reported

List of 9 Events for Episode 1 at Halemaumau and Kilauea caldera

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic) Before eruption.
   - - - -    - - - - Seismicity (tremor) Before eruption.
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
   - - - -    - - - - Pumice
   - - - -    - - - - Audible Sounds
   - - - -    - - - - Deformation (undefined)
1954 May 31    - - - - VEI (Explosivity Index)

1952 Jun 27 - 1952 Nov 10 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1952 Jun 27 - 1952 Nov 10 Evidence from Observations: Reported

List of 7 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (volcanic) Before eruption.
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
   - - - -    - - - - Pumice
   - - - -    - - - - Deformation (undefined)
1952 Jun 27    - - - - VEI (Explosivity Index)

1934 Sep 6 - 1934 Oct 8 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1934 Sep 6 - 1934 Oct 8 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
1934 Sep 6    - - - - VEI (Explosivity Index)

1931 Dec 23 - 1932 Jan 5 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1931 Dec 23 - 1932 Jan 5 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
1931 Dec 23    - - - - VEI (Explosivity Index)

1930 Nov 19 - 1930 Dec 7 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1930 Nov 19 - 1930 Dec 7 Evidence from Observations: Reported

List of 4 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
1930 Nov 19    - - - - VEI (Explosivity Index)

1929 Jul 25 - 1929 Jul 28 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1929 Jul 25 - 1929 Jul 28 Evidence from Observations: Reported

List of 8 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Deformation (inflation)
   - - - -    - - - - Deformation (deflation)
1929 Jul 25    - - - - VEI (Explosivity Index)

1929 Feb 20 - 1929 Feb 21 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1929 Feb 20 - 1929 Feb 21 Evidence from Observations: Reported

List of 8 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Deformation (inflation)
   - - - -    - - - - Deformation (deflation)
1929 Feb 20    - - - - VEI (Explosivity Index)

[ 1928 Jan 11 - 1928 Jan 11 ] Discredited Eruption

1927 Jul 7 - 1927 Jul 20 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1927 Jul 7 - 1927 Jul 20 Evidence from Observations: Reported

List of 6 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Seismicity (tremor)
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
   - - - -    - - - - Earthquakes (undefined)
1927 Jul 7    - - - - VEI (Explosivity Index)

1924 May 10 - 1924 Jul 29 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Halemaumau
1924 May 10 - 1924 May 27 Evidence from Observations: Reported

List of 7 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Ash
   - - - -    - - - - Blocks
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Collapse Event was "Partial collapse at end of eruption"
1924 May 10    - - - - VEI (Explosivity Index)
1924 May 18    - - - - Fatalities
Episode 2 | Eruption Episode Halemaumau
1924 Jul 19 - 1924 Jul 29 Evidence from Observations: Reported

List of 2 Events for Episode 2 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1924 Jul 19    - - - - VEI (Explosivity Index)

1906 Dec 2 - 1924 Feb Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1906 Dec 2 - 1924 Feb Evidence from Observations: Reported

List of 4 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava lake
   - - - -    - - - - Earthquakes (undefined)
1906 Dec 2    - - - - VEI (Explosivity Index)
Episode 2 | Eruption Episode Kilauea Caldera
1918 Feb 23 - 1918 Mar 9 Evidence from Observations: Reported

List of 2 Events for Episode 2 at Kilauea Caldera

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1918 Feb 23    - - - - VEI (Explosivity Index)
Episode 3 | Eruption Episode Kilauea Caldera
1919 Feb 7 - 1919 Nov 28 Evidence from Observations: Reported

List of 2 Events for Episode 3 at Kilauea Caldera

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1919 Feb 7    - - - - VEI (Explosivity Index)
Episode 4 | Eruption Episode SW rift zone (Mauna Iki, 915 m)
1919 Dec 21 - 1920 Jul 30 Evidence from Observations: Reported

List of 2 Events for Episode 4 at SW rift zone (Mauna Iki, 915 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1919 Dec 21    - - - - VEI (Explosivity Index)
Episode 5 | Eruption Episode Kilauea Caldera
1921 Mar 18 - 1921 Mar 25 Evidence from Observations: Reported

List of 2 Events for Episode 5 at Kilauea Caldera

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1921 Mar 18    - - - - VEI (Explosivity Index)
Episode 6 | Eruption Episode East rift zone, Makaopuhi, Napau
1922 May 28 - 1922 May 30 Evidence from Observations: Reported

List of 3 Events for Episode 6 at East rift zone, Makaopuhi, Napau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
   - - - -    - - - - Earthquakes (undefined)
1922 May 28    - - - - VEI (Explosivity Index)
Episode 7 | Eruption Episode East rift zone (915 m)
1923 Aug 25 - 1923 Aug 25 Evidence from Observations: Reported

List of 2 Events for Episode 7 at East rift zone (915 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1923 Aug 25    - - - - VEI (Explosivity Index)

1905 Feb 22 - 1906 Apr Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1905 Feb 22 - 1906 Apr Evidence from Observations: Reported

List of 3 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava lake
1905 Feb 22    - - - - VEI (Explosivity Index)

1903 Nov 25 - 1904 Jan 10 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1903 Nov 25 - 1904 Jan 10 Evidence from Observations: Reported

List of 3 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava lake
1903 Nov 25    - - - - VEI (Explosivity Index)

1902 Jun 3 - 1903 Mar 5 ± 5 days Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1902 Jun 3 - 1903 Mar 5 ± 5 days Evidence from Observations: Reported

List of 2 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava lake
1902 Jun 3    - - - - VEI (Explosivity Index)

1902 Feb 14 (in or before) - 1902 Feb Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1902 Feb 14 (in or before) - 1902 Feb Evidence from Observations: Reported

List of 2 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1902 Feb 14
(in or before)
   - - - - VEI (Explosivity Index)

1897 Jun 24 - 1897 Jun 27 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1897 Jun 24 - 1897 Jun 27 Evidence from Observations: Reported

List of 2 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow Uncertain
1897 Jun 24    - - - - VEI (Explosivity Index)

1896 Jul 11 - 1896 Sep 25 ± 5 days Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1896 Jul 11 - 1896 Sep 25 ± 5 days Evidence from Observations: Reported

List of 2 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava lake
1896 Jul 11    - - - - VEI (Explosivity Index)

1896 Jan 3 - 1896 Jan 28 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Halemaumau
1896 Jan 3 - 1896 Jan 28 Evidence from Observations: Reported

List of 2 Events for Episode 1 at Halemaumau

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava lake
1896 Jan 3    - - - - VEI (Explosivity Index)

1823 Feb - 1894 Dec 6 Confirmed Eruption Max VEI: 1 (?)

Multiple episodes of activity from different locations during February 1823 to December 1894. Lava lake activity at Halemaumau was essentially continuous from at least August 1823 to December 1894.

Episode 1 | Eruption Episode Southwest Rift Zone (Great Crack, 75-580 m elevation)
1823 Feb - 1823 Jul Evidence from Observations: Reported
 Lava flows issued from the entire 9 km length of the Great Crack on the Southwest Rift Zone. The Keiwa flow reached the sea from Kapaoo Point to Waiapele Bay. Macdonald (1972) indicated that the flow advanced so rapidly on a coastal village that a few older persons and children were killed. Minor phreatic explosions at the end of the eruption ejected large blocks. Stearns (1926) does not mention fatalities, but quotes the report of Ellis (1825) that the sudden inundation burnt one canoe and carried others out to sea.

List of 7 Events for Episode 1 at Southwest Rift Zone (Great Crack, 75-580 m elevation)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava flow Entered water.
   - - - -    - - - - Blocks
   - - - -    - - - - Property Damage
1823 Feb    - - - - Fatalities
1823 Feb    - - - - VEI (Explosivity Index) 0
Episode 2 | Eruption Episode Halemaumau Caldera
1823 Aug (in or before) - 1894 Dec 6 Evidence from Observations: Reported
 Lava lake activity at Halemaumau was essentially continuous from at least August 1823 to December 1894 (Wright et al., 1992). The date of cessation of 1849 activity is not known, but CAVW does not list activity in 1850; Wood (1917) notes that the depth of the lava lake presumably had not changed in 1850, and smoke and steam had increased greatly in December of that year. Some of the more pronounced lava overflows into Kīlauea Caldera and/or caldera fissure eruptions (1851, 1866 ?, 1879, 1882-85, 1888-89, 1892-94) are listed separately by some compilers.

List of 14 Events for Episode 2 at Halemaumau Caldera

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava lake
   - - - -    - - - - Earthquakes (undefined)
   - - - -    - - - - Collapse Event was "Partial collapse at end of eruption"
1823 Aug
(in or before)
   - - - - VEI (Explosivity Index)
1851 Jan    - - - - VEI (Explosivity Index)
1866
(?)
   - - - - VEI (Explosivity Index)
1879 Jul 14    - - - - VEI (Explosivity Index)
1882 Sep    - - - - VEI (Explosivity Index)
1885 Mar    - - - - VEI (Explosivity Index)
1888 Aug    - - - - VEI (Explosivity Index)
1892    - - - - VEI (Explosivity Index)
1894 Mar 21    - - - - VEI (Explosivity Index)
1894 Jul 7    - - - - VEI (Explosivity Index)
Episode 3 | Eruption Episode East rim of Kilauea Caldera (Byron Ledge), Kilauea Iki
1832 Jan 9 - 1832 Jan 10 Evidence from Observations: Reported
 Following fieldwork and a comprehensive review of contemporaneous reports (Dibble and Green, 1833; Green, 1832; Goodrich, 1834), Orr et al. (2021) described the Byron Ledge eruption as follows: "...the 1832 fissure and associated cracks extended up the northeastern caldera wall, across Byron Ledge, and into Kīlauea Iki Crater, passing near the location of the hut where Lord Byron's party slept and burying the area in lava." Lava flows went into both Kīlauea Caldera and Kīlauea Iki crater. Though many compilers report this activity as 14 January, Dibble and Green (1833) clearly report seeing intense glow and earthquakes on 9-10 January, and visiting the site a few days later (Orr et al., 2021).

List of 4 Events for Episode 3 at East rim of Kilauea Caldera (Byron Ledge), Kilauea Iki

Start Date End Date Event Type Event Remarks
1832 Jan 9    - - - - Fissure
1832 Jan 9 1832 Jan 10 Lava flow
1832 Jan 9 1832 Jan 10 VEI (Explosivity Index) VEI 0
1832 Jan 10    - - - - Earthquakes (undefined)
Episode 4 | Eruption Episode East Rift Zone (230-950 m elevation)
1840 May 30 - 1840 Jun 25 Evidence from Observations: Reported
 Eruptions from a 7.5-km-long fissure on the Lower East Rift Zone produced extensive lava flows that reached the north coast.

List of 6 Events for Episode 4 at East Rift Zone (230-950 m elevation)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava flow Entered water.
   - - - -    - - - - Lava lake
   - - - -    - - - - Collapse Event was "Partial collapse at end of eruption"
   - - - -    - - - - Property Damage
1840 May 30    - - - - VEI (Explosivity Index)
Episode 5 | Eruption Episode Southwest Rift Zone (775 m elevation)
1868 Apr 2 (?) - Unknown Evidence from Observations: Reported
 Explosive activity and lava flows were reported from the Southwest Rift Zone and summit area following a moment magnitude 7.9 earthquake on 2 April 1868.

List of 6 Events for Episode 5 at Southwest Rift Zone (775 m elevation)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Scoria
   - - - -    - - - - Pumice
1868 Apr 2    - - - - Earthquakes (undefined) Moment magnitude 7.9.
1868 Apr 2
(?)
   - - - - VEI (Explosivity Index)
Episode 6 | Eruption Episode East rim of Kilauea Caldera (Poliokeawe scarp), Kilauea Iki
1877 May 4 - 1877 May 4 Evidence from Observations: Reported
 Following fieldwork and a comprehensive review of contemporaneous and later reports or maps, and petrological analysis, Orr et al. (2021) considered 1877 the most likely year for the eruption of the Poliokeawe lava, rather than 1832 or 1868.
Episode 7 | Eruption Episode East rift zone (-20? m)
1884 Jan 22 - 1884 Jan 22 Evidence from Observations: Reported

List of 2 Events for Episode 7 at East rift zone (-20? m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow Uncertain
1884 Jan 22    - - - - VEI (Explosivity Index)

1820 (?) Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Kilauea Caldera
1820 (?) - Unknown Evidence from Observations: Reported

List of 6 Events for Episode 1 at Kilauea Caldera

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Pumice
1820
(?)
   - - - - VEI (Explosivity Index)

1790 Nov (?) Confirmed Eruption Max VEI: 4

Episode 1 | Eruption Episode Kilauea Caldera (Keanakakoi ash)
1790 Nov (?) - Unknown Evidence from Observations: Reported

List of 10 Events for Episode 1 at Kilauea Caldera (Keanakakoi ash)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Blocks
   - - - -    - - - - Pumice
1790 Nov    - - - - Fatalities
1790 Nov    - - - - Fatalities
1790 Nov
(?)
   - - - - VEI (Explosivity Index)

1790 (?) Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Lower east rift zone (230-375 m)
1790 (?) - Unknown Evidence from Observations: Reported

List of 3 Events for Episode 1 at Lower east rift zone (230-375 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava flow Entered water.
1790
(?)
   - - - - VEI (Explosivity Index)

1750 (?) Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode East rift zone (Heiheiahulu, 520 m)
1750 (?) - Unknown Evidence from Observations: Reported

List of 3 Events for Episode 1 at East rift zone (Heiheiahulu, 520 m)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava flow Entered water.
1750
(?)
   - - - - VEI (Explosivity Index)

1700 ± 25 years Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Upper east rift zone (Kokoolau)
1700 ± 25 years - Unknown Evidence from Correlation: Magnetism

List of 2 Events for Episode 1 at Upper east rift zone (Kokoolau)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1700 ± 25 years    - - - - VEI (Explosivity Index)

1650 ± 50 years Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Kilauea summit (Observatory vent)
1650 ± 50 years - Unknown Evidence from Correlation: Tephrochronology

List of 2 Events for Episode 1 at Kilauea summit (Observatory vent)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1650 ± 50 years    - - - - VEI (Explosivity Index)

1610 ± 50 years Confirmed Eruption Max VEI: 1 (?)

Episode 1 | Eruption Episode Lower east rift zone (Puu Honuaula)
1610 ± 50 years - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 4 Events for Episode 1 at Lower east rift zone (Puu Honuaula)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Cinder Cone
1610 ± 50 years    - - - - VEI (Explosivity Index)

1510 ± 50 years Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Lower east rift zone (near Kehena)
1510 ± 50 years - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 3 Events for Episode 1 at Lower east rift zone (near Kehena)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava flow Entered water.
1510 ± 50 years    - - - - VEI (Explosivity Index)

1500 (?) Confirmed Eruption Max VEI: 1 (?)

Episode 1 | Eruption Episode
1500 (?) - Unknown Evidence from Isotopic: 14C (calibrated)

List of 3 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Tephra
1500
(?)
   - - - - VEI (Explosivity Index)

1490 ± 16 years Confirmed Eruption Max VEI: 1 (?)

Episode 1 | Eruption Episode Kilauea caldera
1490 ± 16 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 3 Events for Episode 1 at Kilauea caldera

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Caldera
1490 ± 16 years    - - - - VEI (Explosivity Index)

1460 ± 50 years Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Lower east rift zone (near Puu Kaliu)
1460 ± 50 years - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 2 Events for Episode 1 at Lower east rift zone (near Puu Kaliu)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1460 ± 50 years    - - - - VEI (Explosivity Index)

1410 (?) - 1470 (?) Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Kilauea summit (Aila'au shield)
1410 (?) - 1470 (?) Evidence from Isotopic: 14C (calibrated)

List of 3 Events for Episode 1 at Kilauea summit (Aila'au shield)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava flow Entered water.
1410
(?)
   - - - - VEI (Explosivity Index)

1340 ± 40 years Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Upper east rift zone (Kane Nui o Hamo)
1340 ± 40 years - Unknown Evidence from Correlation: Anthropology

List of 3 Events for Episode 1 at Upper east rift zone (Kane Nui o Hamo)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava flow Entered water.
1340 ± 40 years    - - - - VEI (Explosivity Index)

1140 ± 75 years Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Old Kalue flows
1140 ± 75 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 2 Events for Episode 1 at Old Kalue flows

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1140 ± 75 years    - - - - VEI (Explosivity Index)

1050 ± 75 years Confirmed Eruption Max VEI: 1 (?)

Episode 1 | Eruption Episode Lower east rift zone (NE of Iilewa)
1050 ± 75 years - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 4 Events for Episode 1 at Lower east rift zone (NE of Iilewa)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Cinder Cone
1050 ± 75 years    - - - - VEI (Explosivity Index)

0900 ± 50 years Confirmed Eruption  

Episode 1 | Eruption Episode Upper Kulanaokuaiki tephra
0900 ± 50 years - Unknown Evidence from Correlation: Tephrochronology

List of 7 Events for Episode 1 at Upper Kulanaokuaiki tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Bombs
   - - - -    - - - - Blocks
   - - - -    - - - - Scoria
   - - - -    - - - - Pumice

0850 ± 150 years Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Kipuka Hornet flows
0850 ± 150 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 2 Events for Episode 1 at Kipuka Hornet flows

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
0850 ± 150 years    - - - - VEI (Explosivity Index)

0680 ± 75 years Confirmed Eruption Max VEI: 1 (?)

Episode 1 | Eruption Episode East (near Kaipu) and SW rift zones
0680 ± 75 years - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 4 Events for Episode 1 at East (near Kaipu) and SW rift zones

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Cinder Cone
0680 ± 75 years    - - - - VEI (Explosivity Index)

0540 ± 200 years Confirmed Eruption  

Episode 1 | Eruption Episode Kulanaokuaiki 2 tephra
0540 ± 200 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 6 Events for Episode 1 at Kulanaokuaiki 2 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava fountains
   - - - -    - - - - Lava flow
   - - - -    - - - - Ash
   - - - -    - - - - Blocks
   - - - -    - - - - Pumice

0450 (in or before) Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Lower east rift zone
0450 (in or before) - Unknown Evidence from Correlation: Magnetism

List of 2 Events for Episode 1 at Lower east rift zone

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
0450
(in or before)
   - - - - VEI (Explosivity Index)

0420 ± 20 years Confirmed Eruption  

Episode 1 | Eruption Episode Kulanaokuaiki 1 tephra
0420 ± 20 years - Unknown Evidence from Correlation: Tephrochronology

List of 4 Events for Episode 1 at Kulanaokuaiki 1 tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava fountains
   - - - -    - - - - Ash
   - - - -    - - - - Scoria

0150 ± 300 years Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Kilauea summit (Powers Caldera)
0150 ± 300 years - Unknown Evidence from Correlation: Magnetism

List of 2 Events for Episode 1 at Kilauea summit (Powers Caldera)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
0150 ± 300 years    - - - - VEI (Explosivity Index)

0050 BCE ± 150 years Confirmed Eruption  

Episode 1 | Eruption Episode Pre-Kulanaokuaiki tephra
0050 BCE ± 150 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 3 Events for Episode 1 at Pre-Kulanaokuaiki tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Scoria

0200 BCE ± 150 years Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Summit, East and SW rift zones
0200 BCE ± 150 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 2 Events for Episode 1 at Summit, East and SW rift zones

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
0200 BCE ± 150 years    - - - - VEI (Explosivity Index)

0270 BCE ± 75 years Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Kipuka Nene flows
0270 BCE ± 75 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 2 Events for Episode 1 at Kipuka Nene flows

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
0270 BCE ± 75 years    - - - - VEI (Explosivity Index)

0410 BCE ± 100 years Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode East rift zone
0410 BCE ± 100 years - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 3 Events for Episode 1 at East rift zone

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
   - - - -    - - - - Lava flow Entered water.
0410 BCE ± 100 years    - - - - VEI (Explosivity Index)

0800 BCE (?) Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode
0800 BCE (?) - Unknown Evidence from Isotopic: 14C (calibrated)

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
0800 BCE
(?)
   - - - - VEI (Explosivity Index)

1550 BCE (?) Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode SW rift zone
1550 BCE (?) - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 2 Events for Episode 1 at SW rift zone

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1550 BCE
(?)
   - - - - VEI (Explosivity Index)

1650 BCE (?) Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode SW rift zone
1650 BCE (?) - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 2 Events for Episode 1 at SW rift zone

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
1650 BCE
(?)
   - - - - VEI (Explosivity Index)

2080 BCE (?) Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode
2080 BCE (?) - Unknown Evidence from Isotopic: 14C (calibrated)

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
2080 BCE
(?)
   - - - - VEI (Explosivity Index)

2200 BCE ± 500 years Confirmed Eruption  

Episode 1 | Eruption Episode
2200 BCE ± 500 years - Unknown Evidence from Correlation: Tephrochronology

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash

2850 BCE (?) Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode SW rift zone
2850 BCE (?) - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 2 Events for Episode 1 at SW rift zone

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
2850 BCE
(?)
   - - - - VEI (Explosivity Index)

3300 BCE (?) Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode
3300 BCE (?) - Unknown Evidence from Isotopic: 14C (calibrated)

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
3300 BCE
(?)
   - - - - VEI (Explosivity Index)

4650 BCE (?) Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode SW rift zone
4650 BCE (?) - Unknown Evidence from Isotopic: 14C (uncalibrated)

List of 2 Events for Episode 1 at SW rift zone

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow
4650 BCE
(?)
   - - - - VEI (Explosivity Index)
Deformation History

There is data available for 7 deformation periods. Expand each entry for additional details.


Deformation during 2011 Mar 05 - 2011 Mar 09 [Variable (uplift / subsidence); Observed by InSAR]

Start Date: 2011 Mar 05 Stop Date: 2011 Mar 09 Direction: Variable (uplift / subsidence) Method: InSAR
Magnitude: 20.000 cm Spatial Extent: Unknown Latitude: Unknown Longitude: Unknown

Remarks: InSAR and multiple aperture interferometry were used to create 3-D displacement maps for the March 5-9, 2011 Kamoamoa fissure eruption.

Figure (see Caption)

3-D Surface displacement field retrieved by combining stacked LOS and along-track measurements from from ascending and descending data. Arrows indicate the horizontal displacements, and the base map colour represents the vertical displacements.

From: Jo et al. 2014.


Reference List: Jo et al. 2014.

Full References:

Jo, M. J., Jung, H. S., Won, J. S., Poland, M. P., & Miklius, A., 2014. Measurement of three-dimensional surface deformation of the March 2011 Kamoamoa Fissure eruption, Kilauea volcano, Hawai'i. In: 2014 IEEE Geoscience and Remote Sensing Symposium (pp. 437-440). IEEE.

Deformation during 2007 Jul 20 - 2008 Mar 17 [Subsidence; Observed by InSAR]

Start Date: 2007 Jul 20 Stop Date: 2008 Mar 17 Direction: Subsidence Method: InSAR
Magnitude: 25.000 cm Spatial Extent: Unknown Latitude: Unknown Longitude: Unknown

Remarks: Subsidence followed the intrusion and eruption in the east rift zone.

Figure (see Caption)

(a?l) Vertical displacement maps for the 12 defined time periods between January 2000 and March 2008 (Table 1) showing the shifts in the center of deformation during this time. Arrows represent the horizontal GPS velocity vectors for the stations labeled in Figure 1. The black dots shown in Figures 6e?6h are the earthquake locations during swarm activity described in the text. The color scale for all periods is plotted with the same range (10 to +10 cm). The scale for the arrows showing horizontal GPS velocities varies (between 5 cm/yr and 20 cm/yr).

From: Baker et al. 2012.


Reference List: Baker et al. 2012; Casu et al. 2008.

Full References:

Baker S, Amelung F, 2012. Top-down inflation and deflation at the summit of Kilauea Volcano, Hawai`i observed with InSAR. J. Geophys. Res., 117(B12), B12406. https://doi.org/10.1029/2011JB009123

Casu, F., Solaro, G., Tizzani, P., Poland, M., Miklius, A., Sansosti, E., & Lanari, R., 2008. Surface deformation analysis of the Mauna Loa and Kilauea volcanoes, Hawai`i, based on InSAR displacement time series. In 2008 Second Workshop on Use of Remote Sensing Techniques for Monitoring Volcanoes and Seismogenic Areas (pp. 1-4). IEEE.

Deformation during 2007 Jun 27 - 2007 Jul 21 [Uplift; Observed by InSAR]

Start Date: 2007 Jun 27 Stop Date: 2007 Jul 21 Direction: Uplift Method: InSAR
Magnitude: 6.000 cm Spatial Extent: Unknown Latitude: Unknown Longitude: Unknown

Remarks: inflation of 6 cm in a small concentrated area to the northeast of Halemaumau

Figure (see Caption)

(a?l) Vertical displacement maps for the 12 defined time periods between January 2000 and March 2008 (Table 1) showing the shifts in the center of deformation during this time. Arrows represent the horizontal GPS velocity vectors for the stations labeled in Figure 1. The black dots shown in Figures 6e?6h are the earthquake locations during swarm activity described in the text. The color scale for all periods is plotted with the same range (10 to +10 cm). The scale for the arrows showing horizontal GPS velocities varies (between 5 cm/yr and 20 cm/yr).

From: Baker et al. 2012.


Reference List: Baker et al. 2012; Casu et al. 2008.

Full References:

Baker S, Amelung F, 2012. Top-down inflation and deflation at the summit of Kilauea Volcano, Hawai`i observed with InSAR. J. Geophys. Res., 117(B12), B12406. https://doi.org/10.1029/2011JB009123

Casu, F., Solaro, G., Tizzani, P., Poland, M., Miklius, A., Sansosti, E., & Lanari, R., 2008. Surface deformation analysis of the Mauna Loa and Kilauea volcanoes, Hawai`i, based on InSAR displacement time series. In 2008 Second Workshop on Use of Remote Sensing Techniques for Monitoring Volcanoes and Seismogenic Areas (pp. 1-4). IEEE.

Deformation during 2007 Jun 03 - 2007 Jun 27 [Variable (uplift / subsidence); Observed by InSAR]

Start Date: 2007 Jun 03 Stop Date: 2007 Jun 27 Direction: Variable (uplift / subsidence) Method: InSAR
Magnitude: 30.000 cm Spatial Extent: Unknown Latitude: Unknown Longitude: Unknown

Remarks: The 17 June 2007 (Father''s Day) intrusion and eruption in the upper east rift zone created large amounts of ground displacement

Figure (see Caption)

(a?l) Vertical displacement maps for the 12 defined time periods between January 2000 and March 2008 (Table 1) showing the shifts in the center of deformation during this time. Arrows represent the horizontal GPS velocity vectors for the stations labeled in Figure 1. The black dots shown in Figures 6e?6h are the earthquake locations during swarm activity described in the text. The color scale for all periods is plotted with the same range (10 to +10 cm). The scale for the arrows showing horizontal GPS velocities varies (between 5 cm/yr and 20 cm/yr).

From: Baker et al. 2012.


Reference List: Baker et al. 2012; Sandwell et al. 2008; Casu et al. 2008.

Full References:

Baker S, Amelung F, 2012. Top-down inflation and deflation at the summit of Kilauea Volcano, Hawai`i observed with InSAR. J. Geophys. Res., 117(B12), B12406. https://doi.org/10.1029/2011JB009123

Casu, F., Solaro, G., Tizzani, P., Poland, M., Miklius, A., Sansosti, E., & Lanari, R., 2008. Surface deformation analysis of the Mauna Loa and Kilauea volcanoes, Hawai`i, based on InSAR displacement time series. In 2008 Second Workshop on Use of Remote Sensing Techniques for Monitoring Volcanoes and Seismogenic Areas (pp. 1-4). IEEE.

Sandwell, D. T., Myer, D., Mellors, R., Shimada, M., Brooks, B., & Foster, J., 2008. Accuracy and resolution of ALOS interferometry: Vector deformation maps of the Father's Day intrusion at Kilauea. IEEE Transactions on Geoscience and Remote Sensing, 46(11), 3524-3534.

Deformation during 2003 Sep 28 - 2007 Jun 03 [Uplift; Observed by InSAR]

Start Date: 2003 Sep 28 Stop Date: 2007 Jun 03 Direction: Uplift Method: InSAR
Magnitude: 43.000 cm Spatial Extent: Unknown Latitude: Unknown Longitude: Unknown

Remarks: A summit inflation episode between 2003 and 2007 led up to the 2007 intrusion and eruption. The location of the inflation shifts periodically.

Figure (see Caption)

(a?l) Vertical displacement maps for the 12 defined time periods between January 2000 and March 2008 (Table 1) showing the shifts in the center of deformation during this time. Arrows represent the horizontal GPS velocity vectors for the stations labeled in Figure 1. The black dots shown in Figures 6e?6h are the earthquake locations during swarm activity described in the text. The color scale for all periods is plotted with the same range (10 to +10 cm). The scale for the arrows showing horizontal GPS velocities varies (between 5 cm/yr and 20 cm/yr).

From: Baker et al. 2012.


Reference List: Baker et al. 2012; Myer et al. 2008; Casu et al. 2008.

Full References:

Baker S, Amelung F, 2012. Top-down inflation and deflation at the summit of Kilauea Volcano, Hawai`i observed with InSAR. J. Geophys. Res., 117(B12), B12406. https://doi.org/10.1029/2011JB009123

Casu, F., Solaro, G., Tizzani, P., Poland, M., Miklius, A., Sansosti, E., & Lanari, R., 2008. Surface deformation analysis of the Mauna Loa and Kilauea volcanoes, Hawai`i, based on InSAR displacement time series. In 2008 Second Workshop on Use of Remote Sensing Techniques for Monitoring Volcanoes and Seismogenic Areas (pp. 1-4). IEEE.

Myer, D., D. Sandwell, B. Brooks, J. Foster, and M. Shimada, 2008. Inflation along Kilauea's Southwest Rift Zone in 2006. J. Volcanol. Geotherm. Res., 177: 418-424. https://doi.org/10.1016/j.jvolgeores.2008.06.006

Deformation during 2000 Jan 22 - 2003 Sep 28 [Subsidence; Observed by InSAR]

Start Date: 2000 Jan 22 Stop Date: 2003 Sep 28 Direction: Subsidence Method: InSAR
Magnitude: 23.000 cm Spatial Extent: Unknown Latitude: Unknown Longitude: Unknown

Remarks: Secular deformation

Figure (see Caption)

(a?l) Vertical displacement maps for the 12 defined time periods between January 2000 and March 2008 (Table 1) showing the shifts in the center of deformation during this time. Arrows represent the horizontal GPS velocity vectors for the stations labeled in Figure 1. The black dots shown in Figures 6e?6h are the earthquake locations during swarm activity described in the text. The color scale for all periods is plotted with the same range (10 to +10 cm). The scale for the arrows showing horizontal GPS velocities varies (between 5 cm/yr and 20 cm/yr).

From: Baker et al. 2012.


Reference List: Baker et al. 2012.

Full References:

Baker S, Amelung F, 2012. Top-down inflation and deflation at the summit of Kilauea Volcano, Hawai`i observed with InSAR. J. Geophys. Res., 117(B12), B12406. https://doi.org/10.1029/2011JB009123

Deformation during 1999 Sep 12 - 1999 Sep 12 [Variable (uplift / subsidence); Observed by GPS, InSAR, leveling]

Start Date: 1999 Sep 12 Stop Date: 1999 Sep 12 Direction: Variable (uplift / subsidence) Method: GPS, InSAR, leveling
Magnitude: Unknown Spatial Extent: Unknown Latitude: Unknown Longitude: Unknown

Remarks: Deformation is associated with an earthquake swarm on 12 Sep 1999 in the Upper East Rift Zone and is modeled by a dike intrusion.

Figure (see Caption)

INSAR data. (a) Observed unwrapped range change, (b) trend from Owen et al. [2000b], (c) detrended range change, (d) downsized and downsampled data set, (e) model prediction (phase ramp included), and (f) residual.

From: Cervelli et al. 2002.


Reference List: Cervelli et al. 2002.

Full References:

Cervelli, P. F., P. Segall, F. Amelung, H. Garbeil, C. Meertens, S. Owen, A. Miklius, and M. Lisowski, 2002. The 12 September 1999 Upper East Rift Zone dike intrusion at Kilauea Volcano, Hawaii. J. Geophys. Res., 107(B7): 2150. https://doi.org/10.1029/2001JB000602

Emission History

There is data available for 35 emission periods. Expand each entry for additional details.


Emissions during 1986 May 07 - 1986 May 07 [36 kt SO2 at 5 km altitude]

Start Date: 1986 May 07 Stop Date: 1986 May 07 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 36 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19860507 5.2 36.200

Emissions during 1986 Mar 22 - 1986 Mar 22 [5 kt SO2 at 5 km altitude]

Start Date: 1986 Mar 22 Stop Date: 1986 Mar 22 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 5 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19860322 5.2 5.400

Emissions during 1986 Jun 26 - 1986 Jun 26 [37 kt SO2 at 5 km altitude]

Start Date: 1986 Jun 26 Stop Date: 1986 Jun 26 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 37 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19860626 5.2 37.200

Emissions during 1986 Jun 02 - 1986 Jun 02 [48 kt SO2 at 5 km altitude]

Start Date: 1986 Jun 02 Stop Date: 1986 Jun 02 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 48 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19860602 5.2 48.000

Emissions during 1986 Jan 27 - 1986 Jan 27 [25 kt SO2 at 5 km altitude]

Start Date: 1986 Jan 27 Stop Date: 1986 Jan 27 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 25 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19860127 5.2 25.000

Emissions during 1986 Jan 01 - 1986 Jan 01 [8 kt SO2 at 5 km altitude]

Start Date: 1986 Jan 01 Stop Date: 1986 Jan 01 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 8 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19860101 5.2 7.900

Emissions during 1986 Feb 22 - 1986 Feb 22 [37 kt SO2 at 5 km altitude]

Start Date: 1986 Feb 22 Stop Date: 1986 Feb 22 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 37 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19860222 5.2 37.400

Emissions during 1986 Apr 13 - 1986 Apr 13 [24 kt SO2 at 5 km altitude]

Start Date: 1986 Apr 13 Stop Date: 1986 Apr 13 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 24 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19860413 5.2 24.200

Emissions during 1985 Sep 24 - 1985 Sep 24 [35 kt SO2 at 5 km altitude]

Start Date: 1985 Sep 24 Stop Date: 1985 Sep 24 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 35 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19850924 5.2 35.300

Emissions during 1985 Sep 02 - 1985 Sep 02 [58 kt SO2 at 5 km altitude]

Start Date: 1985 Sep 02 Stop Date: 1985 Sep 02 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 58 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19850902 5.2 57.700

Emissions during 1985 Oct 21 - 1985 Oct 21 [24 kt SO2 at 5 km altitude]

Start Date: 1985 Oct 21 Stop Date: 1985 Oct 21 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 24 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19851021 5.2 23.900

Emissions during 1985 Nov 13 - 1985 Nov 13 [11 kt SO2 at 5 km altitude]

Start Date: 1985 Nov 13 Stop Date: 1985 Nov 13 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 11 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19851113 5.2 11.000

Emissions during 1985 Jun 12 - 1985 Jun 12 [31 kt SO2 at 5 km altitude]

Start Date: 1985 Jun 12 Stop Date: 1985 Jun 12 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 31 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19850612 5.2 30.800

Emissions during 1985 Jul 26 - 1985 Jul 26 [18 kt SO2 at 5 km altitude]

Start Date: 1985 Jul 26 Stop Date: 1985 Jul 26 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 18 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19850726 5.2 17.900

Emissions during 1985 Jul 06 - 1985 Jul 06 [33 kt SO2 at 5 km altitude]

Start Date: 1985 Jul 06 Stop Date: 1985 Jul 06 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 33 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19850706 5.2 33.100

Emissions during 1985 Jan 03 - 1985 Jan 03 [48 kt SO2 at 5 km altitude]

Start Date: 1985 Jan 03 Stop Date: 1985 Jan 03 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 48 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19850103 5.2 47.900

Emissions during 1985 Feb 04 - 1985 Feb 04 [49 kt SO2 at 5 km altitude]

Start Date: 1985 Feb 04 Stop Date: 1985 Feb 04 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 49 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19850204 5.2 48.500

Emissions during 1985 Apr 21 - 1985 Apr 21 [73 kt SO2 at 5 km altitude]

Start Date: 1985 Apr 21 Stop Date: 1985 Apr 21 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 73 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19850421 5.2 72.700

Emissions during 1984 Sep 19 - 1984 Sep 19 [38 kt SO2 at 5 km altitude]

Start Date: 1984 Sep 19 Stop Date: 1984 Sep 19 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 38 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19840919 5.2 37.900

Emissions during 1984 Nov 19 - 1984 Dec 03 [124 kt SO2 at 5 km altitude]

Start Date: 1984 Nov 19 Stop Date: 1984 Dec 03 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 124 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19841203 5.2 78.100
19841119 5.2 46.000

Emissions during 1984 Nov 02 - 1984 Nov 02 [15 kt SO2 at 5 km altitude]

Start Date: 1984 Nov 02 Stop Date: 1984 Nov 02 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 15 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19841102 5.2 15.200

Emissions during 1984 Mar 04 - 1984 Mar 04 [14 kt SO2 at 5 km altitude]

Start Date: 1984 Mar 04 Stop Date: 1984 Mar 04 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 14 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19840304 5.2 13.500

Emissions during 1984 Jun 30 - 1984 Jul 08 [81 kt SO2 at 5 km altitude]

Start Date: 1984 Jun 30 Stop Date: 1984 Jul 08 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 81 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19840708 5.2 31.900
19840630 5.2 48.900

Emissions during 1984 Jun 07 - 1984 Jun 07 [30 kt SO2 at 5 km altitude]

Start Date: 1984 Jun 07 Stop Date: 1984 Jun 07 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 30 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19840607 5.2 30.200

Emissions during 1984 Jul 28 - 1984 Jul 28 [30 kt SO2 at 5 km altitude]

Start Date: 1984 Jul 28 Stop Date: 1984 Jul 28 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 30 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19840728 5.2 29.800

Emissions during 1984 Jan 30 - 1984 Feb 14 [52 kt SO2 at 5 km altitude]

Start Date: 1984 Jan 30 Stop Date: 1984 Feb 14 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 52 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19840214 5.2 27.400
19840130 5.2 24.400

Emissions during 1984 Aug 19 - 1984 Aug 19 [46 kt SO2 at 5 km altitude]

Start Date: 1984 Aug 19 Stop Date: 1984 Aug 19 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 46 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19840819 5.2 45.900

Emissions during 1984 Apr 18 - 1984 Apr 18 [30 kt SO2 at 5 km altitude]

Start Date: 1984 Apr 18 Stop Date: 1984 Apr 18 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 30 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19840418 5.2 29.800

Emissions during 1983 Sep 06 - 1983 Sep 15 [13 kt SO2 at 5 km altitude]

Start Date: 1983 Sep 06 Stop Date: 1983 Sep 15 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 13 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19830915 5.2 9.800
19830906 5.2 2.800

Emissions during 1983 Oct 05 - 1983 Oct 05 [12 kt SO2 at 5 km altitude]

Start Date: 1983 Oct 05 Stop Date: 1983 Oct 05 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 12 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19831005 5.2 11.600

Emissions during 1983 Nov 29 - 1983 Nov 29 [15 kt SO2 at 5 km altitude]

Start Date: 1983 Nov 29 Stop Date: 1983 Nov 29 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 15 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19831129 5.2 14.500

Emissions during 1983 Nov 05 - 1983 Nov 05 [32 kt SO2 at 5 km altitude]

Start Date: 1983 Nov 05 Stop Date: 1983 Nov 05 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 32 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19831105 5.2 31.800

Emissions during 1983 Mar 29 - 1983 Mar 29 [1 kt SO2 at 5 km altitude]

Start Date: 1983 Mar 29 Stop Date: 1983 Mar 29 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 1 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19830329 5.2 1.000

Emissions during 1983 Jul 21 - 1983 Jul 21 [11 kt SO2 at 5 km altitude]

Start Date: 1983 Jul 21 Stop Date: 1983 Jul 21 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 11 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19830721 5.2 11.000

Emissions during 1983 Jul 03 - 1983 Jul 03 [6 kt SO2 at 5 km altitude]

Start Date: 1983 Jul 03 Stop Date: 1983 Jul 03 Method: Satellite (Nimbus-7 TOMS)
SO2 Altitude Min: 5 km SO2 Altitude Max: 5 km Total SO2 Mass: 6 kt

Data Details

Date Start Date End Assumed SO2 Altitude SO2 Algorithm SO2 Mass
19830703 5.2 5.500
Photo Gallery

This September 1880 painting shows fountaining from the active lava lake in Halemaumau crater. Lava lake activity within Kīlauea's summit caldera was continuous from at least August 1823 until December 1894. With short periods of interruption, Halemaumau's lava lake remained active for a century before ceasing after an explosive eruption in 1924. This spectacular long-term activity, in which the magma conduit remained at the surface, drew visitors from around the world.

From the collection of Maurice and Katia Krafft.
Low lava fountains rise above an active lava lake in Halema‘uma‘u crater on 31 May 1954, near the beginning of a three-day eruption. About a half hour after the start of the eruption lava flows effused from a fissure that opened across the floor of the Kīlauea caldera, ENE of Halema‘uma‘u.

Photo by Jerry Eaton, 1954 (U.S. Geological Survey).
The Halema‘uma‘u lava lake is seen from the east on 31 May 1954. Several areas of vigorous lava fountaining occurred here as well as lower fountaining along nearby fissures. Later in the first day of the three-day-long eruption the fissures extended over the crater wall and to the ENE to produce lava flows on the caldera floor. Thin lava flows exposed in the Halema‘uma‘u pit crater walls appear in the background.

Photo by Jerry Eaton, 1954 (U.S. Geological Survey).
A laze plume (hydrochloric acid, steam, and fine glass particles) rises from a lava flow entering the sea on 28 March 1955. The eruption began on 28 February and formed 24 vents across 15 km on the lower East Rift Zone. Three lava flows reached the sea, and a fourth flow stopped just short of the Puna coast near the eastern tip of the Island of Hawaii. The eruption lasted 88 days, ending on 26 May.

Photo by Jerry Eaton, 1955 (U.S. Geological Survey).
Lava flows from the 1955 eruption low on the East Rift Zone of Kīlauea destroyed 15 houses on the outskirts of Kapoho village. The main part of the village was not impacted, only to be destroyed by another eruption five years later.

Photo by Jerry Eaton. 1955 (U.S. Geological Survey).
Lava fountains along a fissure on the SW side of the Kīlauea Iki crater erupted this lava that flowed down to the crater floor at the beginning of an eruption on 14 November 1959. This view, looking SW from Bryon's Ledge overlook, shows lava ponding on the crater floor. The initial fissure was about 1 km long and produced fountains about 15 m high. Lava from the western part of the fissure dropped 50 m onto a platform before reaching the crater floor; flows on the eastern side descended 90 m directly to the crater floor.

Photo by Jerry Eaton, 1959 (U.S. Geological Survey).
A bulldozer works to create a barrier to lava flows threatening areas below the village of Kapoho, on the lower East Rift Zone of Kīlauea, in January 1960. Lava fountains tower in the background from the eruptive vent, which was less than 1 km from the center of the village. Lava flows eventually engulfed the entire village, but the 5 km of walls that were constructed may have helped prevent the flows from reaching houses and a lighthouse at the coast.

Photo by Hawaii Volcanoes National Park, 1960.
A line of lava fountains rises above a fissure on the lower East Rift Zone of Kīlauea in January 1960. The eruption originated near the village of Kapoho, which was overrun by lava flows. Lava flows traveled to the coast, reaching the ocean along a broad front.

Photo by Hawaii Volcanoes National Park, 1960.
An aerial view from the SE on 11 February 1960 shows steam rising from Kīlauea lava flows that reached the coast. The lava flows extended the shoreline at the NE tip of the island of Hawaii up to nearly 1 km along a 5-km-long front. The entire area of this photo, with the exception of the wedge-shaped lighter-gray area extending to the coast from the Cape Kumukahi lighthouse, was inundated by 1960 lava flows. The eruption ended eight days after this photo was taken.

Photo by Hawaii Volcanoes National Park, 1960.
Lava flows from a fissure that opened on 5 March 1965 extended 13 km from Makaopuhi to beyond Nāpau crater. The lava cascaded into Makaopuhi crater, forming a lava lake more than 100 m deep.

Photo by Tom Wright, 1965 (U.S. Geological Survey).
This January 1968 photo of Halema‘uma‘u crater shows lava fountaining within the partly solidified crust of lava lake, and also overflowing below. This eruption began on 5 November 1967 and lasted until 13 July 1968.

Photo by Richard Fiske, 1968 (Smithsonian Institution).
A brief eruption lasting five days in February 1969 took place along a fissure system between Alae and Nāpau craters on Kīlauea's East Rift Zone. Lava fountains produced flows that cascaded into Makaopuhi and Nāpau craters. Lava flows buried 5 km of the Chain of Craters Road.

Photo by Don Swanson, 1969 (U.S. Geological Survey).
This heart-shaped tree mold was produced during an eruption along the East Rift Zone that began on 7 October 1968. Molten lava solidified around the tree, which eventually burned away, leaving the mold with incandescence from the hot rock below.

Photo by Don Swanson, 1968 (U.S. Geological Survey).
A Hawaiian Volcano Observatory team uses a drilling rig to extract drill core from the cooling lava lake in Kīlauea Iki crater. At the time of this 1968 project, nearly a decade after a lava lake filled Kīlauea Iki during the 1959 eruption, the crust had solidified to a depth of about 30 m. The drill core penetrated to 60 m depth without reaching the bottom of the still partially molten lava lake. This project, the first to use a drill rig to sample a lava lake, allowed study of vertical variations in chemistry, mineralogy, and temperature within a cooling lava lake.

Photo by Jean Tobin, 1968.
A powerful lava fountain towers above Kīlauea Iki on 11 December 1959. Lava fountains reached heights up to 580 m on the 17th, the tallest recorded from any Hawaiian volcano at the time. The temperature at the core of the fountain sometimes reached 1,200°C, another record in Hawaii for the highest temperature of erupting lavas at the time. Ejecta built a conical spatter cone around the vent.

Photo by Jerry Eaton, 1959 (U.S. Geological Survey).
On 14 August 1971 a line of lava fountains erupted across the floor of Kīlauea caldera. The 10-hour eruption was observed by tourists from overlooks along the road around the caldera. The fissure that opened across Halema‘uma‘u crater produced lava flows both on its floor and within the caldera on either side.

Photo by Hawaii Volcanoes National Park, 1971.
Among the many monitoring techniques used by Hawaiian Volcano Observatory staff at Kīlauea volcano is precision leveling. Millimeter-scale changes can be detected with an optical-level instrument by measuring the precise difference in elevation on leveling rods placed above two fixed points. Slight changes in the shape of a volcanic edifice commonly occurs prior to eruptions. Measurements such as these in 1968, with the Puʻu ʻŌʻō scoria cone in the background, are one of several techniques used to help forecast eruptive events.

Photo by Richard Fiske, 1986 (Smithsonian Institution).
Kīlauea Iki crater in the foreground was the site of a major eruption in 1959. The crater is in Kīlauea's East Rift Zone and is seen here from the east with snow-capped Mauna Loa in the background. Gases rise from the Kīlauea caldera to the left.

Photo by Richard Fiske, 1967 (Smithsonian Institution).
A lava lake formed within Halema‘uma‘u crater on 5 November 1967. In the background of this view from the SE can be seen thin, light-colored lava flows exposed in the crater walls, with the Kīlauea caldera wall above it, and the flank of Mauna Loa in the distance. Lava lake activity continued until 13 July 1968.

Photo by U.S. Geological Survey, 1967.
A stream of lava from a vent at Mauna Ulu (above the top of the photo) cascades into Makaopuhi crater during an early stage of the 1969-74 Mauna Ulu eruption. A thick stack of older lava flows that were erupted along Kīlauea's East Rift Zone is exposed in the Makaopuhi crater wall.

Photo by Jim Moore (U.S. Geological Survey).
This 13 January 1987 view from the east shows the principal vents of the current eruption on Kīlauea's East Rift Zone, taken four years after the start of the eruption. The Pu‘u ‘Ō‘ō scoria cone to the left formed during the early stages of the eruption. Kūpaianaha to the lower right contains an actively convecting lava lake in this photo. The linear extension in the center foreground is at the head of a lava tube system, which insulated lava flows that reached the coast.

Photo by J.D. Griggs, 1987 (U.S. Geological Survey).
Laze (a plume of hydrochloric acid, steam, and fine glass particles) rises along the Puna coast where lava flows enter the sea in this 28 December 1987 photo. The flows originated from a fissure along Kīlauea's East Rift Zone from the Pu‘u ‘Ō‘ō scoria cone (upper left) to the Kūpaianaha lava lake (small gas plume in the center of the horizon). Lava flows traveled 10 km to the coast and inundated several subdivisions and villages.

Photo by J.D. Griggs, 1987 (U.S. Geological Survey).
This tall lava fountain erupted from Pu‘u ‘Ō‘ō vent at Kīlauea on 30 June 1984, producing incandescent lava flows. An eruption on the East Rift Zone began on 3 January 1983, and with short interruptions remained active through to September 2018. Eruptions initially occurred in the Pu‘u ‘Ō‘ō area, but activity shifted to various locations on the East Rift Zone, including the Kūpaianaha vent 3 km farther down the rift. An extensive lava flow field formed between the east rift and the coast.

Photo by J.D. Griggs, 1984 (U.S. Geological Survey).
Explosions like this can occur when lava flows enter the ocean. This photo, taken along the Kalapana ocean entry point on 27 November 1989, documents a common occurrence during the East Rift Zone eruption of Kīlauea that began in 1983 and ended in 2018.

Photo by J.D. Griggs, 1989 (U.S. Geological Survey).
Lava fountains along an October 1968 East Rift Zone fissure at Kīlauea produced the lava flow in the foreground. Starting on 7 October a series of fissures extended from the E flank of Kane Nui o Hamo to 3.5 km E of Nāpau Crater. The eruption continued until the 21st, covering much of the March 1965 lava flows and again produced lava cascades into Nāpau Crater.

Photo by U.S. Geological Survey, 1968.
Lava flows from fountains at the Mauna Ulu cone in the background cascade down the Aloi crater walls on 30 December 1969. The 1969-74 Mauna Ulu eruption eventually filled both Aloi crater west of Mauna Ulu, and Alae crater to the east.

Photo by Don Swanson, 1969 (U.S. Geological Survey).
The 3 x 5 km caldera at the summit of Kīlauea is home of the Goddess Pele and has been Hawaii's most active volcano during historical time. Kīlauea is a shield volcano on the east flank of Mauna Loa, visible in the distance. Eruptions originate both from within the summit caldera and from SW and E rift zones that extend to the sea and predominately produce lava flows, with occasional explosive eruptions.

Photo by Richard Fiske, 1967 (Smithsonian Institution).
A lava lake within Halema‘uma‘u produces a gas plume on 23 November 1968, shortly after activity began. This period of lava lake activity continued through to July 1968.

Photo by Richard Fiske, 1967 (Smithsonian Institution).
A cascade of lava flows down the walls of Alae crater on 5 August 1969. During the course of the 1969-1974 Mauna Ulu eruption lava entirely filled both Alae and nearby Aloi craters. Lava flows from this eruption traveled 12 km to the sea.

Photo by Jeffrey Judd, 1969 (U.S. Geological Survey).
A dome fountain reached heights of about 20 m for hours on 11 October 1969. This unusual activity, produced by fountaining from a circular, vertical conduit at relatively constant gas pressures, occurred early during the Mauna Ulu eruption. This East Rift Zone eruption lasted from 1969 until 1974.

Photo by Jeffrey Judd, 1969 (U.S. Geological Survey).
Lava flows are commonly fed through tubes beneath the crusted-over surface of the flow. The ceilings of lava tubes frequently collapse, producing skylights, through which the flowing lava is visible. This 21 October 1970 photo of a lava flow from Mauna Ulu at Hawaii's Kīlauea volcano shows several ledges within the lava tube that mark previous levels of flow. The walls and roofs of lava tubes are efficient thermal insulators that allow the lava to travel long distances without solidifying. Some tubes formed during the Mauna Ulu eruption were 11 km long.

Photo by Jeffrey Judd, 1970 (U.S. Geological Survey).
An incandescent lava flow from Mauna Ulu emerges from a lava tube and descends the Poliokeawe Pali cliff on 1 January 1973. Lava flows traveled 12 km to reach the coast over a 9-km-wide front during the 1969-74 eruption.

Photo by Don Peterson, 1973 (U.S. Geological Survey).
A volcanologist from the Hawaiian Volcano Observatory extracts a sample of fresh lava from an active lava tube during the 1969-74 Mauna Ulu eruption. Asbestos gloves were used for protection against the intense radiant heat. Sampling at various stages of an eruption is used to determine changes in the chemistry and mineralogy of erupted lavas.

Photo by Bob Tilling, 1973 (U.S. Geological Survey).
The Hawaiian Volcano Observatory sits on the rim of Kīlauea caldera. Staff scientists are responsible for monitoring the volcanoes on the island of Hawaii and Maui's active volcano, Haleakala. Volcanologists also conduct an active research and field mapping program to determine the geologic history of individual volcanoes. Halemaumau pit crater, at the top of the photo, was the site of long-term lava lake activity that continued at Kīlauea for a century prior to 1924. Brief, intermittent eruptions at Halemaumau have occurred since then, most recently in 1975.

Copyrighted photo by Katia and Maurice Krafft, 1984.
These footprints in hardened ash are those of Hawaiian warriors and their families who were crossing the Kau Desert, SW of Kīlauea caldera, at the time of a violent explosive eruption in 1790. The eruption produced pyroclastic surges that killed 80-100 people. The rest of the party of 250 warriors and family members survived, leaving these and other footprints in the muddy ash. Explosive eruptions are not unknown at Kīlauea. They have occurred on several occasions when collapse of the summit allowed groundwater access to the magma column.

Copyrighted photo by Katia and Maurice Krafft, 1987.
Two shield volcanoes of radically different scale appear in this photo. Mauna Ulu, a small, 120-m-high shield volcano on the east rift zone of Kīlauea volcano, is dwarfed by massive Mauna Loa in the background, the world's largest active volcano. Both volcanoes were constructed by the repetitive eruption of thin, overlapping lava flows, but over greatly differing time spans. Maunu Ulu was built during a 5-year eruption during 1969-1974, whereas Mauna Loa grew nearly 9 km up from the sea floor over a period of a few hundred thousand years.

Copyrighted photo by Katia and Maurice Krafft, 1979.
The Kupaianaha lava pond was active for many years during the east rift zone eruption of Kīlauea, which began in 1983. This February 1987 aerial view shows the crusted-over surface of the pond, with incandescent lava visible between segments of the crust. Convection of the lava lake produces lateral movement and descent of the solidified crust, which mimic many plate tectonic processes. The smooth slopes surrounding Kupaianaha were formed by overflows of pahoehoe lava.

Copyrighted photo by Katia and Maurice Krafft, 1987.
Many volcanic eruptions originate from fractures that reach the Earth's surface. Eruptive fissures, such as producing this curtain of fire along the east rift zone of Kīlauea volcano in July 1986, often extend radially away from the summit of a volcano. Light-colored lava flows fed by the lava fountains move downslope on both sides of the fissure. At some volcanoes fissures follow the direction of regional faults, and circumferential fissures can open around the rim of a volcanic caldera.

Copyrighted photo by Katia and Maurice Krafft, 1986.
A lava flow drips into the sea, a common sight during the long-term eruption from Kīlauea's east rift zone that began in 1983. This closeup view was taken in May 1987.

Copyrighted photo by Katia and Maurice Krafft, 1987.
Lava flows dripping over low coastal cliffs are reflected in the sea in this May 1987 nighttime photo. Flows from Kīlauea's east rift zone have repeatedly reached the sea over a broad front during an eruption that began in 1983.

Copyrighted photo by Katia and Maurice Krafft, 1987.
A house near Hawaii's Puna coast burns in May 1987, one of many ignited by lava flows from Kīlauea's long-term east rift zone eruption. Lava flows overran the coastal village of Kalapana in 1990 and buried the popular black sand beach at Kaimu. Although some houses were removed before the housing lots were overrun, more than 75 houses were destroyed by lava flows in 1990.

Copyrighted photo by Katia and Maurice Krafft, 1987.
Lava flows from the East Rift Zone eruption that began in 1983 at Hawaii's Kīlauea volcano frequently overran the coastal highway, enveloping traffic signs such as this one. Lava flows can travel fast enough to block roads and evacuation routes, closing off access to communities and trapping residents.

Photo by Lee Siebert, 1987 (Smithsonian Institution).
Two types of lava flows, pahoehoe (left) and `a`a (right), are different textural forms of otherwise identical lava. The different textures relate to different flow dynamics and both can form in the same lava flow. Because of differential weathering rates, the overlying pahoehoe flows look younger than the associated aa flows, and the two flows are easily mistaken for flows of greatly differing age.

Photo by Lee Siebert, 1987 (Smithsonian Institution).
This eruption was observed by Hawaiian Volcano Observatory volcanologist Jack Lockwood on 28 February 1974, near the end of the 5-year-long Mauna Ulu eruption. As the erupting lava solidifies around the vent the feature gets progressively larger.

Photo by Robin Holcomb, 1974 (U.S. Geological Survey).
Pahoehoe lava flows on Kīlauea are fed from low lava fountains in June 1974, near the end of the major 1969-74 Mauna Ulu eruption. This final stage of the eruption ended on 22 July 1974 after producing a lava lake, lava fountains up to 80 m high, and lava flows.

Photo by Robin Holcomb, 1974 (U.S. Geological Survey).
An eruption lasting 5 hours took place in the Kaʻū Desert region SW of Kīlauea caldera on 31 December 1974, producing lava flows that traveled 12 km SW. This was the first eruption on Kīlauea's SW rift zone since the 1920 Mauna Iki eruption.

Photo by Robin Holcomb, 1974 (U.S. Geological Survey).
Lava flows are produced when magma reaches the surface and is erupted non-explosively. Basaltic lava flows, such as this September 1979 flow from the East Rift Zone of Kīlauea volcano, are Earth's most common volcanic product. Basaltic lava flows typically have initial temperatures of 1,000-1,250°C with a range of flow velocities.

Photo by Richard Moore, 1977 (U.S. Geological Survey).
Lava fountains on 30 September 1977 produced lava flows from the Pu`u Kiai vent at Kīlauea. The eruption began along the East Rift Zone near Kalalau Crater on 13 September. The eruption ended on 1 October after producing lava flows that traveled 10 km SE to within 1 km of the coastal town of Kalapana.

Photo by Peter Lipman, 1977 (U.S. Geological Survey).
Fire fountains along fissures near the Pauahi Crater parking lot on the upper East Rift Zone on 16 November 1979. The eruption ended the following day, after producing lava flows across the Chain of Craters Road and moving about 500 m downslope west of the road into Pauahi Crater.

Photo by Bob Decker, 1979 (U.S. Geological Survey).
A 19-hour eruption of Kīlauea began on 30 April 1982, from fissures east of Halema’uma’u crater. This view from the north shows lava spatter feeding a lava flow two hours after the start of the eruption. Spatter ramparts of the 1964 eruption are partly buried by 1982 spatter.

Photo by Jack Lockwood, 1982 (U.S. Geological Survey).
An `a`a lava flow, with a characteristic surface containing abundant angular chunks as it cools, advancing across a smooth-textured pahoehoe lava flow. The hot, incandescent flow interior is visible. The front of this 3 June 1994 flow at Laeapuki, near the Puna coast of Kīlauea volcano, is about 1 m thick.

Photo by Paul Kimberly, 1994 (Smithsonian Institution).
The Laeapuki lava flow on Kīlauea overran the coastal highway in April 1993, barely missing the Laeapuki ruins between the highway and the coast. After this June 1994 photo looking SW along the coast, lava flows overran the ruins. Lava flows from the East Rift Zone eruption that began in 1983 first reached the coast in 1986. By 1995 the flows had created 11 km of new coastline.

Photo by Paul Kimberly, 1994 (Smithsonian Institution).
The black, newly solidified glassy surface of pahoehoe lava flows commonly has a silvery or iridescent color. Pahoehoe lavas form during eruptions that are characterized by the upwelling of hot, low-viscosity magma. This smooth-textured pahoehoe flow at Kīlauea volcano was photographed in August 1994.

Photo by Paul Kimberly, 1994 (Smithsonian Institution).
An aerial view in 1985 looks from Kīlauea caldera in the foreground down the East Rift Zone to the Puʻuʻōʻō vent producing a gas plume in the background. The Hawaiian Volcano Observatory lies at the lower left on the western rim of Kīlauea's 5-km-wide summit caldera with the inner Halema’uma’u crater to the lower right. Lava flows cover the floor of the summit caldera and can be seen extending downslope from multiple vents along the rift zone, including the dark-colored most recent flows erupted beginning in 1983 from the Kupaianaha vent.

Photo by Jim Griggs, 1985 (U.S. Geological Survey).
GVP Map Holdings

The maps shown below have been scanned from the GVP map archives and include the volcano on this page. Clicking on the small images will load the full 300 dpi map. Very small-scale maps (such as world maps) are not included. The maps database originated over 30 years ago, but was only recently updated and connected to our main database. We welcome users to tell us if they see incorrect information or other problems with the maps; please use the Contact GVP link at the bottom of the page to send us email.

Smithsonian Sample Collections Database

The following 2406 samples associated with this volcano can be found in the Smithsonian's NMNH Department of Mineral Sciences collections, and may be availble for research (contact the Rock and Ore Collections Manager). Catalog number links will open a window with more information.

Catalog Number Sample Description Lava Source Collection Date
NMNH 100000 Picrite Basalt -- --
NMNH 100001 Picrite Basalt -- --
NMNH 100002 Basalt MAUNA IKI --
NMNH 100003-00 Thenardite -- --
NMNH 100003-01 Thenardite -- --
NMNH 100003-02 Thenardite -- --
NMNH 100004-1 Volcanic Sublimate HALEMAUMAU --
NMNH 100004-2 Volcanic Sublimate HALEMAUMAU --
NMNH 106808-00 Cristobalite -- --
NMNH 109060 Pumice HALEMAUMAU --
NMNH 109409-1 Picrite Basalt -- --
NMNH 109409-10 Andesine Basalt -- --
NMNH 109409-2 Olivine Basalt SUMMIT --
NMNH 109409-3 Olivine Basalt KILAUEA IKI --
NMNH 109409-4 Volcanic Glass KILAUEA IKI --
NMNH 110046 Basaltic Pumice -- --
NMNH 110046 Basaltic Pumice HALEMAUMAU --
NMNH 110047 Tholeiitic Basalt -- --
NMNH 110048 Tholeiitic Basalt -- --
NMNH 110778 Dunite (?) HALEMAUMAU --
NMNH 111123-1847 Gabbro UWEKAHUNA LACCOLITH --
NMNH 111123-1865 Picritic Basalt -- --
NMNH 111740 Picrite -- --
NMNH 111741 Picrite -- --
NMNH 111742 Picrite -- --
NMNH 111743 Picrite -- --
NMNH 111744 Picrite -- --
NMNH 111745 Picrite -- --
NMNH 111746 Picrite -- --
NMNH 111747 Picrite -- --
NMNH 111748 Picrite -- --
NMNH 111749 Picrite -- --
NMNH 111750 Picrite -- --
NMNH 111751 Picrite -- --
NMNH 111752 Picrite -- --
NMNH 111753 Picrite -- --
NMNH 111754 Picrite -- --
NMNH 111755 Picrite -- --
NMNH 111756 Picrite -- --
NMNH 111757 Picrite -- --
NMNH 111758 Picrite -- --
NMNH 111759 Picrite -- --
NMNH 111760 Picrite -- --
NMNH 111761 Picrite -- --
NMNH 111762 Picrite -- --
NMNH 111763 Picrite -- --
NMNH 111764 Picrite -- --
NMNH 111765 Picrite -- --
NMNH 111766 Picrite -- --
NMNH 111767 Picrite -- --
NMNH 111768 Picrite -- --
NMNH 111769 Picrite -- --
NMNH 111770 Picrite -- --
NMNH 111771 Picrite -- --
NMNH 111772 Picrite -- --
NMNH 111773 Picrite -- --
NMNH 111776 Picrite -- --
NMNH 111791 Basalt SOUTHWEST RIFT --
NMNH 111792 Basalt SOUTHWEST RIFT --
NMNH 111793 Basalt SOUTHWEST RIFT --
NMNH 111794 Basalt EAST RIFT --
NMNH 111795 Basalt EAST RIFT --
NMNH 111796 Basalt EAST RIFT --
NMNH 111835 Basalt -- --
NMNH 112521-41 Olivine Tholeiite -- --
NMNH 112522-00 Sal Ammoniac -- --
NMNH 112553-00 Cristobalite -- --
NMNH 112553-01 Cristobalite -- --
NMNH 112554-00 Iddingsite -- --
NMNH 113095-10 Sulfur -- --
NMNH 113095-19 Unidentified SW RIFT ZONE, KAMAKAIA CONE (MIDDLE) --
NMNH 113095-19 Unidentified SW RIFT ZONE, KAMAKAIA CONE (MIDDLE) --
NMNH 113095-20 Unidentified SW RIFT ZONE, CONE CRATER --
NMNH 113095-20 Unidentified SW RIFT ZONE, CONE CRATER --
NMNH 113095-21 Unidentified SW RIFT ZONE, KAMAKAIA CONE (MIDDLE) --
NMNH 113095-21 Unidentified SW RIFT ZONE, KAMAKAIA CONE (MIDDLE) --
NMNH 113095-22 Unidentified MAKAOPUHI LAVA LAKE --
NMNH 113095-22 Unidentified MAKAOPUHI LAVA LAKE --
NMNH 113095-23 Unidentified MAKAOPUHI LAVA LAKE --
NMNH 113095-23 Unidentified MAKAOPUHI LAVA LAKE --
NMNH 113095-24 Unidentified UWEKAHUNA LACCOLITH --
NMNH 113095-24 Unidentified UWEKAHUNA LACCOLITH --
NMNH 113095-25A Olivine Gabbro UWEKAHUNA LACCOLITH --
NMNH 113095-26 Gabbro-Picrite UWEKAHUNA LACCOLITH --
NMNH 113095-26 Gabbro-Picrite UWEKAHUNA LACCOLITH --
NMNH 113095-27 Unidentified SW RIFT ZONE --
NMNH 113095-27 Unidentified SW RIFT ZONE --
NMNH 113095-29 Unidentified KILAUEA CALDERA FLOOR --
NMNH 113095-29 Unidentified KILAUEA CALDERA FLOOR --
NMNH 113095-3 Basalt KEHENA FLOW --
NMNH 113095-3 Basalt KEHENA FLOW --
NMNH 113095-31 Unidentified -- --
NMNH 113095-31 Unidentified -- --
NMNH 113095-33 Unidentified PUNA FLOW --
NMNH 113095-33 Unidentified PUNA FLOW --
NMNH 113095-34 Pumice KILAUEA IKI 21 Nov 1959
NMNH 113095-35 Unidentified VENT A --
NMNH 113095-36 Unidentified VENT B --
NMNH 113095-36 Unidentified VENT B --
NMNH 113095-37 Pumice HALEMAUMAU 13 Jul 1961
NMNH 113095-4 Andesitic Basalt KU FLOW --
NMNH 113095-4 Andesitic Basalt KU FLOW --
NMNH 113343 Basalt KILAUEA IKI --
NMNH 113400 Basalt -- 18 Apr 1975
NMNH 113401 Basalt -- 18 Apr 1975
NMNH 113402 Basalt -- 18 Apr 1975
NMNH 113403 Basalt -- 18 Apr 1975
NMNH 113405 Basalt -- 18 Apr 1975
NMNH 113406 Basalt -- 22 Apr 1975
NMNH 113409 Basalt -- 22 Apr 1975
NMNH 113410 Basalt -- 22 Apr 1975
NMNH 113411 Basalt -- 22 Apr 1975
NMNH 113412 Basalt -- 22 May 1975
NMNH 113413 Basalt -- 22 Apr 1975
NMNH 113414 Basalt -- 22 Apr 1975
NMNH 113415 Sand -- 1 Apr 1973
NMNH 113416 Sand -- 17 Nov 1974
NMNH 113447 Basalt -- --
NMNH 113447 Basalt HALEMAUMAU --
NMNH 113449 Volcanic Glass HALEMAUMAU --
NMNH 113468 Basalt -- --
NMNH 113469 Basalt -- --
NMNH 113470 Basalt -- --
NMNH 113496-1 Basalt SW RIFT ZONE - MIDDLE KAMAKAIA HILL --
NMNH 113496-1A Pumiceous Basalt SW RIFT ZONE - MIDDLE KAMAKAIA CONE --
NMNH 113496-2 Basalt SW RIFT ZONE - RED CONES --
NMNH 113496-3 Basalt SW RIFT ZONE - YELLOW CONE --
NMNH 113496-4 Picritic Basalt SW RIFT ZONE --
NMNH 113496-5 Basalt SW RIFT ZONE - GREAT CRACK --
NMNH 113496-6 Basalt SW RIFT ZONE - MAIN VENT --
NMNH 113496-7 Basalt SW RIFT ZONE - NORTHERNMOST VENT --
NMNH 113496-8 Basalt SW RIFT ZONE - MAUNA IKI --
NMNH 113496-9 Basalt SW RIFT ZONE - MAUNA IKI --
NMNH 113497-1 Basalt E RIFT ZONE - KANE NUI O HAMO --
NMNH 113497-2 Basalt E RIFT ZONE - KANE NUI O HAMO --
NMNH 113497-3 Basalt E RIFT ZONE - KANE NUI O HAMO --
NMNH 113497-4 Picritic Basalt E RIFT ZONE --
NMNH 113497-5 Basalt E RIFT ZONE --
NMNH 113497-6 Basalt E RIFT ZONE --
NMNH 113497-7 Basalt E RIFT ZONE --
NMNH 113497-8 Basalt E RIFT ZONE --
NMNH 113498-1 Basalt Glass E RIFT ZONE - MAKAOPUHI CRATER 31 Jan 1969
NMNH 113498-1 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 31 Jan 1969
NMNH 113498-10 Basalt E RIFT ZONE - MAKAOPUHI CRATER 9 Nov 1965
NMNH 113498-11 Basalt E RIFT ZONE - MAKAOPUHI CRATER 9 Nov 1965
NMNH 113498-12 Basalt E RIFT ZONE - MAKAOPUHI CRATER 9 Nov 1965
NMNH 113498-13 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 18 Dec 1968
NMNH 113498-14 Basalt E RIFT ZONE - MAKAOPUHI CRATER 1 Nov 1968
NMNH 113498-15 Basalt E RIFT ZONE - MAKAOPUHI CRATER 1 Nov 1968
NMNH 113498-15A Basalt E RIFT ZONE - MAKAOPUHI CRATER 20 Nov 1968
NMNH 113498-2 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 31 Jan 1969
NMNH 113498-3 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 31 Jan 1969
NMNH 113498-4 Basalt E RIFT ZONE - MAKAOPUHI CRATER 14 Mar 1965
NMNH 113498-5 Basalt E RIFT ZONE - MAKAOPUHI CRATER 12 Mar 1965
NMNH 113498-6 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 11 Mar 1965
NMNH 113498-7 Basaltic Pumice E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 113498-8 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 19 Apr 1965
NMNH 113498-9 Basalt E RIFT ZONE - MAKAOPUHI CRATER 27 Sep 1965
NMNH 113499-1 Basalt HALEMAUMAU CRATER --
NMNH 113499-2 Basalt HALEMAUMAU CRATER --
NMNH 113499-3 Basalt HALEMAUMAU CRATER --
NMNH 113499-4 Basalt HALEMAUMAU CRATER --
NMNH 113499-5 Basalt HALEMAUMAU CRATER --
NMNH 113499-6 Basalt HALEMAUMAU CRATER --
NMNH 113499-7 Basalt HALEMAUMAU CRATER --
NMNH 113500-34 Basalt KILAUEA IKI CRATER --
NMNH 113897 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113898 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113899 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113900 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113901 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113902 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113903 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113904 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113905 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113906 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113907 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113908 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113909 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113910 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113911 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113912 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113913 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113914 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113915 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113915-1 Basalt E RIFT ZONE - MAKAOPUHI CRATER 12 Jul 1965
NMNH 113915-2 Basalt E RIFT ZONE - MAKAOPUHI CRATER 12 Jul 1965
NMNH 113916 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113916-1 Basalt E RIFT ZONE - MAKAOPUHI CRATER 12 Jul 1965
NMNH 113916-2 Basalt E RIFT ZONE - MAKAOPUHI CRATER 12 Jul 1965
NMNH 113917 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113918 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113918 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113919 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113920 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113921 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113923 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113923 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113923-1 Basalt E RIFT ZONE - MAKAOPUHI CRATER 12 Nov 1968
NMNH 113923-2 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 18 Nov 1968
NMNH 113923-3 Basaltic Sand E RIFT ZONE - MAKAOPUHI CRATER 20 Nov 1968
NMNH 113923-4 Basaltic Sand E RIFT ZONE - MAKAOPUHI CRATER 20 Nov 1968
NMNH 113923-5 Basaltic Sand E RIFT ZONE - MAKAOPUHI CRATER 20 Nov 1968
NMNH 113923-6 Basaltic Sand E RIFT ZONE - MAKAOPUHI CRATER 20 Nov 1968
NMNH 113924 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113924-1 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 18 Dec 1968
NMNH 113925 Tholeiitic Basalt MAKAOPUHI LAVA LAKE --
NMNH 113925-1 Basalt E RIFT ZONE - MAKAOPUHI CRATER 22 Jan 1969
NMNH 114007 Basalt (?) EAST RIFT ZONE --
NMNH 114367-1 Basalt -- --
NMNH 114368-1 Basalt -- --
NMNH 114368-2 Basalt -- --
NMNH 114368-3 Basalt -- --
NMNH 114368-4 Basalt -- --
NMNH 114368-5 Basalt -- --
NMNH 114663 Volcanic Ash -- --
NMNH 114665-4 Volcanic Sublimate -- --
NMNH 114666 Basalt HALEMAUMAU --
NMNH 114757-10 Basalt KAPOHO --
NMNH 114757-11 Basalt KAPOHO --
NMNH 114757-12 Basalt KAPOHO --
NMNH 114757-13 Basalt KAPOHO --
NMNH 114757-14 Basalt KAPOHO --
NMNH 114757-15 Basalt KAPOHO --
NMNH 114757-16 Basalt KAPOHO --
NMNH 114757-17 Basalt KAPOHO --
NMNH 114757-18 Basalt KAPOHO --
NMNH 114757-19 Basalt KAPOHO --
NMNH 114757-2 Basalt KAPOHO --
NMNH 114757-20 Basalt KAPOHO --
NMNH 114757-21 Basalt KAPOHO --
NMNH 114757-22 Ultramafic Nodule KAPOHO --
NMNH 114757-23 Basalt KAPOHO --
NMNH 114757-24 Basalt -- --
NMNH 114757-25 Basalt -- --
NMNH 114757-26 Basalt -- --
NMNH 114757-27 Basalt -- --
NMNH 114757-28 Basalt -- --
NMNH 114757-29 Basalt -- --
NMNH 114757-3 Basalt KAPOHO --
NMNH 114757-30 Basalt -- --
NMNH 114757-31 Basalt -- --
NMNH 114757-32 Basalt -- --
NMNH 114757-33 Basalt -- --
NMNH 114757-34 Basalt -- --
NMNH 114757-35 Basalt -- --
NMNH 114757-36 Basalt -- --
NMNH 114757-37 Basalt -- --
NMNH 114757-38 Basalt -- --
NMNH 114757-39 Basalt -- --
NMNH 114757-4 Basalt KAPOHO --
NMNH 114757-40 Basalt -- --
NMNH 114757-5 Basalt KAPOHO --
NMNH 114757-6 Basalt KAPOHO --
NMNH 114757-7 Basalt KAPOHO --
NMNH 114757-8 Basalt KAPOHO --
NMNH 114757-9 Basalt KAPOHO --
NMNH 114758-1 Basalt KAPOHO --
NMNH 114770-1 Unidentified -- --
NMNH 114771-10 Basalt -- --
NMNH 114771-11 Basalt -- --
NMNH 114771-12 Basalt -- --
NMNH 114771-13 Basalt -- --
NMNH 114771-14 Basalt -- --
NMNH 114771-15 Basalt -- --
NMNH 114771-16 Basalt -- --
NMNH 114771-17 Basalt -- --
NMNH 114771-18 Basalt -- --
NMNH 114771-19 Basalt -- --
NMNH 114771-2 Basalt -- --
NMNH 114771-20 Basalt -- --
NMNH 114771-21 Basalt -- --
NMNH 114771-22 Basalt -- --
NMNH 114771-23 Basalt -- --
NMNH 114771-24 Basalt -- --
NMNH 114771-3 Basalt -- --
NMNH 114771-4 Basalt -- --
NMNH 114771-5 Basalt -- --
NMNH 114771-6 Basalt -- --
NMNH 114771-7 Basalt -- --
NMNH 114771-8 Basalt -- --
NMNH 114771-9 Basalt -- --
NMNH 114772-1 Basalt -- --
NMNH 114772-2 Basalt -- --
NMNH 114773-1 Basalt -- --
NMNH 114773-2 Basalt -- --
NMNH 114774-1 Basalt -- --
NMNH 114775-1 Basalt -- --
NMNH 114775-2 Basalt -- --
NMNH 114775-3 Basalt -- --
NMNH 114776-1 Basalt -- --
NMNH 114777-1 Basalt -- --
NMNH 114777-2 Basalt -- --
NMNH 114778-1 Volcanic Rock HALEMAUMAU CRATER --
NMNH 114778-10 Volcanic Rock HALEMAUMAU CRATER --
NMNH 114778-11 Volcanic Rock HALEMAUMAU CRATER --
NMNH 114778-12 Volcanic Rock HALEMAUMAU CRATER --
NMNH 114778-2 Volcanic Rock HALEMAUMAU CRATER --
NMNH 114778-3 Volcanic Rock HALEMAUMAU CRATER --
NMNH 114778-4 Volcanic Rock HALEMAUMAU CRATER --
NMNH 114778-5 Volcanic Rock HALEMAUMAU CRATER --
NMNH 114778-6 Volcanic Rock HALEMAUMAU CRATER --
NMNH 114778-7 Volcanic Rock HALEMAUMAU CRATER --
NMNH 114778-8 Volcanic Rock HALEMAUMAU CRATER --
NMNH 114778-9 Volcanic Rock HALEMAUMAU CRATER --
NMNH 114824-1 Basalt -- --
NMNH 114976-1 Ultramafic Nodule -- --
NMNH 114976-2 Ultramafic Nodule -- --
NMNH 115008-1 Basalt E RIFT ZONE --
NMNH 115008-10 Basalt E RIFT ZONE --
NMNH 115008-11 Basalt E RIFT ZONE --
NMNH 115008-12 Basalt E RIFT ZONE --
NMNH 115008-13 Basalt E RIFT ZONE --
NMNH 115008-14 Basalt E RIFT ZONE --
NMNH 115008-15 Basalt E RIFT ZONE --
NMNH 115008-16 Basalt E RIFT ZONE --
NMNH 115008-17 Basalt E RIFT ZONE --
NMNH 115008-22 Basalt E RIFT ZONE --
NMNH 115008-23 Basalt E RIFT ZONE --
NMNH 115008-24 Basalt E RIFT ZONE --
NMNH 115008-25 Basalt E RIFT ZONE --
NMNH 115008-26 Basalt E RIFT ZONE --
NMNH 115008-27 Basalt E RIFT ZONE --
NMNH 115008-28 Basalt E RIFT ZONE --
NMNH 115008-29 Basalt E RIFT ZONE --
NMNH 115008-3 Basalt E RIFT ZONE --
NMNH 115008-30 Basalt E RIFT ZONE --
NMNH 115008-31 Basalt E RIFT ZONE --
NMNH 115008-32 Basalt E RIFT ZONE --
NMNH 115008-33 Basalt E RIFT ZONE --
NMNH 115008-34 Basalt E RIFT ZONE --
NMNH 115008-35 Basalt E RIFT ZONE --
NMNH 115008-36 Basalt E RIFT ZONE --
NMNH 115008-37 Basalt E RIFT ZONE --
NMNH 115008-38 Basalt E RIFT ZONE --
NMNH 115008-39 Basalt E RIFT ZONE --
NMNH 115008-4 Basalt E RIFT ZONE --
NMNH 115008-41 Basalt E RIFT ZONE --
NMNH 115008-42 Basalt E RIFT ZONE --
NMNH 115008-43 Basalt E RIFT ZONE --
NMNH 115008-44 Basalt E RIFT ZONE --
NMNH 115008-45 Basalt E RIFT ZONE --
NMNH 115008-46 Basalt E RIFT ZONE --
NMNH 115008-47 Basalt E RIFT ZONE --
NMNH 115008-48 Basalt E RIFT ZONE --
NMNH 115008-49 Basalt E RIFT ZONE --
NMNH 115008-5 Basalt E RIFT ZONE --
NMNH 115008-50 Basalt E RIFT ZONE --
NMNH 115008-51 Basalt E RIFT ZONE --
NMNH 115008-9 Basalt E RIFT ZONE --
NMNH 115247-1 Basalt Glass SW RIFT ZONE --
NMNH 115247-10 Basalt Glass SW RIFT ZONE --
NMNH 115247-100 Basalt Glass SW RIFT ZONE --
NMNH 115247-101 Basalt Glass SW RIFT ZONE --
NMNH 115247-102 Basalt Glass SW RIFT ZONE --
NMNH 115247-103 Basalt Glass SW RIFT ZONE --
NMNH 115247-104 Basalt Glass SW RIFT ZONE --
NMNH 115247-105 Basalt Glass SW RIFT ZONE --
NMNH 115247-106 Basalt Glass SW RIFT ZONE --
NMNH 115247-107 Basalt Glass SW RIFT ZONE --
NMNH 115247-108 Basalt Glass SW RIFT ZONE --
NMNH 115247-109 Basalt Glass SW RIFT ZONE --
NMNH 115247-11 Basalt Glass SW RIFT ZONE --
NMNH 115247-110 Basalt Glass SW RIFT ZONE --
NMNH 115247-111 Basalt Glass SW RIFT ZONE --
NMNH 115247-112 Basalt Glass SW RIFT ZONE --
NMNH 115247-113 Basalt Glass SW RIFT ZONE --
NMNH 115247-114 Basalt Glass SW RIFT ZONE --
NMNH 115247-115 Basalt Glass SW RIFT ZONE --
NMNH 115247-116 Basalt Glass SW RIFT ZONE --
NMNH 115247-117 Basalt Glass SW RIFT ZONE --
NMNH 115247-118 Basalt Glass SW RIFT ZONE --
NMNH 115247-119 Basalt Glass SW RIFT ZONE --
NMNH 115247-12 Basalt Glass SW RIFT ZONE --
NMNH 115247-120 Basalt Glass SW RIFT ZONE --
NMNH 115247-121 Basalt Glass SW RIFT ZONE --
NMNH 115247-122 Basalt Glass SW RIFT ZONE --
NMNH 115247-123 Basalt Glass SW RIFT ZONE --
NMNH 115247-124 Basalt Glass SW RIFT ZONE --
NMNH 115247-125 Basalt Glass SW RIFT ZONE --
NMNH 115247-126 Basalt Glass SW RIFT ZONE --
NMNH 115247-127 Basalt Glass SW RIFT ZONE --
NMNH 115247-128 Basalt Glass SW RIFT ZONE --
NMNH 115247-129 Basalt Glass SW RIFT ZONE --
NMNH 115247-13 Basalt Glass SW RIFT ZONE --
NMNH 115247-130 Basalt Glass SW RIFT ZONE --
NMNH 115247-131 Basalt Glass SW RIFT ZONE --
NMNH 115247-132 Basalt Glass SW RIFT ZONE --
NMNH 115247-133 Basalt Glass SW RIFT ZONE --
NMNH 115247-134 Basalt Glass SW RIFT ZONE --
NMNH 115247-135 Basalt Glass SW RIFT ZONE --
NMNH 115247-136 Basalt Glass SW RIFT ZONE --
NMNH 115247-137 Basalt Glass SW RIFT ZONE --
NMNH 115247-14 Basalt Glass SW RIFT ZONE --
NMNH 115247-15 Basalt Glass SW RIFT ZONE --
NMNH 115247-16 Basalt Glass SW RIFT ZONE --
NMNH 115247-17 Basalt Glass SW RIFT ZONE --
NMNH 115247-18 Basalt Glass SW RIFT ZONE --
NMNH 115247-19 Basalt Glass SW RIFT ZONE --
NMNH 115247-2 Basalt Glass SW RIFT ZONE --
NMNH 115247-20 Basalt Glass SW RIFT ZONE --
NMNH 115247-21 Basalt Glass SW RIFT ZONE --
NMNH 115247-22 Basalt Glass SW RIFT ZONE --
NMNH 115247-23 Basalt Glass SW RIFT ZONE --
NMNH 115247-24 Basalt Glass SW RIFT ZONE --
NMNH 115247-25 Basalt Glass SW RIFT ZONE --
NMNH 115247-26 Basalt Glass SW RIFT ZONE --
NMNH 115247-27 Basalt Glass SW RIFT ZONE --
NMNH 115247-28 Basalt Glass SW RIFT ZONE --
NMNH 115247-29 Basalt Glass SW RIFT ZONE --
NMNH 115247-3 Basalt Glass SW RIFT ZONE --
NMNH 115247-30 Basalt Glass SW RIFT ZONE --
NMNH 115247-31 Basalt Glass SW RIFT ZONE --
NMNH 115247-32 Basalt Glass SW RIFT ZONE --
NMNH 115247-33 Basalt Glass SW RIFT ZONE --
NMNH 115247-34 Basalt Glass SW RIFT ZONE --
NMNH 115247-35 Basalt Glass SW RIFT ZONE --
NMNH 115247-36 Basalt Glass SW RIFT ZONE --
NMNH 115247-37 Basalt Glass SW RIFT ZONE --
NMNH 115247-38 Basalt Glass SW RIFT ZONE --
NMNH 115247-39 Basalt Glass SW RIFT ZONE --
NMNH 115247-4 Basalt Glass SW RIFT ZONE --
NMNH 115247-40 Basalt Glass SW RIFT ZONE --
NMNH 115247-41 Basalt Glass SW RIFT ZONE --
NMNH 115247-42 Basalt Glass SW RIFT ZONE --
NMNH 115247-43 Basalt Glass SW RIFT ZONE --
NMNH 115247-44 Basalt Glass SW RIFT ZONE --
NMNH 115247-45 Basalt Glass SW RIFT ZONE --
NMNH 115247-46 Basalt Glass SW RIFT ZONE --
NMNH 115247-47 Basalt Glass SW RIFT ZONE --
NMNH 115247-48 Basalt Glass SW RIFT ZONE --
NMNH 115247-49 Basalt Glass SW RIFT ZONE --
NMNH 115247-5 Basalt Glass SW RIFT ZONE --
NMNH 115247-50 Basalt Glass SW RIFT ZONE --
NMNH 115247-51 Basalt Glass SW RIFT ZONE --
NMNH 115247-52 Basalt Glass SW RIFT ZONE --
NMNH 115247-53 Basalt Glass SW RIFT ZONE --
NMNH 115247-54 Basalt Glass SW RIFT ZONE --
NMNH 115247-55 Basalt Glass SW RIFT ZONE --
NMNH 115247-56 Basalt Glass SW RIFT ZONE --
NMNH 115247-57 Basalt Glass SW RIFT ZONE --
NMNH 115247-58 Basalt Glass SW RIFT ZONE --
NMNH 115247-59 Basalt Glass SW RIFT ZONE --
NMNH 115247-6 Basalt Glass SW RIFT ZONE --
NMNH 115247-60 Basalt Glass SW RIFT ZONE --
NMNH 115247-61 Basalt Glass SW RIFT ZONE --
NMNH 115247-62 Basalt Glass SW RIFT ZONE --
NMNH 115247-63 Basalt Glass SW RIFT ZONE --
NMNH 115247-64 Basalt Glass SW RIFT ZONE --
NMNH 115247-65 Basalt Glass SW RIFT ZONE --
NMNH 115247-66 Basalt Glass SW RIFT ZONE --
NMNH 115247-67 Basalt Glass SW RIFT ZONE --
NMNH 115247-68 Basalt Glass SW RIFT ZONE --
NMNH 115247-69 Basalt Glass SW RIFT ZONE --
NMNH 115247-7 Basalt Glass SW RIFT ZONE --
NMNH 115247-70 Basalt Glass SW RIFT ZONE --
NMNH 115247-71 Basalt Glass SW RIFT ZONE --
NMNH 115247-72 Basalt Glass SW RIFT ZONE --
NMNH 115247-73 Basalt Glass SW RIFT ZONE --
NMNH 115247-74 Basalt Glass SW RIFT ZONE --
NMNH 115247-75 Basalt Glass SW RIFT ZONE --
NMNH 115247-76 Basalt Glass SW RIFT ZONE --
NMNH 115247-77 Basalt Glass SW RIFT ZONE --
NMNH 115247-78 Basalt Glass SW RIFT ZONE --
NMNH 115247-79 Basalt Glass SW RIFT ZONE --
NMNH 115247-8 Basalt Glass SW RIFT ZONE --
NMNH 115247-80 Basalt Glass SW RIFT ZONE --
NMNH 115247-81 Basalt Glass SW RIFT ZONE --
NMNH 115247-82 Basalt Glass SW RIFT ZONE --
NMNH 115247-83 Basalt Glass SW RIFT ZONE --
NMNH 115247-84 Basalt Glass SW RIFT ZONE --
NMNH 115247-85 Basalt Glass SW RIFT ZONE --
NMNH 115247-86 Basalt Glass SW RIFT ZONE --
NMNH 115247-87 Basalt Glass SW RIFT ZONE --
NMNH 115247-88 Basalt Glass SW RIFT ZONE --
NMNH 115247-89 Basalt Glass SW RIFT ZONE --
NMNH 115247-9 Basalt Glass SW RIFT ZONE --
NMNH 115247-90 Basalt Glass SW RIFT ZONE --
NMNH 115247-91 Basalt Glass SW RIFT ZONE --
NMNH 115247-92 Basalt Glass SW RIFT ZONE --
NMNH 115247-93 Basalt Glass SW RIFT ZONE --
NMNH 115247-94 Basalt Glass SW RIFT ZONE --
NMNH 115247-95 Basalt Glass SW RIFT ZONE --
NMNH 115247-96 Basalt Glass SW RIFT ZONE --
NMNH 115247-97 Basalt Glass SW RIFT ZONE --
NMNH 115247-98 Basalt Glass SW RIFT ZONE --
NMNH 115247-99 Basalt Glass SW RIFT ZONE --
NMNH 115467-1 Olivine Basalt KILAUEA IKI --
NMNH 115467-1 Olivine Basalt KILAUEA IKI --
NMNH 115467-10 Olivine Basalt KILAUEA IKI --
NMNH 115467-10 Olivine Basalt KILAUEA IKI --
NMNH 115467-11 Olivine Basalt KILAUEA IKI --
NMNH 115467-11 Olivine Basalt KILAUEA IKI --
NMNH 115467-12 Olivine Basalt KILAUEA IKI --
NMNH 115467-13 Olivine Basalt KILAUEA IKI --
NMNH 115467-13 Olivine Basalt KILAUEA IKI --
NMNH 115467-14 Olivine Basalt KILAUEA IKI --
NMNH 115467-15 Olivine Basalt KILAUEA IKI --
NMNH 115467-16 Olivine Basalt KILAUEA IKI --
NMNH 115467-16 Olivine Basalt KILAUEA IKI --
NMNH 115467-17 Olivine Basalt KILAUEA IKI --
NMNH 115467-18 Olivine Basalt KILAUEA IKI --
NMNH 115467-18 Olivine Basalt KILAUEA IKI --
NMNH 115467-2 Olivine Basalt KILAUEA IKI --
NMNH 115467-2 Olivine Basalt KILAUEA IKI --
NMNH 115467-3 Olivine Basalt KILAUEA IKI --
NMNH 115467-4 Olivine Basalt KILAUEA IKI --
NMNH 115467-5 Olivine Basalt KILAUEA IKI --
NMNH 115467-5 Olivine Basalt KILAUEA IKI --
NMNH 115467-6 Olivine Basalt KILAUEA IKI --
NMNH 115467-6 Olivine Basalt KILAUEA IKI --
NMNH 115467-7 Olivine Basalt KILAUEA IKI --
NMNH 115467-8 Olivine Basalt KILAUEA IKI --
NMNH 115467-8 Olivine Basalt KILAUEA IKI --
NMNH 115467-9 Olivine Basalt KILAUEA IKI --
NMNH 115468-1 Olivine Basalt KILAUEA IKI --
NMNH 115468-10 Olivine Basalt KILAUEA IKI --
NMNH 115468-11 Olivine Basalt KILAUEA IKI --
NMNH 115468-12 Olivine Basalt KILAUEA IKI --
NMNH 115468-13 Olivine Basalt KILAUEA IKI --
NMNH 115468-14 Olivine Basalt KILAUEA IKI --
NMNH 115468-15 Olivine Basalt KILAUEA IKI --
NMNH 115468-16 Olivine Basalt KILAUEA IKI --
NMNH 115468-17 Olivine Basalt KILAUEA IKI --
NMNH 115468-18 Olivine Basalt KILAUEA IKI --
NMNH 115468-19 Olivine Basalt KILAUEA IKI --
NMNH 115468-2 Olivine Basalt KILAUEA IKI --
NMNH 115468-20 Olivine Basalt KILAUEA IKI --
NMNH 115468-21 Olivine Basalt KILAUEA IKI --
NMNH 115468-22 Olivine Basalt KILAUEA IKI --
NMNH 115468-3 Olivine Basalt KILAUEA IKI --
NMNH 115468-4 Olivine Basalt KILAUEA IKI --
NMNH 115468-5 Olivine Basalt KILAUEA IKI --
NMNH 115468-6 Olivine Basalt KILAUEA IKI --
NMNH 115468-7 Olivine Basalt KILAUEA IKI --
NMNH 115468-8 Olivine Basalt KILAUEA IKI --
NMNH 115468-9 Olivine Basalt KILAUEA IKI --
NMNH 115469-1 Olivine Basalt KILAUEA IKI --
NMNH 115469-10 Olivine Basalt KILAUEA IKI --
NMNH 115469-11 Olivine Basalt KILAUEA IKI --
NMNH 115469-12 Olivine Basalt KILAUEA IKI --
NMNH 115469-13 Olivine Basalt KILAUEA IKI --
NMNH 115469-14 Olivine Basalt KILAUEA IKI --
NMNH 115469-15 Olivine Basalt KILAUEA IKI --
NMNH 115469-16 Olivine Basalt KILAUEA IKI --
NMNH 115469-17 Olivine Basalt KILAUEA IKI --
NMNH 115469-2 Olivine Basalt KILAUEA IKI --
NMNH 115469-3 Olivine Basalt KILAUEA IKI --
NMNH 115469-4 Olivine Basalt KILAUEA IKI --
NMNH 115469-5 Olivine Basalt KILAUEA IKI --
NMNH 115469-6 Olivine Basalt KILAUEA IKI --
NMNH 115469-7 Olivine Basalt KILAUEA IKI --
NMNH 115469-8 Olivine Basalt KILAUEA IKI --
NMNH 115469-9 Olivine Basalt KILAUEA IKI --
NMNH 115470-1 Olivine Basalt KILAUEA IKI --
NMNH 115470-1 Olivine Basalt KILAUEA IKI --
NMNH 115470-2 Olivine Basalt KILAUEA IKI --
NMNH 115470-2 Olivine Basalt KILAUEA IKI --
NMNH 115470-3 Olivine Basalt KILAUEA IKI --
NMNH 115470-3 Olivine Basalt KILAUEA IKI --
NMNH 115470-4 Olivine Basalt KILAUEA IKI --
NMNH 115470-4 Olivine Basalt KILAUEA IKI --
NMNH 115470-5 Olivine Basalt KILAUEA IKI --
NMNH 115470-5 Olivine Basalt KILAUEA IKI --
NMNH 115471-1 Olivine Basalt KILAUEA IKI --
NMNH 115471-2 Olivine Basalt KILAUEA IKI --
NMNH 115471-3 Olivine Basalt KILAUEA IKI --
NMNH 115471-4 Olivine Basalt KILAUEA IKI --
NMNH 115471-5 Olivine Basalt KILAUEA IKI --
NMNH 115472-1 Olivine Basalt KILAUEA IKI --
NMNH 115472-1 Olivine Basalt KILAUEA IKI --
NMNH 115472-2 Olivine Basalt KILAUEA IKI --
NMNH 115472-2 Olivine Basalt KILAUEA IKI --
NMNH 115472-3 Olivine Basalt KILAUEA IKI --
NMNH 115472-3 Olivine Basalt KILAUEA IKI --
NMNH 115472-4 Olivine Basalt KILAUEA IKI --
NMNH 115472-4 Olivine Basalt KILAUEA IKI --
NMNH 115472-5 Olivine Basalt KILAUEA IKI --
NMNH 115472-5 Olivine Basalt KILAUEA IKI --
NMNH 115473-1 Olivine Basalt KILAUEA IKI --
NMNH 115473-2 Olivine Basalt KILAUEA IKI --
NMNH 115473-3 Olivine Basalt KILAUEA IKI --
NMNH 115473-4 Olivine Basalt KILAUEA IKI --
NMNH 115473-5 Olivine Basalt KILAUEA IKI --
NMNH 115473-6 Olivine Basalt KILAUEA IKI --
NMNH 115473-7 Olivine Basalt KILAUEA IKI --
NMNH 115473-8 Olivine Basalt KILAUEA IKI --
NMNH 115474-1 Olivine Basalt KILAUEA IKI --
NMNH 115474-10 Olivine Basalt KILAUEA IKI --
NMNH 115474-11 Olivine Basalt KILAUEA IKI --
NMNH 115474-12 Olivine Basalt KILAUEA IKI --
NMNH 115474-13 Olivine Basalt KILAUEA IKI --
NMNH 115474-14 Olivine Basalt KILAUEA IKI --
NMNH 115474-15 Olivine Basalt KILAUEA IKI --
NMNH 115474-16 Olivine Basalt KILAUEA IKI --
NMNH 115474-17 Olivine Basalt KILAUEA IKI --
NMNH 115474-18 Olivine Basalt KILAUEA IKI --
NMNH 115474-19 Olivine Basalt KILAUEA IKI --
NMNH 115474-2 Olivine Basalt KILAUEA IKI --
NMNH 115474-20 Olivine Basalt KILAUEA IKI --
NMNH 115474-21 Olivine Basalt KILAUEA IKI --
NMNH 115474-22 Olivine Basalt KILAUEA IKI --
NMNH 115474-23 Olivine Basalt KILAUEA IKI --
NMNH 115474-24 Olivine Basalt KILAUEA IKI --
NMNH 115474-25 Olivine Basalt KILAUEA IKI --
NMNH 115474-26 Olivine Basalt KILAUEA IKI --
NMNH 115474-27 Olivine Basalt KILAUEA IKI --
NMNH 115474-28 Olivine Basalt KILAUEA IKI --
NMNH 115474-29 Olivine Basalt KILAUEA IKI --
NMNH 115474-3 Olivine Basalt KILAUEA IKI --
NMNH 115474-30 Olivine Basalt KILAUEA IKI --
NMNH 115474-4 Olivine Basalt KILAUEA IKI --
NMNH 115474-5 Olivine Basalt KILAUEA IKI --
NMNH 115474-6 Olivine Basalt KILAUEA IKI --
NMNH 115474-7 Olivine Basalt KILAUEA IKI --
NMNH 115474-8 Olivine Basalt KILAUEA IKI --
NMNH 115474-9 Olivine Basalt KILAUEA IKI --
NMNH 115475-1 Olivine Basalt KILAUEA IKI --
NMNH 115475-10 Olivine Basalt KILAUEA IKI --
NMNH 115475-11 Olivine Basalt KILAUEA IKI --
NMNH 115475-12 Olivine Basalt KILAUEA IKI --
NMNH 115475-13 Olivine Basalt KILAUEA IKI --
NMNH 115475-14 Olivine Basalt KILAUEA IKI --
NMNH 115475-15 Olivine Basalt KILAUEA IKI --
NMNH 115475-16 Olivine Basalt KILAUEA IKI --
NMNH 115475-17 Olivine Basalt KILAUEA IKI --
NMNH 115475-18 Olivine Basalt KILAUEA IKI --
NMNH 115475-19 Olivine Basalt KILAUEA IKI --
NMNH 115475-2 Olivine Basalt KILAUEA IKI --
NMNH 115475-20 Olivine Basalt KILAUEA IKI --
NMNH 115475-21 Olivine Basalt KILAUEA IKI --
NMNH 115475-22 Olivine Basalt KILAUEA IKI --
NMNH 115475-23 Olivine Basalt KILAUEA IKI --
NMNH 115475-24 Olivine Basalt KILAUEA IKI --
NMNH 115475-25 Olivine Basalt KILAUEA IKI --
NMNH 115475-26 Olivine Basalt KILAUEA IKI --
NMNH 115475-27 Olivine Basalt KILAUEA IKI --
NMNH 115475-28 Olivine Basalt KILAUEA IKI --
NMNH 115475-29 Olivine Basalt KILAUEA IKI --
NMNH 115475-3 Olivine Basalt KILAUEA IKI --
NMNH 115475-30 Olivine Basalt KILAUEA IKI --
NMNH 115475-31 Olivine Basalt KILAUEA IKI --
NMNH 115475-32 Olivine Basalt KILAUEA IKI --
NMNH 115475-33 Olivine Basalt KILAUEA IKI --
NMNH 115475-34 Olivine Basalt KILAUEA IKI --
NMNH 115475-35 Olivine Basalt KILAUEA IKI --
NMNH 115475-35 Olivine Basalt KILAUEA IKI --
NMNH 115475-36 Olivine Basalt KILAUEA IKI --
NMNH 115475-37 Olivine Basalt KILAUEA IKI --
NMNH 115475-39 Olivine Basalt KILAUEA IKI --
NMNH 115475-39 Olivine Basalt KILAUEA IKI --
NMNH 115475-4 Olivine Basalt KILAUEA IKI --
NMNH 115475-40 Olivine Basalt KILAUEA IKI --
NMNH 115475-41 Olivine Basalt KILAUEA IKI --
NMNH 115475-41 Olivine Basalt KILAUEA IKI --
NMNH 115475-42 Olivine Basalt KILAUEA IKI --
NMNH 115475-43 Olivine Basalt KILAUEA IKI --
NMNH 115475-44 Olivine Basalt KILAUEA IKI --
NMNH 115475-45 Olivine Basalt KILAUEA IKI --
NMNH 115475-46 Olivine Basalt KILAUEA IKI --
NMNH 115475-5 Olivine Basalt KILAUEA IKI --
NMNH 115475-6 Olivine Basalt KILAUEA IKI --
NMNH 115475-7 Olivine Basalt KILAUEA IKI --
NMNH 115475-8 Olivine Basalt KILAUEA IKI --
NMNH 115475-9 Olivine Basalt KILAUEA IKI --
NMNH 115476-1 Olivine Basalt KILAUEA IKI --
NMNH 115476-10 Olivine Basalt KILAUEA IKI --
NMNH 115476-11 Olivine Basalt KILAUEA IKI --
NMNH 115476-12 Olivine Basalt KILAUEA IKI --
NMNH 115476-13 Olivine Basalt KILAUEA IKI --
NMNH 115476-14 Olivine Basalt KILAUEA IKI --
NMNH 115476-15 Olivine Basalt KILAUEA IKI --
NMNH 115476-16 Olivine Basalt KILAUEA IKI --
NMNH 115476-17 Olivine Basalt KILAUEA IKI --
NMNH 115476-18 Olivine Basalt KILAUEA IKI --
NMNH 115476-19 Olivine Basalt KILAUEA IKI --
NMNH 115476-2 Olivine Basalt KILAUEA IKI --
NMNH 115476-20 Olivine Basalt KILAUEA IKI --
NMNH 115476-21 Olivine Basalt KILAUEA IKI --
NMNH 115476-22 Olivine Basalt KILAUEA IKI --
NMNH 115476-23 Olivine Basalt KILAUEA IKI --
NMNH 115476-24 Olivine Basalt KILAUEA IKI --
NMNH 115476-25 Olivine Basalt KILAUEA IKI --
NMNH 115476-26 Olivine Basalt KILAUEA IKI --
NMNH 115476-27 Olivine Basalt KILAUEA IKI --
NMNH 115476-28 Olivine Basalt KILAUEA IKI --
NMNH 115476-29 Olivine Basalt KILAUEA IKI --
NMNH 115476-3 Olivine Basalt KILAUEA IKI --
NMNH 115476-30 Olivine Basalt KILAUEA IKI --
NMNH 115476-31 Olivine Basalt KILAUEA IKI --
NMNH 115476-32 Olivine Basalt KILAUEA IKI --
NMNH 115476-33 Olivine Basalt KILAUEA IKI --
NMNH 115476-34 Olivine Basalt KILAUEA IKI --
NMNH 115476-35 Olivine Basalt KILAUEA IKI --
NMNH 115476-36 Olivine Basalt KILAUEA IKI --
NMNH 115476-37 Olivine Basalt KILAUEA IKI --
NMNH 115476-4 Olivine Basalt KILAUEA IKI --
NMNH 115476-5 Olivine Basalt KILAUEA IKI --
NMNH 115476-6 Olivine Basalt KILAUEA IKI --
NMNH 115476-7 Olivine Basalt KILAUEA IKI --
NMNH 115476-8 Olivine Basalt KILAUEA IKI --
NMNH 115476-9 Olivine Basalt KILAUEA IKI --
NMNH 115477-1 Olivine Basalt KILAUEA IKI --
NMNH 115477-10 Olivine Basalt KILAUEA IKI --
NMNH 115477-11 Olivine Basalt KILAUEA IKI --
NMNH 115477-12 Olivine Basalt KILAUEA IKI --
NMNH 115477-13 Olivine Basalt KILAUEA IKI --
NMNH 115477-14 Olivine Basalt KILAUEA IKI --
NMNH 115477-15 Olivine Basalt KILAUEA IKI --
NMNH 115477-16 Olivine Basalt KILAUEA IKI --
NMNH 115477-17 Olivine Basalt KILAUEA IKI --
NMNH 115477-18 Olivine Basalt KILAUEA IKI --
NMNH 115477-19 Olivine Basalt KILAUEA IKI --
NMNH 115477-2 Olivine Basalt KILAUEA IKI --
NMNH 115477-20 Olivine Basalt KILAUEA IKI --
NMNH 115477-21 Olivine Basalt KILAUEA IKI --
NMNH 115477-22 Olivine Basalt KILAUEA IKI --
NMNH 115477-23 Olivine Basalt KILAUEA IKI --
NMNH 115477-24 Olivine Basalt KILAUEA IKI --
NMNH 115477-25 Olivine Basalt KILAUEA IKI --
NMNH 115477-26 Olivine Basalt KILAUEA IKI --
NMNH 115477-27 Olivine Basalt KILAUEA IKI --
NMNH 115477-28 Olivine Basalt KILAUEA IKI --
NMNH 115477-29 Olivine Basalt KILAUEA IKI --
NMNH 115477-3 Olivine Basalt KILAUEA IKI --
NMNH 115477-30 Olivine Basalt KILAUEA IKI --
NMNH 115477-31 Olivine Basalt KILAUEA IKI --
NMNH 115477-32 Olivine Basalt KILAUEA IKI --
NMNH 115477-33 Olivine Basalt KILAUEA IKI --
NMNH 115477-34 Olivine Basalt KILAUEA IKI --
NMNH 115477-35 Olivine Basalt KILAUEA IKI --
NMNH 115477-36 Olivine Basalt KILAUEA IKI --
NMNH 115477-37 Olivine Basalt KILAUEA IKI --
NMNH 115477-38 Olivine Basalt KILAUEA IKI --
NMNH 115477-4 Olivine Basalt KILAUEA IKI --
NMNH 115477-5 Olivine Basalt KILAUEA IKI --
NMNH 115477-6 Olivine Basalt KILAUEA IKI --
NMNH 115477-7 Olivine Basalt KILAUEA IKI --
NMNH 115477-8 Olivine Basalt KILAUEA IKI --
NMNH 115477-9 Olivine Basalt KILAUEA IKI --
NMNH 115478-1 Olivine Basalt KILAUEA IKI --
NMNH 115478-10 Olivine Basalt KILAUEA IKI --
NMNH 115478-11 Olivine Basalt KILAUEA IKI --
NMNH 115478-12 Olivine Basalt KILAUEA IKI --
NMNH 115478-13 Olivine Basalt KILAUEA IKI --
NMNH 115478-14 Olivine Basalt KILAUEA IKI --
NMNH 115478-15 Olivine Basalt KILAUEA IKI --
NMNH 115478-16 Olivine Basalt KILAUEA IKI --
NMNH 115478-17 Olivine Basalt KILAUEA IKI --
NMNH 115478-18 Olivine Basalt KILAUEA IKI --
NMNH 115478-19 Olivine Basalt KILAUEA IKI --
NMNH 115478-2 Olivine Basalt KILAUEA IKI --
NMNH 115478-20 Olivine Basalt KILAUEA IKI --
NMNH 115478-21 Olivine Basalt KILAUEA IKI --
NMNH 115478-22 Olivine Basalt KILAUEA IKI --
NMNH 115478-23 Olivine Basalt KILAUEA IKI --
NMNH 115478-24 Olivine Basalt KILAUEA IKI --
NMNH 115478-25 Olivine Basalt KILAUEA IKI --
NMNH 115478-26 Olivine Basalt KILAUEA IKI --
NMNH 115478-27 Olivine Basalt KILAUEA IKI --
NMNH 115478-28 Olivine Basalt KILAUEA IKI --
NMNH 115478-29 Olivine Basalt KILAUEA IKI --
NMNH 115478-3 Olivine Basalt KILAUEA IKI --
NMNH 115478-30 Olivine Basalt KILAUEA IKI --
NMNH 115478-31 Olivine Basalt KILAUEA IKI --
NMNH 115478-32 Olivine Basalt KILAUEA IKI --
NMNH 115478-33 Olivine Basalt KILAUEA IKI --
NMNH 115478-34 Olivine Basalt KILAUEA IKI --
NMNH 115478-35 Olivine Basalt KILAUEA IKI --
NMNH 115478-36 Olivine Basalt KILAUEA IKI --
NMNH 115478-37 Olivine Basalt KILAUEA IKI --
NMNH 115478-38 Olivine Basalt KILAUEA IKI --
NMNH 115478-39 Olivine Basalt KILAUEA IKI --
NMNH 115478-4 Olivine Basalt KILAUEA IKI --
NMNH 115478-40 Olivine Basalt KILAUEA IKI --
NMNH 115478-41 Olivine Basalt KILAUEA IKI --
NMNH 115478-42 Olivine Basalt KILAUEA IKI --
NMNH 115478-43 Olivine Basalt KILAUEA IKI --
NMNH 115478-44 Olivine Basalt KILAUEA IKI --
NMNH 115478-45 Olivine Basalt KILAUEA IKI --
NMNH 115478-46 Olivine Basalt KILAUEA IKI --
NMNH 115478-47 Olivine Basalt KILAUEA IKI --
NMNH 115478-48 Olivine Basalt KILAUEA IKI --
NMNH 115478-49 Olivine Basalt KILAUEA IKI --
NMNH 115478-5 Olivine Basalt KILAUEA IKI --
NMNH 115478-50 Olivine Basalt KILAUEA IKI --
NMNH 115478-51 Olivine Basalt KILAUEA IKI --
NMNH 115478-52 Olivine Basalt KILAUEA IKI --
NMNH 115478-53 Olivine Basalt KILAUEA IKI --
NMNH 115478-54 Olivine Basalt KILAUEA IKI --
NMNH 115478-55 Olivine Basalt KILAUEA IKI --
NMNH 115478-56 Olivine Basalt KILAUEA IKI --
NMNH 115478-57 Olivine Basalt KILAUEA IKI --
NMNH 115478-58 Olivine Basalt KILAUEA IKI --
NMNH 115478-59 Olivine Basalt KILAUEA IKI --
NMNH 115478-6 Olivine Basalt KILAUEA IKI --
NMNH 115478-60 Olivine Basalt KILAUEA IKI --
NMNH 115478-61 Olivine Basalt KILAUEA IKI --
NMNH 115478-62 Olivine Basalt KILAUEA IKI --
NMNH 115478-63 Olivine Basalt KILAUEA IKI --
NMNH 115478-64 Olivine Basalt KILAUEA IKI --
NMNH 115478-65 Olivine Basalt KILAUEA IKI --
NMNH 115478-66 Olivine Basalt KILAUEA IKI --
NMNH 115478-67 Olivine Basalt KILAUEA IKI --
NMNH 115478-68 Olivine Basalt KILAUEA IKI --
NMNH 115478-69 Olivine Basalt KILAUEA IKI --
NMNH 115478-7 Olivine Basalt KILAUEA IKI --
NMNH 115478-70 Olivine Basalt KILAUEA IKI --
NMNH 115478-8 Olivine Basalt KILAUEA IKI --
NMNH 115478-9 Olivine Basalt KILAUEA IKI --
NMNH 115479-1 Olivine Basalt KILAUEA IKI --
NMNH 115479-10 Olivine Basalt KILAUEA IKI --
NMNH 115479-11 Olivine Basalt KILAUEA IKI --
NMNH 115479-12 Olivine Basalt KILAUEA IKI --
NMNH 115479-13 Olivine Basalt KILAUEA IKI --
NMNH 115479-14 Olivine Basalt KILAUEA IKI --
NMNH 115479-15 Olivine Basalt KILAUEA IKI --
NMNH 115479-16 Olivine Basalt KILAUEA IKI --
NMNH 115479-17 Olivine Basalt KILAUEA IKI --
NMNH 115479-18 Olivine Basalt KILAUEA IKI --
NMNH 115479-19 Olivine Basalt KILAUEA IKI --
NMNH 115479-2 Olivine Basalt KILAUEA IKI --
NMNH 115479-20 Olivine Basalt KILAUEA IKI --
NMNH 115479-21 Olivine Basalt KILAUEA IKI --
NMNH 115479-22 Olivine Basalt KILAUEA IKI --
NMNH 115479-23 Olivine Basalt KILAUEA IKI --
NMNH 115479-24 Olivine Basalt KILAUEA IKI --
NMNH 115479-25 Olivine Basalt KILAUEA IKI --
NMNH 115479-26 Olivine Basalt KILAUEA IKI --
NMNH 115479-27 Olivine Basalt KILAUEA IKI --
NMNH 115479-28 Olivine Basalt KILAUEA IKI --
NMNH 115479-29 Olivine Basalt KILAUEA IKI --
NMNH 115479-3 Olivine Basalt KILAUEA IKI --
NMNH 115479-30 Olivine Basalt KILAUEA IKI --
NMNH 115479-31 Olivine Basalt KILAUEA IKI --
NMNH 115479-32 Olivine Basalt KILAUEA IKI --
NMNH 115479-33 Olivine Basalt KILAUEA IKI --
NMNH 115479-34 Olivine Basalt KILAUEA IKI --
NMNH 115479-35 Olivine Basalt KILAUEA IKI --
NMNH 115479-36 Olivine Basalt KILAUEA IKI --
NMNH 115479-37 Olivine Basalt KILAUEA IKI --
NMNH 115479-38 Olivine Basalt KILAUEA IKI --
NMNH 115479-39 Olivine Basalt KILAUEA IKI --
NMNH 115479-4 Olivine Basalt KILAUEA IKI --
NMNH 115479-40 Olivine Basalt KILAUEA IKI --
NMNH 115479-41 Olivine Basalt KILAUEA IKI --
NMNH 115479-5 Olivine Basalt KILAUEA IKI --
NMNH 115479-6 Olivine Basalt KILAUEA IKI --
NMNH 115479-7 Olivine Basalt KILAUEA IKI --
NMNH 115479-8 Olivine Basalt KILAUEA IKI --
NMNH 115479-9 Olivine Basalt KILAUEA IKI --
NMNH 115756 Basalt -- --
NMNH 116028 Basalt SW RIFT ZONE - PUU KOAE --
NMNH 116029 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116030 Scoriaceous Basalt CALDERA --
NMNH 116031 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116032 Olivine Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116033-A Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116033-B Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116034 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116082-1 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-10 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-11 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-12 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-13 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-14 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-15 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-16 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-17 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-18 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-19 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-2 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-20 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-21 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-22 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-23 Olivine Basalt E RIFT ZONE --
NMNH 116082-24 Scoriaceous Basalt E RIFT ZONE --
NMNH 116082-25 Scoriaceous Basalt E RIFT ZONE --
NMNH 116082-26 Scoriaceous Basalt E RIFT ZONE --
NMNH 116082-27 Scoriaceous Basalt E RIFT ZONE --
NMNH 116082-28 Scoriaceous Basalt E RIFT ZONE --
NMNH 116082-29 Scoriaceous Basalt E RIFT ZONE 27 Sep 1961
NMNH 116082-3 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-30 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-4 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-5 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-6 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-7 Basaltic Pumice HALEMAUMAU CRATER 11 Jul 1961
NMNH 116082-8 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116082-9 Basaltic Pumice HALEMAUMAU CRATER --
NMNH 116083-1 Scoriaceous Basalt E RIFT ZONE --
NMNH 116083-2 Scoriaceous Basalt E RIFT ZONE --
NMNH 116083-3 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116083-4 Scoriaceous Basalt E RIFT ZONE --
NMNH 116083-5 Scoriaceous Basalt E RIFT ZONE --
NMNH 116083-6 Scoriaceous Basalt E RIFT ZONE --
NMNH 116083-7 Scoriaceous Basalt E RIFT ZONE 9 Dec 1962
NMNH 116083-8 Scoriaceous Basalt E RIFT ZONE - ALOI CRATER --
NMNH 116084-1 Vesicular Basalt E RIFT ZONE --
NMNH 116084-10 Basaltic Pumice E RIFT ZONE - ALAE CRATER --
NMNH 116084-11 Scoriaceous Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116084-2 Scoriaceous Basalt E RIFT ZONE --
NMNH 116084-3 Vesicular Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116084-4 Scoriaceous Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116084-5 Scoriaceous Basalt E RIFT ZONE --
NMNH 116084-6 Basaltic Pumice E RIFT ZONE - ALAE CRATER --
NMNH 116084-7 Basaltic Pumice E RIFT ZONE - ALAE CRATER --
NMNH 116084-8 Basaltic Pumice E RIFT ZONE - ALAE CRATER --
NMNH 116084-9 Basaltic Pumice E RIFT ZONE - ALAE CRATER --
NMNH 116085-1 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-10 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-11 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER 4 Oct 1963
NMNH 116085-12 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-13 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-14 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-15 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-2 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-3 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-4 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-5 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-6 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-7 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-8 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116085-9 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116086-1 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-10 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-100 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-101 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-102 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-103 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-104 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-105 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-106 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-107 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-108 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-109 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-11 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-110 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-111 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-112 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-113 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-114 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-115 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-116 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-117 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-118 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-119 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-12 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-120 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-121 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-122 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-123 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-124 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-125 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-126 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-127 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-128 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-129 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-13 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-130 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-131 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-132 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-133 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-134 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-135 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-136 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-137 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-138 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-139 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-14 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-140 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-141 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-142 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-143 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-144 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-145 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-146 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-147 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-148 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-149 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-15 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-150 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-151 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-152 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-153 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-154 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-155 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-156 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-157 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-158 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-159 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-16 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-160 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-161 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-162 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-163 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-164 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-165 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-166 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-17 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-18 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-19 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-2 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-20 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-21 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-22 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-23 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-24 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-25 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-26 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-27 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-28 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-29 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-3 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-30 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-31 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-32 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-33 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-34 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-35 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-36 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-37 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-38 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-39 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-4 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-40 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-41 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-42 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-43 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-44 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-45 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-46 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-47 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-48 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-49 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-5 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-50 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-51 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-52 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-53 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-54 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-55 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-56 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-57 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-58 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-59 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-6 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-60 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-61 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-62 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-63 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-64 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-65 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-66 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-67 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-68 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-69 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-7 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-70 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-71 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-72 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-73 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-74 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-75 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-76 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-77 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-78 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-79 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-8 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-80 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-81 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-82 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-83 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-84 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-85 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-86 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-87 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-88 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-89 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-9 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-90 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-91 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-92 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-93 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-94 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-95 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-96 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-97 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-98 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116086-99 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116087-1 Basaltic Pumice E RIFT ZONE - ALOI CRATER --
NMNH 116087-2 Scoriaceous Basalt E RIFT ZONE - ALOI CRATER --
NMNH 116087-3 Scoriaceous Basalt E RIFT ZONE - ALOI CRATER --
NMNH 116087-4 Scoriaceous Basalt E RIFT ZONE - ALOI CRATER --
NMNH 116087-5 Scoriaceous Basalt E RIFT ZONE - ALOI CRATER --
NMNH 116087-6 Scoriaceous Basalt E RIFT ZONE - ALOI CRATER --
NMNH 116087-7 Scoriaceous Basalt E RIFT ZONE - ALOI CRATER --
NMNH 116088-1 Basalt HALEMAUMAU CRATER --
NMNH 116088-10 Basalt HALEMAUMAU CRATER --
NMNH 116088-11 Basalt HALEMAUMAU CRATER --
NMNH 116088-12 Basalt HALEMAUMAU CRATER --
NMNH 116088-13 Basalt HALEMAUMAU CRATER --
NMNH 116088-14 Basalt HALEMAUMAU CRATER --
NMNH 116088-15 Basalt HALEMAUMAU CRATER --
NMNH 116088-2 Basalt HALEMAUMAU CRATER --
NMNH 116088-3 Basalt HALEMAUMAU CRATER --
NMNH 116088-4 Basalt HALEMAUMAU CRATER --
NMNH 116088-5 Basalt HALEMAUMAU CRATER --
NMNH 116088-6 Basalt HALEMAUMAU CRATER --
NMNH 116088-7 Basalt HALEMAUMAU CRATER --
NMNH 116088-8 Basalt HALEMAUMAU CRATER --
NMNH 116088-9 Basalt HALEMAUMAU CRATER --
NMNH 116089-1 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-10 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-11 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-12 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-13 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-14 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-15 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-2 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-3 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-4 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-5 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-6 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-7 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-8 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116089-9 Basalt E RIFT ZONE - HIIAKA CRATER --
NMNH 116090-1 Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116090-10 Basalt E RIFT ZONE - KANE NUI O HAMO, KALALUA --
NMNH 116090-11 Basalt E RIFT ZONE - KANE NUI O HAMO, KALALUA --
NMNH 116090-12 Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116090-13 Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116090-14 Basalt E RIFT ZONE - KANE NUI O HAMO --
NMNH 116090-15 Basalt E RIFT ZONE - KANE NUI O HAMO --
NMNH 116090-16 Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116090-17A Pele's Hair E RIFT ZONE - KANE NUI O HAMO, KALALUA --
NMNH 116090-17B Basaltic Pumice E RIFT ZONE - KANE NUI O HAMO, KALALUA --
NMNH 116090-18 Basalt E RIFT ZONE - KANE NUI O HAMO --
NMNH 116090-19 Basalt E RIFT ZONE - KANE NUI O HAMO, KALALUA --
NMNH 116090-2 Basaltic Pumice E RIFT ZONE - NAPAU CRATER --
NMNH 116090-3 Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116090-4 Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116090-5 Basalt E RIFT ZONE - NAPAU CRATER --
NMNH 116090-6 Basalt E RIFT ZONE - NAPAU CRATER 14 Oct 1968
NMNH 116090-7 Basalt E RIFT ZONE - NAPAU CRATER 14 Oct 1968
NMNH 116090-8 Basalt E RIFT ZONE - KANE NUI O HAMO, KALALUA --
NMNH 116090-9 Basalt E RIFT ZONE - KANE NUI O HAMO, KALALUA --
NMNH 116091-1 Basaltic Pumice E RIFT ZONE - ALAE CRATER 22 Feb 1969
NMNH 116091-10 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116091-11 Basalt E RIFT ZONE - ALAE CRATER 18 Jul 1969
NMNH 116091-12 Basalt E RIFT ZONE - ALAE CRATER 28 Jul 1969
NMNH 116091-13 Basalt E RIFT ZONE - ALAE CRATER 31 Jul 1969
NMNH 116091-14 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116091-15 Olivine Basalt E RIFT ZONE - ALAE CRATER 3 Aug 1969
NMNH 116091-16 Basalt E RIFT ZONE - ALAE CRATER 12 Aug 1969
NMNH 116091-17 Basaltic Pumice E RIFT ZONE - ALAE CRATER --
NMNH 116091-18 Volcanic Ash E RIFT ZONE - ALAE CRATER --
NMNH 116091-2 Basaltic Pumice E RIFT ZONE - ALAE CRATER 22 Feb 1969
NMNH 116091-3 Basaltic Pumice E RIFT ZONE - ALAE CRATER 22 Feb 1969
NMNH 116091-4 Basaltic Pumice E RIFT ZONE - ALAE CRATER 23 Feb 1969
NMNH 116091-5 Basalt E RIFT ZONE - ALAE CRATER 28 Feb 1969
NMNH 116091-6 Basalt E RIFT ZONE - ALAE CRATER 19 Mar 1969
NMNH 116091-7 Basalt E RIFT ZONE - ALAE CRATER 23 Jul 1969
NMNH 116091-8 Scoriaceous Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116091-9 Basalt E RIFT ZONE - ALAE CRATER --
NMNH 116092-1 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-10 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-100 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 30 Nov 1969
NMNH 116092-101 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 30 Nov 1969
NMNH 116092-102 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 30 Nov 1969
NMNH 116092-103 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 1 Dec 1969
NMNH 116092-104 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 1 Dec 1969
NMNH 116092-105 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 3 Dec 1969
NMNH 116092-106 Basalt E RIFT ZONE - MAUNA ULU 3 Dec 1969
NMNH 116092-107 Basalt E RIFT ZONE - MAUNA ULU 3 Dec 1969
NMNH 116092-108 Basalt E RIFT ZONE - MAUNA ULU 5 Dec 1969
NMNH 116092-109 Basalt E RIFT ZONE - MAUNA ULU 5 Dec 1969
NMNH 116092-11 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-110 Basalt E RIFT ZONE - MAUNA ULU 8 Dec 1969
NMNH 116092-111 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 8 Dec 1969
NMNH 116092-112 Basalt E RIFT ZONE - MAUNA ULU 8 Dec 1969
NMNH 116092-113 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-114 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-115 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 13 Dec 1969
NMNH 116092-116 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 13 Dec 1969
NMNH 116092-117 Basalt E RIFT ZONE - MAUNA ULU 13 Dec 1969
NMNH 116092-118 Basalt E RIFT ZONE - MAUNA ULU 13 Dec 1969
NMNH 116092-119 Basalt E RIFT ZONE - MAUNA ULU 14 Dec 1969
NMNH 116092-12 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-120 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 14 Dec 1969
NMNH 116092-121 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 14 Dec 1969
NMNH 116092-122 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 16 Dec 1969
NMNH 116092-123 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-124 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-125 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 16 Dec 1969
NMNH 116092-126 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 17 Dec 1969
NMNH 116092-127 Basalt E RIFT ZONE - MAUNA ULU 17 Dec 1969
NMNH 116092-128 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 18 Dec 1969
NMNH 116092-129 Basalt E RIFT ZONE - MAUNA ULU 18 Dec 1969
NMNH 116092-13 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-130 Basalt E RIFT ZONE - MAUNA ULU 19 Dec 1969
NMNH 116092-131 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 29 Dec 1969
NMNH 116092-132 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-133 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-134 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-135 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 30 Dec 1969
NMNH 116092-136 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-137 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-138 Olivine Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-139 Olivine Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-14 Basaltic Pumice E RIFT ZONE - MAUNA ULU 13 Jun 1969
NMNH 116092-140 Olivine Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-141 Glassy Basalt E RIFT ZONE - MAUNA ULU 2 Jan 1970
NMNH 116092-142 Olivine Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-143 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-144 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-145 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-146 Vesicular Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-15 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-16 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-17 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-18 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-19 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-2 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-20 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-21 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-22 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-23 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-24 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-25 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-26 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-27 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-28 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-29 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-3 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-30 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-31 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-32 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-33 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-34 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-35 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-36 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-37 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-38 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-39 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-4 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-40 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-41 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-42 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-43 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-44 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-45 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-46 Olivine Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-47 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-48 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-49 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-5 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-50 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-51 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-52 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-53 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-54 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-55 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-56 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-57 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-58 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 19 Aug 1969
NMNH 116092-59 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-6 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-60 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 Sep 1969
NMNH 116092-61 Glassy Basalt E RIFT ZONE - MAUNA ULU 26 Sep 1969
NMNH 116092-62 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-63 Basalt E RIFT ZONE - MAUNA ULU 10 Oct 1969
NMNH 116092-64 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-65 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 11 Oct 1969
NMNH 116092-66 Basalt E RIFT ZONE - MAUNA ULU 19 Oct 1969
NMNH 116092-67 Basalt E RIFT ZONE - MAUNA ULU 15 Oct 1969
NMNH 116092-68 Basaltic Pumice E RIFT ZONE - MAUNA ULU 20 Oct 1969
NMNH 116092-69 Basaltic Reticulite E RIFT ZONE - MAUNA ULU 20 Oct 1969
NMNH 116092-7 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-70 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-71 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-72 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-73 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-74 Olivine Basalt E RIFT ZONE - MAUNA ULU 2 Jan 1970
NMNH 116092-75 Olivine Basalt E RIFT ZONE - MAUNA ULU 24 Oct 1969
NMNH 116092-76 Basalt E RIFT ZONE - MAUNA ULU 27 Oct 1969
NMNH 116092-77 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-78 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 Nov 1969
NMNH 116092-79 Basalt E RIFT ZONE - MAUNA ULU 8 Nov 1969
NMNH 116092-8 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-80 Basalt E RIFT ZONE - MAUNA ULU 9 Nov 1969
NMNH 116092-81 Basalt E RIFT ZONE - MAUNA ULU 9 Nov 1969
NMNH 116092-82 Basalt E RIFT ZONE - MAUNA ULU 9 Nov 1969
NMNH 116092-83 Basalt E RIFT ZONE - MAUNA ULU 9 Nov 1969
NMNH 116092-84 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-85 Basalt E RIFT ZONE - MAUNA ULU 9 Nov 1969
NMNH 116092-86 Basalt E RIFT ZONE - MAUNA ULU 10 Nov 1969
NMNH 116092-87 Basalt E RIFT ZONE - MAUNA ULU 10 Nov 1969
NMNH 116092-88 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 23 May 1970
NMNH 116092-89 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 12 Nov 1969
NMNH 116092-9 Basaltic Pumice E RIFT ZONE - MAUNA ULU --
NMNH 116092-90 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 13 Nov 1969
NMNH 116092-91 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-92 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-93 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 17 Nov 1969
NMNH 116092-94 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-95 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-96 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-97 Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116092-98 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 30 Nov 1969
NMNH 116092-99 Basalt E RIFT ZONE - MAUNA ULU 30 Nov 1969
NMNH 116093-1 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-10 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 11 Feb 1970
NMNH 116093-100 Glassy Basalt E RIFT ZONE - MAUNA ULU 1 Oct 1970
NMNH 116093-101 Basalt E RIFT ZONE - MAUNA ULU 3 Oct 1970
NMNH 116093-102 Glassy Basalt E RIFT ZONE - MAUNA ULU 6 Oct 1970
NMNH 116093-103 Basalt E RIFT ZONE - MAUNA ULU 8 Oct 1970
NMNH 116093-104 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-105 Glassy Basalt E RIFT ZONE - MAUNA ULU 21 Oct 1970
NMNH 116093-106 Glassy Basalt E RIFT ZONE - MAUNA ULU 24 Oct 1970
NMNH 116093-107 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-108 Glassy Basalt E RIFT ZONE - MAUNA ULU 29 Oct 1970
NMNH 116093-109 Glassy Basalt E RIFT ZONE - MAUNA ULU 29 Oct 1970
NMNH 116093-11 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-110 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-111 Glassy Basalt E RIFT ZONE - MAUNA ULU 2 Nov 1970
NMNH 116093-112 Glassy Basalt E RIFT ZONE - MAUNA ULU 5 Nov 1970
NMNH 116093-113 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 Nov 1970
NMNH 116093-12 Basaltic Pumice E RIFT ZONE - MAUNA ULU 13 Feb 1970
NMNH 116093-13 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-14 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 14 Feb 1970
NMNH 116093-15 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 14 Feb 1970
NMNH 116093-16 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 15 Feb 1970
NMNH 116093-17 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-18 Glassy Basalt E RIFT ZONE - MAUNA ULU 22 Feb 1970
NMNH 116093-19 Glassy Basalt E RIFT ZONE - MAUNA ULU 22 Feb 1970
NMNH 116093-2 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-20 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 1 Mar 1970
NMNH 116093-21 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 1 Mar 1970
NMNH 116093-22 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 1 Mar 1970
NMNH 116093-23 Glassy Basalt E RIFT ZONE - MAUNA ULU 7 Mar 1970
NMNH 116093-24 Glassy Basalt E RIFT ZONE - MAUNA ULU 7 Mar 1970
NMNH 116093-25 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-26 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-27 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 9 Apr 1970
NMNH 116093-28 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-29 Glassy Basalt E RIFT ZONE - MAUNA ULU 12 Apr 1970
NMNH 116093-3 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 30 Jan 1970
NMNH 116093-30 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 15 Apr 1970
NMNH 116093-31 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 15 Apr 1970
NMNH 116093-32 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-33 Vesicular Basalt E RIFT ZONE - MAUNA ULU 13 May 1970
NMNH 116093-34 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 20 May 1970
NMNH 116093-35 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-36 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 21 May 1970
NMNH 116093-37 Glassy Basalt E RIFT ZONE - MAUNA ULU 21 May 1970
NMNH 116093-38 Glassy Basalt E RIFT ZONE - MAUNA ULU 21 May 1970
NMNH 116093-39 Olivine Basalt E RIFT ZONE - MAUNA ULU 22 May 1970
NMNH 116093-4 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 30 Jan 1970
NMNH 116093-40 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 22 May 1970
NMNH 116093-41 Glassy Basalt E RIFT ZONE - MAUNA ULU 24 May 1970
NMNH 116093-42 Glassy Basalt E RIFT ZONE - MAUNA ULU 24 May 1970
NMNH 116093-43 Glassy Basalt E RIFT ZONE - MAUNA ULU 24 May 1970
NMNH 116093-44 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 23 May 1970
NMNH 116093-45 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-46 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 26 May 1970
NMNH 116093-47 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 29 May 1970
NMNH 116093-48 Glassy Basalt E RIFT ZONE - MAUNA ULU 31 May 1970
NMNH 116093-49 Glassy Basalt E RIFT ZONE - MAUNA ULU 7 Jun 1970
NMNH 116093-5 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-50 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-51 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 Jun 1970
NMNH 116093-52 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 Jun 1970
NMNH 116093-53 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-54 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-55 Glassy Basalt E RIFT ZONE - MAUNA ULU 20 Jun 1970
NMNH 116093-56 Glassy Basalt E RIFT ZONE - MAUNA ULU 20 Jun 1970
NMNH 116093-57 Glassy Basalt E RIFT ZONE - MAUNA ULU 25 Jun 1970
NMNH 116093-58 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-59 Glassy Basalt E RIFT ZONE - MAUNA ULU 29 Jun 1970
NMNH 116093-6 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-60 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 7 Jul 1970
NMNH 116093-61 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-62 Glassy Basalt E RIFT ZONE - MAUNA ULU 7 Jul 1970
NMNH 116093-63 Glassy Basalt E RIFT ZONE - MAUNA ULU 7 Jul 1970
NMNH 116093-64 Glassy Basalt E RIFT ZONE - MAUNA ULU 9 Jul 1970
NMNH 116093-65 Pele's Hair E RIFT ZONE - MAUNA ULU 9 Jul 1970
NMNH 116093-66 Glassy Basalt E RIFT ZONE - MAUNA ULU 9 Jul 1970
NMNH 116093-67 Basalt E RIFT ZONE - MAUNA ULU 13 Jul 1970
NMNH 116093-68 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 13 Jul 1970
NMNH 116093-69 Glassy Basalt E RIFT ZONE - MAUNA ULU 21 Jul 1970
NMNH 116093-7 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-70 Glassy Basalt E RIFT ZONE - MAUNA ULU 21 Jul 1970
NMNH 116093-71 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 23 Jul 1970
NMNH 116093-72 Glassy Basalt E RIFT ZONE - MAUNA ULU 25 Jul 1970
NMNH 116093-73 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 3 Aug 1970
NMNH 116093-74 Glassy Basalt E RIFT ZONE - MAUNA ULU 3 Aug 1970
NMNH 116093-75 Glassy Basalt E RIFT ZONE - MAUNA ULU 10 Aug 1970
NMNH 116093-76 Glassy Basalt E RIFT ZONE - MAUNA ULU 10 Aug 1970
NMNH 116093-77 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 11 Aug 1970
NMNH 116093-78 Glassy Basalt E RIFT ZONE - MAUNA ULU 15 Aug 1970
NMNH 116093-79 Glassy Basalt E RIFT ZONE - MAUNA ULU 16 Aug 1970
NMNH 116093-8 Pumiceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-80 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-81 Basalt E RIFT ZONE - MAUNA ULU 19 Aug 1970
NMNH 116093-82 Basalt E RIFT ZONE - MAUNA ULU 22 Aug 1970
NMNH 116093-83 Glassy Basalt E RIFT ZONE - MAUNA ULU 27 Aug 1970
NMNH 116093-84 Glassy Basalt E RIFT ZONE - MAUNA ULU 27 Aug 1970
NMNH 116093-85 Glassy Basalt E RIFT ZONE - MAUNA ULU 1 Sep 1970
NMNH 116093-86 Glassy Basalt E RIFT ZONE - MAUNA ULU 1 Sep 1970
NMNH 116093-87 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-88 Glassy Basalt E RIFT ZONE - MAUNA ULU 3 Sep 1970
NMNH 116093-89 Basalt E RIFT ZONE - MAUNA ULU 5 Sep 1970
NMNH 116093-9 Basalt E RIFT ZONE - MAUNA ULU 11 Feb 1970
NMNH 116093-90 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 Sep 1970
NMNH 116093-91 Glassy Basalt E RIFT ZONE - MAUNA ULU 11 Sep 1970
NMNH 116093-92 Basalt E RIFT ZONE - MAUNA ULU 21 Sep 1970
NMNH 116093-93 Olivine Basalt E RIFT ZONE - MAUNA ULU 21 Sep 1970
NMNH 116093-94 Olivine Basalt E RIFT ZONE - MAUNA ULU 21 Sep 1970
NMNH 116093-95 Glassy Basalt E RIFT ZONE - MAUNA ULU 21 Sep 1970
NMNH 116093-96 Glassy Basalt E RIFT ZONE - MAUNA ULU 22 Sep 1970
NMNH 116093-97 Glassy Basalt E RIFT ZONE - MAUNA ULU 22 Sep 1970
NMNH 116093-98 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116093-99 Glassy Basalt E RIFT ZONE - MAUNA ULU 1 Oct 1970
NMNH 116094-1 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116094-10 Glassy Basalt E RIFT ZONE - MAUNA ULU 12 Apr 1971
NMNH 116094-11 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116094-12 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116094-13 Glassy Basalt E RIFT ZONE - MAUNA ULU 12 Apr 1971
NMNH 116094-14 Glassy Basalt E RIFT ZONE - MAUNA ULU 19 Apr 1971
NMNH 116094-15 Basalt E RIFT ZONE - MAUNA ULU 19 Apr 1971
NMNH 116094-16 Basalt E RIFT ZONE - MAUNA ULU 19 Apr 1971
NMNH 116094-2 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116094-3 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116094-4 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116094-5 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116094-6 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 15 Feb 1971
NMNH 116094-7 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 28 Feb 1971
NMNH 116094-8 Basaltic Sand E RIFT ZONE - MAUNA ULU 25 Mar 1971
NMNH 116094-9 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116095-1 Pumice-Pele's Hair CALDERA 14 Aug 1971
NMNH 116095-10 Pumiceous Basalt CALDERA 20 Aug 1971
NMNH 116095-11 Glassy Basalt CALDERA 20 Aug 1971
NMNH 116095-12 Glassy Basalt CALDERA 19 Aug 1971
NMNH 116095-13 Glassy Basalt CALDERA --
NMNH 116095-14 Glassy Basalt CALDERA --
NMNH 116095-15 Scoriaceous Basalt CALDERA --
NMNH 116095-16 Glassy Basalt CALDERA 9 May 1972
NMNH 116095-17 Vesicular Basalt CALDERA --
NMNH 116095-18 Glassy Basalt CALDERA --
NMNH 116095-19 Scoriaceous Basalt CALDERA --
NMNH 116095-2 Basaltic Pumice CALDERA 14 Aug 1971
NMNH 116095-20 Glassy Basalt CALDERA --
NMNH 116095-21 Scoriaceous Basalt CALDERA --
NMNH 116095-22 Pumiceous Basalt CALDERA --
NMNH 116095-3 Glassy Basalt CALDERA 14 Aug 1971
NMNH 116095-4 Glassy Basalt CALDERA 14 Aug 1971
NMNH 116095-5 Glassy Basalt CALDERA 14 Aug 1971
NMNH 116095-6 Scoriaceous Basalt CALDERA 14 Aug 1971
NMNH 116095-7 Basaltic Pumice CALDERA 14 Aug 1971
NMNH 116095-8 Basaltic Pumice CALDERA --
NMNH 116095-9 Scoriaceous Basalt CALDERA 15 Aug 1971
NMNH 116096-1 Basaltic Pumice CALDERA 24 Sep 1971
NMNH 116096-10 Glassy Basalt CALDERA/SW RIFT ZONE --
NMNH 116096-11 Glassy Basalt CALDERA/SW RIFT ZONE --
NMNH 116096-12 Scoriaceous Basalt CALDERA/SW RIFT ZONE --
NMNH 116096-13 Scoriaceous Basalt CALDERA/SW RIFT ZONE --
NMNH 116096-2 Glassy Basalt CALDERA/SW RIFT ZONE 25 Sep 1971
NMNH 116096-3 Glassy Basalt CALDERA/SW RIFT ZONE 26 Sep 1971
NMNH 116096-4 Glassy Basalt SW RIFT ZONE 5 Oct 1971
NMNH 116096-5 Glassy Basalt CALDERA 26 Sep 1971
NMNH 116096-6 Scoriaceous Basalt CALDERA 24 Sep 1971
NMNH 116096-7 Scoriaceous Basalt SW RIFT ZONE 25 Sep 1971
NMNH 116096-8 Scoriaceous Basalt SW RIFT ZONE 26 Sep 1971
NMNH 116096-9 Glassy Basalt CALDERA 15 Nov 1971
NMNH 116097-1 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 Feb 1972
NMNH 116097-10 Basaltic Pumice E RIFT ZONE - MAUNA ULU 22 Feb 1972
NMNH 116097-11 Glassy Basalt E RIFT ZONE - MAUNA ULU 25 Feb 1972
NMNH 116097-12 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116097-13 Glassy Basalt E RIFT ZONE - MAUNA ULU 26 Feb 1972
NMNH 116097-14 Glassy Basalt E RIFT ZONE - MAUNA ULU 26 Feb 1972
NMNH 116097-15 Glassy Basalt E RIFT ZONE - MAUNA ULU 26 Feb 1972
NMNH 116097-16 Glassy Basalt E RIFT ZONE - MAUNA ULU 27 Feb 1972
NMNH 116097-17 Glassy Basalt E RIFT ZONE - MAUNA ULU 28 Feb 1972
NMNH 116097-18 Glassy Basalt E RIFT ZONE - MAUNA ULU 1 Mar 1972
NMNH 116097-19 Glassy Basalt E RIFT ZONE - MAUNA ULU 1 Mar 1972
NMNH 116097-2 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 Feb 1972
NMNH 116097-20 Glassy Basalt E RIFT ZONE - MAUNA ULU 14 Mar 1972
NMNH 116097-21 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116097-22 Glassy Basalt E RIFT ZONE - MAUNA ULU 16 Mar 1972
NMNH 116097-23 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 19 Mar 1972
NMNH 116097-24 Glassy Basalt E RIFT ZONE - MAUNA ULU 20 Mar 1972
NMNH 116097-25 Glassy Basalt E RIFT ZONE - MAUNA ULU 20 Mar 1972
NMNH 116097-26 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 20 Mar 1972
NMNH 116097-27 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 21 Mar 1972
NMNH 116097-28 Glassy Basalt E RIFT ZONE - MAUNA ULU 3 Apr 1972
NMNH 116097-29 Glassy Basalt E RIFT ZONE - MAUNA ULU 5 Apr 1972
NMNH 116097-3 Glassy Basalt E RIFT ZONE - MAUNA ULU 9 Feb 1972
NMNH 116097-30 Glassy Basalt E RIFT ZONE - MAUNA ULU 11 Apr 1972
NMNH 116097-31 Basalt E RIFT ZONE - MAUNA ULU 14 Apr 1972
NMNH 116097-32 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 14 Apr 1972
NMNH 116097-33 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 14 Apr 1972
NMNH 116097-34 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 May 1972
NMNH 116097-35 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 May 1972
NMNH 116097-36 Glassy Basalt E RIFT ZONE - MAUNA ULU 15 May 1972
NMNH 116097-37 Glassy Basalt E RIFT ZONE - MAUNA ULU 17 May 1972
NMNH 116097-38 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116097-39 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116097-4 Glassy Basalt E RIFT ZONE - MAUNA ULU 13 Feb 1972
NMNH 116097-40 Glassy Basalt E RIFT ZONE - MAUNA ULU 23 May 1972
NMNH 116097-41 Basalt E RIFT ZONE - MAUNA ULU 1 Jun 1972
NMNH 116097-42 Glassy Basalt E RIFT ZONE - MAUNA ULU 9 Jun 1972
NMNH 116097-43 Glassy Basalt E RIFT ZONE - MAUNA ULU 9 Jun 1972
NMNH 116097-44 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 21 Jun 1972
NMNH 116097-45 Glassy Basalt E RIFT ZONE - MAUNA ULU 21 Jun 1972
NMNH 116097-46 Glassy Basalt E RIFT ZONE - MAUNA ULU 6 Jul 1972
NMNH 116097-47 Glassy Basalt E RIFT ZONE - MAUNA ULU 11 Jul 1972
NMNH 116097-48 Glassy Basalt E RIFT ZONE - MAUNA ULU 11 Jul 1972
NMNH 116097-49 Pele's Hair E RIFT ZONE - MAUNA ULU --
NMNH 116097-5 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116097-50 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116097-51 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116097-52 Glassy Basalt E RIFT ZONE - MAUNA ULU 10 Aug 1972
NMNH 116097-53 Vesicular Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116097-54 Vesicular Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116097-55 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116097-56 Glassy Basalt E RIFT ZONE - MAUNA ULU 24 Aug 1972
NMNH 116097-57 Glassy Basalt E RIFT ZONE - MAUNA ULU 21 Aug 1972
NMNH 116097-58 Glassy Basalt E RIFT ZONE - MAUNA ULU 5 Sep 1972
NMNH 116097-59 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116097-6 Basaltic Pumice E RIFT ZONE - MAUNA ULU 15 Feb 1972
NMNH 116097-60 Glassy Basalt E RIFT ZONE - MAUNA ULU 7 Sep 1972
NMNH 116097-61 Glassy Basalt E RIFT ZONE - MAUNA ULU 9 Sep 1972
NMNH 116097-62 Glassy Basalt E RIFT ZONE - MAUNA ULU 28 Sep 1972
NMNH 116097-63 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116097-64 Basalt E RIFT ZONE - MAUNA ULU 13 Oct 1972
NMNH 116097-65 Glassy Basalt E RIFT ZONE - MAUNA ULU 17 Oct 1972
NMNH 116097-66 Glassy Basalt E RIFT ZONE - MAUNA ULU 25 Oct 1972
NMNH 116097-67 Glassy Basalt E RIFT ZONE - MAUNA ULU 25 Oct 1972
NMNH 116097-68 Glassy Basalt E RIFT ZONE - MAUNA ULU 7 Nov 1972
NMNH 116097-69 Glassy Basalt E RIFT ZONE - MAUNA ULU 7 Nov 1972
NMNH 116097-7 Glassy Basalt E RIFT ZONE - MAUNA ULU 7 Feb 1972
NMNH 116097-70 Glassy Basalt E RIFT ZONE - MAUNA ULU 28 Nov 1972
NMNH 116097-71 Glassy Basalt E RIFT ZONE - MAUNA ULU 1 Dec 1972
NMNH 116097-72 Glassy Basalt E RIFT ZONE - MAUNA ULU 13 Dec 1972
NMNH 116097-73 Glassy Basalt E RIFT ZONE - MAUNA ULU 14 Dec 1972
NMNH 116097-74 Glassy Basalt E RIFT ZONE - MAUNA ULU 14 Dec 1972
NMNH 116097-8 Glassy Basalt E RIFT ZONE - MAUNA ULU 12 Feb 1972
NMNH 116097-9 Glassy Basalt E RIFT ZONE - MAUNA ULU 16 Feb 1972
NMNH 116098-1 Pele's Hair E RIFT ZONE - MAUNA ULU 15 Jan 1973
NMNH 116098-10 Glassy Basalt E RIFT ZONE - MAUNA ULU 2 Feb 1973
NMNH 116098-11 Glassy Basalt E RIFT ZONE - MAUNA ULU 1 Feb 1973
NMNH 116098-12 Glassy Basalt E RIFT ZONE - MAUNA ULU 14 Feb 1973
NMNH 116098-13 Glassy Basalt E RIFT ZONE - MAUNA ULU 18 Feb 1973
NMNH 116098-14 Glassy Basalt E RIFT ZONE - MAUNA ULU 28 Feb 1973
NMNH 116098-15 Glassy Basalt E RIFT ZONE - MAUNA ULU 3 Mar 1973
NMNH 116098-16 Glassy Basalt E RIFT ZONE - MAUNA ULU 4 Mar 1973
NMNH 116098-17 Glassy Basalt E RIFT ZONE - MAUNA ULU 6 Mar 1973
NMNH 116098-18 Glassy Basalt E RIFT ZONE - MAUNA ULU 6 Mar 1973
NMNH 116098-19 Basaltic Sand E RIFT ZONE - MAUNA ULU 6 Mar 1973
NMNH 116098-2 Glassy Basalt E RIFT ZONE - MAUNA ULU 16 Jan 1973
NMNH 116098-20 Glassy Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116098-21 Glassy Basalt E RIFT ZONE - MAUNA ULU 14 Mar 1973
NMNH 116098-22 Glassy Basalt E RIFT ZONE - MAUNA ULU 14 Mar 1973
NMNH 116098-23 Glassy Basalt E RIFT ZONE - MAUNA ULU 15 Mar 1973
NMNH 116098-24 Glassy Basalt E RIFT ZONE - MAUNA ULU 20 Mar 1973
NMNH 116098-25 Glassy Basalt E RIFT ZONE - MAUNA ULU 23 Mar 1973
NMNH 116098-26 Glassy Basalt E RIFT ZONE - MAUNA ULU 3 Mar 1973
NMNH 116098-27 Glassy Basalt E RIFT ZONE - MAUNA ULU 10 Apr 1973
NMNH 116098-28 Glassy Basalt E RIFT ZONE - MAUNA ULU 10 Apr 1973
NMNH 116098-29 Basalt E RIFT ZONE - MAUNA ULU 1 Apr 1973
NMNH 116098-3 Glassy Basalt E RIFT ZONE - MAUNA ULU 26 Jan 1973
NMNH 116098-30 Glassy Basalt E RIFT ZONE - MAUNA ULU 1 May 1973
NMNH 116098-31 Glassy Basalt E RIFT ZONE - MAUNA ULU 1 May 1973
NMNH 116098-32 Glassy Basalt E RIFT ZONE - MAUNA ULU 2 May 1973
NMNH 116098-33 Glassy Basalt E RIFT ZONE - MAUNA ULU 7 Jun 1973
NMNH 116098-34 Glassy Basalt E RIFT ZONE - MAUNA ULU 7 Jun 1973
NMNH 116098-35 Glassy Basalt E RIFT ZONE - MAUNA ULU 9 Jun 1973
NMNH 116098-36 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 30 Oct 1973
NMNH 116098-37 Basalt E RIFT ZONE - MAUNA ULU 30 Oct 1973
NMNH 116098-38 Basalt E RIFT ZONE - MAUNA ULU 30 Oct 1973
NMNH 116098-39 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 4 Nov 1973
NMNH 116098-4 Glassy Basalt E RIFT ZONE - MAUNA ULU 24 Jan 1973
NMNH 116098-40 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 4 Nov 1973
NMNH 116098-41 Glassy Basalt E RIFT ZONE - MAUNA ULU 4 Nov 1973
NMNH 116098-42 Glassy Basalt E RIFT ZONE - MAUNA ULU 4 Nov 1973
NMNH 116098-43 Glassy Basalt E RIFT ZONE - MAUNA ULU 4 Nov 1973
NMNH 116098-44 Glassy Basalt E RIFT ZONE - MAUNA ULU 5 Nov 1973
NMNH 116098-45 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 Nov 1973
NMNH 116098-46 Basalt E RIFT ZONE - MAUNA ULU 27 Dec 1973
NMNH 116098-47 Glassy Basalt E RIFT ZONE - MAUNA ULU 27 Dec 1973
NMNH 116098-5 Glassy Basalt E RIFT ZONE - MAUNA ULU 30 Jan 1973
NMNH 116098-6 Glassy Basalt E RIFT ZONE - MAUNA ULU 31 Jan 1973
NMNH 116098-7 Glassy Basalt E RIFT ZONE - MAUNA ULU 31 Jan 1973
NMNH 116098-8 Glassy Basalt E RIFT ZONE - MAUNA ULU 31 Jan 1973
NMNH 116098-9 Glassy Basalt E RIFT ZONE - MAUNA ULU 2 Feb 1973
NMNH 116099-1 Glassy Basalt E RIFT ZONE - MAUNA ULU 2 Jan 1974
NMNH 116099-10 Glassy Basalt E RIFT ZONE - MAUNA ULU 30 Jan 1974
NMNH 116099-11 Basaltic Pumice E RIFT ZONE - MAUNA ULU 31 Jan 1974
NMNH 116099-12 Glassy Basalt E RIFT ZONE - MAUNA ULU 31 Jan 1974
NMNH 116099-13 Basaltic Pumice E RIFT ZONE - MAUNA ULU 2 Feb 1974
NMNH 116099-14 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 2 Feb 1974
NMNH 116099-15 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU --
NMNH 116099-16 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 2 Feb 1974
NMNH 116099-17 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 8 Feb 1974
NMNH 116099-18 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 9 Feb 1974
NMNH 116099-19 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 12 Feb 1974
NMNH 116099-2 Glassy Basalt E RIFT ZONE - MAUNA ULU 23 Jan 1974
NMNH 116099-20 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 14 Feb 1974
NMNH 116099-21 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 14 Feb 1974
NMNH 116099-22 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 28 Feb 1974
NMNH 116099-23 Glassy Basalt E RIFT ZONE - MAUNA ULU 28 Feb 1974
NMNH 116099-24 Glassy Basalt E RIFT ZONE - MAUNA ULU 28 Feb 1974
NMNH 116099-25 Glassy Basalt E RIFT ZONE - MAUNA ULU 28 Feb 1974
NMNH 116099-26 Glassy Basalt E RIFT ZONE - MAUNA ULU 28 Feb 1974
NMNH 116099-27 Glassy Basalt E RIFT ZONE - MAUNA ULU 28 Feb 1974
NMNH 116099-28 Glassy Basalt E RIFT ZONE - MAUNA ULU 28 Feb 1974
NMNH 116099-29 Glassy Basalt E RIFT ZONE - MAUNA ULU 28 Feb 1974
NMNH 116099-3 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 24 Jan 1974
NMNH 116099-30 Glassy Basalt E RIFT ZONE - MAUNA ULU 28 Feb 1974
NMNH 116099-31 Reticulite E RIFT ZONE - MAUNA ULU 28 Feb 1974
NMNH 116099-32 Glassy Basalt E RIFT ZONE - MAUNA ULU 5 Mar 1974
NMNH 116099-33 Glassy Basalt E RIFT ZONE - MAUNA ULU 18 Mar 1974
NMNH 116099-34 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 23 Mar 1974
NMNH 116099-35 Pumiceous Basalt E RIFT ZONE - MAUNA ULU 23 Mar 1974
NMNH 116099-36 Glassy Basalt E RIFT ZONE - MAUNA ULU 23 Mar 1974
NMNH 116099-37 Glassy Basalt E RIFT ZONE - MAUNA ULU 27 Mar 1974
NMNH 116099-38 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 3 Apr 1974
NMNH 116099-39 Glassy Basalt E RIFT ZONE - MAUNA ULU 5 Apr 1974
NMNH 116099-4 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 25 Jan 1974
NMNH 116099-40 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 Apr 1974
NMNH 116099-41 Glassy Basalt E RIFT ZONE - MAUNA ULU 10 Apr 1974
NMNH 116099-42 Glassy Basalt E RIFT ZONE - MAUNA ULU 11 Apr 1974
NMNH 116099-43 Glassy Basalt E RIFT ZONE - MAUNA ULU 13 Apr 1974
NMNH 116099-44 Glassy Basalt E RIFT ZONE - MAUNA ULU 15 Apr 1974
NMNH 116099-45 Glassy Basalt E RIFT ZONE - MAUNA ULU 22 Apr 1974
NMNH 116099-46 Glassy Basalt E RIFT ZONE - MAUNA ULU 3 May 1974
NMNH 116099-47 Glassy Basalt E RIFT ZONE - MAUNA ULU 6 May 1974
NMNH 116099-48 Glassy Basalt E RIFT ZONE - MAUNA ULU 30 May 1974
NMNH 116099-49 Glassy Basalt E RIFT ZONE - MAUNA ULU 31 May 1974
NMNH 116099-5 Basaltic Pumice E RIFT ZONE - MAUNA ULU 25 Jan 1974
NMNH 116099-50 Glassy Basalt E RIFT ZONE - MAUNA ULU 8 Jun 1974
NMNH 116099-6 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 25 Jan 1974
NMNH 116099-7 Scoriaceous Basalt E RIFT ZONE - MAUNA ULU 25 Jan 1974
NMNH 116099-8 Glassy Basalt E RIFT ZONE - MAUNA ULU 26 Jan 1974
NMNH 116099-9 Glassy Basalt E RIFT ZONE - MAUNA ULU 30 Jan 1974
NMNH 116100 Scoriaceous Basalt E RIFT ZONE --
NMNH 116101 Scoriaceous Basalt E RIFT ZONE --
NMNH 116102 Scoriaceous Basalt E RIFT ZONE --
NMNH 116103 Scoriaceous Basalt E RIFT ZONE --
NMNH 116104 Scoriaceous Basalt E RIFT ZONE --
NMNH 116111-1 Basalt KILAUEA IKI CRATER --
NMNH 116111-10 Basalt KILAUEA IKI CRATER --
NMNH 116111-11 Basalt KILAUEA IKI CRATER --
NMNH 116111-12 Basalt KILAUEA IKI CRATER --
NMNH 116111-13 Basalt KILAUEA IKI CRATER --
NMNH 116111-14 Basalt KILAUEA IKI CRATER --
NMNH 116111-15 Basalt KILAUEA IKI CRATER --
NMNH 116111-16 Basalt KILAUEA IKI CRATER --
NMNH 116111-17 Basalt KILAUEA IKI CRATER --
NMNH 116111-18 Basalt KILAUEA IKI CRATER --
NMNH 116111-19 Basalt KILAUEA IKI CRATER --
NMNH 116111-2 Basaltic Pumice KILAUEA IKI CRATER --
NMNH 116111-20 Basalt KILAUEA IKI CRATER --
NMNH 116111-21 Basalt KILAUEA IKI CRATER --
NMNH 116111-22 Basalt KILAUEA IKI CRATER --
NMNH 116111-23 Basalt KILAUEA IKI CRATER --
NMNH 116111-24 Basalt KILAUEA IKI CRATER --
NMNH 116111-25 Basalt KILAUEA IKI CRATER --
NMNH 116111-26 Basalt KILAUEA IKI CRATER --
NMNH 116111-27 Basalt KILAUEA IKI CRATER --
NMNH 116111-28 Basalt KILAUEA IKI CRATER --
NMNH 116111-29 Basalt KILAUEA IKI CRATER --
NMNH 116111-3 Basalt KILAUEA IKI CRATER --
NMNH 116111-30 Basalt KILAUEA IKI CRATER --
NMNH 116111-31 Basalt KILAUEA IKI CRATER --
NMNH 116111-32 Basalt KILAUEA IKI CRATER --
NMNH 116111-33 Basalt KILAUEA IKI CRATER --
NMNH 116111-34 Basalt KILAUEA IKI CRATER --
NMNH 116111-35 Basalt KILAUEA IKI CRATER --
NMNH 116111-36 Basalt KILAUEA IKI CRATER --
NMNH 116111-37 Basalt KILAUEA IKI CRATER --
NMNH 116111-38 Basalt KILAUEA IKI CRATER --
NMNH 116111-39 Basalt KILAUEA IKI CRATER --
NMNH 116111-4 Basaltic Pumice KILAUEA IKI CRATER --
NMNH 116111-40 Basalt KILAUEA IKI CRATER --
NMNH 116111-41 Basalt KILAUEA IKI CRATER --
NMNH 116111-42 Basalt KILAUEA IKI CRATER --
NMNH 116111-43 Basalt KILAUEA IKI CRATER --
NMNH 116111-44 Basalt KILAUEA IKI CRATER --
NMNH 116111-45 Basalt KILAUEA IKI CRATER --
NMNH 116111-46 Basalt KILAUEA IKI CRATER --
NMNH 116111-47 Basalt KILAUEA IKI CRATER --
NMNH 116111-48 Basalt KILAUEA IKI CRATER --
NMNH 116111-49 Basalt KILAUEA IKI CRATER --
NMNH 116111-5 Basalt KILAUEA IKI CRATER --
NMNH 116111-50 Basalt KILAUEA IKI CRATER --
NMNH 116111-51 Basalt KILAUEA IKI CRATER --
NMNH 116111-52 Basalt KILAUEA IKI CRATER --
NMNH 116111-53 Basalt KILAUEA IKI CRATER --
NMNH 116111-54 Basalt KILAUEA IKI CRATER --
NMNH 116111-55 Basalt KILAUEA IKI CRATER --
NMNH 116111-56 Basalt KILAUEA IKI CRATER --
NMNH 116111-57 Basalt KILAUEA IKI CRATER 15 Nov 1959
NMNH 116111-58 Basalt KILAUEA IKI CRATER --
NMNH 116111-59 Basalt KILAUEA IKI CRATER 5 Dec 1959
NMNH 116111-6 Pele's Hair KILAUEA IKI CRATER --
NMNH 116111-60 Basalt KILAUEA IKI CRATER --
NMNH 116111-61 Basalt KILAUEA IKI CRATER --
NMNH 116111-62 Basalt KILAUEA IKI CRATER --
NMNH 116111-63 Basalt KILAUEA IKI CRATER --
NMNH 116111-64 Basalt KILAUEA IKI CRATER --
NMNH 116111-65 Basalt KILAUEA IKI CRATER --
NMNH 116111-66 Basalt KILAUEA IKI CRATER --
NMNH 116111-67 Basalt KILAUEA IKI CRATER --
NMNH 116111-68 Basalt KILAUEA IKI CRATER --
NMNH 116111-69 Basalt KILAUEA IKI CRATER --
NMNH 116111-7 Basalt KILAUEA IKI CRATER --
NMNH 116111-70 Basalt KILAUEA IKI CRATER --
NMNH 116111-71 Basalt KILAUEA IKI CRATER --
NMNH 116111-72 Basalt KILAUEA IKI CRATER --
NMNH 116111-73 Basalt KILAUEA IKI CRATER --
NMNH 116111-74 Basalt KILAUEA IKI CRATER --
NMNH 116111-75 Basalt KILAUEA IKI CRATER --
NMNH 116111-76 Basalt KILAUEA IKI CRATER 5 Dec 1959
NMNH 116111-77 Basalt KILAUEA IKI CRATER --
NMNH 116111-78 Olivine KILAUEA IKI CRATER --
NMNH 116111-8 Glassy Basalt KILAUEA IKI CRATER --
NMNH 116111-9 Basalt KILAUEA IKI CRATER --
NMNH 116112-1 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-10 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-11 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-12 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-13 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-14 Scoriaceous Basalt E RIFT ZONE - PUNA --
NMNH 116112-15 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-16 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-17 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-18 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-19 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-2 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-20 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-21 Olivine Basalt E RIFT ZONE - PUNA --
NMNH 116112-22 Olivine Basalt E RIFT ZONE - PUNA --
NMNH 116112-23 Olivine Basalt E RIFT ZONE - PUNA --
NMNH 116112-24 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-25 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-26 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-27 Olivine Basalt E RIFT ZONE - PUNA --
NMNH 116112-28 Basalt E RIFT ZONE - PUNA --
NMNH 116112-29 Basalt E RIFT ZONE - PUNA --
NMNH 116112-3 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-30 Basalt E RIFT ZONE - PUNA --
NMNH 116112-31 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-32 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-33 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-34 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-35 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-36 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-37 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-38 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-39 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-4 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-40 Scoriaceous Basalt E RIFT ZONE - PUNA --
NMNH 116112-41 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-42 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-43 Scoriaceous Basalt E RIFT ZONE - PUNA --
NMNH 116112-44 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-45 Scoriaceous Basalt E RIFT ZONE - PUNA --
NMNH 116112-46 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-47 Olivine Basalt E RIFT ZONE - PUNA --
NMNH 116112-48 Olivine Basalt E RIFT ZONE - PUNA --
NMNH 116112-49 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-5 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-50 Scoriaceous Basalt E RIFT ZONE - PUNA --
NMNH 116112-51 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-6 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-7 Scoriaceous Basalt E RIFT ZONE - PUNA --
NMNH 116112-8 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116112-9 Basaltic Pumice E RIFT ZONE - PUNA --
NMNH 116113-1 Scoriaceous Basalt KILAUEA IKI CRATER 15 Nov 1959
NMNH 116113-10 Basalt KILAUEA IKI CRATER 17 Nov 1959
NMNH 116113-11 Basaltic Pumice KILAUEA IKI CRATER 18 Nov 1959
NMNH 116113-12 Basalt KILAUEA IKI CRATER 19 Nov 1959
NMNH 116113-13 Basalt KILAUEA IKI CRATER 19 Nov 1959
NMNH 116113-14 Olivine Basalt KILAUEA IKI CRATER 23 Nov 1959
NMNH 116113-15 Basalt KILAUEA IKI CRATER 23 Nov 1959
NMNH 116113-16 Scoriaceous Basalt KILAUEA IKI CRATER 26 Nov 1959
NMNH 116113-17 Basalt KILAUEA IKI CRATER --
NMNH 116113-18 Basalt KILAUEA IKI CRATER 19 Nov 1959
NMNH 116113-2 Scoriaceous Basalt KILAUEA IKI CRATER 15 Nov 1959
NMNH 116113-3 Scoriaceous Basalt KILAUEA IKI CRATER 15 Nov 1959
NMNH 116113-4 Scoriaceous Basalt KILAUEA IKI CRATER 15 Nov 1959
NMNH 116113-5 Scoriaceous Basalt KILAUEA IKI CRATER 15 Nov 1959
NMNH 116113-6 Scoriaceous Basalt KILAUEA IKI CRATER 16 Nov 1959
NMNH 116113-7 Scoriaceous Basalt KILAUEA IKI CRATER 16 Nov 1959
NMNH 116113-8 Vesicular Basalt KILAUEA IKI CRATER 17 Nov 1959
NMNH 116113-9 Vesicular Basalt KILAUEA IKI CRATER 17 Nov 1959
NMNH 116124-1 Basaltic Pumice E RIFT ZONE - PAUAHI CRATER 5 May 1973
NMNH 116124-10 Scoriaceous Basalt E RIFT ZONE - PAUAHI CRATER 10 Sep 1973
NMNH 116124-11 Olivine Basalt E RIFT ZONE - PAUAHI CRATER 10 Sep 1973
NMNH 116124-12 Pumiceous Basalt E RIFT ZONE - PAUAHI CRATER 10 Nov 1973
NMNH 116124-13 Basaltic Pumice E RIFT ZONE - PAUAHI CRATER 12 Nov 1973
NMNH 116124-14 Pele's Hair E RIFT ZONE - PAUAHI CRATER 12 Nov 1973
NMNH 116124-15 Glassy Basalt E RIFT ZONE - PAUAHI CRATER 12 Nov 1973
NMNH 116124-16 Glassy Basalt E RIFT ZONE - PAUAHI CRATER 11 Nov 1973
NMNH 116124-17 Pumiceous Basalt E RIFT ZONE - PAUAHI CRATER --
NMNH 116124-18 Glassy Basalt E RIFT ZONE - PAUAHI CRATER --
NMNH 116124-19 Scoriaceous Basalt E RIFT ZONE - PAUAHI CRATER 29 Nov 1973
NMNH 116124-2 Glassy Basalt E RIFT ZONE - HIIAKA CRATER 5 May 1973
NMNH 116124-20 Glassy Basalt E RIFT ZONE - PAUAHI CRATER 29 Nov 1973
NMNH 116124-21 Scoriaceous Basalt E RIFT ZONE - PAUAHI CRATER 29 Nov 1973
NMNH 116124-22 Scoriaceous Basalt E RIFT ZONE - PAUAHI CRATER 29 Nov 1973
NMNH 116124-23 Scoriaceous Basalt E RIFT ZONE - PAUAHI CRATER 29 Nov 1973
NMNH 116124-24 Glassy Basalt E RIFT ZONE - PAUAHI CRATER 4 Dec 1973
NMNH 116124-25 Scoriaceous Basalt E RIFT ZONE - PAUAHI CRATER 1 May 1974
NMNH 116124-26 Basalt E RIFT ZONE - PAUAHI CRATER 1 May 1974
NMNH 116124-3 Glassy Basalt E RIFT ZONE - HIIAKA CRATER 5 May 1973
NMNH 116124-4 Glassy Basalt E RIFT ZONE - PAUAHI/HIIAKA 5 May 1973
NMNH 116124-5 Scoriaceous Basalt E RIFT ZONE - HIIAKA CRATER 23 May 1973
NMNH 116124-6 Basaltic Pumice E RIFT ZONE - HIIAKA CRATER 23 May 1973
NMNH 116124-7 Pumiceous Basalt E RIFT ZONE - HIIAKA CRATER 23 May 1973
NMNH 116124-8 Pumiceous Basalt E RIFT ZONE - PAUAHI CRATER 10 Sep 1973
NMNH 116124-9 Pumiceous Basalt E RIFT ZONE - PAUAHI CRATER 10 Sep 1973
NMNH 116125-1 Pumiceous Basalt CALDERA 19 Jul 1974
NMNH 116125-10 Scoriaceous Basalt CALDERA 19 Sep 1974
NMNH 116125-11 Scoriaceous Basalt CALDERA 21 Dec 1974
NMNH 116125-2 Pumiceous Basalt CALDERA 19 Jul 1974
NMNH 116125-3 Pumiceous Basalt CALDERA 20 Jul 1974
NMNH 116125-4 Scoriaceous Basalt CALDERA 20 Jul 1974
NMNH 116125-5 Basaltic Pumice CALDERA 20 Jul 1974
NMNH 116125-6 Pele's Hair CALDERA 20 Jul 1974
NMNH 116125-7 Scoriaceous Basalt CALDERA 20 Jul 1974
NMNH 116125-8 Pele's Hair CALDERA 20 Jul 1974
NMNH 116125-9 Scoriaceous Basalt CALDERA 22 Jul 1974
NMNH 116126-1 Pumiceous Basalt SW RIFT ZONE 31 Dec 1974
NMNH 116126-10 Vesicular Basalt SW RIFT ZONE 18 Jan 1975
NMNH 116126-11 Vesicular Basalt SW RIFT ZONE 18 Jan 1975
NMNH 116126-12 Basalt SW RIFT ZONE 18 Jan 1975
NMNH 116126-13 Scoriaceous Basalt SW RIFT ZONE 9 Mar 1975
NMNH 116126-14 Scoriaceous Basalt SW RIFT ZONE 9 Mar 1975
NMNH 116126-15 Scoriaceous Basalt SW RIFT ZONE 9 Mar 1975
NMNH 116126-16 Pumiceous Basalt SW RIFT ZONE 9 Mar 1975
NMNH 116126-17 Scoriaceous Basalt SW RIFT ZONE 9 Mar 1975
NMNH 116126-18 Scoriaceous Basalt SW RIFT ZONE 9 Mar 1975
NMNH 116126-2 Scoriaceous Basalt SW RIFT ZONE 31 Dec 1974
NMNH 116126-3 Pumiceous Basalt SW RIFT ZONE 31 Dec 1974
NMNH 116126-4 Glassy Basalt SW RIFT ZONE 31 Dec 1974
NMNH 116126-5 Scoriaceous Basalt SW RIFT ZONE 31 Dec 1974
NMNH 116126-6 Glassy Basalt SW RIFT ZONE 31 Dec 1974
NMNH 116126-7 Scoriaceous Basalt SW RIFT ZONE 18 Jan 1975
NMNH 116126-8 Scoriaceous Basalt SW RIFT ZONE 18 Jan 1975
NMNH 116126-9 Scoriaceous Basalt SW RIFT ZONE 18 Jan 1975
NMNH 116127-1 Scoriaceous Basalt CALDERA 16 Feb 1975
NMNH 116127-10 Scoriaceous Basalt CALDERA 6 May 1976
NMNH 116127-11 Scoriaceous Basalt CALDERA 6 May 1976
NMNH 116127-12 Vesicular Basalt CALDERA 6 May 1976
NMNH 116127-13 Vesicular Basalt CALDERA 6 May 1976
NMNH 116127-14 Vesicular Basalt CALDERA 6 May 1976
NMNH 116127-2 Scoriaceous Basalt CALDERA 16 Feb 1975
NMNH 116127-3 Scoriaceous Basalt CALDERA 16 Feb 1975
NMNH 116127-4 Scoriaceous Basalt CALDERA 16 Feb 1975
NMNH 116127-5 Scoriaceous Basalt CALDERA 24 Mar 1975
NMNH 116127-6 Pumiceous Basalt CALDERA 24 Mar 1975
NMNH 116127-7 Glassy Basalt CALDERA 24 Mar 1975
NMNH 116127-8 Pumiceous Basalt CALDERA 6 May 1976
NMNH 116127-9 Glassy Basalt CALDERA 6 May 1976
NMNH 116128-1 Scoriaceous Basalt CALDERA 29 Nov 1975
NMNH 116128-10 Scoriaceous Basalt CALDERA 4 Dec 1975
NMNH 116128-2 Scoriaceous Basalt CALDERA 3 Dec 1975
NMNH 116128-3 Scoriaceous Basalt CALDERA 3 Dec 1975
NMNH 116128-4 Scoriaceous Basalt CALDERA 3 Dec 1975
NMNH 116128-5 Scoriaceous Basalt CALDERA 3 Dec 1975
NMNH 116128-6 Basalt CALDERA 3 Dec 1975
NMNH 116128-7 Scoriaceous Basalt CALDERA 4 Dec 1975
NMNH 116128-8 Scoriaceous Basalt CALDERA 4 Dec 1975
NMNH 116128-9 Scoriaceous Basalt CALDERA 4 Dec 1975
NMNH 116129-1 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-10 Basalt E RIFT ZONE - PUU KIAI 20 Sep 1977
NMNH 116129-11 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 20 Sep 1977
NMNH 116129-12 Pumiceous Basalt E RIFT ZONE - PUU KIAI 23 Sep 1977
NMNH 116129-13 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-14 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-15 Pumiceous Basalt E RIFT ZONE - PUU KIAI 26 Sep 1977
NMNH 116129-16 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 27 Sep 1977
NMNH 116129-17 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 27 Sep 1977
NMNH 116129-18 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 28 Sep 1977
NMNH 116129-19 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 29 Sep 1977
NMNH 116129-2 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-20 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 29 Sep 1977
NMNH 116129-21 Pumiceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-22 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 30 Sep 1977
NMNH 116129-23 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 30 Sep 1977
NMNH 116129-24 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 30 Sep 1977
NMNH 116129-25 Pumiceous Basalt E RIFT ZONE - PUU KIAI 1 Oct 1977
NMNH 116129-26 Basaltic Pumice E RIFT ZONE - PUU KIAI 1 Oct 1977
NMNH 116129-27 Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-28 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-29 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-3 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-30 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-31 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-32 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-33 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-34 Pumiceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-35 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-36 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-37 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-38 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 20 Sep 1977
NMNH 116129-39 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 26 Sep 1977
NMNH 116129-4 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 16 Sep 1977
NMNH 116129-40 Glassy Basalt E RIFT ZONE - PUU KIAI 29 Sep 1977
NMNH 116129-5 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-6 Scoriaceous Basalt E RIFT ZONE - PUU KIAI --
NMNH 116129-7 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 18 Sep 1977
NMNH 116129-8 Scoriaceous Basalt E RIFT ZONE - PUU KIAI 18 Sep 1977
NMNH 116129-9 Basalt E RIFT ZONE - PUU KIAI 20 Sep 1977
NMNH 116131-1 Glassy Basalt SW RIFT ZONE --
NMNH 116131-10 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116131-11 Basalt SW RIFT ZONE --
NMNH 116131-12 Glassy Basalt SW RIFT ZONE --
NMNH 116131-2 Picritic Basalt SW RIFT ZONE --
NMNH 116131-3 Glassy Basalt SW RIFT ZONE --
NMNH 116131-4 Glassy Basalt SW RIFT ZONE --
NMNH 116131-5 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116131-6 Olivine Basalt SW RIFT ZONE --
NMNH 116131-7 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116131-8 Glassy Basalt SW RIFT ZONE --
NMNH 116131-9 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116149-1 Scoriaceous Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-10 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-11 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-12 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-13 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-14 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-15 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-16 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-17 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-18 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-19 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-2 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-20 Scoriaceous Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-21 Vesicular Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-3 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-4 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-5 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-6 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-7 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-8 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116149-9 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116153 Basalt E RIFT ZONE --
NMNH 116155-1 Basalt E RIFT ZONE --
NMNH 116155-2 Basalt E RIFT ZONE --
NMNH 116155-3 Basalt E RIFT ZONE --
NMNH 116155-4 Basalt E RIFT ZONE --
NMNH 116155-5 Basalt E RIFT ZONE --
NMNH 116155-6 Basalt E RIFT ZONE --
NMNH 116155-7 Andesitic Basalt E RIFT ZONE --
NMNH 116155-8 Andesitic Basalt E RIFT ZONE --
NMNH 116249-1 Basalt SW RIFT ZONE --
NMNH 116249-10 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116249-11 Pumiceous Basalt SW RIFT ZONE --
NMNH 116249-12 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116249-13 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116249-14 Basalt SW RIFT ZONE --
NMNH 116249-15 Vesicular Basalt SW RIFT ZONE --
NMNH 116249-16 Pumiceous Basalt SW RIFT ZONE --
NMNH 116249-17 Olivine Basalt SW RIFT ZONE --
NMNH 116249-18 Vesicular Basalt SW RIFT ZONE --
NMNH 116249-19 Scoriaceous Basalt E RIFT ZONE --
NMNH 116249-2 Picritic Basalt SW RIFT ZONE --
NMNH 116249-20 Scoriaceous Basalt E RIFT ZONE --
NMNH 116249-21 Scoriaceous Basalt E RIFT ZONE --
NMNH 116249-22 Basalt E RIFT ZONE --
NMNH 116249-23 Basalt E RIFT ZONE --
NMNH 116249-24 Basalt E RIFT ZONE --
NMNH 116249-25 Basalt E RIFT ZONE --
NMNH 116249-26 Basalt SW RIFT ZONE --
NMNH 116249-27 Scoriaceous Basalt E RIFT ZONE --
NMNH 116249-28 Scoriaceous Basalt E RIFT ZONE --
NMNH 116249-29 Scoriaceous Basalt E RIFT ZONE --
NMNH 116249-3 Vesicular Basalt SW RIFT ZONE - MAUNA IKI --
NMNH 116249-30 Scoriaceous Basalt E RIFT ZONE --
NMNH 116249-31 Basalt E RIFT ZONE --
NMNH 116249-4 Basalt SW RIFT ZONE --
NMNH 116249-5 Olivine Basalt SW RIFT ZONE --
NMNH 116249-53 Basalt E RIFT ZONE --
NMNH 116249-5A Olivine Basalt SW RIFT ZONE --
NMNH 116249-6 Vesicular Basalt SW RIFT ZONE --
NMNH 116249-7 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116249-78 Scoriaceous Basalt -- --
NMNH 116249-79 Basaltic Pumice SW RIFT ZONE --
NMNH 116249-8 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116249-80A Picritic Basalt SW RIFT ZONE --
NMNH 116249-80B Picritic Basalt SW RIFT ZONE --
NMNH 116249-82A Olivine Basalt SW RIFT ZONE - PUU KOLEKOLE --
NMNH 116249-82B Basalt SW RIFT ZONE - PUU KOLEKOLE --
NMNH 116249-83 Basalt SW RIFT ZONE - PUU ULAULU --
NMNH 116249-84 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116249-85 Scoriaceous Basalt E RIFT ZONE - KANE NUI O HAMO --
NMNH 116249-86 Scoriaceous Basalt E RIFT ZONE - KANE NUI O HAMO --
NMNH 116249-87 Basalt SW RIFT ZONE - PUU KOAE --
NMNH 116249-88 Scoriaceous Basalt SW RIFT ZONE - PUU KOAE --
NMNH 116249-89 Scoriaceous Basalt E RIFT ZONE - KANE NUI O HAMO --
NMNH 116249-9 Scoriaceous Basalt SW RIFT ZONE --
NMNH 116249-94A Basalt -- --
NMNH 116249-94B Basalt -- --
NMNH 116249-94C Basalt -- --
NMNH 116249-95A Picritic Basalt -- --
NMNH 116249-95B Picritic Basalt -- --
NMNH 116249-96 Basalt E RIFT ZONE - MAKAOPUHI CRATER --
NMNH 116253-10 Olivine Sand -- --
NMNH 116253-11 Glassy Basalt SW RIFT ZONE-MAUNA IKI --
NMNH 116253-12 Labradorite Basalt SW RIFT ZONE-MAUNA IKI --
NMNH 116253-24 Olivine Basalt -- 22 Aug 1920
NMNH 116253-25 Olivine Basalt -- --
NMNH 116253-29 Olivine Basalt HALEMAUMAU 16 Jul 1924
NMNH 116253-3 Glass HALEMAUMAU --
NMNH 116253-30 Olivine Basalt HALEMAUMAU 16 Jul 1924
NMNH 116253-31 Olivine Basalt HALEMAUMAU 16 Jul 1924
NMNH 116253-32 Olivine Basalt HALEMAUMAU 16 Jul 1924
NMNH 116253-33 Olivine Basalt HALEMAUMAU 16 Jul 1924
NMNH 116253-34 Olivine Basalt HALEMAUMAU 16 Jul 1924
NMNH 116253-35 Lava HALEMAUMAU 16 Jul 1924
NMNH 116253-36 Lava -- --
NMNH 116253-37 Stalactitic Lava -- --
NMNH 116253-38 Salt Stalactite -- 30 Aug 1920
NMNH 116253-39 Lava -- --
NMNH 116253-4 Gypsum HALEMAUMAU --
NMNH 116253-40 Basaltic Lava SW RIFT ZONE-MAUNA IKI --
NMNH 116253-41 Reddish Scoria SW RIFT ZONE-MAUNA IKI --
NMNH 116253-42 Lava SW RIFT ZONE-MAUNA IKI --
NMNH 116253-43 Glassy Basalt SW RIFT ZONE-MAUNA IKI --
NMNH 116253-44 Pele's Hair -- 1 Jan 1920
NMNH 116253-45 Pele's Hair -- --
NMNH 116253-46 Lava -- 7 Jul 1920
NMNH 116253-5 Labradorite Basalt -- --
NMNH 116253-6 Labradorite Basalt -- --
NMNH 116253-7 Basalt Glass -- --
NMNH 116253-9 Olivine Sand -- --
NMNH 116299-1 Basaltic Pumice E RIFT ZONE - NAPAU CRATER 5 Mar 1965
NMNH 116299-10 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 12 Mar 1965
NMNH 116299-11 Basaltic Pumice E RIFT ZONE - MAKAOPUHI CRATER 12 Mar 1965
NMNH 116299-12 Scoriaceous Basalt E RIFT ZONE - MAKAOPUHI CRATER 14 Mar 1965
NMNH 116299-13 Basaltic Pumice E RIFT ZONE - MAKAOPUHI CRATER 14 Mar 1965
NMNH 116299-14 Basaltic Pumice E RIFT ZONE - MAKAOPUHI CRATER 14 Mar 1965
NMNH 116299-15 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 15 Mar 1965
NMNH 116299-16 Scoriaceous Basalt E RIFT ZONE - MAKAOPUHI CRATER 15 Mar 1965
NMNH 116299-17 Basaltic Pumice E RIFT ZONE - MAKAOPUHI CRATER 14 Mar 1965
NMNH 116299-18 Basaltic Pumice E RIFT ZONE - MAKAOPUHI CRATER 15 Mar 1965
NMNH 116299-19 Basaltic Pumice E RIFT ZONE - MAKAOPUHI CRATER 14 Mar 1965
NMNH 116299-2 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 7 Mar 1965
NMNH 116299-20 Basaltic Pumice E RIFT ZONE - MAKAOPUHI CRATER 14 Mar 1965
NMNH 116299-21 Basaltic Pumice E RIFT ZONE - MAKAOPUHI CRATER 14 Mar 1965
NMNH 116299-22 Basaltic Pumice E RIFT ZONE - MAKAOPUHI CRATER 15 Mar 1965
NMNH 116299-23 Glassy Basalt E RIFT ZONE - NAPAU CRATER 17 Mar 1965
NMNH 116299-24 Sulfur E RIFT ZONE - NAPAU CRATER --
NMNH 116299-25 Glassy Basalt E RIFT ZONE - NAPAU CRATER 17 Mar 1965
NMNH 116299-26 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER 17 Mar 1965
NMNH 116299-27 Glassy Basalt E RIFT ZONE - NAPAU CRATER 17 Mar 1965
NMNH 116299-28 Glassy Basalt E RIFT ZONE - NAPAU CRATER 17 Mar 1965
NMNH 116299-29 Glassy Basalt E RIFT ZONE - NAPAU CRATER 17 Mar 1965
NMNH 116299-3 Basalt E RIFT ZONE - MAKAOPUHI CRATER 7 Mar 1965
NMNH 116299-30 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 17 Mar 1965
NMNH 116299-31 Scoriaceous Basalt E RIFT ZONE - MAKAOPUHI CRATER 17 Mar 1965
NMNH 116299-32 Glassy Basalt E RIFT ZONE - NAPAU CRATER 22 Mar 1965
NMNH 116299-33 Scoriaceous Basalt E RIFT ZONE - NAPAU CRATER 22 Mar 1965
NMNH 116299-34 Glassy Basalt E RIFT ZONE - KALALUA 22 Mar 1965
NMNH 116299-35 Basaltic Pumice E RIFT ZONE - KALALUA 22 Mar 1965
NMNH 116299-36 Scoriaceous Basalt E RIFT ZONE - NAPAU/KALALUA 22 Mar 1965
NMNH 116299-37 Scoriaceous Basalt E RIFT ZONE - NAPAU/KALALUA 22 Mar 1965
NMNH 116299-38 Scoriaceous Basalt E RIFT ZONE - NAPAU/KALALUA 22 Mar 1965
NMNH 116299-4 Basalt E RIFT ZONE - MAKAOPUHI CRATER 7 Mar 1965
NMNH 116299-5 Basaltic Pumice E RIFT ZONE - NAPAU CRATER 7 Mar 1965
NMNH 116299-6 Glassy Basalt E RIFT ZONE - MAKAOPUHI CRATER 8 Mar 1965
NMNH 116299-7 Scoriaceous Basalt E RIFT ZONE - MAKAOPUHI CRATER 8 Mar 1965
NMNH 116299-8 Scoriaceous Basalt E RIFT ZONE - MAKAOPUHI CRATER 8 Mar 1965
NMNH 116299-9 Glassy Basalt E RIFT ZONE - NAPAU CRATER 12 Mar 1965
NMNH 116564-20 Basalt KILAUEA-IKI --
NMNH 116564-21 Olivine Basalt MAUNA LOA --
NMNH 116633-10 Olivine Basalt -- --
NMNH 116633-11 Lava -- --
NMNH 116633-12 Basalt -- --
NMNH 116633-13 Basalt -- --
NMNH 116633-14 Basalt -- --
NMNH 116633-15 Reticulite -- --
NMNH 116633-16 Ultramafic Nodule -- --
NMNH 116633-17 Lava -- --
NMNH 116633-18 Basalt -- --
NMNH 116633-19 Basalt -- --
NMNH 116633-8 Sulfur -- --
NMNH 116633-9 Stalactite -- --
NMNH 116651 Olivine Basalt -- --
NMNH 116652 Olivine Basalt -- --
NMNH 116691-2 Stalagmite MAUNA IKI 1 Jul 1979
NMNH 116691-3 Stalactite MAUNA ULU 1 Aug 1979
NMNH 116691-7 Stalactite MAUNA ULU 1 Aug 1979
NMNH 116771 Basalt KILAUEA IKI --
NMNH 116772 Basalt KILAUEA IKI --
NMNH 116773 Basalt KILAUEA IKI --
NMNH 116774 Basalt KILAUEA IKI --
NMNH 116775 Basalt KILAUEA IKI --
NMNH 116859-1 Tholeiite -- --
NMNH 116859-2 Tholeiite -- --
NMNH 116859-20 Tholeiite SUMMIT CALDERA --
NMNH 116859-21 Tholeiite PUNA RIFT, KAUELAU FLOW --
NMNH 116859-22 Tholeiite KILAUEA IKI --
NMNH 116859-23 Tholeiite KILAUEA IKI --
NMNH 116859-24 Tholeiite PUNA RIFT --
NMNH 116859-25 Tholeiite PUNA RIFT --
NMNH 116859-26 Tholeiite SUMMIT CALDERA --
NMNH 116859-3 Tholeiite -- --
NMNH 116860-1 Lava -- 1 Oct 1919
NMNH 116860-10 Volcanic Cinder HALEMAUMAU, W RIM 2 Jul 1929
NMNH 116860-11 Volcanic Cinder HALEMAUMAU --
NMNH 116860-12 Volcanic Cinder -- --
NMNH 116860-13 Lava -- 28 May 1916
NMNH 116860-14 Lava -- 17 Apr 1921
NMNH 116860-15 Volcanic Spatter -- 1 Jan 1918
NMNH 116860-16 Lava -- 1 Feb 1918
NMNH 116860-17 Scoria -- --
NMNH 116860-18 Lava HALEMAUMAU 20 Oct 1919
NMNH 116860-19 Lava HALEMAUMAU 1 Jan 1921
NMNH 116860-2 Volcanic Spatter -- 16 Mar 1918
NMNH 116860-20 Lava HALEMAUMAU 1 Jan 1919
NMNH 116860-21 Volcanic Spatter -- 1 Jan 1918
NMNH 116860-22 Lava -- 1 Jan 1919
NMNH 116860-23 Lava -- 1 Jan 1917
NMNH 116860-24 Volcanic Spatter HALEMAUMAU 1 Jan 1917
NMNH 116860-25 Lava -- --
NMNH 116860-26 Picrite -- --
NMNH 116860-27 Lava -- 1 Jan 1921
NMNH 116860-28 Lava HALEMAUMAU LAVA LAKE 17 Mar 1919
NMNH 116860-29 Lava -- --
NMNH 116860-3 Pele's Hair -- 1 Jan 1912
NMNH 116860-30 Lava -- 1 Jan 1970
NMNH 116860-31 Lava -- 1 Jan 1970
NMNH 116860-32 Lava -- 1 Jan 1970
NMNH 116860-33 Lava -- --
NMNH 116860-34 Lava -- 6 Oct 1919
NMNH 116860-35 Volcanic Bomb -- 28 Jul 1924
NMNH 116860-36 Pele's Hair -- --
NMNH 116860-4 Pele's Hair -- 1 Jan 1913
NMNH 116860-5 Volcanic Spatter HALEMAUMAU 1 Jan 1917
NMNH 116860-6 Pele's Hair SW RIFT 1 Nov 1920
NMNH 116860-7 Volcanic Lapilli HALEMAUMAU 21 Mar 1921
NMNH 116860-8 Lava -- 21 Mar 1921
NMNH 116860-9 Pele's Hair HALEMAUMAU, LEEWARD EDGE 28 Aug 1923
NMNH 116865-1 Tholeiite KILAUEA CALDERA --
NMNH 116865-2 Tholeiite SW RIFT ZONE --
NMNH 116865-24 Pele's Tears HALEMAUMAU --
NMNH 116865-25 Lava VENT "E" --
NMNH 116865-26 Basalt -- --
NMNH 116865-27 Basalt E RIFT ZONE --
NMNH 116865-28 Basalt -- --
NMNH 116865-3 Tholeiite SW RIFT ZONE --
NMNH 116865-30 Basalt SUMMIT REGION SW OF CALDERA --
NMNH 116865-31 Basalt CALDERA, S WALL --
NMNH 116865-32 Basalt MAKAOPUHI LAVA LAKE --
NMNH 116865-33 Lava MAKAOPUHI CRATER, N WALL --
NMNH 116865-34 Lava MAKAOPUHI CRATER, N WALL --
NMNH 116865-35 Lava MAKAUPUHI CRATER, N WALL --
NMNH 116865-36 Lava MAKAOPUHI CRATER, N WALL --
NMNH 116865-37 Lava MAKAOPUHI CRATER, N WALL --
NMNH 116865-38 Lava E RIFT ZONE, FLOW AT VENT "A" 8 May 1905
NMNH 116865-39 Lava SUMMIT FLOW 2 Apr 1905
NMNH 116865-40 Lava E RIFT ZONE, FLOW FROM VENT "A" 8 May 1905
NMNH 116865-41 Lava SW RIFT ZONE --
NMNH 116865-42 Lava SUMMIT 7 May 1905
NMNH 117133 Basalt -- --
NMNH 117133 Basalt -- --
NMNH 117254-100 Basalt -- --
NMNH 117254-120 Pumice-Pele's Hair -- --
NMNH 117254-121 Pumice-Pele's Hair -- 15 Nov 1920
NMNH 117254-129 Lava -- --
NMNH 117254-180 Olivine Tholeiite -- 1 Jan 1921
NMNH 117254-185 Olivine Tholeiite -- --
NMNH 117394-1 Volcanic Ash -- 4 Aug 2008
NMNH 117394-2 Lapilli -- 4 Oct 2008
NMNH 117643-2 Basalt -- --
NMNH 117774-1 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-10 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-100 Picrite KILAUEA IKI 3 Dec 1962
NMNH 117774-101 Picrite KILAUEA IKI 3 Dec 1962
NMNH 117774-102 Picrite KILAUEA IKI 3 Dec 1962
NMNH 117774-103 Picrite KILAUEA IKI 3 Dec 1962
NMNH 117774-104 Picrite KILAUEA IKI 3 Dec 1962
NMNH 117774-105 Picrite KILAUEA IKI 3 Jun 1962
NMNH 117774-11 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-12 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-13 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-14 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-15 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-16 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-17 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-18 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-19 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-2 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-20 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-21 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-22 Basalt KILAUEA IKI 13 Apr 2013
NMNH 117774-23 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-24 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-25 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-26 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-27 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-28 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-29 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-3 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-30 Basalt KILAUEA IKI 13 Apr 2013
NMNH 117774-31 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-32 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-33 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-34 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-35 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-36 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-37 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-38 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-39 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-4 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-40 Basalt KILAUEA IKI 13 Apr 1961
NMNH 117774-41 Basalt KILAUEA IKI 9 May 1961
NMNH 117774-42 Basalt KILAUEA IKI 9 May 1961
NMNH 117774-43 Basalt KILAUEA IKI 9 May 1961
NMNH 117774-44 Basalt KILAUEA IKI 9 May 1961
NMNH 117774-45 Basalt KILAUEA IKI 9 May 1961
NMNH 117774-46 Basalt KILAUEA IKI 10 May 1961
NMNH 117774-47 Basalt KILAUEA IKI 10 May 1961
NMNH 117774-48 Basalt KILAUEA IKI 10 May 1961
NMNH 117774-49 Basalt KILAUEA IKI 11 May 1961
NMNH 117774-5 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-50 Basalt KILAUEA IKI 3 Oct 1961
NMNH 117774-51 Basalt KILAUEA IKI 3 Oct 1961
NMNH 117774-52 Basalt KILAUEA IKI 3 Oct 1961
NMNH 117774-53 Basalt KILAUEA IKI 4 Oct 1961
NMNH 117774-54 Basalt KILAUEA IKI 4 Oct 1961
NMNH 117774-55 Basalt KILAUEA IKI 4 Oct 1961
NMNH 117774-56 Basalt KILAUEA IKI 4 Oct 1961
NMNH 117774-57 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-58 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-59 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-6 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-60 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-61 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-62 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-63 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-64 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-65 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-66 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-67 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-68 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-69 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-7 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-70 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-71 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-72 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-73 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-74 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-75 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-76 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-77 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-78 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-79 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-8 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-80 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-81 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-82 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-83 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-84 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-85 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-86 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-87 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-88 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-89 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-9 Basalt KILAUEA IKI 9 Apr 1961
NMNH 117774-90 Basalt KILAUEA IKI 1 Jun 2013
NMNH 117774-91 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-92 Basalt KILAUEA IKI 27 Jun 1962
NMNH 117774-93 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-94 Basalt KILAUEA IKI 1 Jun 1962
NMNH 117774-95 Basalt KILAUEA IKI 21 Jun 1962
NMNH 117774-96 Picrite KILAUEA IKI 3 Dec 1962
NMNH 117774-97 Picrite KILAUEA IKI 3 Dec 1962
NMNH 117774-98 Picrite KILAUEA IKI 3 Dec 1962
NMNH 117774-99 Picrite KILAUEA IKI 3 Dec 1962
NMNH 117806-1434 Picrite Caldera --
NMNH 118148-14 Basalt -- --
NMNH 118148-54 Tholeiite basalt -- --
NMNH 118188 Lava -- --
NMNH 12901-00 Sulfur -- --
NMNH 12901-01 Sulfur -- --
NMNH 134961-00 Blodite -- --
NMNH 135245-00 Sulfur -- --
NMNH 141523-00 Sulfur -- --
NMNH 35560 Tachylite -- --
NMNH 40981 Glass -- --
NMNH 40982 Glass -- --
NMNH 40983 Glass -- --
NMNH 53157 Volcanic Ash -- --
NMNH 54044 Basalt -- --
NMNH 54045-1 Basalt -- --
NMNH 54045-2 Basalt -- --
NMNH 54069-1 Lava -- --
NMNH 54069-2 Lava -- --
NMNH 54070 Basalt -- --
NMNH 54071 Volcanic Ash -- --
NMNH 54073 Basalt -- --
NMNH 54074 Lava -- --
NMNH 54074 Basalt -- --
NMNH 54074-1 Lava -- --
NMNH 54074-2 Lava -- --
NMNH 54075 Lava -- --
NMNH 54077 Lava -- --
NMNH 61414 Basalt -- --
NMNH 63545 Basalt -- --
NMNH 68400 Pahoehoe Lava -- --
NMNH 68410 Basalt -- --
NMNH 68411 Basalt -- --
NMNH 68414 Lava -- --
NMNH 68415 Basalt -- --
NMNH 68415 Lava -- --
NMNH 68416 Basalt -- --
NMNH 68417 Basalt -- --
NMNH 68419 Lava -- --
NMNH 68420 Lava -- --
NMNH 68420 Basalt -- --
NMNH 68421 Basalt -- --
NMNH 68423 Lava -- --
NMNH 68424 Lava -- --
NMNH 68426 Basalt -- --
NMNH 68431 Lava -- --
NMNH 68433 Volcanic Glass HALEMAUMAU PIT --
NMNH 68433 Glass -- --
NMNH 68444 Basalt -- --
NMNH 70569 Lava -- --
NMNH 72947 Volcanic Glass -- --
NMNH 88126-30 Micro Diabase -- --
NMNH 88126-31 Olivine-Plagioclase Basalt -- --
NMNH 88126-32 Olivine-Plagioclase Basalt -- --
NMNH 88126-33 Basalt -- --
NMNH 88126-34 Olivine-Plagioclase Basalt -- --
NMNH 88126-35 Olivine-Plagioclase Basalt -- --
NMNH 88126-36 Olivine-Plagioclase Basalt -- --
NMNH 88126-37 Basalt -- --
NMNH 88126-38 Basalt -- --
NMNH 91048 Volcanic Glass -- --
NMNH 91170 Lava -- --
NMNH 92133 Basalt HALEMAUMAU --
NMNH 92134-1 Gypsum HALEMAUMAU --
NMNH 92134-2 Gypsum HALEMAUMAU --
NMNH 92134-3 Gypsum HALEMAUMAU --
NMNH 92134-4 Gypsum HALEMAUMAU --
NMNH 94122-00 Aphthitalite -- --
NMNH 97714-1 Lava -- --
NMNH 97714-10 Lava -- --
NMNH 97714-11 Lava -- --
NMNH 97714-12 Lava -- --
NMNH 97714-13 Lava -- --
NMNH 97714-14 Lava -- --
NMNH 97714-15 Lava -- --
NMNH 97714-16 Lava -- --
NMNH 97714-17 Lava -- --
NMNH 97714-18 Lava -- --
NMNH 97714-19 Lava -- --
NMNH 97714-2 Lava -- --
NMNH 97714-20 Lava -- --
NMNH 97714-21 Lava -- --
NMNH 97714-22 Lava -- --
NMNH 97714-23 Lava -- --
NMNH 97714-24 Lava -- --
NMNH 97714-25 Lava -- --
NMNH 97714-26 Lava -- --
NMNH 97714-27 Lava -- --
NMNH 97714-28 Lava -- --
NMNH 97714-29 Lava -- --
NMNH 97714-3 Lava -- --
NMNH 97714-30 Lava -- --
NMNH 97714-31 Lava -- --
NMNH 97714-32 Lava -- --
NMNH 97714-4 Lava -- --
NMNH 97714-5 Lava -- --
NMNH 97714-6 Lava -- --
NMNH 97714-7 Lava -- --
NMNH 97714-8 Lava -- --
NMNH 97714-9 Lava -- --
NMNH 99991 Labradorite Basalt -- --
NMNH 99992 Labradorite Basalt -- --
NMNH 99993 Labradorite Basalt -- --
NMNH 99994 Picrite Basalt -- --
NMNH 99995 Picrite Basalt -- --
NMNH 99996 Basalt -- --
NMNH 99997-1 Basalt HALEMAUMAU --
NMNH 99997-2 Basalt -- --
NMNH 99997-3 Basalt HALEMAUMAU --
NMNH 99997-4 Basalt HALEMAUMAU --
NMNH 99997-5 Basalt HALEMAUMAU --
NMNH 99997-6 Basalt HALEMAUMAU --
NMNH 99997-7 Basalt HALEMAUMAU --
NMNH 99997-8 Basalt -- --
NMNH 99998-1 Basalt MAUNA IKI --
NMNH 99998-2 Basalt MAUNA IKI --
NMNH 99998-3 Basalt MAUNA IKI --
NMNH 99999-1 Picritic Basalt -- --
NMNH 99999-2 Picritic Basalt -- --
NMNH 99999-3 Picritic Basalt -- --
NMNH M11216-00 Olivine -- --
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