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Bulletin of the Global Volcanism Network

All reports of volcanic activity published by the Smithsonian since 1968 are available through a monthly table of contents or by searching for a specific volcano. Until 1975, reports were issued for individual volcanoes as information became available; these have been organized by month for convenience. Later publications were done in a monthly newsletter format. Links go to the profile page for each volcano with the Bulletin tab open.

Information is preliminary at time of publication and subject to change.

Recently Published Bulletin Reports

Nyamuragira (DR Congo) Intermittent thermal anomalies within the summit crater during December 2019-May 2020

Nyiragongo (DR Congo) Activity in the lava lake and small eruptive cone persists during December 2019-May 2020

Kavachi (Solomon Islands) Discolored water plumes seen using satellite imagery in 2018 and 2020

Kuchinoerabujima (Japan) Eruption and ash plumes begin on 11 January 2020 and continue through April 2020

Soputan (Indonesia) Minor ash emissions during 23 March and 2 April 2020

Heard (Australia) Eruptive activity including a lava flow during October 2019-April 2020

Kikai (Japan) Ash explosion on 29 April 2020

Fuego (Guatemala) Ongoing ash explosions, block avalanches, and intermittent lava flows

Ebeko (Russia) Frequent moderate explosions, ash plumes, and ashfall continue, December 2019-May 2020

Piton de la Fournaise (France) Fissure eruptions in February and April 2020 included lava fountains and flows

Sabancaya (Peru) Daily explosions with ash emissions, large SO2 flux, ongoing thermal anomalies, December 2019-May 2020

Sheveluch (Russia) Lava dome growth and thermal anomalies continue through April 2020, but few ash explosions



Nyamuragira (DR Congo) — June 2020 Citation iconCite this Report

Nyamuragira

DR Congo

1.408°S, 29.2°E; summit elev. 3058 m

All times are local (unless otherwise noted)


Intermittent thermal anomalies within the summit crater during December 2019-May 2020

Nyamuragira (also known as Nyamulagira) is located in the Virunga Volcanic Province (VVP) in the Democratic Republic of the Congo and consists of a lava lake that reappeared in the summit crater in mid-April 2018. Volcanism has been characterized by lava emissions, thermal anomalies, seismicity, and gas-and-steam emissions. This report summarizes activity during December 2019 through May 2020 using information from monthly reports by the Observatoire Volcanologique de Goma (OVG) and satellite data.

According to OVG, intermittent eruptive activity was detected in the lava lake of the central crater during December 2019 and January-April 2020, which also resulted in few seismic events. MIROVA (Middle InfraRed Observation of Volcanic Activity) analysis of MODIS satellite data shows thermal anomalies within the summit crater that varied in both frequency and power between August 2019 and mid-March 2020, but very few were recorded afterward through late May (figure 88). Thermal hotspots identified by MODVOLC from 15 December 2019 through March 2020 were mainly located in the active central crater, with only three hotspots just outside the SW crater rim (figure 89). Sentinel-2 thermal satellite imagery also showed activity within the summit crater during January-May 2020, but by mid-March the thermal anomaly had visibly decreased in power (figure 90).

Figure (see Caption) Figure 88. The MIROVA graph of thermal activity (log radiative power) at Nyamuragira during 27 July through May 2020 shows variably strong, intermittent thermal anomalies with a variation in power and frequency from August 2019 to mid-March 2020. Courtesy of MIROVA.
Figure (see Caption) Figure 89. Map showing the number of MODVOLC hotspot pixels at Nyamuragira from 1 December 2019 t0 31 May 2020. 37 pixels were registered within the summit crater while 3 were detected just outside the SW crater rim. Courtesy of HIGP-MODVOLC Thermal Alerts System.
Figure (see Caption) Figure 90. Sentinel-2 thermal satellite imagery (bands 12, 11, 8A) confirmed ongoing thermal activity (bright yellow-orange) at Nyamuragira from February into April 2020. The strength of the thermal anomaly in the summit crater decreased by late March 2020, but was still visible. Courtesy of Sentinel Hub Playground.

Geologic Background. Africa's most active volcano, Nyamuragira, is a massive high-potassium basaltic shield about 25 km N of Lake Kivu. Also known as Nyamulagira, it has generated extensive lava flows that cover 1500 km2 of the western branch of the East African Rift. The broad low-angle shield volcano contrasts dramatically with the adjacent steep-sided Nyiragongo to the SW. The summit is truncated by a small 2 x 2.3 km caldera that has walls up to about 100 m high. Historical eruptions have occurred within the summit caldera, as well as from the numerous fissures and cinder cones on the flanks. A lava lake in the summit crater, active since at least 1921, drained in 1938, at the time of a major flank eruption. Historical lava flows extend down the flanks more than 30 km from the summit, reaching as far as Lake Kivu.

Information Contacts: Information contacts: Observatoire Volcanologique de Goma (OVG), Departement de Geophysique, Centre de Recherche en Sciences Naturelles, Lwiro, D.S. Bukavu, DR Congo; 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/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/exp.


Nyiragongo (DR Congo) — June 2020 Citation iconCite this Report

Nyiragongo

DR Congo

1.52°S, 29.25°E; summit elev. 3470 m

All times are local (unless otherwise noted)


Activity in the lava lake and small eruptive cone persists during December 2019-May 2020

Nyiragongo is located in the Virunga Volcanic Province (VVP) in the Democratic Republic of the Congo, part of the western branch of the East African Rift System and contains a 1.2 km-wide summit crater with a lava lake that has been active since at least 1971. Volcanism has been characterized by strong and frequent thermal anomalies, incandescence, gas-and-steam emissions, and seismicity. This report summarizes activity during December 2019 through May 2020 using information from monthly reports by the Observatoire Volcanologique de Goma (OVG) and satellite data.

In the December 2019 monthly report, OVG stated that the level of the lava lake had increased. This level of the lava lake was maintained for the duration of the reporting period, according to later OVG monthly reports. Seismicity increased starting in November 2019 and was detected in the NE part of the crater, but it decreased by mid-April 2020. SO2 emissions increased in January 2020 to roughly 7,000 tons/day but decreased again near the end of the month. OVG reported that SO2 emissions rose again in February to roughly 8,500 tons/day before declining to about 6,000 tons/day. Unlike in the previous report (BGVN 44:12), incandescence was visible during the day in the active lava lake and activity at the small eruptive cone within the 1.2-km-wide summit crater has since increased, consisting of incandescence and some lava fountaining (figure 72). A field survey was conducted on 3-4 March where an OVG team observed active lava fountains and ejecta that produced Pele’s hair from the small eruptive cone (figure 73). During this survey, OVG reported that the level of the lava lake had reached the second terrace, which was formed on 17 January 2002 and represents remnants of the lava lake at different eruption stages. There, the open surface lava lake was observed; gas-and-steam emissions accompanied both the active lava lake and the small eruptive cone (figures 72 and 73).

Figure (see Caption) Figure 72. Webcam image of Nyiragongo in February 2020 showing an open lava lake surface and incandescence from the active crater cone within the 1.2 km-wide summit crater visible during the day, accompanied by white gas-and-steam emissions. Courtesy of OVG (Rapport OVG February 2020).
Figure (see Caption) Figure 73. Webcam image of Nyiragongo on 4 March 2020 showing an open lava lake surface and incandescence from the active crater cone within the 1.2 km-wide summit crater visible during the day, accompanied by white gas-and-steam emissions. Courtesy of OVG (Rapport OVG Mars 2020).

MIROVA (Middle InfraRed Observation of Volcanic Activity) analysis of MODIS satellite data continued to show frequent strong thermal anomalies within 5 km of the summit crater through May 2020 (figure 74). Similarly, the MODVOLC algorithm reported multiple thermal hotspots almost daily within the summit crater between December 2019 and May 2020. These thermal signatures were also observed in Sentinel-2 thermal satellite imagery within the summit crater (figure 75).

Figure (see Caption) Figure 74. Thermal anomalies at Nyiragongo from 27 July through May 2020 as recorded by the MIROVA system (Log Radiative Power) were frequent and strong. Courtesy of MIROVA.
Figure (see Caption) Figure 75. Sentinel-2 thermal satellite imagery (bands 12, 11, 8A) showed ongoing thermal activity (bright yellow-orange) in the summit crater at Nyiragongo during January through April 2020. Courtesy of Sentinel Hub Playground.

Geologic Background. One of Africa's most notable volcanoes, Nyiragongo contained a lava lake in its deep summit crater that was active for half a century before draining catastrophically through its outer flanks in 1977. The steep slopes of a stratovolcano contrast to the low profile of its neighboring shield volcano, Nyamuragira. Benches in the steep-walled, 1.2-km-wide summit crater mark levels of former lava lakes, which have been observed since the late-19th century. Two older stratovolcanoes, Baruta and Shaheru, are partially overlapped by Nyiragongo on the north and south. About 100 parasitic cones are located primarily along radial fissures south of Shaheru, east of the summit, and along a NE-SW zone extending as far as Lake Kivu. Many cones are buried by voluminous lava flows that extend long distances down the flanks, which is characterized by the eruption of foiditic rocks. The extremely fluid 1977 lava flows caused many fatalities, as did lava flows that inundated portions of the major city of Goma in January 2002.

Information Contacts: Observatoire Volcanologique de Goma (OVG), Departement de Geophysique, Centre de Recherche en Sciences Naturelles, Lwiro, D.S. Bukavu, DR Congo; 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/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).


Kavachi (Solomon Islands) — May 2020 Citation iconCite this Report

Kavachi

Solomon Islands

8.991°S, 157.979°E; summit elev. -20 m

All times are local (unless otherwise noted)


Discolored water plumes seen using satellite imagery in 2018 and 2020

Kavachi is a submarine volcano located in the Solomon Islands south of Gatokae and Vangunu islands. Volcanism is frequently active, but rarely observed. The most recent eruptions took place during 2014, which consisted of an ash eruption, and during 2016, which included phreatomagmatic explosions (BGVN 42:03). This reporting period covers December 2016-April 2020 primarily using satellite data.

Activity at Kavachi is often only observed through satellite images, and frequently consists of discolored submarine plumes for which the cause is uncertain. On 1 January 2018 a slight yellow discoloration in the water is seen extending to the E from a specific point (figure 20). Similar faint plumes were observed on 16 January, 25 February, 2 March, 26 April, 6 May, and 25 June 2018. No similar water discoloration was noted during 2019, though clouds may have obscured views.

Figure (see Caption) Figure 20. Satellite images from Sentinel-2 revealed intermittent faint water discoloration (yellow) at Kavachi during the first half of 2018, as seen here on 1 January (top left), 25 February (top right), 26 April (bottom left), and 25 June (bottom right). Images with “Natural color” rendering (bands 4, 3, 2); courtesy of Sentinel Hub Playground.

Activity resumed in 2020, showing more discolored water in satellite imagery. The first instance occurred on 16 March, where a distinct plume extended from a specific point to the SE. On 25 April a satellite image showed a larger discolored plume in the water that spread over about 30 km2, encompassing the area around Kavachi (figure 21). Another image on 30 April showed a thin ribbon of discolored water extending about 50 km W of the vent.

Figure (see Caption) Figure 21. Sentinel-2 satellite images of a discolored plume (yellow) at Kavachi beginning on 16 March (top left) with a significant large plume on 25 April (right), which remained until 30 April (bottom left). Images with “Natural color” rendering (bands 4, 3, 2); courtesy of Sentinel Hub Playground.

Geologic Background. Named for a sea-god of the Gatokae and Vangunu peoples, Kavachi is one of the most active submarine volcanoes in the SW Pacific, located in the Solomon Islands south of Vangunu Island about 30 km N of the site of subduction of the Indo-Australian plate beneath the Pacific plate. Sometimes referred to as Rejo te Kvachi ("Kavachi's Oven"), this shallow submarine basaltic-to-andesitic volcano has produced ephemeral islands up to 1 km long many times since its first recorded eruption during 1939. Residents of the nearby islands of Vanguna and Nggatokae (Gatokae) reported "fire on the water" prior to 1939, a possible reference to earlier eruptions. The roughly conical edifice rises from water depths of 1.1-1.2 km on the north and greater depths to the SE. Frequent shallow submarine and occasional subaerial eruptions produce phreatomagmatic explosions that eject steam, ash, and incandescent bombs. On a number of occasions lava flows were observed on the ephemeral islands.

Information Contacts: Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).


Kuchinoerabujima (Japan) — May 2020 Citation iconCite this Report

Kuchinoerabujima

Japan

30.443°N, 130.217°E; summit elev. 657 m

All times are local (unless otherwise noted)


Eruption and ash plumes begin on 11 January 2020 and continue through April 2020

Kuchinoerabujima encompasses a group of young stratovolcanoes located in the northern Ryukyu Islands. All historical eruptions have originated from the Shindake cone, with the exception of a lava flow that originated from the S flank of the Furudake cone. The most recent previous eruptive period took place during October 2018-February 2019 and primarily consisted of weak explosions, ash plumes, and ashfall. The current eruption began on 11 January 2020 after nearly a year of dominantly gas-and-steam emissions. Volcanism for this reporting period from March 2019 to April 2020 included explosions, ash plumes, SO2 emissions, and ashfall. The primary source of information for this report comes from monthly and annual reports from the Japan Meteorological Agency (JMA) and advisories from the Tokyo Volcanic Ash Advisory Center (VAAC). Activity has been limited to Kuchinoerabujima's Shindake Crater.

Volcanism at Kuchinoerabujima was relatively low during March through December 2019, according to JMA. During this time, SO2 emissions ranged from 100 to 1,000 tons/day. Gas-and-steam emissions were frequently observed throughout the entire reporting period, rising to a maximum height of 1.1 km above the crater on 13 December 2019. Satellite imagery from Sentinel-2 showed gas-and-steam and occasional ash emissions rising from the Shindake crater throughout the reporting period (figure 7). Though JMA reported thermal anomalies occurring on 29 January and continuing through late April 2020, Sentinel-2 imagery shows the first thermal signature appearing on 26 April.

Figure (see Caption) Figure 7. Sentinel-2 thermal satellite images showed gas-and-steam and ash emissions rising from Kuchinoerabujima. Some ash deposits can be seen on 6 February 2020 (top right). A thermal anomaly appeared on 26 April 2020 (bottom right). Sentinel-2 atmospheric penetration (bands 12, 11, 8A) images courtesy of Sentinel Hub Playground.

An eruption on 11 January 2020 at 1505 ejected material 300 m from the crater and produced ash plumes that rose 2 km above the crater rim, extending E, according to JMA. The eruption continued through 12 January until 0730. The resulting ash plumes rose 400 m above the crater, drifting SW while the SO2 emissions measured 1,300 tons/day. Ashfall was reported on Yakushima Island (15 km E). Minor eruptive activity was reported during 17-20 January which produced gray-white plumes that rose 300-500 m above the crater. On 23 January, seismicity increased, and an eruption produced an ash plume that rose 1.2 km altitude, according to a Tokyo VAAC report, resulting in ashfall 2 km NE of the crater. A small explosion was detected on 24 January, followed by an increase in the number of earthquakes during 25-26 January (65-71 earthquakes per day were registered). Another small eruptive event detected on 27 January at 0148 was accompanied by a volcanic tremor and a change in tilt data. During the month of January, some inflation was detected at the base on the volcano and a total of 347 earthquakes were recorded. The SO2 emissions ranged from 200-1,600 tons/day.

An eruption on 1 February 2020 produced an eruption column that rose less than 1 km altitude and extended SE and SW (figure 8), according to the Tokyo VAAC report. On 3 February, an eruption from the Shindake crater at 0521 produced an ash plume that rose 7 km above the crater and ejected material as far as 600 m away. As a result, a pyroclastic flow formed, traveling 900-1,500 m SW. The previous pyroclastic flow that was recorded occurred on 29 January 2019. Ashfall was confirmed in the N part of Yakushima Island with a large amount in Miyanoura (32 km ESE) and southern Tanegashima. The SO2 emissions measured 1,700 tons/day during this event.

Figure (see Caption) Figure 8. Webcam images from the Honmura west surveillance camera of an ash plume rising from Kuchinoerabujima on 1 February 2020. Courtesy of JMA (Weekly bulletin report 509, February 2020).

Intermittent small eruptive events occurred during 5-9 February; field observations showed a large amount of ashfall on the SE flank which included lapilli that measured up to 2 cm in diameter. Additionally, thermal images showed 5-km-long pyroclastic flow deposits on the SW flank. An eruption on 9 February produced an ash plume that rose 1.2 km altitude, drifting SE. On 13 February a small eruption was detected in the Shindake crater at 1211, producing gray-white plumes that rose 300 m above the crater, drifting NE. Small eruptive events also occurred during 20-21 February, resulting in gas-and-steam emissions that rose 200 m above the crater. During the month of February, some horizontal extension was observed since January 2020 using GNSS data. The total number of earthquakes during this month drastically increased to 1225 compared to January. The SO2 emissions ranged from 300-1,700 tons/day.

By 2 March 2020, seismicity decreased, and activity declined. Gas-and-steam emissions continued infrequently for the duration of the reporting period. The SO2 emissions during March ranged from 700-2,100 tons/day, the latter of which occurred on 15 March. Seismicity increased again on 27 March. During 5-8 April 2020, small eruptive events were detected, generating ash plumes that rose 900 m above the crater (figure 9). The SO2 emissions on 6 April reached 3,200 tons/day, the maximum measurement for this reporting period. These small eruptive events continued from 13-20 and 23-25 April within the Shindake crater, producing gray-white plumes that rose 300-800 m above the crater.

Figure (see Caption) Figure 9. Webcam images from the Honmura Nishi (top) and Honmura west (bottom) surveillance cameras of ash plumes rising from Kuchinoerabujima on 6 March and 5 April 2020. Courtesy of JMA (Weekly bulletin report 509, March and April 2020).

Geologic Background. A group of young stratovolcanoes forms the eastern end of the irregularly shaped island of Kuchinoerabujima in the northern Ryukyu Islands, 15 km W of Yakushima. The Furudake, Shindake, and Noikeyama cones were erupted from south to north, respectively, forming a composite cone with multiple craters. The youngest cone, centrally-located Shindake, formed after the NW side of Furudake was breached by an explosion. All historical eruptions have occurred from Shindake, although a lava flow from the S flank of Furudake that reached the coast has a very fresh morphology. Frequent explosive eruptions have taken place from Shindake since 1840; the largest of these was in December 1933. Several villages on the 4 x 12 km island are located within a few kilometers of the active crater and have suffered damage from eruptions.

Information Contacts: Japan Meteorological Agency (JMA), 1-3-4 Otemachi, Chiyoda-ku, Tokyo 100-8122, Japan (URL: http://www.jma.go.jp/jma/indexe.html); Tokyo Volcanic Ash Advisory Center (VAAC), 1-3-4 Otemachi, Chiyoda-ku, Tokyo 100-8122, Japan (URL: http://ds.data.jma.go.jp/svd/vaac/data/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).


Soputan (Indonesia) — May 2020 Citation iconCite this Report

Soputan

Indonesia

1.112°N, 124.737°E; summit elev. 1785 m

All times are local (unless otherwise noted)


Minor ash emissions during 23 March and 2 April 2020

Soputan is a stratovolcano located in the northern arm of Sulawesi Island, Indonesia. Previous eruptive periods were characterized by ash explosions, lava flows, and Strombolian eruptions. The most recent eruption occurred during October-December 2018, which consisted mostly of ash plumes and some summit incandescence (BGVN 44:01). This report updates information for January 2019-April 2020 characterized by two ash plumes and gas-and-steam emissions. The primary source of information come from the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) and the Darwin Volcanic Ash Advisory Center (VAAC).

Activity during January 2019-April 2020 was relatively low; three faint thermal anomalies were observed at the summit at Soputan in satellite imagery for a total of three days on 2 and 4 January, and 1 October 2019 (figure 17). The MIROVA (Middle InfraRed Observation of Volcanic Activity) based on analysis of MODIS data detected 12 distal hotspots and six low-power hotspots within 5 km of the summit during August to early October 2019. A single distal thermal hotspot was detected in early March 2020. In March, activity primarily consisted of white to gray gas-and-steam plumes that rose 20-100 m above the crater, according to PVMBG. The Darwin VAAC issued a notice on 23 March 2020 that reported an ash plume rose to 4.3 km altitude; minor ash emissions had been visible in a webcam image the previous day (figure 18). A second notice was issued on 2 April, where an ash plume was observed rising 2.1 km altitude and drifting W.

Figure (see Caption) Figure 17. Sentinel-2 thermal satellite imagery detected a total of three thermal hotspots (bright yellow-orange) at the summit of Soputan on 2 and 4 January and 1 October 2019. Sentinel-2 atmospheric penetration (bands 12, 11, 8A) images courtesy of Sentinel Hub Playground.
Figure (see Caption) Figure 18. Minor ash emissions were seen rising from Soputan on 22 March 2020. Courtesy of MAGMA Indonesia.

Geologic Background. The Soputan stratovolcano on the southern rim of the Quaternary Tondano caldera on the northern arm of Sulawesi Island is one of Sulawesi's most active volcanoes. The youthful, largely unvegetated volcano is located SW of Riendengan-Sempu, which some workers have included with Soputan and Manimporok (3.5 km ESE) as a volcanic complex. It was constructed at the southern end of a SSW-NNE trending line of vents. During historical time the locus of eruptions has included both the summit crater and Aeseput, a prominent NE-flank vent that formed in 1906 and was the source of intermittent major lava flows until 1924.

Information Contacts: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as Indonesian Center for Volcanology and Geological Hazard Mitigation, CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/); MAGMA Indonesia, Kementerian Energi dan Sumber Daya Mineral (URL: https://magma.vsi.esdm.go.id/); Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); 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/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).


Heard (Australia) — May 2020 Citation iconCite this Report

Heard

Australia

53.106°S, 73.513°E; summit elev. 2745 m

All times are local (unless otherwise noted)


Eruptive activity including a lava flow during October 2019-April 2020

Heard Island is located on the Kerguelen Plateau in the southern Indian Ocean and contains Big Ben, a snow-covered stratovolcano with intermittent volcanism reported since 1910. Due to its remote location, visual observations are rare; therefore, thermal anomalies and hotspots detected by satellite-based instruments are the primary source of information. This report updates activity from October 2019 to April 2020.

MIROVA (Middle InfraRed Observation of Volcanic Activity) analysis of MODIS satellite data showed three prominent periods of strong thermal anomaly activity during this reporting period: late October 2019, December 2019, and the end of April 2020 (figure 41). These thermal anomalies were relatively strong and occurred within 5 km of the summit. Similarly, the MODVOLC algorithm reported a total of six thermal hotspots during 28 October, 1 November 2019, and 26 April 2020.

Figure (see Caption) Figure 41. Thermal anomalies at Heard from 29 April 2019 through April 2020 as recorded by the MIROVA system (Log Radiative Power) were strong and frequent in late October, during December 2019, and at the end of April 2020. Courtesy of MIROVA.

Six thermal satellite images ranging from late October 2019 to late March showed evidence of active lava at the summit (figure 42). These images show hot material, possibly a lava flow, extending SW from the summit; a hotspot also remained at the summit. Cloud cover was pervasive during the majority of this reporting period, especially in April 2020, though gas-and-steam emissions were visible on 25 April through the clouds.

Figure (see Caption) Figure 42. Thermal satellite images of Heard Island’s Big Ben showing strong thermal signatures representing a lava flow in the SW direction from 28 October to 17 December 2019. These thermal anomalies are located NE from Mawson Peak. A faint thermal anomaly is also captured on 26 March 2020. Satellite images with atmospheric penetration (bands 12, 11, and 8A), courtesy of Sentinel Hub Playground.

Geologic Background. Heard Island on the Kerguelen Plateau in the southern Indian Ocean consists primarily of the emergent portion of two volcanic structures. The large glacier-covered composite basaltic-to-trachytic cone of Big Ben comprises most of the island, and the smaller Mt. Dixon lies at the NW tip of the island across a narrow isthmus. Little is known about the structure of Big Ben because of its extensive ice cover. The historically active Mawson Peak forms the island's high point and lies within a 5-6 km wide caldera breached to the SW side of Big Ben. Small satellitic scoria cones are mostly located on the northern coast. Several subglacial eruptions have been reported at this isolated volcano, but observations are infrequent and additional activity may have occurred.

Information Contacts: 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/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).


Kikai (Japan) — May 2020 Citation iconCite this Report

Kikai

Japan

30.793°N, 130.305°E; summit elev. 704 m

All times are local (unless otherwise noted)


Ash explosion on 29 April 2020

The Kikai caldera is located at the N end of Japan’s Ryukyu Islands and has been recently characterized by intermittent ash emissions and limited ashfall in nearby communities. On Satsuma Iwo Jima island, the larger subaerial fragment of the Kikai caldera, there was a single explosion with gas-and-steam and ash emissions on 2 November 2019, accompanied by nighttime incandescence (BGVN 45:02). This report covers volcanism from January 2020 through April 2020 with a single-day eruption occurring on 29 April based on reports from the Japan Meteorological Agency (JMA).

Since the last one-day eruption on 2 November 2019, volcanism at Kikai has been relatively low and primarily consisted of 107-170 earthquakes per month and intermittent white gas-and-steam emissions rising up to 1.3 km above the crater summit. Intermittent weak hotspots were observed at night in the summit in Sentinel-2 thermal satellite imagery and webcams, according to JMA (figures 14 and 15).

Figure (see Caption) Figure 14. Weak thermal hotspots (bright yellow-orange) were observed on 7 January (top) and 6 April 2020 (bottom) at Satsuma Iwo Jima (Kikai). Sentinel-2 satellite images with “Atmospheric penetration” (bands 12, 11, 8A) rendering; courtesy of Sentinel Hub Playground.
Figure (see Caption) Figure 15. Incandescence at night on 10 January 2020 was observed at Satsuma Iwo Jima (Kikai) in the Iodake crater with the Iwanogami webcam. Courtesy of JMA (An explanation of volcanic activity at Satsuma Iwo Jima, January 2nd year of Reiwa [2020]).

Weak incandescence continued in April 2020. JMA reported SO2 measurements during April were 400-2000 tons/day. A brief eruption in the Iodake crater on 29 April 2020 at 0609 generated a gray-white ash plume that rose 1 km above the crater (figure 16). No ashfall or ejecta was observed after the eruption on 29 April.

Figure (see Caption) Figure 16. The Iwanogami webcam captured a brief gray-white ash and steam plume rising above the Iodake crater rim on Satsuma Iwo Jima (Kikai) on 29 April 2020 at 0609 local time. The plume rose 1 km above the crater summit. Courtesy of JMA (An explanation of volcanic activity at Satsuma Iwo Jima, April 2nd year of Reiwa [2020]).

Geologic Background. Kikai is a mostly submerged, 19-km-wide caldera near the northern end of the Ryukyu Islands south of Kyushu. It was the source of one of the world's largest Holocene eruptions about 6,300 years ago when rhyolitic pyroclastic flows traveled across the sea for a total distance of 100 km to southern Kyushu, and ashfall reached the northern Japanese island of Hokkaido. The eruption devastated southern and central Kyushu, which remained uninhabited for several centuries. Post-caldera eruptions formed Iodake lava dome and Inamuradake scoria cone, as well as submarine lava domes. Historical eruptions have occurred at or near Satsuma-Iojima (also known as Tokara-Iojima), a small 3 x 6 km island forming part of the NW caldera rim. Showa-Iojima lava dome (also known as Iojima-Shinto), a small island 2 km E of Tokara-Iojima, was formed during submarine eruptions in 1934 and 1935. Mild-to-moderate explosive eruptions have occurred during the past few decades from Iodake, a rhyolitic lava dome at the eastern end of Tokara-Iojima.

Information Contacts: Japan Meteorological Agency (JMA), Otemachi, 1-3-4, Chiyoda-ku Tokyo 100-8122, Japan (URL: http://www.jma.go.jp/jma/indexe.html); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).


Fuego (Guatemala) — April 2020 Citation iconCite this Report

Fuego

Guatemala

14.473°N, 90.88°W; summit elev. 3763 m

All times are local (unless otherwise noted)


Ongoing ash explosions, block avalanches, and intermittent lava flows

Fuego is a stratovolcano in Guatemala that has been erupting since 2002 with historical eruptions that date back to 1531. Volcanism is characterized by major ashfalls, pyroclastic flows, lava flows, and lahars. The previous report (BGVN 44:10) detailed activity that included multiple ash explosions, ash plumes, ashfall, active lava flows, and block avalanches. This report covers this continuing activity from October 2019 through March 2020 and consists of ash plumes, ashfall, incandescent ejecta, block avalanches, and lava flows. The primary source of information comes from the Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH), the Washington Volcanic Ash Advisory Center (VAAC), and various satellite data.

Summary of activity October 2019-March 2020. Daily activity persisted throughout October 2019-March 2020 (table 20) with multiple ash explosions recorded every hour, ash plumes that rose to a maximum of 4.8 km altitude each month drifting in multiple directions, incandescent ejecta reaching a 500 m above the crater resulting in block avalanches traveling down multiple drainages, and ashfall affecting communities in multiple directions. The highest rate of explosions occurred on 7 November with up to 25 per hour. Dominantly white fumaroles occurred frequently throughout this reporting period, rising to a maximum altitude of 4.5 km and drifting in multiple directions. Intermittent lava flows that reached a maximum length of 1.2 km were observed each month in the Seca (Santa Teresa) and Ceniza drainages (figure 128), but rarely in the Trinidad drainage. Thermal activity increased slightly in frequency and strength in late October and remained relatively consistent through mid-March as seen in the MIROVA analysis of MODIS satellite data (figure 129).

Table 20. Activity summary by month for Fuego with information compiled from INSIVUMEH daily reports.

Month Ash plume heights (km) Ash plume distance (km) and direction Drainages affected by avalanche blocks Villages reporting ashfall
Oct 2019 4.3-4.8 km 10-25 km, W-SW-S-NW Seca, Taniluyá, Ceniza, Trinidad, El Jute, Honda, and Las Lajas Panimaché I and II, Morelia, Santa Sofía, Porvenir, Finca Palo Verde, La Rochela, San Andrés Osuna, Sangre de Cristo, and San Pedro Yepocapa
Nov 2019 4.0-4.8 km 10-20 km, W-SW-S-NW Seca, Taniluyá, Trinidad, Las Lajas, Honda, and Ceniza Panimaché I and II, Morelia, Santa Sofía, Porvenir, Sangre de Cristo, Finca Palo Verde, and San Pedro Yepocapa
Dec 2019 4.2-4.8 km 10-25 km, W-SW-S-SE-N-NE Seca, Taniluya, Ceniza, Trinidad, and Las Lajas Morelia, Santa Sofía, Finca Palo Verde, El Porvenir, Sangre de Cristo, San Pedro Yepocapa, Panimaché I and II, La Rochela, and San Andrés Osuna
Jan 2020 4.3-4.8 km 10-25 km, W-SW-S-N-NE-E Seca, Ceniza, Taniluyá, Trinidad, Honda, and Las Lajas Morelia, Santa Sofía, Sangre de Cristo, San Pedro Yepocapa, Panimaché I and II, El Porvenir, Finca Palo Verde, Rodeo, La Rochela, Alotenango, El Zapote, Trinidad, La Reina, Ceilán
Feb 2020 4.3-4.8 km 8-25 km, W-SW-S-SE-E-NE-N-NW Seca, Ceniza, Taniluya, Trinidad, Las Lajas, Honda, La Rochela, El Zapote, and San Andrés Osuna Panimache I and II, Morelia, Santa Sofia, Sangre de Cristo, San Pedro Yepocapa, Rodeo, La Reina, Alotenango, Yucales, Siquinalá, Santa Lucia, El Porvenir, Finca Los Tarros, La Soledad, Buena Vista, La Cruz, Pajales, San Miguel Dueñas, Ciudad Vieja, San Miguel Escobar, San Pedro las Huertas, Antigua, La Rochela, and San Andrés Osuna
Mar 2020 4.3-4.8 km 10-23 km, W-SW-S-SE-N-NW Seca, Ceniza, Trinidad, Taniluyá, Las Lajas, Honda, La Rochela, El Zapote, San Andrés Osuna, Morelia, Panimache, and Santa Sofia San Andrés Osuna, La Rochela, El Rodeo, Chuchu, Panimache I and II, Santa Sofia, Morelia, Finca Palo Verde, El Porvenir, Sangre de Cristo, La Cruz, San Pedro Yepocapa, La Conchita, La Soledad, Alotenango, Aldea la Cruz, Acatenango, Ceilan, Taniluyá, Ceniza, Las Lajas, Trinidad, Seca, and Honda
Figure (see Caption) Figure 128. Sentinel-2 thermal satellite images of Fuego between 21 November 2019 and 20 March 2020 showing lava flows (bright yellow-orange) traveling generally S and W from the crater summit. An ash plume can also be seen on 21 November 2019, accompanying the lava flow. Sentinel-2 satellite images with “Atmospheric penetration” (bands 12, 11, 8A) rendering; courtesy of Sentinel Hub Playground.
Figure (see Caption) Figure 129. Thermal activity at Fuego increased in frequency and strength (log radiative power) in late October 2019 and remained relatively consistent through February 2020. In early March, there is a small decrease in thermal power, followed by a short pulse of activity and another decline. Courtesy of MIROVA.

Activity during October-December 2019. Activity in October 2019 consisted of 6-20 ash explosions per hour; ash plumes rose to 4.8 km altitude, drifting up to 25 km in multiple directions, resulting in ashfall in Panimaché I and II (8 km SW), Morelia (9 km SW), San Pedro Yepocapa (8 km NW), Sangre de Cristo (8 km WSW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), Finca Palo Verde, La Rochela and San Andrés Osuna. The Washington VAAC issued multiple aviation advisories for a total of nine days in October. Continuous white gas-and-steam plumes reached 4.1-4.4 km altitude drifting generally W. Weak SO2 emissions were infrequently observed in satellite imagery during October and January 2020 (figure 130) Incandescent ejecta was frequently observed rising 200-400 m above the summit, which generated block avalanches that traveled down the Seca (W), Taniluyá (SW), Ceniza (SSW), Trinidad (S), El Jute, Honda, and Las Lajas (SE) drainages. During 3-7 October lahars descended the Ceniza, El Mineral, and Seca drainages, carrying tree branches, tree trunks, and blocks 1-3 m in diameter. During 6-8 and 13 October, active lava flows traveled up to 200 m down the Seca drainage.

Figure (see Caption) Figure 130. Weak SO2 emissions were observed rising from Fuego using the TROPOMI instrument on the Sentinel-5P satellite. Top left: 17 October 2019. Top right: 17 November 2019. Bottom left: 20 January 2020. Bottom right: 22 January 2020. Courtesy of NASA Global Sulfur Dioxide Monitoring Page.

During November 2019, the rate of explosions increased to 5-25 per hour, the latter of which occurred on 7 November. The explosions resulted in ash plumes that rose 4-4.8 km altitude, drifting 10-20 km in the W direction. Ashfall was observed in Panimaché I and II, Morelia, Santa Sofía, Porvenir, Sangre de Cristo, Finca Palo Verde, and San Pedro Yepocapa. Multiple Washington VAAC notices were issued for 11 days in November. Continuous white gas-and-steam plumes rose up to 4.5 km altitude drifting generally W. Incandescent ejecta rose 100-500 m above the crater, generating block avalanches in Seca, Taniluyá, Trinidad, Las Lajas, Honda, and Ceniza drainages. Lava flows were observed for a majority of the month into early December measuring 100-900 m long in the Seca and Ceniza drainages.

The number of explosions in December 2019 decreased compared to November, recording 8-19 per hour with incandescent ejecta rising 100-400 m above the crater. The explosions generated block avalanches that traveled in the Seca, Taniluya, Ceniza, Trinidad, and Las Lajas drainages throughout the month. Ash plumes continued to rise above the summit crater to 4.8 km drifting up to 25 km in multiple directions. The Washington VAAC issued multiple daily notices almost daily in December. A continuous lava flow observed during 6-15, 21-22, 24, and 26 November through 9 December measured 100-800 m long in the Seca and Ceniza drainages.

Activity during January-March 2020. Incandescent Strombolian explosions continued daily during January 2020, ejecting material up to 100-500 m above the crater. Ash plumes continued to rise to a maximum altitude of 4.8 km, resulting in ashfall in all directions affecting Morelia, Santa Sofía, Sangre de Cristo, San Pedro Yepocapa, Panimaché I and II, El Porvenir, Finca Palo Verde, Rodeo, La Rochela, Alotenango, El Zapote, Trinidad, La Reina, and Ceilán. The Washington VAAC issued multiple notices for a total of 12 days during January. Block avalanches resulting from the Strombolian explosions traveled down the Seca, Ceniza, Taniluyá, Trinidad, Honda, and Las Lajas drainages. An active lava flow in the Ceniza drainage measured 150-600 m long during 6-10 January.

During February 2020, INSIVUMEH reported a range of 4-16 explosions per hour, accompanied by incandescent material that rose 100-500 m above the crater (figure 131). Block avalanches traveled in the Santa Teresa, Seca, Ceniza, Taniluya, Trinidad, Las Lajas, Honda, La Rochela, El Zapote, and San Andrés Osuna drainages. Ash emissions from the explosions continued to rise 4.8 km altitude, drifting in multiple directions as far as 25 km and resulting in ashfall in the communities of Panimache I and II, Morelia, Santa Sofia, Sangre de Cristo, San Pedro Yepocapa, Rodeo, La Reina, Alotenango, Yucales, Siquinalá, Santa Lucia, El Porvenir, Finca Los Tarros, La Soledad, Buena Vista, La Cruz, Pajales, San Miguel Dueñas, Ciudad Vieja, San Miguel Escobar, San Pedro las Huertas, Antigua, La Rochela, and San Andrés Osuna. Washington VAAC notices were issued almost daily during the month. Lava flows were active in the Ceniza drainage during 13-20, 23-24, and 26-27 February measuring as long as 1.2 km.

Figure (see Caption) Figure 131. Incandescent ejecta rose several hundred meters above the crater of Fuego on 6 February 2020, resulting in block avalanches down multiple drainages. Courtesy of Crelosa.

Daily explosions and incandescent ejecta continued through March 2020, with 8-17 explosions per hour that rose up to 500 m above the crater. Block avalanches from the explosions were observed in the Seca, Ceniza, Trinidad, Taniluyá, Las Lajas, Honda, Santa Teresa, La Rochela, El Zapote, San Andrés Osuna, Morelia, Panimache, and Santa Sofia drainages. Accompanying ash plumes rose 4.8 km altitude, drifting in multiple directions mostly to the W as far as 23 km and resulting in ashfall in San Andrés Osuna, La Rochela, El Rodeo, Chuchu, Panimache I and II, Santa Sofia, Morelia, Finca Palo Verde, El Porvenir, Sangre de Cristo, La Cruz, San Pedro Yepocapa, La Conchita, La Soledad, Alotenango, Aldea la Cruz, Acatenango, Ceilan, Taniluyá, Ceniza, Las Lajas, Trinidad, Seca, and Honda. Multiple Washington VAAC notices were issued for a total of 15 days during March. Active lava flows were observed from 16-21 March in the Trinidad and Ceniza drainages measuring 400-1,200 m long and were accompanied by weak to moderate explosions. By 23 March, active lava flows were no longer observed.

Geologic Background. Volcán Fuego, one of Central America's most active volcanoes, is also one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between Fuego and Acatenango to the north. Construction of Meseta dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at the mostly andesitic Acatenango. Eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows.

Information Contacts: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hydrologia (INSIVUMEH), Unit of Volcanology, Geologic Department of Investigation and Services, 7a Av. 14-57, Zona 13, Guatemala City, Guatemala (URL: http://www.insivumeh.gob.gt/); 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/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground); Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center (NASA/GSFC), 8800 Greenbelt Road, Goddard, Maryland, USA (URL: https://so2.gsfc.nasa.gov/); Washington Volcanic Ash Advisory Center (VAAC), Satellite Analysis Branch (SAB), NOAA/NESDIS OSPO, NOAA Science Center Room 401, 5200 Auth Rd, Camp Springs, MD 20746, USA (URL: www.ospo.noaa.gov/Products/atmosphere/vaac, archive at: http://www.ssd.noaa.gov/VAAC/archive.html); Crelosa, 3ra. avenida. 8-66, Zona 14. Colonia El Campo, Guatemala Ciudad de Guatemala (URL: http://crelosa.com/, post at https://www.youtube.com/watch?v=1P4kWqxU2m0&feature=youtu.be).


Ebeko (Russia) — June 2020 Citation iconCite this Report

Ebeko

Russia

50.686°N, 156.014°E; summit elev. 1103 m

All times are local (unless otherwise noted)


Frequent moderate explosions, ash plumes, and ashfall continue, December 2019-May 2020

The current moderate explosive eruption of Ebeko has been ongoing since October 2016, with frequent ash explosions that have reached altitudes of 1.3-6 km (BGVN 42:08, 43:03, 43:06, 43:12, 44:12). Ashfall is common in Severo-Kurilsk, a town of about 2,500 residents 7 km ESE, where the Kamchatka Volcanic Eruptions Response Team (KVERT) monitor the volcano. During the reporting period, December 2019-May 2020, the Aviation Color Code remained at Orange (the second highest level on a four-color scale).

During December 2019-May 2020, frequent explosions generated ash plumes that reached altitudes of 1.5-4.6 km (table 9); reports of ashfall in Severo-Kurilsk were common. Ash explosions in late April caused ashfall in Severo-Kurilsk during 25-30 April (figure 24), and the plume drifted 180 km SE on the 29th. There was also a higher level of activity during the second half of May (figure 25), when plumes drifted up to 80 km downwind.

Table 9. Summary of activity at Ebeko, December 2019-May 2020. S-K is Severo-Kurilsk (7 km ESE of the volcano). TA is thermal anomaly in satellite images. In the plume distance column, only plumes that drifted more than 10 km are indicated. Dates based on UTC times. Data courtesy of KVERT.

Date Plume Altitude (km) Plume Distance Plume Directions Other Observations
30 Nov-05 Dec 2019 3 -- NE, E Intermittent explosions.
06-13 Dec 2019 4 -- E Explosions all week. Ashfall in S-K on 10-12 Dec.
15-17 Dec 2019 3 -- E Explosions. Ashfall in S-K on 16-17 Dec.
22-24 Dec 2019 3 -- NE Explosions.
01-02 Jan 2020 3 30 km N N Explosions. TA over dome on 1 Jan.
03, 05, 09 Jan 2020 2.9 -- NE, SE Explosions. Ashfall in S-K on 8 Jan.
11, 13-14 Jan 2020 3 -- E Explosions. Ashfall in S-K.
19-20 Jan 2020 3 -- E Ashfall in S-K on 19 Jan.
24-31 Jan 2020 4 -- E Explosions.
01-07 Feb 2020 3 -- E, S Explosions all week.
12-13 Feb 2020 1.5 -- E Explosions. Ashfall in S-K.
18-19 Feb 2020 2.3 -- SE Explosions.
21, 25, 27 Feb 2020 2.9 -- S, SE, NE Explosions. Ashfall in S-K on 22 Feb.
01-02, 05 Mar 2020 2 -- S, E Explosions.
08 Mar 2020 2.5 -- NE Explosions.
13, 17 Mar 2020 2.5 -- NE, SE Bursts of gas, steam, and small amount of ash.
24-25 Mar 2020 2.5 -- NE, W Explosions.
29 Mar-02 Apr 2020 2.2 -- NE, E Explosions. Ashfall in S-K on 1 Apr. TA on 30-31 Mar.
04-05, 09 Apr 2020 1.5 -- NE Explosions. TA on 5 Apr.
13 Apr 2020 2.5 -- SE Explosions.
18, 20 Apr 2020 -- -- -- TA on 18, 20 Apr.
24 Apr-01 May 2020 3.5 180 km SE on 29 Apr E, SE Explosions all week. Ashfall in S-K on 25-30 Apr.
01-08 May 2020 2.6 -- E Explosions all week. Ashfall in S-K on 3-5 May. TA on 3 May.
08-15 May 2020 4 -- E Explosions. Ashfall in S-K on 8-12 May. TA during 12-14 May.
14-15, 19-21 May 2020 3.6 80 km SW, S, SE during 14, 20-21 May -- Explosions. TA on same days.
22-29 May 2020 4.6 60 km SE E, SE Explosions all week. Ashfall in S-K on 22, 24 May.
29-31 May 2020 4.5 -- E, S Explosions. TA on 30 May.
Figure (see Caption) Figure 24. Photo of ash explosion at Ebeko at 2110 UTC on 28 April 2020, as viewed from Severo-Kurilsk. Courtesy of KVERT (L. Kotenko).
Figure (see Caption) Figure 25. Satellite image of Ebeko from Sentinel-2 on 27 May 2020, showing a plume drifting SE. Image using natural color rendering (bands 4, 3, 2) courtesy of Sentinel Hub Playground.

Geologic Background. The flat-topped summit of the central cone of Ebeko volcano, one of the most active in the Kuril Islands, occupies the northern end of Paramushir Island. Three summit craters located along a SSW-NNE line form Ebeko volcano proper, at the northern end of a complex of five volcanic cones. Blocky lava flows extend west from Ebeko and SE from the neighboring Nezametnyi cone. The eastern part of the southern crater contains strong solfataras and a large boiling spring. The central crater is filled by a lake about 20 m deep whose shores are lined with steaming solfataras; the northern crater lies across a narrow, low barrier from the central crater and contains a small, cold crescentic lake. Historical activity, recorded since the late-18th century, has been restricted to small-to-moderate explosive eruptions from the summit craters. Intense fumarolic activity occurs in the summit craters, on the outer flanks of the cone, and in lateral explosion craters.

Information Contacts: Kamchatka Volcanic Eruptions Response Team (KVERT), Far Eastern Branch, Russian Academy of Sciences, 9 Piip Blvd., Petropavlovsk-Kamchatsky, 683006, Russia (URL: http://www.kscnet.ru/ivs/kvert/); Institute of Volcanology and Seismology, Far Eastern Branch, Russian Academy of Sciences (IVS FEB RAS), 9 Piip Blvd., Petropavlovsk-Kamchatsky 683006, Russia (URL: http://www.kscnet.ru/ivs/eng/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).


Piton de la Fournaise (France) — May 2020 Citation iconCite this Report

Piton de la Fournaise

France

21.244°S, 55.708°E; summit elev. 2632 m

All times are local (unless otherwise noted)


Fissure eruptions in February and April 2020 included lava fountains and flows

Piton de la Fournaise is a massive basaltic shield volcano on the French island of Réunion in the western Indian Ocean. Recent volcanism is characterized by multiple fissure eruptions, lava fountains, and lava flows (BGVN 44:11). The activity during this reporting period of November 2019-April 2020 is consistent with the previous eruption, including lava fountaining and lava flows. Information for this report comes from the Observatoire Volcanologique du Piton de la Fournaise (OVPF) and various satellite data.

Activity during November 2019-January 2020 was relatively low; no eruptive events were detected, according to OVPF. Edifice deformation resumed during the last week in December and continued through January. Seismicity significantly increased in early January, registering 258 shallow earthquakes from 1-16 January. During 17-31 January, the seismicity declined, averaging one earthquake per day.

Two eruptive events took place during February-April 2020. OVPF reported that the first occurred from 10 to 16 February on the E and SE flanks of the Dolomieu Crater. The second took place during 2-6 April. Both eruptive events began with a sharp increase in seismicity accompanied by edifice inflation, followed by a fissure eruption that resulted in lava fountains and lava flows (figure 193). MIROVA (Middle InfraRed Observation of Volcanic Activity) analysis of MODIS satellite data showed the two eruptive events occurring during February-April 2020 (figure 194). Similarly, the MODVOLC algorithm reported 72 thermal signatures proximal to the summit crater from 12 February to 6 April. Both of these eruptive events were accompanied by SO2 emissions that were detected by the Sentinel-5P/TROPOMI instrument (figures 195 and 196).

Figure (see Caption) Figure 193. Location maps of the lava flows on the E flank at Piton de la Fournaise on 10-16 February 2020 (left) and 2-6 April 2020 (right) as derived from SAR satellite data. Courtesy of OVPF-IPGP, OPGC, LMV (Monthly bulletins of the Piton de la Fournaise Volcanological Observatory, February and April 2020).
Figure (see Caption) Figure 194. Two significant eruptive events at Piton de la Fournaise took place during February-April 2020 as recorded by the MIROVA system (Log Radiative Power). Courtesy of MIROVA.
Figure (see Caption) Figure 195. Images of the SO2 emissions during the February 2020 eruptive event at Piton de la Fournaise detected by the Sentinel-5P/TROPOMI satellite. Top left: 10 February 2020. Top right: 11 February 2020. Bottom left: 13 February 2020. Bottom right: 14 February 2020. Courtesy of NASA Global Sulfur Dioxide Monitoring Page.
Figure (see Caption) Figure 196. Images of the SO2 emissions during the April 2020 eruptive event at Piton de la Fournaise detected by the Sentinel-5P/TROPOMI satellite. Left: 4 April 2020. Middle: 5 April 2020. Right: 6 April 2020. Courtesy of NASA Global Sulfur Dioxide Monitoring Page.

On 10 February 2020 a seismic swarm was detected at 1027, followed by rapid deformation. At 1050, volcanic tremors were recorded, signaling the start of the eruption. Several fissures opened on the E flank of the Dolomieu Crater between the crater rim and at 2,000 m elevation, as observed by an overflight during 1300 and 1330. These fissures were at least 1 km long and produced lava fountains that rose up to 10 m high. Lava flows were also observed traveling E and S to 1,700 m elevation by 1315 (figures 197 and 198). The farthest flow traveled E to an elevation of 1,400 m. Satellite data from HOTVOLC platform (OPGC - University of Auvergne) was used to estimate the peak lava flow rate on 11 February at 10 m3/s. By 13 February only one lava flow that was traveling E below the Marco Crater remained active. OVPF also reported the formation of a cone, measuring 30 m tall, surrounded by three additional vents that produced lava fountains up to 15 m high. On 15 February the volcanic tremors began to decrease at 1400; by 16 February at 1412 the tremors stopped, indicating the end of the eruptive event.

Figure (see Caption) Figure 197. Photo of a lava flow and degassing at Piton de la Fournaise on 10 February 2020. Courtesy of OVPF-IPGP.
Figure (see Caption) Figure 198. Photos of the lava flows at Piton de la Fournaise taken during the February 2020 eruption by Richard Bouchet courtesy of AFP News Service.

Volcanism during the month of March 2020 consisted of low seismicity, including 21 shallow volcanic tremors and near the end of the month, edifice inflation was detected. A second eruptive event began on 2 April 2020, starting with an increase in seismicity during 0815-0851. Much of this seismicity was located on the SE part of the Dolomieu Crater. A fissure opened on the E flank, consistent with the fissures that were active during the February 2020 event. Seismicity continued to increase in intensity through 6 April located dominantly in the SE part of the Dolomieu Crater. An overflight on 5 April at 1030 showed lava fountains rising more than 50 m high accompanied by gas-and-steam plumes rising to 3-3.5 km altitude (figures 199 and 200). A lava flow advanced to an elevation of 360 m, roughly 2 km from the RN2 national road (figure 199). A significant amount of Pele’s hair and clusters of fine volcanic products were produced during the more intense phase of the eruption (5-6 April) and deposited at distances more than 10 km from the eruptive site (figure 201). It was also during this period that the SO2 emissions peaked (figure 196). The eruption stopped at 1330 after a sharp decrease in volcanic tremors.

Figure (see Caption) Figure 199. Photos of a lava flow (left) and lava fountains (right) at Piton de la Fournaise during the April 2020 eruption. Left: photo taken on 2 April 2020 at 1500. Right: photo taken on 5 April 2020 at 1030. Courtesy of OVPF-IPGP (Monthly bulletin of the Piton de la Fournaise Volcanological Observatory, April 2020).
Figure (see Caption) Figure 200. Photo of the lava fountains erupting from Piton de la Fournaise on 4 April 2020. Photo taken by Richard Bouchet courtesy of Geo Magazine via Jeannie Curtis.
Figure (see Caption) Figure 201. Photos of Pele’s hair deposited due to the April 2020 eruption at Piton de la Fournaise. Samples collected near the Gîte du volcan on 7 April 2020 (left) and a cluster of Pele’s hair found near the Foc-Foc car park on 9 April 2020 (right). Courtesy of OVPF-IPGP (Monthly bulletin of the Piton de la Fournaise Volcanological Observatory, April 2020).

Geologic Background. The massive Piton de la Fournaise basaltic shield volcano on the French island of Réunion in the western Indian Ocean is one of the world's most active volcanoes. Much of its more than 530,000-year history overlapped with eruptions of the deeply dissected Piton des Neiges shield volcano to the NW. Three calderas formed at about 250,000, 65,000, and less than 5000 years ago by progressive eastward slumping of the volcano. Numerous pyroclastic cones dot the floor of the calderas and their outer flanks. Most historical eruptions have originated from the summit and flanks of Dolomieu, a 400-m-high lava shield that has grown within the youngest caldera, which is 8 km wide and breached to below sea level on the eastern side. More than 150 eruptions, most of which have produced fluid basaltic lava flows, have occurred since the 17th century. Only six eruptions, in 1708, 1774, 1776, 1800, 1977, and 1986, have originated from fissures on the outer flanks of the caldera. The Piton de la Fournaise Volcano Observatory, one of several operated by the Institut de Physique du Globe de Paris, monitors this very active volcano.

Information Contacts: Observatoire Volcanologique du Piton de la Fournaise, Institut de Physique du Globe de Paris, 14 route nationale 3, 27 ème km, 97418 La Plaine des Cafres, La Réunion, France (URL: http://www.ipgp.fr/fr); 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/); Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center (NASA/GSFC), 8800 Greenbelt Road, Goddard, Maryland, USA (URL: https://so2.gsfc.nasa.gov/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground); GEO Magazine (AFP story at URL: https://www.geo.fr/environnement/la-reunion-fin-deruption-au-piton-de-la-fournaise-200397); AFP (URL: https://twitter.com/AFP/status/1227140765106622464, Twitter: @AFP, https://twitter.com/AFP); Jeannie Curtis (Twitter: @VolcanoJeannie, https://twitter.com/VolcanoJeannie).


Sabancaya (Peru) — June 2020 Citation iconCite this Report

Sabancaya

Peru

15.787°S, 71.857°W; summit elev. 5960 m

All times are local (unless otherwise noted)


Daily explosions with ash emissions, large SO2 flux, ongoing thermal anomalies, December 2019-May 2020

Although tephrochronology has dated activity at Sabancaya back several thousand years, renewed activity that began in 1986 was the first recorded in over 200 years. Intermittent activity since then has produced significant ashfall deposits, seismic unrest, and fumarolic emissions. A new period of explosive activity that began in November 2016 has been characterized by pulses of ash emissions with some plumes exceeding 10 km altitude, thermal anomalies, and significant SO2 plumes. Ash emissions and high levels of SO2 continued each week during December 2019-May 2020. The Observatorio Vulcanologico INGEMMET (OVI) reports weekly on numbers of daily explosions, ash plume heights and directions of drift, seismicity, and other activity. The Buenos Aires Volcanic Ash Advisory Center (VAAC) issued three or four daily reports of ongoing ash emissions at Sabancaya throughout the period.

The dome inside the summit crater continued to grow throughout this period, along with nearly constant ash, gas, and steam emissions; the average number of daily explosions ranged from 4 to 29. Ash and gas plume heights rose 1,800-3,800 m above the summit crater, and multiple communities around the volcano reported ashfall every month (table 6). Sulfur dioxide emissions were notably high and recorded daily with the TROPOMI satellite instrument (figure 75). Thermal activity declined during December 2019 from levels earlier in the year but remained steady and increased in both frequency and intensity during April and May 2020 (figure 76). Infrared satellite images indicated that the primary heat source throughout the period was from the dome inside the summit crater (figure 77).

Table 6. Persistent activity at Sabancaya during December 2019-May 2020 included multiple daily explosions with ash plumes that rose several kilometers above the summit and drifted in many directions; this resulted in ashfall in communities within 30 km of the volcano. Satellite instruments recorded SO2 emissions daily. Data courtesy of OVI-INGEMMET.

Month Avg. Daily Explosions by week Max plume Heights (m above crater) Plume drift (km) and direction Communities reporting ashfall Min Days with SO2 over 2 DU
Dec 2019 16, 13, 5, 5 2,600-3,800 20-30 NW Pinchollo, Madrigal, Lari, Maca, Achoma, Coporaque, Yanque, Chivay, Huambo, Cabanaconde 27
Jan 2020 10, 8, 11, 14, 4 1,800-3,400 30 km W, NW, SE, S Chivay, Yanque, Achoma 29
Feb 2020 8, 11, 20, 19 2,000-2,200 30 km SE, E, NE, W Huambo 29
Mar 2020 14, 22, 29, 18 2,000-3,000 30 km NE, W, NW, SW Madrigal, Lari, Pinchollo 30
Apr 2020 12, 12, 16, 13, 8 2,000-3,000 30 km SE, NW, E, S Pinchollo, Madrigal, Lari, Maca, Ichupampa, Yanque, Chivay, Coporaque, Achoma 27
May 2020 15, 14, 6, 16 1,800-2,400 30 km SW, SE, E, NE, W Chivay, Achoma, Maca, Lari, Madrigal, Pinchollo 27
Figure (see Caption) Figure 75. Sulfur dioxide anomalies were captured daily from Sabancaya during December 2019-May 2020 by the TROPOMI instrument on the Sentinel-5P satellite. Some of the largest SO2 plumes are shown here with dates listed in the information at the top of each image. Courtesy of NASA Global Sulfur Dioxide Monitoring Page.
Figure (see Caption) Figure 76. Thermal activity at Sabancaya declined during December 2019 from levels earlier in the year but remained steady and increased slightly in frequency and intensity during April and May 2020, according to the MIROVA graph of Log Radiative Power from 23 June 2019 through May 2020. Courtesy of MIROVA.
Figure (see Caption) Figure 77. Sentinel-2 satellite imagery of Sabancaya confirmed the frequent ash emissions and ongoing thermal activity from the dome inside the summit crater during December 2019-May 2020. Top row (left to right): On 6 December 2019 a large plume of steam and ash drifted N from the summit. On 16 December 2019 a thermal anomaly encircled the dome inside the summit caldera while gas and possible ash drifted NW. On 14 April 2020 a very similar pattern persisted inside the crater. Bottom row (left to right): On 19 April an ash plume was clearly visible above dense cloud cover. On 24 May the infrared glow around the dome remained strong; a diffuse plume drifted W. A large plume of ash and steam drifted SE from the summit on 29 May. Infrared images use Atmospheric penetration rendering (bands 12, 11, 8a), other images use Natural Color rendering (bands 4, 3, 2). Courtesy of Sentinel Hub Playground.

The average number of daily explosions during December 2019 decreased from a high of 16 the first week of the month to a low of five during the last week. Six pyroclastic flows occurred on 10 December (figure 78). Tremors were associated with gas-and-ash emissions for most of the month. Ashfall was reported in Pinchollo, Madrigal, Lari, Maca, Achoma, Coporaque, Yanque, and Chivay during the first week of the month, and in Huambo and Cabanaconde during the second week (figure 79). Inflation of the volcano was measured throughout the month. SO2 flux was measured by OVI as ranging from 2,500 to 4,300 tons per day.

Figure (see Caption) Figure 78. Multiple daily explosions at Sabancaya produced ash plumes that rose several kilometers above the summit. Left image is from 5 December and right image is from 11 December 2019. Note pyroclastic flows to the right of the crater on 11 December. Courtesy of OVI (Reporte Semanal de Monitorio de la Actividad de la Volcan Sabancaya, RSSAB-49-2019/INGEMMET Semana del 2 al 8 de diciembre de 2019 and RSSAB-50-2019/INGEMMET Semana del 9 al 15 de diciembre de 2019).
Figure (see Caption) Figure 79. Communities to the N and W of Sabancaya recorded ashfall from the volcano the first week of December and also every month during December 2019-May 2020. The red zone is the area where access is prohibited (about a 12-km radius from the crater). Courtesy of OVI (Reporte Semanal de Monitorio de la Actividad de la Volcan Sabancaya, RSSAB-22-2020/INGEMMET Semana del 25 al 31 de mayo del 2020).

During January and February 2020 the number of daily explosions averaged 4-20. Ash plumes rose as high as 3.4 km above the summit (figure 80) and drifted up to 30 km in multiple directions. Ashfall was reported in Chivay, Yanque, and Achoma on 8 January, and in Huambo on 25 February. Sulfur dioxide flux ranged from a low of 1,200 t/d on 29 February to a high of 8,200 t/d on 28 January. Inflation of the edifice was measured during January; deformation changed to deflation in early February but then returned to inflation by the end of the month.

Figure (see Caption) Figure 80. Ash plumes rose from Sabancaya every day during January and February 2020. Left: 11 January. Right: 28 February. Courtesy of OVI (Reporte Semanal de Monitorio de la Actividad de la Volcan Sabancaya, RSSAB-02-2020/INGEMMET Semana del 06 al 12 de enero del 2020 and RSSAB-09-2020/INGEMMET Semana del 24 de febrero al 01 de marzo del 2020).

Explosions continued during March and April 2020, averaging 8-29 per day. Explosions appeared to come from multiple vents on 11 March (figure 81). Ash plumes rose 3 km above the summit during the first week of March and again the first week of April; they were lower during the other weeks. Ashfall was reported in Madrigal, Lari, and Pinchollo on 27 March and 5 April. On 17 April ashfall was reported in Maca, Ichupampa, Yanque, Chivay, Coporaque, and Achoma. Sulfur dioxide flux ranged from 1,900 t/d on 5 March to 10,700 t/d on 30 March. Inflation at depth continued throughout March and April with 10 +/- 4 mm recorded between 21 and 26 April. Similar activity continued during May 2020; explosions averaged 6-16 per day (figure 82). Ashfall was reported on 6 May in Chivay, Achoma, Maca, Lari, Madrigal, and Pinchollo; heavy ashfall was reported in Achoma on 12 May. Additional ashfall was reported in Achoma, Maca, Madrigal, and Lari on 23 May.

Figure (see Caption) Figure 81. Explosions at Sabancaya on 11 March 2020 appeared to originate simultaneously from two different vents (left). The plume on 12 April was measured at about 2,500 m above the summit. Courtesy of OVI-INGEMMET (Reporte Semanal de Monitorio de la Actividad de la Volcan Sabancaya, RSSAB-11-2020/INGEMMET Semana del 9 al 15 de marzo del 2020 and RSSAB-15-2020/INGEMMET Semana del 6 al 12 de abril del 2020).
Figure (see Caption) Figure 82. Explosions dense with ash continued during May 2020 at Sabancaya. On 11 and 29 May 2020 ash plumes rose from the summit and drifted as far as 30 km before dissipating. Courtesy of OVI-INGEMMET (Reporte Semanal de Monitorio de la Actividad de la Volcan Sabancaya , RSSAB-20-2020/INGEMMET Semana del 11 al 17 de mayo del 2020 and RSSAB-22-2020/INGEMMET Semana del 25 al 31 de mayo del 2020).

Geologic Background. Sabancaya, located in the saddle NE of Ampato and SE of Hualca Hualca volcanoes, is the youngest of these volcanic centers and the only one to have erupted in historical time. The oldest of the three, Nevado Hualca Hualca, is of probable late-Pliocene to early Pleistocene age. The name Sabancaya (meaning "tongue of fire" in the Quechua language) first appeared in records in 1595 CE, suggesting activity prior to that date. Holocene activity has consisted of Plinian eruptions followed by emission of voluminous andesitic and dacitic lava flows, which form an extensive apron around the volcano on all sides but the south. Records of historical eruptions date back to 1750.

Information Contacts: Observatorio Volcanologico del INGEMMET (Instituto Geológical Minero y Metalúrgico), Barrio Magisterial Nro. 2 B-16 Umacollo - Yanahuara Arequipa, Peru (URL: http://ovi.ingemmet.gob.pe); Buenos Aires Volcanic Ash Advisory Center (VAAC), Servicio Meteorológico Nacional-Fuerza Aérea Argentina, 25 de mayo 658, Buenos Aires, Argentina (URL: http://www.smn.gov.ar/vaac/buenosaires/inicio.php); Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center (NASA/GSFC), 8800 Greenbelt Road, Goddard, Maryland, USA (URL: https://so2.gsfc.nasa.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/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).


Sheveluch (Russia) — May 2020 Citation iconCite this Report

Sheveluch

Russia

56.653°N, 161.36°E; summit elev. 3283 m

All times are local (unless otherwise noted)


Lava dome growth and thermal anomalies continue through April 2020, but few ash explosions

The eruption at Sheveluch has continued for more than 20 years, with strong explosions that have produced ash plumes, lava dome growth, hot avalanches, numerous thermal anomalies, and strong fumarolic activity (BGVN 44:05). During this time, there have been periods of greater or lesser activity. The most recent period of increased activity began in December 2018 and continued through October 2019 (BGVN 44:11). This report covers activity between November 2019 to April 2020, a period during which activity waned. The volcano is monitored by the Kamchatka Volcanic Eruptions Response Team (KVERT) and Tokyo Volcanic Ash Advisory Center (VAAC).

During the reporting period, KVERT noted that lava dome growth continued, accompanied by incandescence of the dome blocks and hot avalanches. Strong fumarolic activity was also present (figure 53). However, the overall eruption intensity waned. Ash plumes sometimes rose to 10 km altitude and drifted downwind over 600 km (table 14). The Aviation Color Code (ACC) remained at Orange (the second highest level on a four-color scale), except for 3 November when it was raised briefly to Red (the highest level).

Figure (see Caption) Figure 53. Fumarolic activity of Sheveluch’s lava dome on 24 January 2020. Photo by Y. Demyanchuk; courtesy of KVERT.

Table 14. Explosions and ash plumes at Sheveluch during November 2019-April 2020. Dates and times are UTC, not local. Data courtesy of KVERT and the Tokyo VAAC.

Dates Plume Altitude (km) Drift Distance and Direction Remarks
01-08 Nov 2019 -- 640 km NW 3 November: ACC raised to Red from 0546-0718 UTC before returning to Orange.
08-15 Nov 2019 9-10 1,300 km ESE
17-27 Dec 2019 6.0-6.5 25 km E Explosions at about 23:50 UTC on 21 Dec.
20-27 Mar 2020 -- 45 km N 25 March: Gas-and-steam plume containing some ash.
03-10 Apr 2020 10 km 526 km SE 8 April: Strong explosion at 1910 UTC.
17-24 Apr 2020 -- 140 km NE Re-suspended ash plume.

KVERT reported thermal anomalies over the volcano every day, except for 25-26 January, when clouds obscured observations. During the reporting period, thermal anomalies, based on MODIS satellite instruments analyzed using the MODVOLC algorithm recorded hotspots on 10 days in November, 13 days in December, nine days in January, eight days in both February and March, and five days in April. The MIROVA (Middle InfraRed Observation of Volcanic Activity) volcano hotspot detection system, also based on analysis of MODIS data, detected numerous hotspots every month, almost all of which were of moderate radiative power (figure 54).

Figure (see Caption) Figure 54. Thermal anomalies at Sheveluch continued at elevated levels during November 2019-April 2020, as seen on this MIROVA Log Radiative Power graph for July 2019-April 2020. Courtesy of MIROVA.

High sulfur dioxide levels were occasionally recorded just above or in the close vicinity of Sheveluch by the TROPOspheric Monitoring Instrument (TROPOMI) aboard the Copernicus Sentinel-5 Precursor satellite, but very little drift was observed.

Geologic Background. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1300 km3 volcano is one of Kamchatka's largest and most active volcanic structures. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes dot its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large horseshoe-shaped caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. At least 60 large eruptions have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera.

Information Contacts: Kamchatka Volcanic Eruptions Response Team (KVERT), Far Eastern Branch, Russian Academy of Sciences, 9 Piip Blvd., Petropavlovsk-Kamchatsky, 683006, Russia (URL: http://www.kscnet.ru/ivs/kvert/); Institute of Volcanology and Seismology, Far Eastern Branch, Russian Academy of Sciences (IVS FEB RAS), 9 Piip Blvd., Petropavlovsk-Kamchatsky 683006, Russia (URL: http://www.kscnet.ru/ivs/eng/); Tokyo Volcanic Ash Advisory Center (VAAC), 1-3-4 Otemachi, Chiyoda-ku, Tokyo, Japan (URL: http://ds.data.jma.go.jp/svd/vaac/data/); 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/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground); Global Sulfur Dioxide Monitoring Page, Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center (NASA/GSFC), 8800 Greenbelt Road, Goddard, Maryland, USA (URL: https://so2.gsfc.nasa.gov/).

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Bulletin of the Global Volcanism Network - Volume 38, Number 05 (May 2013)

Managing Editor: Richard Wunderman

Agrigan (United States)

2007 M~3.3 earthquake followed by clouds of equivocal origin

Ambae (Vanuatu)

Minor activity likely continuing into early 2013

Ambrym (Vanuatu)

Roiling lava lake and related observations through mid-2013

Dallol (Ethiopia)

Phreatic eruption in 1st week of January 2011

Fuego (Guatemala)

Continuous activity and a VEI 3 eruption during 13-14 September 2012

Gaua (Vanuatu)

Hazard status raised; emissions continue into 2013; plume observed from above

Kilauea (United States)

Summary of highlights for 2010-2012

Pavlof (United States)

Eruption in May-June 2013 with lava flows and ash emissions to ~8.5 km a.s.l.

Veniaminof (United States)

Ongoing sporadic eruptions as late as 6 October 2013

Yasur (Vanuatu)

Explosive activity continued into at least early 2013



Agrigan (United States) — May 2013 Citation iconCite this Report

Agrigan

United States

18.77°N, 145.67°E; summit elev. 965 m

All times are local (unless otherwise noted)


2007 M~3.3 earthquake followed by clouds of equivocal origin

Our last report on Agrigan volcano covered a May 1992 field visit (BGVN 17:06) by a six-member team of USGS volcanologists that visited the Commonwealth of the Northern Mariana Islands (CNMI) at the request of the CNMI Office of Civil Defense. The team detected thermal activity, but no seismicity, deformation or other signs of an eruption.

The following came from a report by both the USGS and CNMI issued mid-July 2007and labeled Current Update. "An earthquake was reported felt on Agrigan island at 3:49 pm July 16 local time. About 3 seconds of shaking was reported by a local resident. Seismometers on Sarigan and Anatahan recorded the earthquake and allowed estimation the magnitude at approximately 3.3. No sulfur smell or any other signs of volcanic activity were reported on July 16 or in a follow up call on July 17."

Some 2012 and 2013 observations were equivocal. On 29 February 2012, NOAA's Washington Volcanic Ash Advisory Center (VAAC) inferred ash and gas emissions here for the first time on record, but this was later discounted due to lack of forthcoming evidence. The inferred plume was seen in satellite infrared imagery. It extended 74 km NW from the summit.

A possible volcanic plume from Agrigan was spotted again by the VAAC in a satellite image from 22 January 2013.

In a 25 January 2013 USGS update, it was noted that neither the USGS nor NOAA received confirmation of a volcanic source for the satellite anomalies. The authors of the 2013 update interpreted the cloud as weather-related and not volcanic in origin.

Figure 2 shows a photo of Agrigan taken in June 2013. No hotspots were detected during mid-2012 to mid-2013 by the MODVOLC Thermal Alerts System.

Figure (see Caption) Figure 2. Agrigan as seen on 15 June 2013. Photo credit to Yoshi Tamura; featured here thanks to cooperation of Robert Stern.

Agrigan, the highest-standing stratovolcano and largest (by subaerial volume) in the Northern Mariana Islands, stands 882 m a.s.l (figure 3). The island is ~10 by 6.5 km (N-S by E-W) in size, with a surface area of 52.7 km2. The volcano's subaerial volume is ~15.9 km3. The summit contains a large depression, roughly 1.5 by 1.2 km in diameter, and 380 m deep. A spatter cone and flows from the 1917 eruption cover ~50 percent of the crater floor. This large crater implies a local edifice with shallow magma storage within the volcano. The flanks of the volcano are steep (>30 degrees), with deep furrows extending radially away from the crater. To the north is a large canyon into which a recent, large 'a'&#257 flow advanced to form a delta on the coast. Pyroclastic flow deposits mantle most of the interior of the island. Rocks erupted on the island range from basalt to andesite. The southwest coast has several beaches composed of mineral sands; otherwise, the coast is rocky. (Trusdell, F.A. and others, 2009).

Figure (see Caption) Figure 3. Geologic map of Agrigan with 200 m contour intervals (after Stern, 1978) and location map (after Trusdell and others, 2006).

References. Sako, M. K.; Trusdell, F. A.; Koyanagi, R. Y.; Kojima, George; Moore, R. B., 1995, Volcanic investigations in the Commonwealth of the Northern Mariana Islands, April to May 1994, USGS Open-File Report 94-705.

Stern, R.J., 1978, Agrigan: an introduction to the geology of an active volcano in the Northern Mariana Arc: Bulletin of Volcanology, v. 41, p. 43-55.

Trusdell, F.A., Moore, R.B., and Sako, M.K., 2006. Preliminary Geologic Map of Mount Pagan Volcano, Pagan Island, Commonwealth of the Northern Mariana Islands, USGS Open-File Report 2006-1386 (URL: http://pubs.usgs.gov/of/2006/1386/).

Trusdell, F.A. 2009, Geology of the Mariana Islands, in Gillespie, R.G., and Clague, D.A., eds., Encyclopedia of Islands: Enclyclopedias of the Natural World, 2, University of California Press, Chap. 18. P. 598-603.

Geologic Background. The highest of the Marianas arc volcanoes, Agrigan contains a 500-m-deep, flat-floored caldera. The elliptical island is 8 km long; its summit is the top of a massive 4000-m-high submarine volcano. Deep radial valleys dissect the flanks of the thickly vegetated stratovolcano. The elongated caldera is 1 x 2 km wide and is breached to the NW, from where a prominent lava flow extends to the coast and forms a lava delta. The caldera floor is surfaced by fresh-looking lava flows and also contains two cones that may have formed during the only historical eruption in 1917. This eruption deposited large blocks and 3 m of ash and lapilli on a village on the SE coast, prompting its evacuation.

Information Contacts: Emergency Management Office of the Commonwealth of the Northern Mariana Islands (EMO-CNMI) and USGS Volcano Hazards Program, PO Box 100007, Saipan, MP 96950, USA (URL: http://www.cnmihsem.gov.mp/ and http://volcanoes.usgs.gov/nmi/activity/); Washington Volcanic Ash Advisory Center (VAAC), Satellite Analysis Branch (SAB), NOAA/NESDIS E/SP23, NOAA Science Center Room 401, 5200 Auth Rd, Camp Springs, MD 20746, USA (URL: http://www.ospo.noaa.gov/Products/atmosphere/vaac/); 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://httphotspot.higp); Robert J. Stern, University of Texas at Dallas, 800 W Campbell Rd Richardson, TX 75080; and Yoshi Tamura, Institute for Research on Earth Evolution (IFREE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka 237-0061, Japan.


Ambae (Vanuatu) — May 2013 Citation iconCite this Report

Ambae

Vanuatu

15.389°S, 167.835°E; summit elev. 1496 m

All times are local (unless otherwise noted)


Minor activity likely continuing into early 2013

In our May 2011 Bulletin we reported that there was increased degassing at Aoba (also known as Ambae) starting December 2009 through at least April 2010. This report summarizes notices pereiodically posted by the Vanuatu Geohazards Observatory (VGO) and covers the time interval from 4 June 2011 through 26 February 2013. The Vanautu Volcano Alert Level (VVAL) remained at 1 (on a scale of 0-4.)

Observations on 4 June 2011 revealed that small explosions had been occurring from the crater lake and were accompanied by local ashfall around the crater. Some villagers in the N and W parts of the island had observed the explosions.

Based on analysis of data collected by the Vanuatu Meteorology and Geohazards Department (VMGD), the Vanuatu Geohazards Observatory reported that a small series of explosions from Aoba occurred on 10 July 2011. On July 11, VGO noted that there had been recent increases in activity from Ambae and that local earthquakes were volcanic. Satellite images collected by the Ozone Monitoring Instrument showed sulfur dioxide emissions. Photos showed that the volcano was quiet on 12 July 2011, although ongoing earthquakes were detected.

According to the VGO, Ambanga villagers reported that minor activity at Aoba began in December 2012. The OMI instrument detected strong gas emissions on 18 and 25 January 2013; the emissions continued at a lower level through 7 February. Field observations by the Geohazards team during 30 January-2 February 2013 confirmed that activity had significantly changed. Data retrieved from a monitoring station also confirmed ongoing activity. Satellite images acquired on 3 and 26 February 2013 detected substantial sulfur dioxide emissions.

No MODVOLC Thermal Alerts were issued in the previous year ending 16 July 2013.

Geologic Background. The island of Ambae, also known as Aoba, is a massive 2500 km3 basaltic shield that is the most voluminous volcano of the New Hebrides archipelago. A pronounced NE-SW-trending rift zone dotted with scoria cones gives the 16 x 38 km island an elongated form. A broad pyroclastic cone containing three crater lakes (Manaro Ngoru, Voui, and Manaro Lakua) is located at the summit within the youngest of at least two nested calderas, the largest of which is 6 km in diameter. That large central edifice is also called Manaro Voui or Lombenben volcano. Post-caldera explosive eruptions formed the summit craters about 360 years ago. A tuff cone was constructed within Lake Voui (or Vui) about 60 years later. The latest known flank eruption, about 300 years ago, destroyed the population of the Nduindui area near the western coast.

Information Contacts: Vanuatu Geohazards Observatory (URL: http://www.vmgd.gov.vu/vmgd/); and 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/).


Ambrym (Vanuatu) — May 2013 Citation iconCite this Report

Ambrym

Vanuatu

16.25°S, 168.12°E; summit elev. 1334 m

All times are local (unless otherwise noted)


Roiling lava lake and related observations through mid-2013

In our previous Ambrym report, we described ongoing plumes, some bearing ash rising to over 6 km altitude through early June 2011 (BGVN 36:05). The volcano has been known to contain two molten, turbulent lava lakes since August 1999, and that continues at least through June 2011, which was the last time lava-lake activity was noted in a report by the Vanuatu Geohazards Observatory (VGO). Our reporting observations drew heavily on government reports of 3 April 2009 and 29 July 2013. The former report also discussed water supply and other issues of public health and safety associated with inhabiting an active volcano. Vanuatu is located in the South Pacific NE of Australia (figures 24 and 25).

Figure (see Caption) Figure 24. A location map showing Ambrym volcano on Ambrym Island in the South Pacific. Australia is at lower left. On larger map, Ambrym is shown in Vanuatu labeled in red. Map came from Polacci and others (2012).
Figure (see Caption) Figure 25. Map of Ambrym emphasizing risk. Green is low hazard, yellow is medium hazard, and red is high hazard for both areas near the crater and along main stream valleys and their lower, less confined areas at low elevation. Note the two craters, Marum and Benbow, both containing active lava lakes. Courtesy of the Government of Vanuatu (from the 3 April 2009 report by the Vanuatu Natural Disaster Committee).

Reynolds (2010) posted videos of lava lake behavior seen in September 2010. Figure 26 is a screenshot taken from the Reynolds' video of the turbulent lava lake with a climber in the foreground. The high definition videos showed an exceedingly agitated lake surface, everywhere disturbed and molten, without any chilled material in evidence. Violent upwellings of lava occurred continuously. Some fraction of the videos show climbers in the foreground, at one point descending a steep slope or vertical drop by a single rope secured from above (abseiling or rappelling).

Figure (see Caption) Figure 26. A screen capture from a video of Marum, one of Ambrym's two active lava lakes, taken on unstated day in September 2010. Courtesy of James Reynolds (typhoonfury.com and earthuncut.tv).

On 27 June 2011, the VGO reported that data collected from Ambrym's monitoring network showed significant daily degassing and occasional explosions in the crater. Field observers noted that the level of the lava lakes was high. During June, villages reported minor ashfall and that acid rain affected agriculture in general in some areas W, S, and E. The Alert Level remained at 1 (on a scale of 0-4).

During the previous 12 months prior to mid-July 2013, MODVOLC thermal alerts were frequent, on the order of several a week to multiple per day, as would be expected for a volcano with active lava lakes. The alerts referred to the lava lakes in Benbow and Marum craters (figure 25).

On 21 June 2013, VGO reported that satellite images on 2, 4, 11, 14, and 16 June detected gas emissions from Ambrym. Emissions of minor amounts of ash and substantial amounts of gas from the active vents had been detected during the previous week. The report warned that communities on the island, especially those downwind of Ambrym, may experience ashfall and acid rain that could damage the environment and contaminate water. The Alert Level remained at 1. Based on pilot observations and analyses of satellite imagery, the Wellington Volcanic Ash Advisory Center (VAAC) reported that on 19 July 2013 an ash plume rose to an altitude of 3 km a.s.l. and drifted 185 km NW.

VGO reported that activity at Ambrym slightly increased to a minor eruptive phase, and a seismic swarm was detected between 2400 and 0700 on 26 July 2013. The Alert Level remained at 1.

Gas fluxes are generally high for Vanuatu volcanoes and have been the subject of regular reporting online and several recent reports in the literature (for example, Bani and others, 2009; Bani and others, 2012).

References. Bani, P., C. Oppenheimer, V.I. Tsanev, S.A. Carn, S.J. Cronin, R. Crimp, J.A. Calkins, D. Charley, M. Lardy, and T.R. Roberts, 2009, Surge in sulfur and halogen degassing from Ambrym volcano, Vanuatu, Bulletin of Volcanology, 71(10), 1159-1168, doi:10.1007/s00445-009-0293-7.

Bani, P., C. Oppenheimer, P. Allard, H. Shinohara, V. Tsanev, S. Carn, M. Lardy, and E. Garaebeti, 2012, First arc-scale volcanic SO2 budget for the Vanuatu archipelago, Journal of Volcanology and Geothermal Research, 211-212, 36-46, doi:10.1016/j.jvolgeores.2011.10.005.

Polacci, M, Baker, D, La Rue, A., Mancini, L., Allard, P., 2012, Degassing behaviour of vesiculated basaltic magmas: an example from Ambrym volcano, Vanuatu Arc, Journal of Volcanology and Geothermal Research, Vol. 233-234, 1 July 2012, pp. 55-64.

Reynolds, J., 2010, (Video) Abseiling towards a lava lake--extreme video From Marum volcano, Ambrym, Vanuatu (September 2010) YouTube (URL: https://www.youtube.com/watch?v=AtGT-_7Xoal) [also available at typhoonfury.com and earthuncut.tv].

Geologic Background. Ambrym, a large basaltic volcano with a 12-km-wide caldera, is one of the most active volcanoes of the New Hebrides Arc. A thick, almost exclusively pyroclastic sequence, initially dacitic then basaltic, overlies lava flows of a pre-caldera shield volcano. The caldera was formed during a major Plinian eruption with dacitic pyroclastic flows about 1,900 years ago. Post-caldera eruptions, primarily from Marum and Benbow cones, have partially filled the caldera floor and produced lava flows that ponded on the floor or overflowed through gaps in the caldera rim. Post-caldera eruptions have also formed a series of scoria cones and maars along a fissure system oriented ENE-WSW. Eruptions have apparently occurred almost yearly during historical time from cones within the caldera or from flank vents. However, from 1850 to 1950, reporting was mostly limited to extra-caldera eruptions that would have affected local populations.

Information Contacts: Vanuatu Geohazards Observatory, Department of Geology, Mines and Water Resources of Vanuatu (URL: http://geohazards.gov.vu/); Hawai'i Institute of Geophysics and Planetology (HIGP), MODVOLC Thermal Alerts System, School of Ocean and Earth Sciences and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http//hotspot.higp.hawaii.edu/); Wellington Volcanic Ash Advisory Centre (VAAC) (URL: http://vaac.metservice.com/); and NASA Global Sulfur Dioxide Monitoring Home Page, Goddard Space Flight Center, Sciences and Exploration Atmospheric Chemistry and Dynamics Laboratory, Code 614 (URL: http://so2.gsfc.nasa.gov/, http://so2.gsfc.nasa.gov/pix/daily/0813/vanuatu_0813z.html).


Dallol (Ethiopia) — May 2013 Citation iconCite this Report

Dallol

Ethiopia

14.242°N, 40.3°E; summit elev. -48 m

All times are local (unless otherwise noted)


Phreatic eruption in 1st week of January 2011

The Dallol volcano has not been the subject of any previous Bulletin reports; however, the hydrothermal features include diverse brightly colored hot springs that are both dramatic and intriguing. An explosive event at Dallol was noted by observers in January 2011. This report was given to us by Tadiwos Chernet.

Dallol is located in the Danakil Depression in the northern part of the Afar triangle of Ethiopia. The volcano is on the NNW trending Erta Ale axial, a rift segment that hosts a number of active volcanoes, including Erta Ale, itself the host of a perennial lava lake. The elliptical Dallol (figure 1), which rises gently to 60 m above the salt plain (48 m below sea level), has a summit crater (about 100 m diameter) that experienced a phreatic eruption in 1926.

Figure (see Caption) Figure 1. Dallol with salt pools and deposits in the foreground. Photograher uncertain but this photo was apparently online since 2011. Bulletin editors found it on multiple websites including Vieweird.com.

Nearby residents of Almeda observed unusual dark colored smoke from the Dallol crater in the first week of January 2011. The event, which was not strong enough to be recorded by satellite remote sensing, left dark-gray ash and sulfur deposits at Dallol hot springs, suggesting degassing from depth. This process was not unexpected given that the region contains many craters, and the Dallol crater, formed in 1926, was the result of a phreatic eruption. Previous phreatic eruptions at Dallol and the surrounding salt plain have left behind bubbling acid brine pools best explained by a number of active maar craters. Those craters are obscured by the thick evaporite succession and frequent marine invasions of the salt plain during the Holocene.

Evaporites and Geothermal reservoir. According to Chernet, an adjacent salt-crusted depression that lies 120 m below sea level was linked to the Gulf of Zula on the Red Sea in the Pleistocene by the narrow extensional Alid graben to the N. The Alid graben is floored by fissure basalts and the active Alid and Jallua rhyolitic volcanoes. An evaporite succession in the sedimentary basin is mostly bedded halite, but includes minor inter-beds of clay shale, gypsum, anhydrite, and a thick bed of potash. Citing Barberi et al. (1972), Chernet indicated that the deposits, over 1,000 m thick, have continued for 200,000-25,000 years and attest to a number of marine ingressions into the depression which have left behind a number of brine lakes.

At Dallol, a salt dome rises as a notable topographic and geologic feature (figure 1). On the salt dome, several springs with boiling, supersaturated, and extremely acidic waters are discharging on salt cones.

Citing Varet (2010), Chernet stated that geothermal reservoirs, which reside below the evaporite succession, evidently recharge from precipitation on the NW plateau. This suggests the potential for a renewable geothermal energy supply in the area.

Figure (see Caption) Figure 2. (a & b) Two, 3-dimensional representations of the Dallol dome and the subsurface spring sources venting at the surface to feed surface evaporites. Courtesy of Research and Development Center, (Ministry of Mines, P.O. Box 486, Addis Ababa, Ethiopia). Courtesy of Carniel and others (2010), citing a personal communications from M. Rivas (2006).

The salt cones are tall, brilliantly colored mounds of salt with intervening pools of yellow, orange and blue-green brine. These colors may result from oxidation state of species in solution, such as ferrous chloride to ferric chloride.

Dallol waters are characterized by very high total dissolved solids (up to 525 g/kg). The waters can be grouped into three chemical suites, all of which contain high levels of chloride. Two representative water samples were collected and analyzed. One of the samples was from a hot springs with a 110C temperature that solidified shortly after collection, indicating salt supersaturation. An X-ray diffraction pattern of the solidified product showed the presence of bishofite (MgCl2*6H2O). The other was a brine water of pH 0.2. The chemical composition of the samples was that of concentrated sea water.

According to Chernet, X-ray diffraction of samples from hydrothermal deposits within the crater shows that the major constitutents of most samples are halite, sulfur, calcite,. sodalite, and hematite, with minor levels of silica. Metallic oxides and potassium and/or fluorine impurities have given the sites a brown, yellow, or bluish color.

Chernet noted that frequent earthquakes of magnitude 4.5-5.5 occur in the vicinity of Dallol, as reflected by cracks healed with later salt deposits and a number of phreatic eruptions.

References. Barberi, F., Borsi, S., Ferrara, G., Marinelli, G.; Santacroce, R.; Tazieff, H., Varet, J., 1972, Evolution of the Danakil depression (Afar, Ethiopia) in light of radiometric age determinations, The Journal of Geology, v. 80, iss. 6, p. 720-729.

Carniel, R., Muñoz Jolis, E., Jones, J., 2010, A geophysical multi-parametric analysis of hydrothermal activity at Dallol, Ethiopia, Journal of African Earth Sciences, vol. 58, p. 812-819. (Article cited personal communications from M. Rivas, 2006).

Chernet, T., Dallol Volcano and Danakil Depression: Earth Resources and Geo-hazards, 2012, Magmatic Rifting and Active Volcanism Conference, 11-13 January 2012, (Session 3), Afar Rift Consortium, Addis Ababa, Ethiopia. (http://www.see.leeds.ac.uk/afar/new-afar/conference/talks.html).

Darraha, T.H., Tedesco, D., Tassid, F., Vasellid, O., Cuocob, E., Poredaf, RJ, 2013, Gas chemistry of the Dallol region of the Danakil Depression in the Afar region of the northern-most East African Rift, Chemical Geology, vol. 339, p. 16-29.

Nobile, A., C. Pagli, Keir, D., Wright, T. J., Ayele, A., Ruch, J., and Acocella, V., 2012, Dike-fault interaction during the 2004 Dallol intrusion at the northern edge of the Erta Ale Ridge (Afar, Ethiopia), Geophys. Res. Lett., v. 39, L19305.

Varet, J., 2010, Contribution to Favorable Geothermal Site Selection In the Afar Triangle, ARGEO-C3, Third East African Rift Geothermal Conference, Djibouti, 22-25 November 2010, p. 139-154.

Geologic Background. Numerous phreatic explosion craters dot the Salt Plain NNE of the Erta Ale Range in one of the lowest areas of the desolate Danakil depression. These craters mark Earth's lowest known subaerial volcanic vents. The most recent of these craters, Dallol, lies 48 m below sea level and was formed during an eruption in 1926. Colorful hot brine springs are found in the Dallol area. Another phreatic explosion was observed in January 2011.

Information Contacts: Tadiwos Chernet, Research and Development Directorate, Ministry of Mines, P.O.Box 486, Addis Ababa, Ethiopia.


Fuego (Guatemala) — May 2013 Citation iconCite this Report

Fuego

Guatemala

14.473°N, 90.88°W; summit elev. 3763 m

All times are local (unless otherwise noted)


Continuous activity and a VEI 3 eruption during 13-14 September 2012

In this report we highlight Fuego's ongoing eruptive activity during January 2011-March 2013. Elevated activity occurred during May-September 2012 and included regular thermal, gas, and ash emissions with occasional lava fountaining and pyroclastic flows. Activity peaked during 13-14 September 2012 with a VEI 3 (Volcanic Explosivity Index; where 3 is considered moderate (Newhall and Self, 1982)) summit eruption and SW-directed pyroclastic flow.

During this reporting period, continuous monitoring efforts by the Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH) included seismic monitoring, regular ground-based observations, and field visits. The Washington Volcanic Ash Advisory Center (VAAC) regularly included monitoring data from INSIVUMEH with satellite remote sensing emissions announcements. We also summarize a recent international collaboration between INSIVUMEH and the International Volcano Monitoring Fund (IVM-Fund) during 2010-2013.

Local observers reported ashfall, shockwaves, and lahars. According to INSIVUMEH, during 2011-2013, ashfall and explosive sounds were frequently reported by communities located within the W sector and up to 8 km of Fuego's summit. Lahars occurred on the S-sector flank in the Taniluyá, Ceniza, Santa Teresa, Las Lajas, and Trinidad drainages (figure 16). Those drainages were also hazardous due to channelization of pyroclastic flows, block avalanches, and lava flows (figure 17); significant events occurred in mid-to-late 2012 and February 2013 (described later in this report). On the SE flank, Las Lajas was frequently affected by pyroclastic flows, and the drainages Taniluyá and Ceniza (SW flank) occasionally contained active lava flows and block avalanches.

Figure (see Caption) Figure 16. This location map includes villages (numbered), observation sites in Panimaché I (FO-1) and Sangre de Cristo (FO-2), and primary drainages located within 15 km of Fuego's summit vent (red star). Elevation contours are shown for 100 m intervals. Pyroclastic flow deposits from 13 September 2012 are shown as dark gray areas within Ceniza, Trinidad, El Jute, and Las Lajas drainages. Courtesy of Rüdiger Escobar-Wolf (Michigan Technological University).
Figure (see Caption) Figure 17. This annotated photograph is centered on Fuego's SW flank, the location of the Ceniza drainage, which channeled the major pyroclastic flow of 13 September 2012. The yellow dotted line marks the centerline of the pyroclastic flow; the orange lines enclose the region burned and scoured by ash cloud surges. Courtesy of INSIVUMEH.

Thermal anomaly detection during 2011-2013. Hotspots from the summit region were detected by satellite remote sensing instruments including MODIS (onboard the Terra and Aqua satellites), Landsat 7, and EO-1 Advanced Land Imaging (ALI) throughout this reporting period.

The MODVOLC thermal alert system recorded ~90 significant anomalies between 1 January 2011 and 1 January 2012, ~375 between 1 January 2012 and 1 January 2013 when explosive activity escalated, and ~255 between 1 January 2013 and 31 March 2013 when lava flows were active near the summit region (figure 18). Thermal anomalies were detected by satellite images at least once per month from January 2011 through March 2013 except for July 2011, suggesting poor weather may have inhibited satellite observations that month (note that heaviest rainfall typically occurs during June-October (The World Bank, 2013)). During July 2011, ground-based observations of nighttime incandescence were noted in INSIVUMEH's Report # 1863; other reports that month highlighted the effects of heavy rain from tropical storms and Hurricane Calvin.

Figure (see Caption) Figure 18. During 1 January 2011-31 March 2013, the MODVOLC system frequently detected elevated temperatures in the area of Fuego's summit. This series of images includes hotspots detected during three time periods: 2011, 2012, and 1 January-31 March 2013. Courtesy of the Hawai`i Institute of Geophysics and Planetology (HIGP), MODVOLC Thermal Alerts System.

MODVOLC continued to detect hotspots during late April 2013 totaling 22 pixels during 21-28 April. Thermal anomalies became rare during May and June 2013; one pixel was detected on three different days.

Regular images captured by ALI and Landsat 7 detected variable incandescence from Fuego's summit during 2011-2013 (figure 19). During 2011, hotspots were mainly located at Fuego's summit; however, during March and December, distinctively elongate, incandescent lava flows extended from the summit to the SW (figure 19A and 19B).

Figure (see Caption) Figure 19. Satellite images from 2011-2013 detected incandescence from Fuego's summit area. (A) This ALI image from 3 February 2011 showed a small region of incandescence isolated at the summit. (B) A Landsat 7 image from 7 November 2011 revealed a ~300 m incandescent flow originating from the summit and extending down the SW flank. (C) This Landsat 7 image from 4 September 2012 (nine days before the VEI 3 eruption began) captures intense incandescence that extends in three directions from the summit; some image distortion is present from cloudcover and artifact stripes (on the left-hand side). Distinctive yellow regions indicate lava reaching at least 500 m SE and SW. (D) This ALI image from 20 March 2013 captures a lava flow extending ~1,500 m SW from the summit crater within the upper region of the Ceniza drainage; some cloudcover blocks the middle region of the lava flow, but the red glow is visible and especially bright at the termination point SW of the clouds. Image processing by Rüdiger Escobar-Wolf (Michigan Technological University); courtesy of NASA/USGS.

Summit incandescence extending SW, SE, and in the immediate summit area was visible during 2012; some of the strongest incandescence extended at least 1 km from the summit to the SW during November-December. Incandescent flows directed SE appeared in April, June, and September. On 4 September 2012, three narrow flows were visible from the summit extending ≥ 500 m from the summit within the S sector; despite significant cloudcover that day and image artifacts, the lava flows were well-defined (figure 19C).

Satellite images from December 2012 through January 2013 included a long lava flow that persisted in the SW drainage (Ceniza), although cloudcover frequently obscured the full view of Fuego's SW quadrant. That incandescent lava flow remained visible in satellite images until late February 2013. Incandescence was isolated at the summit in early March, but on 20 March incandescence re-appeared within the Ceniza drainage and extended ~2,000 m SW of the summit (figure 19D).

Effusive activity during 2011-2013. The style of eruptive activity at Fuego changed near the end of 2010 when lava effusion events started to occur more frequently than explosive eruptions (figure 20). "At a very general level, the more Strombolian eruptions happen typically during lava effusion times and are much smaller than the more Vulcanian eruptions," commented Rüdiger Escobar-Wolf (Michigan Technological University) with respect to Fuego's more than 12 year-long eruption. Continuous unrest (background-level explosions and effusion) was frequently punctuated by short periods of elevated activity during the preceding six years and, during 2012 and 2013, this activity was interrupted by several significant episodes: in 2012, 25-26 May; 10-11 June; 3-4 and 13-14 September; and in 2013, 17-18 February; 3-4 and 19-20 March (figure 19D).

Figure (see Caption) Figure 20. Fuego time series from late 1999 to early 2013 with color codes indicating eruption style (Escobar-Wolf, 2013). Beginning in 1999, the eruption mainly consisted of periods of explosive events (color coded as green) and lava effusion (coded as gray); this constant unrest is considered background activity that has been occasionally interrupted with significant episodes (red lines). This timeline was created and provided by Rüdiger Escobar-Wolf, Michigan Technological University.

The Washington VAAC released an increasing number of notices for the aviation community about volcanic ash throughout 2011- March 2013 (table 8). During 2011, these announcements rarely contained calculated plume altitudes due to poor viewing conditions with satellite remote sensing. Data from INSIVUMEH supplemented these reports with direct observations from Fuego Volcano Observatory, located in Panimaché, 8 km SW of Fuego. On 1 January, 8 January, 23 October, and 24 December 2011, reported plume altitudes were less than 5.2 km a.s.l. and had drift speeds in the range of 2.5-10 m/s, drifting S and SW of Fuego's peak.

Table 8. The Washington VAAC released regular advisories due to emissions from Fuego during 2011-March 2013. Date, time, altitude, drift direction, and reporting sources are included as well as comments that described additional eruption characteristics such as thermal anomalies and weather conditions that may have affected observations. Drift velocities and plume width were also calculated when viewing conditions were optimal. INSIVUMEH was a frequent contributor to these reports; other reporting sources included the satellite GOES-2 (NOAA geostationary weather satellite), MWO (local Meteorological Watch Office), Guatemala City's (MGGT) meteorological reports (METAR), and the global numerical weather prediction models GFS and NAM. Courtesy of Washington VAAC.

Date - Time (UTC) Altitude (km) Drift Direction VAAC Sources Comments
01 Jan 2011 - 1515 5.2 9 km wide line; W 10 m/s GOES-13. GFS WINDS. Several small emissions.
08 Jan 2011 - 1015 5.2 18.5 km wide plume; SW 2.6-5 m/s GOES-13. GFS WINDS. Multiple exhalations since 08/0600 UTC; these explosions have been seen in satellite before dissipating.
13 Feb 2011 - 0504 -- -- GOES-13. INSIVUMEH. INSIVUMEH reported increased activity within the summit area; low height emissions of volcanic ash moving W; hot spot was also detected in short wave infrared imagery.
14 Feb 2011 - 0427 -- -- GOES-13. INSIVUMEH. INSIVUMEH continued to report low levels of volcanic ash near the summit.
15 Feb 2011 - 0427 -- -- GOES-13. INSIVUMEH. Only steam reported.
23 Oct 2011 - 1327 -- -- GOES-13. Information received about a possible volcanic ash eruption.
23 Oct 2011 - 1245 4.3 W 2.6-5 m/s GOES-13. GFS WINDS. Confidence in height of volcanic ash is medium-high based on movement and density of ash in models and satellite imagery.
22 Nov 2011 - 1530 -- -- GOES-13. INSIVUMEH. Ash observed at 1530 UTC.
22 Nov 2011 - 1745 -- -- Tegucigalpa MWO. GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH observed thin plume of possible ash moving SW at 5 m/s at 1530 UTC. This weak plume was observed in satellite imagery at 1415 UTC but had dissipated by 1545 UTC.
02 Dec 2011 - 1845 -- -- Tegucigalpa MWO. GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH reported emission of gases near the summit and light ash that was too small to see in clear satellite imagery. Ash was reported to 305 m above the summit and dispersing SW around 18.5 km.
06 Dec 2011 - 1845 -- -- GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH reported volcanic ash cloud to 3 km observed at 1600 UTC. No ash was observed in satellite imagery.
24 Dec 2011 - 1904 -- -- GOES-13. INSIVUMEH SEISMIC DETECTION. Small narrow plume of unknown content began around 1645 UTC; VAAC received information suggesting a possible ash eruption.
24 Dec 2011 - 1845 4 5.6 km wide line; S 2.5 m/s GOES-13. INSIVUMEH SEISMIC DETECTION. Small plume of gases with possible ash extended 9 km; small puff seen in visible imagery started around 1645 UTC and drifted S 2.5 m/s; estimated height 4 km a.s.l. with wind forecast uncertain. Plume was projected to dissipate within 6 hours.
25 Dec 2011 - 0015 -- -- GOES-13. A possible eruption at 1845 UTC; ash not identifiable in satellite imagery; there were no reports of ash.
03 Jan 2012 - 2041 -- -- GOES-13. Possible volcanic ash detected in visible imagery at 2015 UTC moving SE.
03 Jan 2012 - 2045 5 3.7 km wide line; S 2.6 - 5 m/s GOES-13. GFS WINDS. INSIVUMEH. Small puff seen in visible imagery at 5 km a.s.l. moving SE 3.5 m/s. At 2045 UTC the leading edge was 12 km SE of summit and dispersing. Plume was projected to dissipate within 6 hours.
16 Jan 2012 - 1724 -- -- INSIVUMEH. The VAAC received information suggesting a possible volcanic ash emission.
16 Jan 2012 - 1740 -- -- GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH reported ash to 4.3 km; no ash seen in imagery through 1715 UTC with clear skies.
18 Jan 2012 - 1215 6.7 W at 5-7.5 m/s GOES-13. GFS WINDS. Visible and multi-spectral imagery showed a single puff of gas and ash moving W from the summit; ash was projected to dissipate within a few hours as it continued W. A hotspot was detected.
01 Feb 2012 - 1645 -- -- GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH reported ash to ~5 km at 01/1600 UTC; ash not observed in satellite imagery even with sparse clouds.
01 Apr 2012 - 1315 5 9.3 km wide line; SW 2.6-5 m/s  GOES-13. GFS WINDS. NAM WINDS. Plume extended 13 km WSW from the summit; well-defined hotspot seen in imagery; forecast confidence was low based on latest GFS and NAM.
19 May 2012 - 0915 -- -- GOES-13. GFS WINDS. INSIVUMEH. Ash was not seen in satellite imagery due to darkness; hotspot was visible; INSIVUMEH reported volcanic ash up to 5.5 km a.s.l. to 40 km SW of the summit.
19 May 2012 - 1515 -- -- GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. INSIVUMEH Photos. Ash was not seen in satellite imagery due to cloudcover; a strong hotspot was visible in satellite multispectral imagery; seismicity was high.
19 May 2012 - 2045 -- -- GOES-13. GFS WINDS. METAR.
INSIVUMEH.
Volcanic ash was not detected in satellite imagery due to extensive cloud cover; INSIVUMEH indicated pyroclastic flows likely and ashfalls have been observed.
20 May 2012 - 0245 -- -- GOES-13. GFS WINDS. Ash was not observed in satellite imagery due to cloudcover; hotspot had decreased in intensity and late afternoon bulletin indicated decreased energy.
20 May 2012 - 1415 -- -- GOES-13. NAM WINDS. INSIVUMEH. No ash was observed in imagery although there were thick clouds in the area; INSIVUMEH reported ash emissions up to 3,000 m above the summit moving SW.
20 May 2012 - 1945 -- -- GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. No ash was seen in imagery due to cloudcover; seismic signal has almost gone to background but with very occasional bursts that may contain volcanic ash.
21 May 2012 - 0045 -- -- GOES-13. GFS WINDS. INSIVUMEH. No volcanic ash detected due to cloudcover; INSIVUMEH's evening report only mentioned occasional emission of ash to 4 km a.s.l. or just above the crater drifting SW and dispersed within 9.3 km; seismic activity was back to normal with only occasional small bursts.
25 May 2012 - 1542 -- --; GOES-13. INSIVUMEH. Eruption of lava began around 1300 UTC; some volcanic ash was possible.
25 May 2012 - 1615 -- -- GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. METAR. Pilot Report. INSIVUMEH. No plume was seen in satellite imagery due to partly cloudy conditions; pilot report of ash to 7 km a.s.l. moving SW; lava flows generated volcanic ash and gas; no explosive eruption seen in the seismic records; ash was forecasted to moving SW; a strong hotspot was visible in satellite imagery.
26 May 2012 - 0415 -- -- GOES-13. GFS WINDS. Volcanic ash was not detected in satellite imagery due to extensive cloudcover; INSIVUMEH indicated constant pyroclastic flows and reports of ashfall.
26 May 2012 - 1015 -- -- GOES-13. GFS WINDS. SEISMIC
DETECTION.
Volcanic ash was not seen due to darkness and weather conditions; strong hot spot was visible in satellite imagery and seismic activity remained elevated.
26 May 2012 - 1615 -- -- GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. Ash was not seen in imagery due to cloud cover; INSIVUMEH indicated that ash and gas emissions continued.
26 May 2012 - 2215 -- -- GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. Ash was not seen in satellite imagery due to cloudcover; INSIVUMEH reported decreasing seismicity; a hot spot persisted in multispectral imagery.
27 May 2012 - 0415 -- -- GOES-13. INSIVUMEH. INSIVUMEH indicated ongoing lava flows; decreasing seismic activity and no mention of ashfall in the most recent report.
05 Jun 2012 - 1732 -- -- GOES-13. INSIVUMEH. INSIVUMEH reported increasing activity and suggested that an explosive eruption with little or no warning was possible; hot spot was seen in satellite imagery but no volcanic ash due to cloud cover.
06 Jun 2012 - 1729 -- -- GOES-13. INSIVUMEH. INSIVUMEH reported intermittent explosions expelling ash and gas up to ~600 m above the summit; they warned that an explosive eruption with little or no warning was possible.
07 Jun 2012 - 1715 -- -- GOES-13. INSIVUMEH. INSIVUMEH reported activity that was limited to within 11 km of the summit; no ash was visible in satellite imagery due to partly cloudy conditions.
11 Jun 2012 - 0945 -- -- Tegucigalpa MWO. GOES-13. GFS WINDS. INSIVUMEH. No ash seen in satellite imagery due to nighttime darkness; hotspots see for last few hours. INSIVUMEH reported ash to 5 km.
11 Jun 2012 - 1545 -- -- GOES-13. INSIVUMEH. No ash was seen in imagery although there was some cloudcover; there was a strong hotspot occasionally seen in shortwave imagery; INSIVUMEH reported continuous ash emissions up to 15 km to the W and WNW of volcano.
21 Jun 2012 - 1552 -- -- Tegucigalpa MWO. GOES-13.
GEOPHYSICAL INST. EMAILED PHOTOS.
No ash detected due to cloudcover; INSIVUMEH reported ash moving E from rockfalls and aided by heat of lava flows; bit hotspots were visible through clouds.
21 Jun 2012 - 2138 -- -- GOES-13. GFS WINDS. No ash detected in visible satellite imagery due to cloudcover; hotspot seen in infrared imagery.
22 Jun 2012 - 0340 -- -- GOES-13. GFS WINDS. No ash seen in visible or multispectral satellite imagery due to night time darkness and cloudcover; hotspot observed prior to clouds moving in 22/0015 UTC.
03 Sep 2012 - 1415 4.3/5.2 5.6 km wide line; SW 5-7.5 m/s
7.4 km wide line; W 2.6-5 m/s
GOES-13. GFS WINDS. Ash plume height confidence is medium, the estimation is based on models and history of volcanic activity; a well-defined hotspot was seen overnight.
03 Sept 2012 - 2015 -- -- GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. Due to clouds, no good detection of ash but before the clouds arrived, faint ash was seen W-SW as far as 27.7 km; strong hotspots due to lava flows and rockfalls.
04 Sep 2012 - 0145 -- -- GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. No ash detected due to clouds and darkness; multiple hotspots were seen due to rockfalls and lava flows; some ashfall was reported SW of the summit up to 13 km.
04 Sep 2012 - 0445 4.5 W 2.6-5 m/s GOES-12. GFS WINDS. INSIVUMEH SEISMIC DETECTION. A plume was visible in multispectral imagery extending about ~145 km W of the summit.
04 Sep 2012 - 1015 4.5 W 2.6-5 m/s GOES-13. A continuous emission of ash was visible in multispectral imagery extending ~145 km W of volcano; large hotspot was detected by shortwave imagery.
04 Sep 2012 - 1615 -- -- GOES-13. GFS WINDS. INSIVUMEH. Ash was not seen due to weather conditions; strong hotspot remains in thermal imagery and INSIVUMEH reported elevated seismic activity.
04 Sep 2012 - 2145 -- -- GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. No ash or hotspots detected due to thick clouds; INSIVUMEH reported continued lava flows and rockfalls that generated ash to ~4.5 km a.s.l. moving SW; ashfall was reported up to 15 m SW and W of the summit.
05 Sep 2012 - 1545 -- -- GOES-13. INSIVUMEH. Ash not seen in the satellite imagery due to partly cloudy skies; a faint hotspot was visible in the morning; INSIVUMEH confirmed that no ash emissions were detected.
13 Sep 2012 - 1115 5 W 7.5 m/s GOES-13. GFS WINDS. INSIVUMEH. Faint plume was detected with multispectral imagery that extended ~111 km W; INSIVUMEH reported ash up to 1,000 m above the summit and moving W and SW.
13 Sep 2012 - 1602 4.5 /6.7 SW 7.5 m/s / SW 7.5-10 m/s GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH reported new emission to 3,000 m above the summit W and SW of the summit. 13/1602 UTC image showed a dense ash plume spreading W and SW. Imagery through 13/1632 UTC showed dense volcanic ash emissions continuing.
13 Sep 2012 - 2045 7.3 W 10-13 m/s GOES-13. GFS WINDS. METAR.
INSIVUMEH.
Ash plume was 148 km wide and extended 226 km W of summit; ash was reported at MGGT METAR station.
14 Sep 2012 - 0045 7.3 W 10-13 m/s GOES-13. GFS WINDS. METAR.
INSIVUMEH.
Ash plume was 111 km wide and extended 417 W of the summit; ash closest to summit was obscured by cloudcover and was likely rained out; METAR from MGGT continued to report ash.
14 Sep 2012 - 0710 4.3 /7.3 W 5 m/s / W 5 m/s GOES-13. GFS WINDS. INSIVUMEH. A bright hotspot persisted with a small plume in multispectral imagery extending 36 km to the W of the summit; latest report indicated current activity was more intermittent and lower in height; larger area to 7.3 km a.s.l. continued to dissipate about 648 km to W of summit moving W.
14 Sep 2012 - 1245 4 /7.3 W 7.5-10 m/s / W 10-13 m/s GOES-13. GFS WINDS. METAR.
INSIVUMEH.
Multispectral imagery showed dissipating ash to 7.3 km a.s.l. between 370 km and 926 km W moving W; in addition, continuous attached plume to 4 km a.s.l. was seen moving SW; local surface observations reported 4 km a.s.l.
14 Sep 2012 - 1845 6 W 10 m/s GOES-13. GFS WINDS. INSIVUMEH. A dissipating area of ash, about ~1,000 km W of the summit, was detected in multispectral imagery; no ash was seen near the summit at 1845 UTC; INSIVUMEH reported ash emissions within 15 km of the summit.
15 Sep 2012 - 0045 -- -- GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. No ash was detected in satellite imagery; the previous plume located S of Mexico had dispersed around 14/2200 UTC. INSIVUMEH reported weaker seismic activity with rockfalls generating ash plumes to 4 km a.s.l. and 15 km W-SW of the summit; a strong hotspot was visible.
29 Sep 2012 - 1245 -- -- GFS WINDS. GOES-14. INSIVUMEH. In the morning, satellite imagery detected discreet puffs of ash moving W and WSW from the summit; INSIVUMEH reported ash 500 m to 900 m above the summit with fine ashfall.
17 Feb 2013 - 0544 -- -- GOES-13. INSIVUMEH. INSIVUMEH reports incredible outpouring of lava from the crater which is confirmed by brilliant hot spot in satellite imagery; INSIVUMEH reported no ash plume at the moment, but emissions are possible over the next few hours up to 10 km to the S and SW of the summit.
17 Feb 2013 - 1315 5 W 2.6-5 m/s Tegucigalpa MWO. GOES-13. GFS WINDS. INSIVUMEH. In the morning, visible imagery showed a plume of ash extending 18.5 km to the W of the volcano; INSIVUMEH reported ash to 4.8 km a.s.l.
17 Feb 2013 - 1445 5 W Tegucigalpa MWO. GOES-13. GFS WINDS. INSIVUMEH. Imagery showed ash moving W-SW and S from the volcano; at 17/1445 UTC ash extended 18.5 km SW and 5.6 km S of the volcano.
17 Feb 2013 - 2015 5.2 0-5 m/s Tegucigalpa MWO. GOES-13. GFS WINDS. INSIVUMEH. Ongoing emissions of lava with gas and light ash; in imagery the ash is mixed with clouds and, due to light winds spreading N-W-SW from the summit ~13 km; this is mainly a lava event but some light ashfall was being reported in cities on the slopes of the volcano.
18 Feb 2013 - 0815 -- -- GOES-13. GFS WINDS. INSIVUMEH. Ongoing lava emission with gases and light ash; no ash detected due to large thunderstorm that developed SW of summit and regional cloudcover. INSIVUMEH reported in the afternoon that less energetic lava, gas, and ash events were occurring.
03 Mar 2013 - 2345 -- -- GOES-13. GFS WINDS. INSIVUMEH. Lava emission with occasional light ash due to rockfalls and small venting; hotspot due to lava but no ash was visible in satellite imagery; plume drifted up to 9 km according to INSIVUMEH; wind forecast was light and variable, so the plume was expected to remain close to the summit region.
04 Mar 2013 - 0334 -- -- GOES-13. GFS WINDS. INSIVUMEH. An INSIVUMEH special report indicated that a new stage of emissions began and possible ash fall was likely around 18.5 km from the summit. Ash was not seen in multispectral satellite imagery; a very large hotspot was observed with infrared.
04 Mar 2013 - 0845 -- -- GOES-13. GFS WINDS. Ash was not seen in overnight satellite imagery; very large and bright hotspot was detected with infrared sensors; emissions of gas and ash were likely.
04 Mar 2013 - 1315 4.3 moving NE 5-7.5 m/s GOES-13. GFS WINDS. INSIVUMEH. Ongoing emissions; satellite imagery showed a faint ash plume 13 km wide and extending 42.5 km NE of the summit; a very bright hot spot was detected with infrared sensors.
04 Mar 2013 - 1915 -- -- GOES-13. GFS WINDS. INSIVUMEH. Ongoing emissions; ash was too light to be seen in visible satellite imagery although reports indicate that ash was present; a strong hot spot persisted.
05 Mar 2013 - 0115 -- -- Tegucigalpa MWO. GOES-13. Ongoing activity; Tegucigalpa MWO canceled Sigmet for the event; a well-defined hotspot was visible in multi-spectral imagery; no ash was present in the last visible images of the day.
18 Mar 2013 - 1345 4.3 moving SW 2.6-5 m/s Tegucigalpa MWO. GOES-13. GFS WINDS. Very light volcanic ash emissions; MWO indicated ash moving SW; the ash had a SSW component in satellite imagery and was very light in nature.
18 Mar 2013 - 1945 -- -- GOES-13. GFS WINDS. INSIVUMEH. Emissions of gas and occasional light ash were near the summit; no ash was detected or reported in cloudy conditions; INSIVUMEH reported near-summit emissions of gas and occasional, very light ash below 4.3 km a.s.l. and within 9 km of the summit.
19 Mar 2013 - 2232 -- -- GOES-13. GFS WINDS. INSIVUMEH. INSIVUMEH reported ash to 5 km a.s.l. at 19/2045 UTC moving SE at 5 m/s; ash not visible in imagery; special observatory report indicated elevated activity with the volcano; a persistent hotspot was present since 1915 UTC and had become increasingly bright in the past hour.
20 Mar 2013 - 0415 -- -- GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. Ash plume was not identifiable in multispectral satellite imagery; a bright hotspot was detected with infrared sensors; occasional bursts of seismic activity were reported; SIGMET reports ash to 5 km a.s.l. moving SE at 5 m/s.
20 Mar 2013 - 1015 -- -- GOES-13. GFS WINDS. Near summit emissions of gases and occasional light volcanic ash; although brilliant hot spot was readily apparent in satellite imagery, no ash was detected under partly cloudy conditions.
21 Mar 2013 - 1332 5.5 E 7.5 m/s GOES-13. GFS WINDS. Intermittent emissions; ash emissions and a persistent hotspot were observed in satellite imagery in clear skies; several discreet puffs were noted; ash plume extends ~32 km to the ESE of the volcano.
28 Mar 2013 - 1315 4.6 W 2.6 - 5 m/s GOES-13. INSIVUMEH. ECMWF HIRES WINDS. Continuous emissions; a series of emissions has resulted in an ash plume extending up to 18.5 km to the WSW of the summit.
30 Mar 2013 - 1415 5 S 8 m/s GOES-13. GFS WINDS. INSIVUMEH SEISMIC DETECTION. INSIVUMEH reported degassing with occasional bursts of ash at 1240 UTC, 1330 UTC, and 1415 UTC; multibursts of gas and ash seen moving to S and SE from the summit extending 55.5 km from the summit and dispersing; light ashfall was reported within 18.5 km of the summit.
30 Mar 2013 - 1945; 5 S 2.6-5 m/s GOES-13. GFS WINDS. Ongoing emissions; satellite imagery showed a 20 km wide plume of light ash extending 13 km S of the summit; ash was expected to disperse within 6 hours.
31 Mar 2013 - 1345 -- -- GOES-13. GFS WINDS. INSIVUMEH. Ongoing emissions; ash not seen in satellite imagery under clear skies; however, sun may be preventing light ash from being observed; ash had been reported in the village of Panimaché.
31 Mar 2013 - 1945 -- -- GOES-13. GFS WINDS. INSIVUMEH. Continuous gas emissions with occasional short bursts of light ash; INSIVUMEH reported continued gas emissions with short bursts of light ash moving S; ashfall was reported within 9.3 km of the summit; ash not seen in satellite imagery due to cloud cover around the summit.

During 2011, INSIVUMEH reported that Fuego's activity included small-scale explosions and effusive lava flows. Lava flow activity was reported mainly during late March, late April, June, and early July. The longest lava flows traveled SW within the Ceniza and Santa Teresa drainages. Maximum flow lengths were in the range of 100-200 m and were frequently incandescent at night during spalling events.

Escalating summit activity during 2012. In early 2012, three VAAC advisories included plume altitudes as high as 6.7 km a.s.l. and drift directions up to 7.5 m/s S, SW, and W (table 8). INSIVUMEH reported that during the first week of January 2012, the Alert Level was raised to Yellow due to elevated activity; incandescent explosions were observed during 18-19 and 23 January. Lava flows and intermittent incandescent spatter continued from the summit throughout the rest of this reporting period (2011-March 2013).

The Coordinadora Nacional para la Reducción de Desastres (CONRED) announced Alert Level Orange (third highest on a four-color scale) and evacuations from El Porvenir in Alotenango (9 km ENE) on 19 May due to escalating activity (figure 21). Energetic Strombolian eruptions occurred during 19-20 and 25-27 May. Pyroclastic flows during 25-26 May were directed E and SE (impacting the Las Lajas and El Jute drainages), unlike previous events that concentrated flows within the W sector. Significant populations, resorts, and infrastructure such as the RN-14 road are located along the Las Lajas and El Jute drainages.

Figure (see Caption) Figure 21. A plot of the daily average RSAM (Real-time Seismic-Amplitude Measurement) from Fuego's seismic station FG3 during January through September 2012. Notable peaks include eruptions during 19-20, 26-27 May and 11 June; the effusive eruption of 1 July; the 3 September eruption, lahars, and lava flows; and the 13 September eruption. During this time period, seismicity was dominated by long-period (LP) earthquakes generated by processes such as explosions, fluid movement, lava flows, and block avalanches. Courtesy of INSIVUMEH.

During May-June, there were ~20 VAAC advisories that highlighted INSIVUMEH observations and the possibility of ash plumes; satellite observations and calculations of plume altitudes, however, were not available (table 8). INSIVUMEH reported lava flows throughout May-August (extending up to 1.7 km from the summit and as wide as 25 m) and pyroclastic flows occurred during May.

Increased explosivity at Fuego during September 2012. During the first week of September 2012, the Washington VAAC issued advisories describing ash plumes up to 5.2 km a.s.l. (table 8). A large event, on 3 September, generated two ash plumes dispersing SW and W, the former was ~5.5 km wide, and the latter was ~7.5 km wide. Ash plumes and hot spots continued to be visible within satellite images through 4 September (figure 19C) with INSIVUMEH reporting a lack of ash clouds on 5 September, followed by a break in reports until the major eruption on 13 September.

Beginning at 0400 on 13 September, a significant eruption occurred which led to evacuations from local communities within a 10-km radius (figures 22 and 23). At 0715, a vertical plume erupted from the summit. Large pyroclastic flows were generated between 0900 and 1000 local time which became channelized within two drainages. Within the Las Lajas drainage (on the SE flank), flows reached as far as 2 km from the summit; within the Ceniza drainage (SSW flank), they traveled as far as 7.7 km, stopping just 3 km short of Panimaché. On 14 September, the Washington VAAC reported ash plumes up to 7.3 km a.s.l. that drifted W at ~10 m/s (table 8).

Figure (see Caption) Figure 22. On 13 September 2012, a large plume of ash erupted from Fuego and pyroclastic flows descended the flanks. Between 0900 and 1000 local time, a lateral cloud and a tall plume expanded from the summit. The sharp peak to the right of Fuego is Agua volcano. This photo was taken from a viewpoint near the base of Pacaya volcano, ~30 km S of Guatemala City. Photo courtesy of Kent Caldwell.
Figure (see Caption) Figure 23. Comparison views of Fuego made from the city of Antigua (~18 km from Fuego) looking SW. (Top) This view from the center of Antigua, was taken on 21 March 2008 at 0915 when volcanic unrest was dominated by intermittent, impulsive eruptions which generated short gas-and-ash plumes (see figure 20 for the timeline of explosive vs. effusive activity). Photo courtesy of Kyle Brill (Michigan Technological University). (Bottom) This photo taken at ~0900 on 13 September 2012 captures a view SW of the ongoing explosive eruption that continued through 14 September. Photo courtesy of Luis Echeverria (Xinhua Press/Corbis).

In a special report by INSIVUMEH, the 13-14 September 2013 eruption was described as the largest explosive event within the last 13 years; they assigned the event VEI 3 (Volcanic Explosivity Index) based on the volume of pyroclastic material. This was the first eruption since 1974 that directly impacted the S and SW zones of Fuego, areas within 5-7 km of the summit that contained numerous small villages (figure 24). Approximately 10,600 people were evacuated from Panimaché I, Panimaché II, Sangre de Cristo, Morelia, and El Porvenir (figure 16) to the town of Santa Lucía Cotzumalguapa (18 km SW). INSIVUMEH estimated that ~5 mm of ashfall accumulated in those regions closest to the channelized pyroclastic flows. Ashfall damaged coffee and other agricultural crops in the region and congested the air, decreasing visibility in many communities within 10 km of the summit.

Figure (see Caption) Figure 24. Two hybrid graphics each merging a regional map and MODIS image centered on Fuego (at the red pushpin icon). (A) Results captured at 1030 local time showing a plume generated by the eruption covered approximately ~900 km2. (B) At 1330 local time, the ash plume covered approximately ~2,500 km2, with less density; 47 municipalities in seven departments were primarily affected. The ash extends off this graphic and later reached Chiapas, Mexico. Image modified from CATHALAC, 2012.

Prior to the eruption, there wsa a notable increase in LP seismicity and high-amplitude tremor that lasted for hours. INSIVUMEH seismic records became saturated between 0947 and 0949, the time period when observers noted ash plumes rising from the summit (figure 7). During the explosive event that began at 0400 on 13 September 2012, a lava flow advanced 300 m down the flank from the S side of the summit crater. At roughly the same time, a vertical plume rose from the crater and drifted SW; strong ENE winds rapidly spread the ash into the coastal Suchitepéquez Department. At 0715 the ash plume had risen up to 2 km above the summit crater; by 1500 that day, a diffuse ash plume was reported over the S region Mexico's Chiapas Province. The ash continued to expand W and NW on 14 September, and was ~100 km wide and more than 415 km W of the summit (table 8 and figure 10); ash persisted in the atmosphere for more than 36 hours.

Figure (see Caption) Figure 25. A large ash plume drifted W and NW from Fuego on 14 September 2012; observations were made at 0045, 0700; 1300; and 1900 local time and remote sensing measurements determined an altitude of ~7 km a.s.l. These graphics notified the aviation community about airspace containing ash plumes. Note that "VA to FL 240" means "volcanic ash to flight level 24,000 (~7 km)." Courtesy of Washington VAAC.

Seismicity and surface activity returned to low levels after the powerful 13-14 September 2012 eruption. Field studies conducted by INSIVUMEH determined that the Las Lajas, El Jute, Trinidad, and Ceniza drainages received the largest concentration of volcanic material during the eruption, making these regions susceptible to lahars with the onset of the rainy season.

Within the Ceniza drainage, in particular, pyroclastic flows had extended ~8 km (figures 17 and 26) and had deposited tree branches and trunks (many that were charred) within the canyon along with large (1-3 m diameter) blocks and volcanic bombs. Preliminary assessments of the deposits within the Ceniza drainage determined that ~13,000,000 m3 of material had been deposited and was already becoming mobilized.

Figure (see Caption) Figure 26. During field investigations immediately after the 13 September 2012 eruption, INSIVUMEH surveyed the Ceniza drainage to assess both the damage and potential new hazards from lahars. This area sits in the region of Siquinala and San Andrés Osuna, ~13 km SSW of Fuego's summit. Courtesy of INSIVUMEH.

Assessments by INSIVUMEH at the end of 2012 determined that two months of heavy rain had cut deep incisions into the new deposits and that loose, fine-grained volcaniclastic material had already migrated down to the road crossing at Siquinala and San Andrés Osuna, ~13 km SSW of the summit. The study also described the increased vulnerability of the road access for Siquinala and the community of La Róchela (figure 16) due to possible stream capture by Ceniza with Platanares. A narrow (~15 m) zone of the Ceniza drainage had been filled with volcaniclastic material, changing the drainage profile in a location ~2 km upstream from an important stream crossing. The Ceniza drainage had been migrating laterally toward the Platanares over time, especially due to erosion following Tropical Storm Agatha in 2010.

Explosive and effusive activity continued during September 2012-March 2013.From late September 2012 through March 2013, INSIVUMEH documented ash plumes (100-1,300 m above the crater), incandescent spatter (50-200 m above the crater), lava flows (mainly flowing 100-900 m down the SW flank), and lahars. In 2012, hot lahars were reported on 1 June, and later on 27 September and 3 October. Lava flows were frequently channelized within the Ceniza, Trinidad, and Taniluya drainages (SW flank). The last significant VAAC report of 2012 highlighted discreet puffs of ash that reached a maximum of 900 m above the crater on 29 September (table 8).

Large pyroclastic flows on 16 and 17 February 2013 traveled 3 km down the Ceniza drainage (table 8). Ash plumes generated on 16 February caused ashfall in communities up to 12 km from the summit, primarily SW. On 17 February there were collapses at lava-flow fronts.

On 4 March 2013 there were large lava flows following incandescent explosions up to 100 m above the crater (table 8).

On 19 March an explosive eruption occurred with effusive lava flows; a ~5 km a.s.l. ash plume was detected by the Washington VAAC (table 8). Lava fountaining reported on 20 March rose 300-400 above the crater; a ~1.5 km long lava flow within the Ceniza drainage was also observed that day (figure 19D). Incandescent explosions were frequently observed through the rest of the month.

International collaboration aids monitoring capabilities in 2013. In 2010, a partnership was established between INSIVUMEH observatories and the International Volcano Monitoring Fund (IVM-Fund), a non-profit organization based in Seattle, WA. After a successful project to improve monitoring efforts at the Santiaguito Volcano Observatory (OVSAN), the IVM-Fund began working with the Fuego Volcano Observatory (OVFGO), located in Panimaché, in 2012. During March 2013, this observatory received significant support from the IVM-Fund and international donors. Jeff Witter, president and CEO of the IVM-Fund, delivered ~$4,500 worth of field equipment to OVFGO to help outfit the observers and contribute to volcano monitoring capacity in Guatemala (figure 27). Additional visits to Guatemala are planned once sufficient funds are raised to continue the IVM-Fund's collaborative work with Guatemalan volcanologists. Volcano monitoring support projects between the IVM-Fund and INSIVUMEH are planned to address additional needs at OVFGO and OVSAN.

Figure (see Caption) Figure 27. On 21 March 2013, INSIVUMEH technician Amilcar Cardenas (left) and Edgar Barrios (far side of river) measure the width of Taniluya drainage to collect baseline data for monitoring geomorphologic changes in the canyon. This drainage is particularly susceptible to lahars and pyroclastic flows. Courtesy of Jeff Witter (IVM-Fund).

References. CATHALAC, 2012, "Preliminary Analysis of the Eruption of Volcan de Fuego, Guatemala -- 13 September 2012," posted on 27 September 2012, https://servirglobal.net/Global/Articles/tabid/86/Article/1169/preliminary-analysis-of-the-eruption-of-volcan-de-fuego-guatemala-13-september.aspx, accessed on 17 July 2013.

Escobar-Wolf, R., 2013, Volcanic processes and human exposure as elements to build a risk model for Volcán de Fuego, Guatemala [PhD Dissertation]: Houghton, MI, Michigan Technological University.

Newhall, C.G., and Self, S., 1982, The volcanic explosivity index (VEI): An estimate of explosive magnitude for historical volcanism, Journal of Geophysical Research: 87, 1231-1238.

The World Bank, 2013, Country Data: Guatemala Climate Change, http://data.worldbank.org/country/guatemala, accessed on 18 June 2013.

Geologic Background. Volcán Fuego, one of Central America's most active volcanoes, is also one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between Fuego and Acatenango to the north. Construction of Meseta dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at the mostly andesitic Acatenango. Eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows.

Information Contacts: Gustavo Chigna M., Instituto Nacional de Sismologia, Vulcanología, Meteorología e Hidrologia (INSIVUMEH), Ministero de Communicaciones, Transporto, Obras Públicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.gob.gt/inicio.html); Coordinadora Nacional para la Reducción de Desastres (CONRED), Av. Hincapié 21-72, Zona 13, Guatemala City, Guatemala (URL: http://conred.gob.gt/www); Washington Volcanic Ash Advisory Center (VAAC), NOAA Science Center Room 401, 5200 Auth road, Camp Springs, MD 20746, USA (URL: http://www.ospo.noaa.gov/Products/atmosphere/vaac/); Rüdiger Escobar-Wolf, Michigan Technological University, Department of Geological and Mining Engineering and Science, Houghton, MI, USA (URL: http://www.geo.mtu.edu/); Hawai`i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System (MODVOLC), 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/); Jeff Witter, International Volcano Monitoring Fund (IVMF) (URL: http://www.ivm-fund.org/guatemala-fuego/); NASA/USGS Landsat Program (URL: https://landsat.usgs.gov/); and NASA ALI (URL: http://eo1.gsfc.nasa.gov/).


Gaua (Vanuatu) — May 2013 Citation iconCite this Report

Gaua

Vanuatu

14.27°S, 167.5°E; summit elev. 797 m

All times are local (unless otherwise noted)


Hazard status raised; emissions continue into 2013; plume observed from above

In our June 2012 Bulletin report (BGVN 37:06), we noted ongoing eruptions from Gaua during much of 2011.

On 5 December 2011, the Vanuatu Meteorology and Geohazards Department (VMGD) changed the status of Gaua volcano from a dormant to an active volcano. An index map showing Vanautu appears in the Ambrym report in this issue.

The Wellington Volcanic Ash Advisory Center (VAAC) reported that on 29 April 2013 a plume from Gaua was observed from an aircraft. Absent were further comments. Satellite imagery did not indicate ash. Astronauts on the International Space Station saw and photographed Gaua's E-blowing plume on 31 May 2013 (figure 24).

Figure (see Caption) Figure 24. Steam plume from Gaua volcano as photographed from the International Space Station on 31 May 2013. For scale, the island is 20 km in diameter. Note N arrow at lower right. This is Astronaut photograph ISS036-E-5647, taken on Expedition 36 with a Nikon D3S digital camera using a 400 mm lens, and is provided by the ISS Crew Earth Observations experiment and the Image Science & Analysis Laboratory, Johnson Space Center. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Original caption was by William L. Stefanov, Jacobs/JETS at NASA-JSC.

The Alert Level of Gaua remained at level 1 (out of 4) signifying that changes in Gaua's activity could occur without, or with little, warning. VMGD continued this status through at least mid-August 2013, although they noted as slight increase in tremor since their June report.

This status indicates that ash falls will continue to be expected in areas exposed to trade winds. Strong degassing of the volcano could be accompanied with acid rainfall.

During the year ending in mid-July 2013, there were no MODVOLC thermal alerts.

Geologic Background. The roughly 20-km-diameter Gaua Island, also known as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with an 6 x 9 km wide summit caldera. Small parasitic vents near the caldera rim fed Pleistocene lava flows that reached the coast on several sides of the island; several littoral cones were formed where these lava flows reached the sea. Quiet collapse that formed the roughly 700-m-deep caldera was followed by extensive ash eruptions. Construction of the historically active cone of Mount Garat (Gharat) and other small cinder cones in the SW part of the caldera has left a crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat cone is topped by three pit craters. The onset of eruptive activity from a vent high on the SE flank in 1962 ended a long period of dormancy.

Information Contacts: Vanuatu Geohazards Observatory (URL: http://www.vmgd.gov.vu/vmgd/); Vanuatu Meteorology and Geohazards Department (URL: http:// http://www.meteo.gov.vu/); Wellington Volcanic Ash Advisory Center (VAAC) (URL: vaac.metservice.com); and Hawai'i Institute of Geophysics and Planetology, MODVOLC Thermal Alert 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/).


Kilauea (United States) — May 2013 Citation iconCite this Report

Kilauea

United States

19.421°N, 155.287°W; summit elev. 1222 m

All times are local (unless otherwise noted)


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 Kilauea 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 Kilauea'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 Kilauea activity (at links provided in the Information Contacts section below).

Figure (see Caption) Figure 209. Small-scale map showing Kilauea'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 Kilauea's ongoing eruption, now active at its summit and east rift zone, on 3 January 2013.

Orr and others (2012) summarized Kilauea'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 Kilauea'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 Kilauea 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 Kilauea's more explosive past is possible (see USGS Fact Sheet 2011-3064, Kilauea-an Explosive Volcano in Hawai'i, available at http://pubs.usgs.gov/fs/2011/3064 {Swanson and others, 2011}). What is certain is that Kilauea 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 Kilauea 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 Kilauea 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 Kilauea, 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 Kilauea 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 Kilauea, 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, Kilauea-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, Kilauea'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 - Kilauea, Kilauea's east rift zone flow field, web site (URL: http://www.wr.usgs.gov/maps; accessed 15 August 2013).

Geologic Background. Kilauea, which overlaps the E flank of the massive Mauna Loa shield volcano, has been Hawaii's most active volcano during historical time. Eruptions are prominent in Polynesian legends; written documentation extending back to only 1820 records frequent summit and flank lava flow eruptions that were interspersed with periods of long-term lava lake activity that lasted until 1924 at Halemaumau crater, within the summit caldera. The 3 x 5 km caldera was formed in several stages about 1500 years ago and during the 18th century; eruptions have also originated from the lengthy East and SW rift zones, which extend to the sea on both sides of the volcano. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1100 years old; 70% of the volcano's surface is younger than 600 years. A long-term eruption from the East rift zone that began in 1983 has produced lava flows covering more than 100 km2, destroying nearly 200 houses and adding new coastline to the island.

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/).


Pavlof (United States) — May 2013 Citation iconCite this Report

Pavlof

United States

55.417°N, 161.894°W; summit elev. 2493 m

All times are local (unless otherwise noted)


Eruption in May-June 2013 with lava flows and ash emissions to ~8.5 km a.s.l.

Pavlof, the most active volcano in the Aleutian arc, erupted on 13 May 2013. Before this, it had most recently erupted on 15 August 2007, following an 11-year period of quiescence. The eruption that began in May 2013 continued through June before slowly subsiding to background levels by 8 August. Pavlof generated several ash plumes during the six-week eruption that disrupted aviation, including an 8-km high plume on 24 June. As in past Pavlof eruptions, the recent eruptions fluctuated in intensity. This report briefly discusses earthquake data during 2007-2011 and, in greater detail, the series of eruptions during May and June 2013.

According to Mangan and others (2009), Pavlof has discharged more than 40 recorded eruptions within the previous 200 years, producing mostly basaltic andesite to andesite products. That work, discussed in a separate subsection near the end of this report, also discusses the adjacent 12x19 km Emmons Lake caldera (a chain of nested calderas) on Pavlof's SW flank (figure 5). The Emmons Lake Volcanic Center (ELCV) is used to collectively describe the entire complex, including the nested caldera, intra-caldera stratovolcanoes, and the adjacent stratovolcanoes (including Pavlof) to the NE.

Figure (see Caption) Figure 5. Maps showing both the location of Pavlof on the lower Alaska Peninsula (upper left) and showing more details of the complex, including the elongate Emmons Lake caldera and six stratovolcanoes. The lake occupies but a small volume of the caldera, which is breached to the SE. Taken from Mangan and others (2009).

According to the Alaska Volcano Observatory (AVO), 48 earthquakes were located beneath Pavlof in 2007, the year of the previous eruption. During the following non-eruptive years, AVO reported 9 earthquakes centered at Pavlof in 2008, 7 earthquakes in 2009, 19 in 2010, and 13 in 2011. As of this writing, AVO has not yet published 2012 earthquake data.

Eruption in May 2013. On 13 May 2013, seismicity increased at 0800 and an intense thermal anomaly was observed at the summit in satellite imagery. Several spikes in seismicity occurred between 0900 and 1000. AVO noted that similar patterns of seismicity and elevated surface temperatures in previous cases had signaled the onset of eruptive activity at Pavlof. The Volcanic Alert Level was increased to Watch (the second highest category of four) and the Aviation Color Code was increased to Orange (the second highest category of four).

On 14 May 2013, pilot reports and satellite images indicated a spatter-fed lava flow that had advanced about 0.5 km down the N flank. The advancing lava had also generated debris-laden deposits, presumably from the interaction of hot lava with snow and ice on the flank. According to AVO, a diffuse ash plume drifted about 160 km NE at an altitude of 4.6 km before dissipating. Minor ashfall was reported the evening of 14 May in a mining camp 80 km NE of the volcano. No other nearby communities reported ashfall. Minor steam-and-ash emissions from the summit were visible from Cold Bay (~58 km SW).

During 14-15 May 2013, elevated seismicity persisted. Steam-and-ash clouds observed with a web camera at Cold Bay (55 km W of the volcano) occasionally rose to an altitude of 6.1 km. Residents in Cold Bay observed incandescence from the summit during the night. On 15 May a pilot reported a dark ash cloud drifting ENE at an altitude of 6.1 km.

On 16 May, AVO observed lava fountaining at the summit and a continuous ash, steam, and gas cloud extending 50-100 km downwind at an altitude of about 6.1 km. Satellite images showed persistent elevated surface temperatures at the summit and on the NW flank, consistent with lava fountaining at the summit and the resulting lava flow.

During 18-19 May 2013, reports noted that a narrow plume of steam, ash, and gas occasionally rising up to an altitude of 6.7 km and drifting SE was visible in satellite and pilot images (figures 6 and 7). Pilots noted that lava fountaining and ash emission continued. Overnight, trace amounts of ash fell on the community of Sand Point (88 km E). During the afternoon on 19 May, pilots reported that ash plumes rose to altitudes of 4.6-6.7 km. Trace amounts of ash fell in Nelson Lagoon (78 km NNE) during 19-20 May.

Figure (see Caption) Figure 6. Photograph of Pavlof taken on 18 May 2013 by astronauts aboard the International Space Station. The space station was ~770 km away and S-SE of the volcano when the photograph was taken. The volcanic plume extended SE over the North Pacific Ocean. Residing next to Pavlof is the white, seemingly ash free stratovolcano Pavlof Sister. Courtesy of NASA Earth Observatory with credit for caption and processing to Robert Simmon, (NASA Earth Observatory) and G. M. Gentry (DB Consulting Group at NASA-JSC).
Figure (see Caption) Figure 7. Photo of Pavlof eruption taken by a commercial pilot on 18 May 2013. Plume direction was not identified, but based on the NASA photo taken the same day (figure 6), the plume is drifting SE and the volcano in the foreground is Pavlof Sister (NE of Pavlof). Courtesy of Brandon Wilson (PenAir) and provided by AVO/Alaska Division of Geological & Geophysical Surveys.

News articles (Associated Press, PRNewswire, Alaska Dispatch) stated that during 19-21 May 2013 two regional airlines canceled flights to several remote communities and delayed or re-routed other flights. On 21 May AVO reported that a low-level plume of steam, gas, and ash occasionally rose to an altitude of 6.1 km and drifted NNE. Trace amounts of ash again fell in Nelson Lagoon.

AVO reported that seismic tremor markedly declined around 1100 on 21 May 2013 and was followed through 23 May by the detection of small discrete events, likely indicative of small explosions, by an infrasonic pressure sensor (Chaparral model 2.5 at site PN7). Although cloud cover prevented satellite observations, elevated surface temperatures at the vent were detected. On 22 May a pilot report and photographs indicated weak steam-and-gas emissions containing little to no ash.

The eruption continued at a lower level during 24-26 May. Neither evidence of elevated surface temperatures nor a plume were observed in partly clear satellite images during 24-25 and 27 May. Clouds obscured views on 26 May. The Volcanic Alert Level was lowered to Advisory and the Aviation Color Code was lowered to Yellow on 28 May.

According to AVO, Pavlof emitted ash on 4 June at about 1100, as observed in satellite images and by pilots. Satellite images showed an ash cloud drifting SE, and pilots estimated that the cloud was at an altitude of 5.8 km. Weak seismicity that began at 1057 accompanied the emissions, and then continued. AVO increased the Volcanic Alert Level to Watch and increased the Aviation Color Code to Orange.

AVO reported that ash emissions continued during 5-11 June 2013, accompanied by tremor and explosion signals. Overnight during 4-8 June, satellite images detected elevated surface temperatures near the vent consistent with lava effusion and fountaining. Elevated surface temperatures persisted until 14 June. On 5 and 6 June, an ash plume drifted 40-45 km W and SW at altitudes of 4.3-5.5 km based on pilot estimates. During 8-10 June, an ash plume drifted 20-53 km SE. During 12-14 June, ash emissions were intermittent and minor; ash plumes remained below an altitude of 6.1 km and mostly drifted SE.

During 14-15 June 2013, seismicity decreased. Minor emissions probably ceased, but web-camera views were partially obscured by clouds. On 17 June no plumes were visible in satellite images, and web camera views showed mostly cloudy conditions.

During 17-18 June, tremor amplitude increased slightly, and elevated surface temperatures were again detected in satellite images. A small ash plume rose from the crater. The eruption continued during 19-25 June, with tremor and occasional explosions. Cloud cover prevented web camera views. Elevated surface temperatures continued to be detected during 19-20 and 24 June. A small ash plume from the summit vent was also detected in a satellite image on 19 June, and possibly during 20-22 June.

On 24 June, seismicity increased to the strongest level to date during 2013 and included continuous intense tremor and frequent small explosions likely associated with lava fountaining and ash production. Seismicity remained high on 25 June. Satellite images and pilot observations indicated that a plume drifted W at altitudes as high as 8.2-8.5 km. Satellite images also detected a strong thermal anomaly at the summit. Trace amounts of ash fell in King Cove (48 km SW). According to a news report (Reuters), regional air traffic was again cancelled or re-routed.

According to AVO, seismicity declined during 25-26 June and consisted of intermittent bursts of tremor and occasional small explosions. Satellite images showed a plume containing small amounts of ash drifting NW, and strong thermal anomalies at the summit. Pilot reports on 26 June indicated that plumes rose to altitudes between 6.1-7.6 km during the morning and then to heights just above the summit later that day. Seismicity during 26 June-1 July continued at low levels and consisted primarily of intervals of continuous, low-level tremor. Thermal anomalies at the summit detected in satellite images were strong during 26-29 June and weak during 30 June-1 July.

AVO reported that activity further declined during 1-2 July; tremor and explosions were no longer detected in seismic and pressure sensor data. Satellite images did not detect elevated surface temperatures, volcanic gas, or ash emissions, and there were no visual observations from pilots or from webcam images of any eruptive activity since 26 June. Consequently, AVO lowered the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory.

On 8 August, AVO reported that no lava or ash emissions had been observed at Pavlof since 26 June and the volcano had exhibited gradually declining levels of unrest. Seismicity was at background levels. Thus, AVO lowered the Aviation Color Code to Green and the Volcano Alert Level to Normal.

Mangan and others (2009) discussion. Mangan and others (2009) cite Power and others (2004) as stating that background (non-eruptive) seismicity at Pavlof occurs as infrequent long-period earthquakes at focal depths between 20-40 km. Mangan and others contend that while only a few of these events at most occur annually, they are a stable feature attributed to quasi-steady fluxing of basaltic magma and exsolved CO2 in a deep dike and sill complex. According to the article, the seismic network at Pavlof is poorly situated to detect deep seismicity under the Emmons Lake caldera.

Mangan and others state, "All witnessed [Emmons Lake Volcanic Center] ELVC eruptions have occurred outside the caldera [,specifically] at Pavlof, the most active volcano in the entire arc. Pavlof's slopes are extensively mantled with tephra and pyroclastic debris produced during [its] historical strombolian, vulcanian, and lava fountain events (Miller et al., 1998). Limited precursory seismicity herald Pavlof eruptions (McNutt, 1989) and, to the extent studied, negligible precursory ground deformation (Lu et al., 2003; Z. Lu personal communication 2008). Of the 20 eruptions occurring since the installation of Pavlof's seismic network (1973), 13 eruptions have occurred with less than 24 h of warning. Pavlof is essentially an "open vent" volcano with magma rising aseismically through a thermally well-groomed conduit. High-frequency volcano-tectonic earthquakes, characteristic of magma rise through brittle crust, are virtually absent."

Figure 8 presents Mangan and others (2009) conceptualization of the plumbing beneath the ELVC, which includes Pavlof.

Figure (see Caption) Figure 8. Conceptual cross-section through the Emmons Lake Volcanic Center looking at a vertical plane parallel to the volcanic axis. The drawing shows two distinct plumbing systems drawing from a common magmatic source at more than 20 km depth. Courtesy of Mangan and others (2009).

The other volcano of the ELVC considered to have high likelihood of eruption is Mt. Hague (Waythomas and others, 2006). That study also presents a set of hazard maps for the complex.

References. Mangan, M., Miller, T., Waythomas, C., Trusdell, F., Calvert, A., and Layer, P., 2009, Diverse lavas from closely spaced volcanoes drawing from a common parent: Emmons Lake Volcanic Center, Eastern Aleutian Arc, Earth and Planetary Science Letters, Vol. 287, pp. 363-372.

Waythomas, CF; Miller, TP, and Mangan, MT, 2006, Preliminary Volcano Hazard Assessment for the Emmons Lake Volcanic Center, Alaska, U.S. Geological Survey Scientific Investigations Report 2006-5248 (URL: http://pubs.usgs.gov/sir/2006/5248/).

Geologic Background. The most active volcano of the Aleutian arc, Pavlof is a 2519-m-high Holocene stratovolcano that was constructed along a line of vents extending NE from the Emmons Lake caldera. Pavlof and its twin volcano to the NE, 2142-m-high Pavlof Sister, form a dramatic pair of symmetrical, glacier-covered stratovolcanoes that tower above Pavlof and Volcano bays. A third cone, Little Pavlof, is a smaller volcano on the SW flank of Pavlof volcano, near the rim of Emmons Lake caldera. Unlike Pavlof Sister, Pavlof has been frequently active in historical time, typically producing Strombolian to Vulcanian explosive eruptions from the summit vents and occasional lava flows. The active vents lie near the summit on the north and east sides. The largest historical eruption took place in 1911, at the end of a 5-year-long eruptive episode, when a fissure opened on the N flank, ejecting large blocks and issuing lava flows.

Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of a)U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667 USA (URL: http://www.avo.alaska.edu/), b)Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and c)Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://www.dggs.alaska.gov/); Associated Press (URL: http://www.ap.org/); PRNewswire (URL: http://www.prnewswire.com); Alaska Dispatch (URL: http://www.alaskadispatch.com/); and Reuters (URL: http://www.reuters.com/).


Veniaminof (United States) — May 2013 Citation iconCite this Report

Veniaminof

United States

56.17°N, 159.38°W; summit elev. 2507 m

All times are local (unless otherwise noted)


Ongoing sporadic eruptions as late as 6 October 2013

In our last report on Veniaminof (figure 12) (BGVN 33:05), we noted that on 22 February 2008 several minor ash bursts had occurred, a process common in ten's of Bulletin and predecessor Smithsonian reports going back to 1983 (SEAN 08:05). In this report we provide a brief summary of activity from 1 March 2008 into October 2013, an interval including several episodes with lava flows, ash bursts, elevated seismicity, and ash fall. During 4 May 2008-7 June 2013 the available data suggest comparative quite, although during part of that time the volcano lacked a seismic monitoring system. During the reporting interval, the Aviation Alert Level often shifted between Orange and Yellow (high to intermediate values on a scale from Green to Red). As discussed below, there was also an interval without seismic monitoring announced 17 November 2009 when the hazard status was termed 'unassigned' owing to a seismic instrument outage. This report omits detailed seismic data published by the USGS (eg. Dixon and Stilher, 2009; Dixon and others, 2012). On 30 August 2013 ash plumes rose to over 6 km altitude.

Figure (see Caption) Figure 12. Location of Veniaminof on the Alaskan Peninsula. Map courtesy of AVO.

Table 1 synthesizes available AVO reporting on Veniaminof behavior during February 2008 through 6 October 2013. See their reports for more details. During the interval 4 May 2008 to 7 June 2013 the volcano was often quietly steaming, although seismicity increased during part of May 2009. Several highlights follow. Weather permitting, satellite images showed some days with high elevated surface temperatures at the cinder cone inside the caldera consistent with lava effusion. For example, during 24 July-30 July 2013, a "river of lava" flowed down the cone. As discussed in a subsection below, several noteworthy images were acquired in mid-2013 showing ash and thermal signatures on the volcano. On 30 August 2013 the plume reached over 6 km altitude as an unusually vigorous eruptive event ensued. The last lava emissions of the reporting interval took place on 6 October 2013.

Table 1. Representative dates and noteworthy eruptive or non-eruptive intervals at Veniaminof during March 2008 through late August 2013. Courtesy of AVO.

Date Ash plume altitude and movement Other comments
Late Feb through May 2008 Below 2.7 km Sporadic increases in seismic and eruptive activity were noted since 11 February, including tremor episodes that lasted 1-2 minutes and occurred several times per hour. Broadly during late February 2008, AVO noted both small ash bursts with local ashfall at the crater accompanied by seismicity, and occasional high thermal fluxes.
4 May 2008-7 June 2013 (Steaming) 7-26 May 2009, often quiet steaming with generally low to occasional high seismicity and with absence of thermal anomalies. No reports during other portions of the interval 4 May 2008 to 7 June 2013. Seismic station outage announced 17 November 2009, with seismic reports returning 8 June 2013.
19 June 2013 4.6 km NE Cloudy weather sometimes prevented views of the caldera, although most days satellite images showed very high elevated surface temperatures at the cinder cone inside the caldera consistent with lava effusion. On 19 June, residents in Sandy River reported ash bursts.
24-30 July 2013 4.5 km NW Lava effusion, a "river of lava," flowing down the cone.
14-20 August 2013 3.7 km W and then SSE AVO reported that during 13-15 August seismic tremor at Veniaminof was high, and persistent elevated surface temperatures consistent with lava effusion were visible on satellite imagery. An 18 August webcamera image revealed minor ash emissions. On 19 August a helicopter overflight revealed two lava flows On 20 August, trace ash fall reported in Perryville ((32 km SSE); they also heard hearing explosions; infrasound equipment in Dillingham (322 km NE) also detected impulses.
21 Aug-20 Oct 2013 4.6-6.7 km SE 27-29 Aug, episodic tremor bursts interpreted as lava effusion and emissions; prominent satellite thermal anomalies. On 30 Aug, some of the strongest emissions since the eruption began in June 2013; ongoing into early Sept but diminishing in late Sept, and without evidence of eruption in satellite and webcamera data on and around 20 Sept. A lava effusion was recognized 6 October, then waning by mid-October.

As noted above and in table 1, non-eruptive steaming prevailed at the volcano during much or all of the interval 4 May 2008-7 May 2009. On 17 November 2009 AVO announced that Veniaminof was one of four volcanoes in Alaska that they could no longer monitor because of seismic station outages. They then shifted both their Alert Level of Normal and the Aviation Color Code of Green to the category "unassigned." AVO stated that these volcanoes "will likely remain without real-time seismic monitoring until next summer, when necessary upgrades at these and other networks will occur. As at other volcanoes without real-time seismic networks, AVO will continue to use satellite data and reports from pilots and ground observers to detect signs of eruptive activity."

Following the announced station outage, the next update at Veniaminof was on 8 June 2013.

Pilots of aircraft PEN241 saw on 27 August 2013 intermittent ash discharges at 1720 UTC . "Occasional ash to [~3 km a.s.l.] moving NNE. Cloud height up to [~4 km a.s.l.] every 2-5 minutes." This reporting was transmitted to Air Traffic authorities and then to Bulletin editors via the Volcanic Activity Reporting Form (VAR; Appendix 2 of Federal Aviation Administration, 2012). Reports like these are valuable to engineers and scientists who benefit from the direct observations provided by pilots.

During 6-7 May 2009, seismic activity from Veniaminof increased, prompting AVO to raise the Volcanic Alert Level to Advisory and the Aviation Color Code to Yellow. Small magnitude earthquakes occurred at rates of 5-10 per hour during quieter periods and 1-3 per minute during periods of more intense activity. Visual observations indicated typical steaming from the summit caldera cone. Seismicity remained elevated during 8-12 May 2009. On 26 May 2009, AVO reported that seismicity from Veniaminof had decreased during the previous week. The Volcanic Alert Level was lowered to Normal and the Aviation Color Code was lowered to Green.

During 2010-12 the volcano was relatively quiet (table 1). There were no AVO weekly reports on Veniaminof during this interval.

On 13 June 2013, low-level emissions led the AVO to increase the aviation color code to orange. The Anchorage Volcanic Ash Advisory Center (VAAC) reported on 15 June 2013 that the eruptions had ended, but AVO still reported intermittent activity continuing through 8 July 2013. In addition, MODVOLC had detected 248 thermal alerts during 14 June-11 July 2013 (figure 13).

Figure (see Caption) Figure 13. This image of Veniaminof displays MODVOLC thermal alerts from 14 June 2013 to 11 July 2013. Thermal alerts from MODVOLC are derived from data collected by the MODIS thermal sensors aboard the Aqua and Terra satellites and processed by the Hawaii Institute of Geophysics and Planetology using the MODVOLC algorithm. Note that the hotspots (red) are clustered in the immediate region of the summit and are not wildfires.

July 2013 activity. Figure 14 shows a satellite image from 4 July 2013 portraying both ash desposits on the snow surface and the thermal signature of an ongoing lava flow. On 8 July 2013, AVO reported that nearly continuous, low-level volcanic tremor had occurred during the previous 24 hours. Cloudy satellite images detected thermal anomalies (figure 14). Web camera images from Perryville (32 m SSE) showed incandescence from the Veniaminof intracaldera cone.

Figure (see Caption) Figure 14. This satellite image from 4 July 2013 shows thermal emissions from an active lava flow as detected by shortwave infrared data, The image also shows ash deposits covering the snow fields that engulf the volcano. N is to the top. The ash appears as radial spokes due to deposition during changing wind directions. The lava flow was active at the time of this photo, extending southward from the vent. Image courtesy of Alaska Volcano Observatory.

AVO reported that the ongoing low-level eruption of Veniaminof, characterized by lava effusion and emission of minor amounts of ash and steam, continued during 26 June-8 July 2013, indicated by nearly continuous volcanic tremor and occasional small explosions detected by the seismic network. Figure 15 shows a photo taken on 26 June. Satellite images showed elevated surface temperatures at the cinder cone inside the caldera consistent with lava effusion. During 26-30 June web camera images from Perryville showed a small light-colored plume rising above the cone to just above the rim of the caldera, and night time images showed persistent incandescence from the cone. The Volcano Alert Level remained at Watch and the Aviation Color code remained at Orange.

Figure (see Caption) Figure 15. Steam rising from the active intracaldera cone of Veniaminof. The photo was taken from ~600 m elevation, looking SW toward the volcano on 26 June 2013. Photo courtesy of Will Lawrence.

2008-2011 seismicity. According to Dixon and others (2009) and additional AVO reports, the monitoring network for Veniaminof included nine stations, at least through 2011. The network experienced intermittent outages (eg. figure 16 of broken solar panel.) The number of recorded earthquakes between 2008-2011 is presented in table 1.

Figure (see Caption) Figure 16. Helena Buurman works to remove smashed solar panels at station VNFG- one of the main repeaters in the Veniaminof network (17 July 2010). Photo courtesy of Cyrus Read.

Table 2. Veniaminof VT and LF earthquakes detected during 2008-2011. Because of occasional equipment outages, values in the table may under-represent actual numbers. Values for 2012 were not yet available. Sources included Dixon and others (2008, 2009, 2010, 2011).

Year Earthquakes located Volcano-tectonic (VT) Low frequency (LF)
2008 17 14 3
2009 4 3 1
2010 22 18 4
2011 7 6 1

2009 annual seismicity. The Aniakchak, Cerberus, Gareloi, Great Sitkin, Pavlof, Veniaminof, and Wrangell subnetworks had insufficient numbers of located earthquakes to calculate a Mc. The Mc ranged from -0.1 to 1.5 for the individual subnetworks.

2010 annual seismicity. The seismograph networks on Aniakchak, Korovin, and Veniaminof were repaired in 2010. There were many station outages in the previous two years.

Seismicity at Veniaminof and Westdahl were the only areas in which an increase over the seismicity in 2009 was noted. The increase in seismicity at Veniaminof was a result of a small swarm of activity northwest of the active cone in late July.

2011 annual seismicity. There were fewer station outages and more than four were operating during the year. Veniaminof had insufficient numbers of located earthquakes in 2011 to calculate a magnitude completeness.

References. Dixon, J.P., Stihler, S.D., Power, J.A., and Searcy, C.K., 2011, Catalog of earthquake hypocenters at Alaskan Volcanoes: January 1 through December 31, 2010: U.S. Geological Survey Data Series 645, 82 p.

Dixon, J.P., Stihler, S.D., Power, J.A., and Searcy, C.K., 2012, Catalog of earthquake hypocenters at Alaskan Volcanoes: January 1 through December 31, 2011: U.S. Geological Survey Data Series 730, 82 p.

Dixon, J.P., Stihler, S.D., Power, J.A., and Searcy, Cheryl, 2010, Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2009: U.S. Geological Survey Data Series 531, 84 p.

Dixon, J.P., and Stihler, S.D., 2009, Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2008: U.S. Geological Survey Data Series 467, 86 p.

Federal Aviation Administration, 2012, Aeronautical Information Manual, Official Guide to Basic Flight Information and ATC Procedures (issued 9 February 2012; with revisions as late as 22 Aug ust 2013) (URL: http://www.faa.gov/air_traffic/publications/atpubs/aim/index.htm).

Geologic Background. Veniaminof, on the Alaska Peninsula, is truncated by a steep-walled, 8 x 11 km, glacier-filled caldera that formed around 3,700 years ago. The caldera rim is up to 520 m high on the north, is deeply notched on the west by Cone Glacier, and is covered by an ice sheet on the south. Post-caldera vents are located along a NW-SE zone bisecting the caldera that extends 55 km from near the Bering Sea coast, across the caldera, and down the Pacific flank. Historical eruptions probably all originated from the westernmost and most prominent of two intra-caldera cones, which rises about 300 m above the surrounding icefield. The other cone is larger, and has a summit crater or caldera that may reach 2.5 km in diameter, but is more subdued and barely rises above the glacier surface.

Information Contacts: Alaska Volcano Observatory, a cooperative program of a)U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667 USA URL: http://www.avo.alaska.edu/); b)Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320 USA and c)Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://www.dggs.alaska.gov/); Anchorage Volcanic Ash Advisory Center (VAAC), 6930 Sand lake Road Anchorage, AK 99502-1845 USA (URL: http://vaac.arh.noaa.gov/); and Hawai'i Institute of Geophysics and Planetology (HIGP), MODVOLC Thermal Alert System, School of Ocean and Earth Science and Technology (SOEST), University of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http:hotspot.higp.hawaiii.edu/).


Yasur (Vanuatu) — May 2013 Citation iconCite this Report

Yasur

Vanuatu

19.532°S, 169.447°E; summit elev. 361 m

All times are local (unless otherwise noted)


Explosive activity continued into at least early 2013

In BGVN 36:05, we reported that on 12 May 2011, the Vanuatu Geohazards Observatory (VGO) reported, based on information collected by the Vanuatu Meteorology and Geohazards Department, that a OMI (ozone monitoring instrument) satellite image showed strong degassing of SO2 from Yasur volcano during the previous week (see map of this island volcano in figure 42 of BGVN 36:05). On 1 June 2011, the Vanuatu Volcano Alert Level (VVAL) was raised from 2 to 3, following increasing explosive activity during May, then lowered to 2 on 13 June (table 3).

Table 3. The Vanuatu Volcanic Alert Level (VVAL) scale for the six volcanoes monitored by Vanuato Geohazard Observatory (Yasur, Lopevi, Ambrym, Aoba, Gaua, and Suretamatai). Courtesy of Vanuatu Geohazards Observatory.

VVAL Description
Lvl. ? Insufficient monitoring to make assessment.
Lvl. 0 Normal low-level activity.
Lvl. 1 Increased activity, danger near crater only.         
Lvl. 2 Moderate eruptions, danger close to the volcano vent, within parts of Volcanic Hazards Map Red Zone.
Lvl. 3 Large eruption, danger in specific areas within parts of Volcanic Hazards Map Red and Yellow Zones.    
Lvl. 4 Very large eruption, island-wide danger (including areas within Red Yellow and Green Zones).

During the week of 7-12 July 2012, VGO observed that explosive activity at Yasur became stronger and more frequent, and shifted from Strombolian to sub Plinian. Bombs ejected from the vents fell in the crater, around the summit area, and on the tourist walk and parking area (within the red zone, figure 43). The explosions were heard, felt, and observed from nearby villages and schools. Activity at all three volcanic vents was characterized by degassing, ash emissions, and ejection of bombs. On 13 July 2012, the Alert Level was raised to 3.

VGO reported an OMI satellite image on 1 April 2013 showed diffuse SO2 from Yasur. Explosive activity increased on 2 April 2013, with explosions becoming stronger and more frequent, and continued to slightly increase through 28 May. Bombs again fell around the summit area, the tourist walk, and the parking area. Moderate ash emissions and ashfall occurred on 2, 4, and 5 April, and 5 and 8 May 2013. Photos included in the report showed dense white plumes on 23 and 24 May. The Alert Level remained at 2 (on a scale of 0 4).

Volcano Ash Advisory Centre (VAAC) reports on Yasur. In many cases the VAAC lacked any satellite data and in cases where they did have data they frequently were unable to detect the plume or in other cases could not detect ash in the plume (table 4).

Table 4. Yasur volcano aviation reports (VAAs, Volcanic Ash Advisories) for the time interval 11 January 2009 to 10 June 2010. In many cases the information sources were the Vanuatu Geohazard Observatory (VGO). On 11 January the source was an AIREP, an aircraft report. Data provided courtesy of the Wellington Volcanic Ash Advisor Centre (VAAC).

Date (time UTC) Info Source (type of observation) Details Altitude (km) Drift or cited wind direction
11 Jan 2009 AIREP Plume sighted over volcano by aircraft (to ~4 km altitude, drifting SE). Ash not seen by VAAC analysts in satellite data. ~4km SE
29 May 2010 VGO Observatory reported plume, however no satellite image was made. ~2km Winds NE
30 May 2010 VGO Observatory reported plume, and a volcanic ash cloud was captured with a Modis image. ~2km Winds E
31 May 2010 VGO Observatory reported plume, and a volcanic ash cloud obscured the satellite image. ~2km Winds NE
01 Jun 2010 VGO Observatory reported plume, and a volcanic ash cloud obscured the satellite image. ~2km Winds N
02 Jun 2010 VGO Observatory reported plume, and a volcanic ash cloud was unidentifiable on satellite image. ~2km Winds N
03 Jun 2010 VGO Observatory reported plume, and a volcanic ash cloud was unidentifiable on satellite image. ~2km Winds E/NE
04 Jun 2010 VGO Observatory reported plume, and a volcanic ash cloud was unidentifiable on satellite image. ~2km Winds NE
05 Jun 2010 VGO Observatory reported a plume, and a volcanic ash could was unidentifiable on satellite image. A remark was made suggesting volcanic eruption may be easing. ~2km Winds NW
06 Jun 2010 VGO Observatory reported a plume,and a volcanic ash cloud was unidentifiable on satellite image. ~2km Winds NW
07 Jun 2010 VGO Observatory reported a plume, and satellite image was unavailable. ~2km Winds NW
08 Jun 2010 VGO Observatory reported a plume, and satellite image was unavailable. ~2km Winds NW
09 Jun 2010 VGO Observatory reported a plume, and satellite image was unavailable. ~2km Winds
10 Jun 2010 VGO Observatory reported a plume, and that no volcanic ash was visible on satellite image. ~2km Winds NE

Satellite Thermal Alerts. The MODIS/MODVOLC satellite thermal alert system has shown least 1 to 10 alerts each month over Yasur since the beginning of 2011. A lava lake has existed at Yasur for many years.

References. Allen, S.R., 2005, Complex spatter and pumice rich pyroclastic deposits from an andesitic caldera forming eruption:The Siwi pyroclastic sequence, Tanna, Vanuatu, Bulletin of Volcanology, v. 67, pp. 27 41.

Calmant, S., Pelletier, B., Lebellegard, P., Bevis, M., Taylor, F.W., and Phillips, D.A., 2003, New insights on the tectonics along the New Hebrides subduction zone based on GPS results, Journal of Geophysical Research, v. 108, no. B6, pp. 2319 2339.

Carnay, JN., and MacFarlane, A, 1979, Geology of Tanna, Aneityum, Futuna and Aniva, New Hebrides Geological Survey Report 1979, pp. 5 29.

Métrich, N., Allard, P., Aiuppa, A., Bani, P., Bertagnini, A., Shinohara, H., Parello, F., Di Muro, A., Garaebiti, E., Belhadj, O., and Massare, D., 2011, Magma and Volatile Supply to Post collapse Volcanism and Block Resurgence in Siwi Caldera (Tanna Island, Vanuatu Arc), Journal of Petrology, v. 52, no. 6, pp. 1077 1105; DOI: 10.1093/petrology/egr019.

Nairn, I.A., Scott, B.J., and Giggenbach, W.F., 1988, Yasur volcanic investigations, Vanuatu September 1988, New Zealand Geological Survey Report 1988, pp.1 74.

Pelletier, B., Calmant, S., and Pillet, R., 1998, Current tectonic of the Tonga New Hebrides region, Earth and Planetary Science Letters, v. 164, pp. 263 276.

Geologic Background. Yasur, the best-known and most frequently visited of the Vanuatu volcanoes, has been in more-or-less continuous Strombolian and Vulcanian activity since Captain Cook observed ash eruptions in 1774. This style of activity may have continued for the past 800 years. Located at the SE tip of Tanna Island, this mostly unvegetated pyroclastic cone has a nearly circular, 400-m-wide summit crater. The active cone is largely contained within the small Yenkahe caldera, and is the youngest of a group of Holocene volcanic centers constructed over the down-dropped NE flank of the Pleistocene Tukosmeru volcano. The Yenkahe horst is located within the Siwi ring fracture, a 4-km-wide, horseshoe-shaped caldera associated with eruption of the andesitic Siwi pyroclastic sequence. Active tectonism along the Yenkahe horst accompanying eruptions has raised Port Resolution harbor more than 20 m during the past century.

Information Contacts: Vanuatu Geohazards Observatory, Department of Geology, Mines and Water Resources of Vanuatu (URL: http://www.geohazards.gov.vu); NASA Earth Observatory (URL: http://earthobservatory.nasa.gov); MODIS/MODVOLC Thermal Alerts System, Hawai'i Institute of Geophysics and Planetology (HIGP), 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/); and Wellington Volcanic Ash Advisory Centre (VAAC), Meteorological Service of New Zealand Ltd (MetService), PO Box 722, Wellington, New Zealand (URL: http://www.metservice.com/vaac/, URL: http://vaac.metservice.com/).

Atmospheric Effects

The enormous aerosol cloud from the March-April 1982 eruption of Mexico's El Chichón persisted for years in the stratosphere, and led to the Atmospheric Effects section becoming a regular feature of the Bulletin. Descriptions of the initial dispersal of major eruption clouds remain with the individual eruption reports, but observations of long-term stratospheric aerosol loading will be found in this section.

Atmospheric Effects (1980-1989)  Atmospheric Effects (1995-2001)

Special Announcements

Special announcements of various kinds and obituaries.

Special Announcements  Obituaries

Misc Reports

Reports are sometimes published that are not related to a Holocene volcano. These might include observations of a Pleistocene volcano, earthquake swarms, or floating pumice. Reports are also sometimes published in which the source of the activity is unknown or the report is determined to be false. All of these types of additional reports are listed below by subject.

Additional Reports  False Reports