Activity for the week of 23 October-29 October 2002
The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports on various volcanoes are published monthly in the Bulletin of the Global Volcanism Network.
New Activity / Unrest
| Sicily (Italy)
| 37.748°N, 14.999°E
| Elevation 3320 m
A relatively large eruption began at Etna on 27 October, following a series of ~200 small earthquakes the previous evening. The eruption began with fissures opening on the volcano's S and NE slopes around 2,700 m elevation, between Southeast Crater and Montagnola cone. Lava fountains rose 100-200 m, lava flows were emitted from the fissures, and significant ash plumes were produced. On the 28th seismicity continued, with a M 3.8 earthquake occurring beneath the volcano. Lava flows cut across the road connecting the towns of Linguaglossa and Piano Provenzana and lava ignited several forest fires near Piano Provenzana. The lava flows were estimated to be 365 m wide and 6.1 m high.
Ditches were dug in an effort to control lava flows, but by the 29th they were completely covered by lava. Authorities also tried to control the flows by having planes douse the lava with water, causing the flows to cool and stagnate, but they continued to travel down the volcano's flanks. Authorities stressed that the popular ski town of Linguaglossa (6,000 residents), located ~15 km NE of Etna's summit, was not in danger of being engulfed by lava flows. As a precautionary measure ~50 residents were evacuated and schools were closed. By the 28th lava flows had destroyed several hotels, restaurants, a ski school, ski lift pylons, and power lines on the volcano's flanks. Ash fell in towns at the base of the volcano. Some streets in the town of Nicolosi, ~15 km S of the summit, were covered with a 5-cm-thick layer of ash.
During 27 to at least 29 October ash clouds were visible on satellite imagery and the Etna volcano video camera, reaching a maximum height of ~6.4 km a.s.l. The clouds drifted towards the SE and on the 27th one had reached ~350 km S to Libya. From the beginning of the eruption, Catania's Fontanarossa airport was closed. Ash emissions continued on the 29th and a M 4.4 earthquake occurred around 1100, damaging hundreds of buildings in the town of Santa Venerina on the volcano's SE flank.
Sources: Toulouse Volcanic Ash Advisory Centre (VAAC), Etna Volcan Sicilien (Charles Rivière), Associated Press, Reuters
| Southern Kamchatka (Russia)
| 52.559°N, 158.03°E
| Elevation 1799 m
According to a Pravda news article, the Laboratory of Active Volcanism at the Institute of Volcanology reported that a seismic station located atop Gorely registered continuous tremor that was four times stronger than background tremor. In addition, "smoke" and steam rose 300 m above the volcano. Another report from the Kamchatkan Experimental-Methodical Seismological Department, which operates the seismic station, stated that the station is in the vicinity of both Gorely and Mutnovsky, therefore it is difficult to attribute the tremor to a specific volcano. They found that during 2-3 October a swarm of about 30 M 1.2-1.7 earthquakes was recorded, and on 26 October there were two M 1.7 earthquakes.
Sources: Kamchatkan Experimental and Methodical Seismological Department, Pravda News
| New Britain (Papua New Guinea)
| 4.271°S, 152.203°E
| Elevation 688 m
An eruption on 20 October from Tavurvur volcano took place at Rabaul caldera. The head of RVO stated that rocks were thrown 700 m from the summit and no lava was erupted. Ash from the eruption caused Tokua airport flights to be suspended on 22 October. It reopened on the 27th, with two flights permitted during the day. Reopening the airport was possible because ash from the eruption shifted away from it. Several small explosions occurred after the 20 October eruption and sent ash clouds to 4 km a.s.l. On the 28th RVO stated that a major increase in volcanic activity seemed unlikely.
Sources: Darwin Volcanic Ash Advisory Centre (VAAC), Reuters, Pacific Island Report
| El Salvador
| 13.434°N, 88.269°W
| Elevation 2130 m
A news report stating that a rockslide released dangerous fumes at San Miguel on 17 October was found to be false.
Source: Associated Press
| 19.514°N, 103.62°W
| Elevation 3850 m
Colima's web video camera showed an ash-and-steam plume rising to a height of ~5.5 km a.s.l. on 24 October at 0430. The plume drifted toward the N. Neither ash nor steam was visible on satellite imagery.
Source: US Air Force Weather Agency
| 0.171°S, 78.598°W
| Elevation 4784 m
A small increase in the number of phreatic explosions occurred at Guagua Pichincha following the 11 October explosion. The activity increase may have occurred due to heavy rain at the volcano.
Source: El Universo
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
Seismicity remained above background levels at Karymsky during 18-25 October, with ~250 shallow earthquakes occurring per day. The character of the seismicity indicated that ash-and-gas explosions reached heights of 1 km above the volcano and vigorous 5- to 10-minute-long gas emissions possibly occurred. KVERT reported that a lava flow was probably traveling down the volcano's slopes. Thermal anomalies were visible on satellite imagery on several days, but ash was not. Karymsky remained at Concern Color Code Yellow.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
During 23-29 October at Kilauea, lava continued to enter the sea from two deltas as it has for several weeks. Surface lava flows were not visible on the coastal flat or Paliuli, and were occasionally seen near Pulama pali. Generally, seismicity was at normal levels beneath Kilauea's caldera. A swarm of long-period earthquakes and tremor beneath the caldera occasionally occurred. A small deflation event began on the 28th that was recorded at Uwekahuna and Pu`u `O`o tiltmeters.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| Hawaiian Islands (USA)
| 19.475°N, 155.608°W
| Elevation 4170 m
As of 28 October Mauna Loa continued to inflate, but seismicity remained at low levels. The permanent, continuous GPS network indicated ongoing lengthening across Moku`aweoweo summit caldera, as it has since late April or May 2002.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
During 18-25 October seismicity remained above background levels at Shiveluch, but the number of earthquakes decreased. During this interval, seismic data indicated that there had been hot avalanches and 10 ash-and-gas explosions in which clouds reached 1 km above the lava dome. Gas-and-steam plumes rose to ~4.5 km a.s.l. and thermal anomalies were visible on satellite imagery. Shiveluch remained at Concern Color Code Yellow.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| 16.72°N, 62.18°W
| Elevation 915 m
Volcanic and seismic activity at Soufrière Hills remained at a similar level during 18-25 October to that of the previous week. Occasional clear views of the lava dome revealed that the active extrusion lobe in the NW continued to grow steadily, increasing in height and bulging out on the N and W sides. The most notable event of the week occurred on the afternoon of 22 October when intense rainfall at midday produced large mudflows NW in the Belham Valley where residents had recently been evacuated. At the peak of flow, the entire width of the valley floor at Belham Bridge was flooded and standing waves up to 2.5 m high were observed. By 1430, pyroclastic-flow activity began. For several hours, pyroclastic flows were generated off of the N flank of the dome and were channeled northeastwards into the upper parts of Tuitt's Ghaut, from where they crossed over into White's Bottom Ghaut. Flows also occurred on the dome's E flank in the Tar River Valley. SO2 emission rates were low at the beginning of the report period and increased towards the end of the week.
Sources: Montserrat Volcano Observatory (MVO), Associated Press
| 1.467°S, 78.442°W
| Elevation 5023 m
During 22-29 October, emissions of steam, gas, and ash continued at Tungurahua. Plumes rose to a maximum height of ~8 km a.s.l.
Source: Washington Volcanic Ash Advisory Center (VAAC)
| United States
| 56.17°N, 159.38°W
| Elevation 2507 m
Veniaminof remained restless during 18-25 October. Although the current seismic activity is lower than when first noted in early September, it is still above background level. No new visual observations of Veniaminof were received since the last update. No thermal anomalies were observed in satellite views. AVO considered the activity at Veniaminof to be minor, but the exact nature of the unrest was unknown. Veniaminof remained at Concern Color Code Yellow.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Criteria & Disclaimers
The Weekly Volcanic Activity Report does not necessarily include all volcanic activity that occurred on Earth during the week. More than a dozen volcanoes globally have displayed more-or-less continuous eruptive activity for decades or longer, and such routine activity is typically not reported here. Moreover, Earth's sea-floor volcanism is seldom reported even though in theory it represents the single most prolific source of erupted material. The Weekly Volcanic Activity Report summarizes volcanic activity that meets one or more of the following criteria:
- A volcano observatory raises or lowers the alert level at the volcano.
- A volcanic ash advisory has been released by a volcanic ash advisory center (VAAC) stating that an ash cloud has been produced from the volcano.
- A verifiable news report of new activity or a change in activity at the volcano has been issued.
- Observers have reported a significant change in volcanic activity. Such activity can include, but is not restricted to, pyroclastic flows, lahars, lava flows, dome collapse, or increased unrest.
Volcanoes are included in the "New Activity/Unrest" section of the Weekly Volcanic Activity Report if the activity occurs after at least 3 months of quiescence. Once a volcano is included in the "New Activity/Unrest" section, updates will remain in that section unless the activity continues for more than 1 month without escalating, after which time updates will be listed in the "Continuing Activity" section. Volcanoes are also included in the "New Activity/Unrest" section if the volcano is undergoing a period of relatively high unrest, or increasing unrest. This is commonly equal to Alert Level Orange on a scale of Green, Yellow, Orange, Red, where Red is the highest alert. Or alert level 3 on a scale of 1-4 or 1-5.
It is important to note that volcanic activity meeting one or more of these criteria may occur during the week, but may not be included in the Weekly Volcanic Activity Report because we did not receive a report.
1. The Weekly Volcanic Activity Report is intended to provide timely information about global volcanism on a weekly basis. Consequently, the report is generated rapidly by summarizing volcanic reports from various sources, with little time for fact checking. The accuracy of the Weekly Volcanic Activity Report is dependent upon the quality of the volcanic activity reports we receive. Reports published in the Bulletin of the Global Volcanism Network are monthly, and more carefully reviewed, although all of the volcanoes discussed in the Weekly Volcanic Activity Report are not necessarily reported in the Bulletin. Because of our emphasis on rapid reporting on the web we have avoided diacritical marks. Reports are updated on the Weekly Volcanic Activity Report web page as they are received, therefore information may be included regarding events that occurred before the current report period.
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