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SI/USGS Weekly Volcanic Activity Report 20-26 October 2010
From: "Kuhn, Sally" <KUHNS@xxxxxx>
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SI/USGS Weekly Volcanic Activity Report
20-26 October 2010
Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/
New Activity/Unrest: | Kliuchevskoi, Central Kamchatka (Russia) | Merapi, Central Java (Indonesia) | Piton de la Fournaise, Reunion Island
Ongoing Activity: | Chaitén, Southern Chile | Fuego, Guatemala | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Manam, Northeast of New Guinea (SW Pacific) | Pacaya, Guatemala | Sakura-jima, Kyushu | Santa María, Guatemala | Shiveluch, Central Kamchatka (Russia) | Suwanose-jima, Ryukyu Islands (Japan) | Villarrica, Central Chile
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.
Note: Many news agencies do not archive the articles they post on the Internet, and therefore the links to some sources may not be active. To obtain information about the cited articles that are no longer available on the Internet contact the source.
New Activity/Unrest
KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit elev. 4835 m
KVERT reported that during 15-22 October seismic activity from Kliuchevskoi was above background levels and two lava flows from the summit crater traveled down the SW and W flanks. Satellite imagery analyses showed a large and intense daily thermal anomaly over the volcano and ash plumes that drifted 420 km E and SE. Strombolian activity, observed every day, ejected material 250 m above the crater. Ash plumes rose to an altitude of 7.5 km (24,600 ft) a.s.l. during 20-21 October and to an altitude of 6.5 km (21,300 ft) a.s.l. on the other days during 15-22 October. The Aviation Color Code level remained at Orange.
On 23 October, KVERT reported increased seismicity, characterized by an abrupt change in volcanic tremor, and explosive activity. Ash plumes rose to altitudes of 8-9 km (26,200-29,500 ft) a.s.l. and drifted more than 300 km N. The Aviation Color Code level was raised to Red. The next day the magnitude of tremor decreased and gas-and-steam plumes rose to an altitude of 6.5 km (21,300 ft) a.s.l. Gas-and-steam plumes possibly containing ash drifted SE. The Aviation Color Code level was lowered to Orange. On 25 October, the magnitude of volcanic tremor fluctuated. Ash plumes rose to altitudes of 8-8.5 km (26,200-27,900 ft) a.s.l. and drifted SE. The Aviation Color Code level was again raised to Red. The VAAC reported on 26 October that ash was observed in satellite imagery.
Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active volcano. Since its origin about 7,000 years ago, the beautifully symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. More than 100 flank eruptions, mostly on the NE and SE flanks of the conical volcano between 500 m and 3,600 m elevation, have occurred during the past 3,000 years. The morphology of its 700-m-wide summit crater has been frequently modified by historical eruptions, which have been recorded since the late-17th century. Historical eruptions have originated primarily from the summit crater, but have also included major explosive and effusive events from flank craters.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php,
Tokyo Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AK/messages.html
MERAPI Central Java (Indonesia) 7.542°S, 110.442°E; summit elev. 2968 m
CVGHM reported that from the end of September to 20 October the rate of inflation at Merapi was 0.6 cm per day. On 21 October the rate increased to 10.5 cm per day, and incidents of incandescence from the lava dome increased. CVGHM raised the Alert Level to 3 (on a scale of 1-4). The rate of inflation increased sharply on 24 October to a rate of 42 cm per day. The next day, CVGHM raised the Alert Level to 4, and recommended immediate evacuation for several communities (news reports estimated 11,000-19,000 people) within a 10-km radius.
An eruption began at about 1700 on 26 October that was characterized by explosions along with pyroclastic flows that traveled WSW and SE. CVGHM reported that multiple pyroclastic flows occurred until 1854, when the pyroclastic flow activity started to subside. Most of the pyroclastic flows lasted 2 to 9 minutes, except for two that lasted 33 minutes each. Booming noises were heard, and incandescence from the crater was seen from the Selo observation post to the N. An ash plume was also observed rising 1.5 km above the crater.
According to news articles, officials noted that about 15,000 people had not yet evacuated, even though several minor eruptions had already occurred prior to 26 October. Reports on 27 October noted that about 25 people had died and several were injured.
Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM) http://www.vsi.esdm.go.id/,
Associated Press http://www.heraldsun.com.au/news/world/indonesian-volcano-erupts-at-least-20-hurt-by-hot-ash/story-e6frf7lf-1225943960033,
Associated Press http://www.thejakartapost.com/news/2010/10/26/mount-merapi-erupts-20-hurt-hot-ash.html,
The Jakarta Globe http://www.thejakartaglobe.com/news/breaking-news-mount-merapi-volcano-finally-erupts/403376,
BBC News http://www.bbc.co.uk/news/world-asia-pacific-11634150
PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev. 2632 m
OVPDLF reported that an eruption from Piton de la Fournaise that began on 14 October from a fissure near the Château Fort crater, about 1.5 km SE of the Dolomieu crater rim, continued during 19-25 October. On 19 October, explosive and degassing activity from vents along the fissure increased, but was still below the intensity noted at the beginning of the eruption. During 20-21 October small lava fountains fed lava flows that traveled as far as 2 km E and SE. Decreased gas emissions were concentrated to the S and W of the fissure. During 22-24 October fountains and gas emissions originated from one vent, and lava traveled ESE. Gas emissions decreased significantly.
Geologic Summary. Massive Piton de la Fournaise shield volcano on the island of Réunion is one of the world's most active volcanoes. Most historical eruptions have originated from the summit and flanks of a 400-m-high lava shield, Dolomieu, that has grown within the youngest of three large calderas. This depression is 8 km wide and is breached to below sea level on the eastern side. More than 150 eruptions, most of which have produced fluid basaltic lava flows within the caldera, have been documented since the 17th century. The volcano is monitored by the Piton de la Fournaise Volcano Observatory, one of several operated by the Institut de Physique du Globe de Paris.
Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF) http://www.ipgp.fr/pages/03030810.php
Ongoing Activity
CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m
Based on analyses of web camera footage, the Buenos Aires VAAC reported that an ash plume from Chaitén's lava-dome complex rose to an altitude of 2.1 km (7,000 ft) a.s.l. The report also noted a plume drifting ENE.
Geologic Summary. Chaitén is a small, glacier-free caldera with a Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf of Corcovado. A pyroclastic-surge and pumice layer that was considered to originate from the eruption that formed the elliptical 2.5 x 4 km wide summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-high obsidian lava dome occupies much of the caldera floor. Obsidian cobbles from this dome found in the Blanco River are the source of prehistorical artifacts from archaeological sites along the Pacific coast as far as 400 km away from the volcano to the north and south. The caldera is breached on the SW side by a river that drains to the bay of Chaitén, and the high point on its southern rim reaches 1122 m. Two small lakes occupy the caldera floor on the west and north sides of the lava dome. The first historical eruption of Chaitén volcano in 2008 produced major rhyolitic explosive activity and growth of a lava dome that filled much of the caldera.
Source: Buenos Aires Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AG/messages.html
FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m
During 21-22 and 26 October, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose 500-700 m above the SW crater. Rumbling and degassing sounds were occasionally heard, and incandescence was observed at night. Block avalanches occurred on the flanks. On 26 October, ash plumes drifted N and NW, and incandescent material was ejected 75 m above the crater.
Geologic Summary. Volcán Fuego, one of Central America's most active volcanoes, is one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N, Acatenango. Construction of Meseta volcano continued until the late Pleistocene or early Holocene, after which growth of the modern Fuego volcano continued the southward migration of volcanism that began at Acatenango. Frequent vigorous historical eruptions have been recorded at Fuego since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows. The last major explosive eruption from Fuego took place in 1974, producing spectacular pyroclastic flows visible from Antigua.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) http://www.insivumeh.gob.gt/
KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported that seismic activity from Karymsky was above background levels during 15-22 October, suggesting that possible ash plumes rose to altitudes of 2-4 km (6,600-13,100 ft) a.s.l. Volcanologists working at Karymsky observed Strombolian activity at night, along with ash plumes during 14-16 October that rose to altitudes of 2.5-3 km (8,200-10,000 ft) a.s.l. and drifted E. A thermal anomaly was seen in satellite imagery during 15-16 and 18-19 October. The Aviation Color Code level remained at Orange.
Geologic Summary. Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon years ago. Construction of the Karymsky stratovolcano began about 2,000 years later. The latest eruptive period began about 500 years ago, following a 2,300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been Vulcanian or Vulcanian-Strombolian with moderate explosive activity and occasional lava flows from the summit crater. Most seismicity preceding Karymsky eruptions has originated beneath Akademia Nauk caldera, which is located immediately S of Karymsky volcano and erupted simultaneously with Karymsky in 1996.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php
KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m
During 20-26 October, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable; periodically the lava rose above that level, producing nighttime incandescence seen from the Jaggar Museum, on the NW caldera rim. A plume from the vent drifted mainly SW.
At the east rift zone, lava that flowed through the TEB lava-tube system fed at least one ocean entry at the Puhi-o-Kalaikini delta. Small surface flows on the coastal plain and pali were visible during 20-22 October. A vent on the N part of the Pu'u 'O'o crater floor ejected spatter on 20 October. Incandescence was visible from the vent the next day and from multiple vents during 22-23 October.
Geologic Summary. Kilauea, one of five coalescing volcanoes that comprise the island of Hawaii, is one of the world's most active volcanoes. Eruptions at Kilauea originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. About 90% of the surface of Kilauea is formed of lava flows less than about 1,100 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 sq km, destroying nearly 200 houses and adding new coastline to the island.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO) http://hvo.wr.usgs.gov/
MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit elev. 1807 m
Based on analysis of satellite imagery, the Darwin VAAC reported that on 22 October an ash plume from Manam rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted 130 km NW. A subsequent notice stated that the ash plume had dissipated.
Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the northern coast of mainland Papua New Guinea, is one of the country's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical 1807-m-high basaltic-andesitic stratovolcano to its lower flanks. These "avalanche valleys," regularly spaced 90 degrees apart, channel lava flows and pyroclastic avalanches that have sometimes reached the coast. Two summit craters are present; both are active, although most historical eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE avalanche valley. Frequent historical eruptions, typically of mild-to-moderate scale, have been recorded at Manam since 1616. Occasional larger eruptions have produced pyroclastic flows and lava flows that reached flat-lying coastal areas and entered the sea, sometimes impacting populated areas.
Source: Darwin Volcanic Ash Advisory Centre (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m
During 21-22 and 26 October, INSIVUMEH reported Strombolian explosions originating from Pacaya's MacKenney crater, although the explosions were not visually observed.
Geologic Summary. Eruptions from Pacaya, one of Guatemala's most active volcanoes, are frequently visible from Guatemala City, the nation's capital. Pacaya is a complex volcano constructed on the southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A cluster of dacitic lava domes occupies the caldera floor. The Pacaya massif includes the Cerro Grande lava dome and a younger volcano to the SW. Collapse of Pacaya volcano about 1,100 years ago produced a debris-avalanche deposit that extends 25 km onto the Pacific coastal plain and left an arcuate somma rim inside which the modern Pacaya volcano (MacKenney cone) grew. During the past several decades, activity at Pacaya has consisted of frequent Strombolian eruptions with intermittent lava flow extrusion on the flanks of MacKenney cone, punctuated by occasional larger explosive eruptions.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) http://www.insivumeh.gob.gt/
SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m
Based on information from JMA, the Tokyo VAAC reported an explosion from Sakura-jima on 20 October.
Geologic Summary. Sakura-jima, one of Japan's most active volcanoes, is a post-caldera cone of the Aira caldera at the northern half of Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was associated with the formation of the 17 x 23-km-wide Aira caldera about 22,000 years ago. The construction of Sakura-jima began about 13,000 years ago and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kita-dake summit cone ended about 4,850 years ago, after which eruptions took place at Minami-dake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76.
Source: Tokyo Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AK/messages.html
SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m
INSIVUMEH reported that on 22 October explosions from Santa María's Santiaguito lava dome complex produced ash plumes that rose 300 m above Caliente dome and drifted SW. Block avalanches traveled down the S and SW flanks. On 26 October steam plumes rose 150 m above the crater.
Geologic Summary. Symmetrical, forest-covered Santa María volcano is one of a chain of large stratovolcanoes that rises dramatically above the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-topped, conical profile that is cut on the SW flank by a large, 1-km-wide crater, which formed during a catastrophic eruption in 1902 and extends from just below the summit to the lower flank. The renowned Plinian eruption of 1902 followed a long repose period and devastated much of SW Guatemala. The large dacitic Santiaguito lava-dome complex has been growing at the base of the 1902 crater since 1922. Compound dome growth at Santiaguito has occurred episodically from four westward-younging vents, accompanied by almost continuous minor explosions and periodic lava extrusion, larger explosions, pyroclastic flows, and lahars.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) http://www.insivumeh.gob.gt/
SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev. 3283 m
KVERT reported that seismic activity from Shiveluch was above background levels during 14-16 October and at background levels during 17-22 October. Seismic data on 14 October suggested that ash plumes rose to an altitude of 3.8 km (12,500 ft) a.s.l. Satellite imagery analyses showed a daily thermal anomaly on the volcano and ash plumes that drifted 72 km SE on 15 and 16 October. Gas-and-steam plumes sometimes containing ash were observed during 15-18 October. The Aviation Color Code level remained at Orange.
Geologic Summary. The high, isolated massif of Shiveluch volcano (also spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group and forms one of Kamchatka's largest and most active volcanoes. The currently active Molodoy Shiveluch lava-dome complex was constructed during the Holocene within a large breached caldera formed by collapse of the massive late-Pleistocene Strary Shiveluch volcano. At least 60 large eruptions of Shiveluch have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most recently in 1964, have produced large debris avalanches whose deposits cover much of the floor of the breached caldera. Intermittent explosive eruptions began in the 1990s from a new lava dome that began growing in 1980. The largest historical eruptions from Shiveluch occurred in 1854 and 1964.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php
SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev. 799 m
Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima on 26 October.
Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-jima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two historically active summit craters. Only about 50 persons live on the sparsely populated island. The summit of the volcano is truncated by a large breached crater extending to the sea on the east flank that was formed by edifice collapse. Suwanose-jima, one of Japan's most frequently active volcanoes, was in a state of intermittent Strombolian activity from On-take, the NE summit crater, that began in 1949 and lasted nearly a half century. The largest historical eruption took place in 1813-14, when thick scoria deposits blanketed residential areas, after which the island was uninhabited for about 70 years. The SW crater produced lava flows that reached the western coast in 1813, and lava flows reached the eastern coast of the island in 1884.
Source: Tokyo Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AK/messages.html
VILLARRICA Central Chile 39.42°S, 71.93°W; summit elev. 2847 m
According to the Projecto Observación Visual Volcán Villarrica (POVI), a series of images of Villarrica captured from a web camera on 24 October showed an ash cloud rising from the crater.
Geologic Summary. Villarrica, one of Chile's most active volcanoes, rises above the lake and town of the same name. It is the westernmost of three large stratovolcanoes that trend perpendicular to the Andean chain. A 6-km wide caldera formed during the late Pleistocene, more than 0.9 million years ago. A 2-km-wide postglacial caldera is located at the base of the presently active, dominantly basaltic-to-andesitic cone at the NW margin of the Pleistocene caldera. About 25 scoria cones dot Villarrica's flanks. Plinian eruptions and pyroclastic flows have been produced during the Holocene from this dominantly basaltic volcano, but historical eruptions have consisted largely of mild-to-moderate explosive activity with occasional lava effusion. Lahars from the glacier-covered volcano have damaged towns on its flanks.
Source: Projecto Observación Visual Volcán Villarrica (POVI) http://www.povi.cl/
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