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SI/USGS Weekly Volcanic Activity Report 18-24 November 2009
From: Sally Kuhn Sennert kuhns@xxxxxx
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SI/USGS Weekly Volcanic Activity Report
18-24 November 2009
Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/
New Activity/Unrest: | Galeras, Colombia | Sarychev Peak, Matua Island
Ongoing Activity: | Batu Tara, Komba Island (Indonesia) | Chaitén, Southern Chile | Karymsky, Eastern Kamchatka | Kilauea, Hawaii (USA) | Kliuchevskoi, Central Kamchatka (Russia) | Pacaya, Guatemala | Popocatépetl, México | Rabaul, New Britain | Reventador, Ecuador | Sakura-jima, Kyushu | Santa María, Guatemala | Shiveluch, Central Kamchatka (Russia) | Soufrière Hills, Montserrat | Suwanose-jima, Ryukyu Islands (Japan)
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
GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m
An explosive eruption from Galeras detected by the seismic network on 20 November prompted INGEOMINAS to raise the Alert Level to I (Red; "imminent eruption or in progress"). Residents reported five explosions, sound waves, and incandescence from multiple areas in the crater. Plume modelling from the Washington VAAC suggested that the resulting ash plume may have risen as high as 14.3 km (46,900 ft) a.s.l. and drifted N. Ashfall was reported in areas 10 km E, N, and NNW. Seismicity increased after the eruption and then gradually decreased. On 21 November, INGEOMINAS lowered the Alert Level to II (Orange; "probable eruption in term of days or weeks"). According to news articles, 900-1,000 people out of about 9,000 ordered to evacuate went to shelters.
Geologic Summary. Galeras, a stratovolcano with a large breached caldera located immediately W of the city of Pasto, is one of Colombia's most frequently active volcanoes. The dominantly andesitic Galeras volcanic complex has been active for more than 1 million years, and two major caldera collapse eruptions took place during the late Pleistocene. Longterm extensive hydrothermal alteration has affected the volcano. This has contributed to large-scale edifice collapse that has occurred on at least three occasions, producing debris avalanches that swept to the W and left a large horseshoe-shaped caldera inside which the modern cone has been constructed. Major explosive eruptions since the mid Holocene have produced widespread tephra deposits and pyroclastic flows that swept all but the southern flanks. A central cone slightly lower than the caldera rim has been the site of numerous small-to-moderate historical eruptions since the time of the Spanish conquistadors.
Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS) http://www.ingeominas.gov.co//,
Agence France-Presse http://www.channelnewsasia.com/stories/afp_world/view/1019907/1/.html
SARYCHEV PEAK Matua Island 48.092°N, 153.20°E; summit elev. 1496 m
SVERT reported that a thermal anomaly on Sarychev Peak was detected by satellite on 21 November.
Geologic Summary. Sarychev Peak, one of the most active volcanoes of the Kuril Islands, occupies the NW end of Matua Island in the central Kuriles. The andesitic central cone was constructed within a 3-3.5 km wide caldera, whose rim is exposed only on the SW side. A dramatic 250-m-wide, very steep-walled crater with a jagged rim caps the volcano. The substantially higher SE rim forms the 1496 m high point of the island. Fresh-looking lava flows descend all sides of Sarychev Peak and often form capes along the coast. Much of the lower-angle outer flanks of the volcano are overlain by pyroclastic-flow deposits. Eruptions have been recorded since the 1760's and include both quiet lava effusion and violent explosions. The largest historical eruption of Sarychev Peak in 1946 produced pyroclastic flows that reached the sea.
Source: Sakhalin Volcanic Eruption Response Team (SVERT) http://www.imgg.ru/rus/labs_vulcan_hazard.php
Ongoing Activity
BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev. 748 m
Based on analyses of satellite imagery, the Darwin VAAC reported that on 24 November an ash plume from Batu Tara rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 90 km NW.
Geologic Summary. The small isolated island of Batu Tara in the Flores Sea about 50 km north of Lembata (formerly Lomblen) Island contains a scarp on the eastern side similar to the Sciara del Fuoco of Italy's Stromboli volcano. Vegetation covers the flanks of Batu Tara to within 50 m of the 748-m-high summit. Batu Tara lies north of the main volcanic arc and is noted for its potassic leucite-bearing basanitic and tephritic rocks. The first historical eruption from Batu Tara, during 1847-52, produced explosions and a lava flow.
Source: Darwin Volcanic Ash Advisory Centre (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m
Based on web camera views, the Buenos Aires VAAC reported that on 23 November a gas plume from Chaitén's lava-dome complex rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted SSE.
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 deposit 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.
Source: Buenos Aires Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AG/messages.html
KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported that seismic activity at Karymsky was above background levels on 12, 14, and 16 November; data were not available on the other days during 13-20 November due to technical reasons. Elevated seismicity possibly indicated that ash plumes rose to an altitude of 3 km (9,900 ft) a.s.l. Analyses of satellite imagery revealed a daily thermal anomaly and ash plumes that drifted 130 km E during 12-14 and 17 November. The Level of Concern Color Code remained at Orange. Based on information from KEMSD, the Tokyo VAAC reported that on 23 November an eruption produced a plume that rose to an altitude of 4 km (13,000 ft) a.s.l.
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.
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/JP/messages.html
KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m
During 18-24 November, HVO reported that lava flowed SE from beneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at multiple locations between Waikupanaha and an area 700 m farther to the W. Thermal anomalies detected by satellite and visual observations revealed active surface lava flows at locations on and at the base of the pali, at the TEB vent, and on the coastal plain. Incandescence was seen on the Pu'u 'O'o crater floor.
The vent in Halema'uma'u crater continued to produce a white or off-white plume that drifted mainly SW and dropped small amounts of ash downwind. Incandescence originated from a circulating and spattering lava pond that occasionally rose above and drained back below holes in the vent cavity floor. On 21 November, a sliver of the rim collapsed and was followed by an explosion that produced a dense brown plume that dissipated after a few minutes (http://hvo.wr.usgs.gov/kilauea/update/archive/2009/Nov/HMMvent_21Nov2009_x2speed.mov). Measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 700-1,100 tonnes per day was measured during 18-20 and 23 November. The 2003-2007 average rate was 140 tonnes per day.
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/
KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit elev. 4835 m
KVERT reported that during 13-20 November seismic activity from Kliuchevskoi was above background levels. Strombolian activity ejected tephra 200 m above the crater during 13-15 November. On 14 November, a new lava flow traveled 500 m down the ESE flank. Satellite imagery revealed a large daily thermal anomaly at the volcano. The Level of Concern Color Code remained at Orange.
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.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php
PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m
On 20 and 24 November, INSIVUMEH reported that white and blue plumes from Pacaya's MacKenney cone rose up to 400 m and drifted SSW. Multiple lava flows on the S and SW flanks traveled 100-250 m SE and SW. Incandescence at night was noted.
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/
POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m
CENAPRED reported that during 18-20 November steam-and-gas plumes from Popocatépetl sometimes contained ash. A small explosion detected by the seismic network on 21 November was accompanied by an ash plume that rose to an altitude of 8.9 km (29,200 ft) a.s.l. The ash plume drifted E and caused ashfall in Atlixco (23 km SE), Huejotzingo (27 km NE), and areas in the state of Tlaxcala.
Geologic Summary. Popocatépetl, whose name is the Aztec word for smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is North America's second-highest volcano. Frequent historical eruptions have been recorded since the beginning of the Spanish colonial era. A small eruption on 21 December 1994 ended five decades of quiescence. Since 1996 small lava domes have incrementally been constructed within the summit crater and destroyed by explosive eruptions. Intermittent small-to-moderate gas-and-ash eruptions have continued, occasionally producing ashfall in neighboring towns and villages.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED) http://www.cenapred.unam.mx/es/
RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m
Based on analyses of satellite imagery, the Darwin VAAC reported that on 19 November ash plumes from Rabaul caldera's Tavurvur cone rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 35-90 km NW.
Geologic Summary. The low-lying Rabaul caldera on the tip of the Gazelle Peninsula at the NE end of New Britain forms a broad sheltered harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic shield volcano are formed by thick pyroclastic-flow deposits. The 8 x 14 km caldera is widely breached on the E, where its floor is flooded by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul took place as recently as 3,500 and 1,400 years ago. Three small stratovolcanoes lie outside the northern and NE caldera rims. Post-caldera eruptions built basaltic-to-dacitic pyroclastic cones on the caldera floor near the NE and western caldera walls. Several of these, including Vulcan cone, which was formed during a large eruption in 1878, have produced major explosive activity during historical time. A powerful explosive eruption in 1994 occurred simultaneously from Vulcan and Tavurvur volcanoes and forced the temporary abandonment of Rabaul city.
Source: Darwin Volcanic Ash Advisory Centre (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m
Based on a pilot observation, the Washington VAAC reported that on 20 November an ash plume from Reventador rose to an altitude of 6.1 km (20,000 ft) a.s.l. A thermal anomaly was detected on satellite imagery.
Geologic Summary. Reventador is the most frequently active of a chain of Ecuadorian volcanoes in the Cordillera Real, well E of the principal volcanic axis. It is a forested stratovolcano that rises above the remote jungles of the western Amazon basin. A 3-km-wide caldera breached to the E was formed by edifice collapse and is partially filled by a young, unvegetated stratovolcano that rises about 1,300 m above the caldera floor. Reventador has been the source of numerous lava flows as well as explosive eruptions that were visible from Quito in historical time. Frequent lahars in this region of heavy rainfall have constructed a debris plain on the eastern floor of the caldera.
Source: Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html
SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m
Based on information from JMA, the Tokyo VAAC reported that explosions from Sakura-jima on 18 and 23 November produced plumes that rose to altitudes of 2.1-2.7 km (7,000-9,000 ft) a.s.l. and drifted S and E.
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/JP/messages.html
SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m
On 20 November, INSIVUMEH reported that two explosions from Santa María's Santiaguito lava dome complex produced an ash plume that drifted SW. Avalanches descended the SW flank of the dome. An explosion on 24 November produced an ash plume the rose to an altitude of 3.3 km (10,800 ft) a.s.l. and drifted SE. Ashfall was reported in areas downwind.
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 during 13-20 November seismic activity from Shiveluch was above background levels, possibly indicating that ash plumes rose to an altitude of 5.3 km (17,400 ft) a.s.l. According to video camera data, fumarolic activity and hot avalanches were noted on 14 and 15 November. Analyses of satellite imagery revealed a large daily thermal anomaly on the lava dome. The Level of Concern Color Code remained at Orange. Based on information from KEMSD, the Tokyo VAAC reported that on 18 November an eruption produced a plume that rose to an altitude of 5.5 km (18,000 ft) a.s.l.
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.
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/JP/messages.html
SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m
MVO reported that during 13-20 November activity from the Soufrière Hills lava dome consisted of ash venting along with semi-continuous rockfalls and pyroclastic flows that were concentrated on the W flank. Ashfall occurred across many areas of the island. Views of the lava dome on 16 November showed that the dome height had decreased because of collapses and that a deep channel had developed NE of Chances Peak. Pyroclastic flows in the Gages Valley (W) continued down Spring Ghaut and Aymer's Ghaut, and spread onto the alluvial fan below St. Georges Hill. On 19 November, heavy ashfall occurred to the NW between Old Towne and Brades. The Hazard Level remained at 3.
Geologic Summary. The complex dominantly andesitic Soufrière Hills volcano occupies the southern half of the island of Montserrat. The summit area consists primarily of a series of lava domes emplaced along an ESE-trending zone. English's Crater, a 1-km-wide crater breached widely to the E, was formed during an eruption about 4,000 years ago in which the summit collapsed, producing a large submarine debris avalanche. Block-and-ash flow and surge deposits associated with dome growth predominate in flank deposits at Soufrière Hills. Non-eruptive seismic swarms occurred at 30-year intervals in the 20th century, but with the exception of a 17th-century eruption that produced the Castle Peak lava dome, no historical eruptions were recorded on Montserrat until 1995. Long-term small-to-moderate ash eruptions beginning in that year were later accompanied by lava-dome growth and pyroclastic flows that forced evacuation of the southern half of the island and ultimately destroyed the capital city of Plymouth, causing major social and economic disruption.
Source: Montserrat Volcano Observatory (MVO) http://www.mvo.ms/
SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev. 799 m
Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 18 November. Details of possible resulting emissions were not reported.
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/JP/messages.html
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