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Smithsonian/USGS Weekly Volcanic Activity Report 22-28 December 2010
From: "Venzke, Ed" <VENZKEE@si.edu>
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Smithsonian/USGS Weekly Volcanic Activity Report
22-28 December 2010
Sally Kuhn Sennert - Weekly Report Editor
kuhns@si.edu
URL: http://www.volcano.si.edu/reports/usgs/
New Activity/Unrest: | Etna, Sicily (Italy) | Kizimen, Eastern Kamchatka (Russia) | San Cristóbal, Nicaragua | Stromboli, Aeolian Islands (Italy) | Tengger Caldera, Eastern Java (Indonesia) | Tungurahua, Ecuador
Ongoing Activity: | Bulusan, Luzon | Fuego, Guatemala | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Krakatau, Indonesia | Sakura-jima, Kyushu | Shiveluch, Central Kamchatka (Russia) | Soufrière Hills, Montserrat
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
ETNA Sicily (Italy) 37.734°N, 15.004°E; summit elev. 3330 m
INGV-CT reported that a strong explosion from the W vent of Etna's Bocca Nuova crater at 0446 on 22 December produced an ash plume that rose a few hundred meters above the summit and drifted NE. The explosion of hot, though not incandescent, material and subsequent ash emission was observed and recorded by thermal cameras at Montagnola and Nicolosi (14 km S). Light ashfall was reported as far away as Linguaglossa (18 km NE). Small emissions of reddish-brown ash continued to occur before noon.
Geologic Summary. Mount Etna, towering above Catania, Sicily's second largest city, has one of the world's longest documented records of historical volcanism, dating back to 1500 BC. Historical lava flows cover much of the surface of this massive basaltic stratovolcano, the highest and most voluminous in Italy. Two styles of eruptive activity typically occur at Etna. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more of the three prominent summit craters, the Central Crater, NE Crater, and SE Crater. Flank eruptions, typically with higher effusion rates, occur less frequently and originate from fissures that open progressively downward from near the summit. A period of more intense intermittent explosive eruptions from Etna's summit craters began in 1995. The active volcano is monitored by the Instituto Nazionale di Geofisica e Volcanologia (INGV) in Catania.
Source: Istituto Nazionale di Geofisica e Vulcanologia Sezione di Catania (INGV-CT) http://www.ct.ingv.it/index.php
KIZIMEN Eastern Kamchatka (Russia) 55.130°N, 160.32°E; summit elev. 2376 m
KVERT reported that during 17-24 December seismic activity at Kizimen was above background levels, and a thermal anomaly over the lava dome was detected in satellite imagery. The number of shallow seismic earthquakes increased from 110 events on 17 December to 304 events on 22 December. Volcanic tremor was detected on 23 December. The Aviation Color Code remained at Orange.
During 26-28 December seismicity increased and there were possible small ash explosions and hot avalanches. A thermal anomaly over the lava dome was seen in satellite imagery. The Aviation Color Code was raised to Red. On 27 December seismic analysis indicated that ash plumes possibly rose to altitudes of 3.5-4.5 km (11,500-14,800 ft) a.s.l. Satellite imagery showed ash plumes drifting 140 km W at an altitude of 4 km (13,100 ft) a.s.l. On 28 December, based on a Yelizovo Airport (UHPP) notice, the Tokyo VAAC reported an ash plume drifting W at an altitude of 3.7 km (12,000 ft) a.s.l.
Geologic Summary. Kizimen is an isolated, conical stratovolcano that is morphologically similar to Mount St. Helens prior to its 1980 eruption. The summit of Kizimen consists of overlapping lava domes, and blocky lava flows descend the flanks of the volcano, which is the westernmost of a volcanic chain north of Kronotsky volcano. The 2,376-m-high Kizimen was formed during four eruptive cycles beginning about 12,000 years ago and lasting 2,000-3,500 years. The largest eruptions took place about 10,000 and 8300-8400 years ago, and three periods of longterm lava-dome growth have occurred. The latest eruptive cycle began about 3,000 years ago with a large explosion and was followed by lava-dome growth lasting intermittently about 1,000 years. An explosive eruption about 1,100 years ago produced a lateral blast and created a 1.0 x 0.7 km wide crater breached to the NE, inside which a small lava dome (the fourth at Kizimen) has grown. A single explosive eruption, during 1927-28, has been recorded in historical time.
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
SAN CRISTOBAL Nicaragua 12.702°N, 87.004°W; summit elev. 1745 m
Based on a METAR weather notice from the Chinandega airport (MNCH), the Washington VAAC reported that a 13-km-wide volcanic plume from San Cristóbal drifted 75 km SW. Additional details of the plume content were not known.
Geologic Summary. The San Cristóbal volcanic complex, consisting of five principal volcanic edifices, forms the NW end of the Marrabios Range. The symmetrical 1,745-m-high youngest cone, San Cristóbal itself (also known as El Viejo), is Nicaragua's highest volcano and is capped by a 500 x 600 m wide crater. El Chonco, with several flank lava domes, is located 4 km to the west of San Cristóbal; it and the eroded Moyotepe volcano, 4 km to the NE of San Cristóbal, are of Pleistocene age. Volcán Casita contains an elongated summit crater and lies immediately E of San Cristóbal; Casita was the site of a catastrophic landslide and lahar in 1998. The Plio-Pleistocene La Pelona caldera is located at the eastern end of the San Cristóbal complex. Historical eruptions from San Cristóbal, consisting of small-to-moderate explosive activity, have been reported since the 16th century. Some other 16th-century eruptions attributed to Casita volcano are uncertain and may pertain to other Marrabios Range volcanoes.
Source: Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html
STROMBOLI Aeolian Islands (Italy) 38.789°N, 15.213°E; summit elev. 924 m
INGV-CT reported that a sequence of three explosions from Stromboli's "S" vent in the S part of the crater terrace were recorded on 19 December by thermal monitoring cameras in Vancori and Pizzo. The first explosion ejected coarse-grained pyroclastic material, followed by fine-grained tephra, more than 250 m above the crater terrace. A slightly less intense explosion occurred less than a minute later. The third and weakest explosion ejected material 180-200 m above the crater, generating an ash plume that dispersed over the W and NE parts of the island.
Geologic Summary. Spectacular incandescent nighttime explosions at Stromboli volcano have long attracted visitors to the "Lighthouse of the Mediterranean."Stromboli, the NE-most of the Aeolian Islands, has lent its name to the frequent mild explosive activity that has characterized its eruptions throughout historical time. The small, 926-m-high island of Stromboli is the emergent summit of a volcano that grew in two main eruptive cycles, the last of which formed the western portion of the island. The active summit vents are located at the head of the Sciara del Fuoco, a horseshoe-shaped scarp formed as a result of slope failure that extends to below sea level and funnels pyroclastic ejecta and lava flows to the NW. Essentially continuous mild Strombolian explosions, sometimes accompanied by lava flows, have been recorded at Stromboli since Roman times.
Source: Istituto Nazionale di Geofisica e Vulcanologia Sezione di Catania (INGV-CT) http://www.ct.ingv.it/
TENGGER CALDERA Eastern Java (Indonesia) 7.942°S, 112.95°E; summit elev. 2329 m
CVGHM reported that during 8-19 December gray-to-brown plumes from Tengger Caldera's Bromo cone rose 400-800 m above the crater and drifted E, NE, and N. On 19 December explosions produced an ash plume that rose 2 km above the crater rim. Ashfall was heavy around the crater and was reported in areas as far away as the Juanda Airport (70 km NNW) in Surabaya. The ash damaged agricultural land, impacted trees and river valleys, and disrupted transportation infrastructure. The Alert Level remained at 3 (on a scale of 1-4). Residents and tourists were not permitted within a 2-km-radius of the active crater.
During 20-25 December gray-to-brown plumes rose 800-1,200 m above the crater and drifted N and NE. Ejected material fell back around the crater. On 25 December, ash and occasionally lapilli fell at the Bromo observation post, about 2 km away. The ashfall was about 20 cm thick.
Based on analysis of satellite imagery and information from CVGHM, the Darwin VAAC reported that during 26-27 December an ash plume rose to an altitude of 5.5 km (18,000 ft) a.s.l. and drifted 150 km NE.
Geologic Summary. The 16-km-wide Tengger caldera in eastern Java is located at the northern end of a volcanic massif extending from Semeru volcano. The massive Tengger volcanic complex consists of five overlapping stratovolcanoes, each truncated by a caldera. The most recent is the 9 x 10 km wide Sandsea caldera, which formed incrementally during the late Pleistocene and early Holocene. An overlapping cluster of post-caldera cones was constructed on the floor of the Sandsea caldera within the past several thousand years. The youngest of these is Bromo, one of Java's most frequently visited and most active volcanoes. More than 50 mild-to-moderate explosive eruptions have occurred since 1804.
Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM) http://www.vsi.esdm.go.id/,
Darwin Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m
The IG reported that during 21-23 December steam-and-ash plumes rose from Tungurahua and drifted NW, W, and SW. Ash fell in Bilbao, 8 km W, on 22 December. On 23 December explosions caused windows to vibrate in Cusúa (8 km NW), Pondoa (8 km N), and Baños (9 km N), producing sounds resembling "cannon shots." One of the explosions ejected incandescent material that rolled down to the lower flanks. Another produced a steam-and-ash plume that rose to an altitude of 11 km (36,100 ft) a.s.l. and drifted W and NW.
On 24 December steam-and-ash plumes rose 8 km (26,200 ft) a.s.l. and drifted NW and SW. Explosions caused windows to vibrate and sounds resembling "cannon shots" were noted. On 25 December incandescent material was ejected from the crater and rolled 2 km down the flanks. Steam-and-ash plumes rose from the crater during 25-27 December; ashfall was reported in Choglontús (SW) on the 25th. Ash plumes observed on 28 December drifted W. Incandescence from the crater was also noted.
Geologic Summary. The steep-sided Tungurahua stratovolcano towers more than 3 km above its northern base. It sits ~140 km S of Quito, Ecuador's capital city, and is one of Ecuador's most active volcanoes. Historical eruptions have all originated from the summit crater. They have been accompanied by strong explosions and sometimes by pyroclastic flows and lava flows that reached populated areas at the volcano's base. The last major eruption took place from 1916 to 1918, although minor activity continued until 1925. The latest eruption began in October 1999 and prompted temporary evacuation of the town of Baños on the N side of the volcano.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG) http://www.igepn.edu.ec/
Ongoing Activity
BULUSAN Luzon 12.770°N, 124.05°E; summit elev. 1565 m
On 23 December, PHIVOLCS reported that an explosion from Bulusan's summit crater was recorded by seismographs as an explosion-type earthquake following tremor that lasted for almost 31 minutes. A grayish steam-and-ash plume rose to about 500 m above the crater rim and drifted S-SW. Based on information from PHIVOLCS, the Tokyo VAAC reported that on 24 December an ash plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SW.
Geologic Summary. Luzon's southernmost volcano, Bulusan, was constructed within the 11-km-diameter dacitic Irosin caldera, which was formed more than 36,000 years ago. A broad, flat moat is located below the prominent SW caldera rim; the NE rim is buried by the andesitic Bulusan complex. Bulusan is flanked by several other large intracaldera lava domes and cones, including the prominent Mount Jormajan lava dome on the SW flank and Sharp Peak to the NE. The summit of Bulusan volcano is unvegetated and contains a 300-m-wide, 50-m-deep crater. Three small craters are located on the SE flank. Many moderate explosive eruptions have been recorded at Bulusan since the mid-19th century.
Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS) http://www.phivolcs.dost.gov.ph/index.php,
Tokyo Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html
FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m
On 22 December, the Washington VAAC reported that an ash plume from Fuego observed in satellite imagery drifted 28 km NW. INSIVUMEH reported that on 23 December explosions produced ash plumes that rose 600-1,200 m above the crater and drifted 10-15 km SE. Explosions the next day generated ash plumes 400 m above the crater. Incandescent material was ejected 100 m above the crater at night during 27-28 December. On 28 December ash plumes from explosions rose as high as 500 m above the crater and drifted more than 5 km S and SW. Avalanches descended multiple drainages.
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.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) http://www.insivumeh.gob.gt/,
Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html
KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported that seismic activity at Karymsky was slightly above background levels during 16-19 December and did not exceed background levels during 20-24 December. Seismic data suggested that possible ash plumes rose to an altitude of 3 km (9,800 ft) a.s.l. Thermal anomalies were detected in satellite imagery during 18-21 December. 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 22-28 December, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable at approximately 125-130 m below the crater floor, periodically rising 20-30 m higher. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent that drifted NW, N, and NE deposited ash and fresh spatter nearby.
At the east rift zone, lava that broke out of the Quarry tube onto the surface, at a saddle between two rootless shields at around the 610 m elevation, continued to advance in two branches. The E branch advanced along the E edge of the Quarry flow to about 60 m elevation and burned small remnants of a forest. On 22 December a breakout lava flow from the 365-m elevation advanced 820 m. Multiple scattered breakout lava flows were observed during the reporting period. Incandescence from a small spatter cone on the north-central part of Pu'u 'O'o crater floor continued. Lava from a second spatter cone, located on the NW edge of the crater, advanced E on the crater floor and then stalled on 27 December.
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/
KRAKATAU Indonesia 6.102°S, 105.423°E; summit elev. 813 m
Based on analysis of satellite imagery, the Darwin VAAC reported that on 24 December an ash plume from Anak Krakatau rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 65-75 km SE.
Geologic Summary. Renowned Krakatau volcano lies in the Sunda Strait between Java and Sumatra. Collapse of the ancestral Krakatau edifice, perhaps in 416 AD, resulted in a 7-km-wide caldera. Remnants of this volcano formed Verlaten and Lang Islands; subsequently Rakata, Danan and Perbuwatan volcanoes were formed, coalescing to create the pre-1883 Krakatau Island. Caldera collapse during the catastrophic 1883 eruption destroyed Danan and Perbuwatan volcanoes, and left only a remnant of Rakata volcano. The post-collapse cone of Anak Krakatau (Child of Krakatau), constructed within the 1883 caldera at a point between the former cones of Danan and Perbuwatan, has been the site of frequent eruptions since 1927.
Source: Darwin Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m
Based on pilot observations, the Tokyo VAAC reported that during 22-23, 25, and 27 December ash plumes from Sakura-jima rose to altitudes of 1.8-3.7 km (6,000-12,000 ft) a.s.l. and drifted E and SE.
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
SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev. 3283 m
KVERT reported that moderate seismic activity from Shiveluch was detected during 17-24 December. A bright thermal anomaly over the volcano was observed in satellite imagery. Moderate gas-and-steam activity was visually observed during 19-20 and 23 December. Ash explosions on 23 December produced ash plumes that rose to altitudes as high as 4.5 km (14,800 ft) a.s.l. 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
SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m
MVO reported that during 17-24 December activity from the Soufrière Hills lava dome was at a low level. A small pyroclastic flow traveled 1.5 km down the Gages valley to the W on 19 December. 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/
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