SI/USGS Weekly Volcanic Activity Report
3-9 November 2010
Sally Kuhn Sennert - Weekly Report Editor
New Activity/Unrest: | Bulusan, Luzon | Colima, México | Kliuchevskoi, Central Kamchatka (Russia) | Merapi, Central Java (Indonesia) | Semeru, Eastern Java (Indonesia) | Shiveluch, Central Kamchatka (Russia)
Ongoing Activity: | Chaitén, Southern Chile | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Pagan, Mariana Islands (Central Pacific) | Reventador, Ecuador | Sakura-jima, Kyushu | 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.
BULUSAN Luzon 12.770°N, 124.05°E; summit elev. 1565 m
PHIVOLCS reported an explosion-type earthquake at Bulusan on 6 November coincident with a steam-and-ash plume that rose 600 m above the crater at 0811. Trace amounts of ashfall were reported in multiple areas 6-10 km NW. The Alert Level was raised from 0 to 1 (out of 5), and PHIVOLCS reminded the public not to enter the permanent danger zone, defined as a 4-km radius around the volcano. White steam plumes were observed rising 200 m above the crater before 1400, when cloud cover prevented observations. On 7 November, PHIVOLCS noted that seismic activity had increased during the previous 24 hours. A phreatic explosion on 8 November was produced a brownish-to-light-gray plume that rose 700 m above the crater. Several neighborhoods to the NW, W, and WSW reported ashfall. Steam rose from the crater after the explosion. On 9 November two consecutive ash explosions, accompanied by rumbling sounds, produced ash plumes that rose as high as 1 km above the crater and drifted SW. Ashfall up to 2 mm thick was reported in areas to the SW and WNW.
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.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS) http://www.phivolcs.dost.gov.ph/
COLIMA México 19.514°N, 103.62°W; summit elev. 3850 m
Based on analyses of satellite imagery and information from the Mexico City MWO, the Washington VAAC reported that on 7 November an ash plume from Colima rose to an altitude of 6.7 km (22,000 ft) a.s.l. and drifted 19 km SW.
Geologic Summary. The Colima volcanic complex is the most prominent volcanic center of the western Mexican Volcanic Belt. It consists of two southward-younging volcanoes, Nevado de Colima (the 4,320 m high point of the complex) on the N and the historically active Volcán de Colima on the S. Volcán de Colima (also known as Volcán Fuego) is a youthful stratovolcano constructed within a 5-km-wide caldera, breached to the S, that has been the source of large debris avalanches. Major slope failures have occurred repeatedly from both the Nevado and Colima cones, and have produced a thick apron of debris-avalanche deposits on three sides of the complex. Frequent historical eruptions date back to the 16th century. Occasional major explosive eruptions (most recently in 1913) have destroyed the summit and left a deep, steep-sided crater that was slowly refilled and then overtopped by lava dome growth.
Source: Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html
KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit elev. 4835 m
KVERT reported that during 29 October-3 November seismic activity at Kliuchevskoi was above background levels and Strombolian activity was observed. Satellite imagery analyses showed a thermal anomaly over the volcano and ash plumes that drifted 480 km SE. Vulcanian activity produced ash plumes that rose to an altitude of 7 km (23,000 ft) a.s.l. during 31 October and 1-4 November. Seismicity sharply decreased on 4 November, and only gas-and-steam activity was observed. On 9 November, KVERT reported that the eruption that began in August 2009 had finished on 4 November and that seismicity had continued to decrease. The Aviation Color Code level was lowered to Yellow.
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
MERAPI Central Java (Indonesia) 7.542°S, 110.442°E; summit elev. 2968 m
CVGHM reported that during 3-8 November the eruption from Merapi continued at a high level, characterized by incandescent avalanches from the lava dome, pyroclastic flows, ash plumes, and occasional explosions. Visual observations were often difficult due to inclement weather and gas-and-ash plumes from the eruption. On 7 November, a news article stated that since the eruption began on 26 October approximately156 people have died and more that 200,000 people have been displaced.
On 3 November observers stationed at multiple posts reported ash plumes from pyroclastic flows. One pyroclastic flow traveled 10 km, prompting CVGHM to extend the hazard zone to a 15-km-radius and recommend evacuations from several more communities. Another pyroclastic flow traveled 9 km SE later that day. The Darwin VAAC reported that an ash plume rose to an altitude of 18.3 km (60,000 ft) a.s.l. and drifted 110 km W. Ground observers noted a significant eruption, but could not confirm the plume altitude. On 4 November an ash-and-gas plume rose to an altitude of 11 km (36,100 ft) a.s.l., and pyroclastic flows descended the NW, NNW, and N flanks as far as 3 km. Based on analyses of satellite imagery, the Darwin VAAC reported that ash plumes rose to altitudes of 10.7-11.9 km (35,000-39,000 ft) a.s.l. and drifted W. On 5 November, rumbling sounds were heard in areas 30 km away. Pyroclastic flows continued to descend the flanks. Ash fell in Yogyakarta, 30 km SSW, and "sand"-sized tephra fell within 15 km. CVGHM recommended evacuations from several more towns within a 20-km radius.
Activity remained very intense on 6 November. Pyroclastic flows descended the flanks; one traveled 4 km W. Incandescent avalanches traveled 2 km down multiple drainages to the SSE, S, and SSW. Ash plumes rose to an altitude of 7 km (23,000 ft) a.s.l. Flashes from the lava dome were reported from observations posts and incandescent material was ejected above the crater. A subsequent pyroclastic flow sent an ash plume to an altitude of 6 km (19,700 ft) a.s.l. that drifted W, N, and E. Throughout the day, ashfall was heavy on Merapi's flanks, and was observed in surrounding areas including Selo (6 km NNW) and Magelang (26 km WNW). In Muntilan (18 km WSW) tephra and ash depths reached 4 cm. On 5 and 6 November, the Darwin VAAC reported that ash plumes observed in satellite imagery rose to an altitude of 16.8 km (55,000 ft) a.s.l. News articles stated that three airlines cancelled flights to Jakarta due to the ash-induced aviation hazard.
On 7 November, the number of seismic signals indicating pyroclastic flows increased from the previous day. An explosion was heard and ash plumes rose 6 km and drifted W. Lightning was seen from Yogyakarta and ash fell within 10 km. Pyroclastic flows traveled 5 km and lava avalanches moved 600 m S and SW. High-altitude ash plumes drifted SW. According to the Darwin VAAC, during 7-8 November satellite imagery revealed ash plumes drifting 165-220 km W and SW at an altitude of 7.6 km (25,000 ft) a.s.l. On 8 November an SO2 cloud was seen over the Indian Ocean at altitudes of 12.2-15.2 km (40,000-50,000 ft) a.s.l. The airport in Yogyakarta closed. CVGHM reported that incandescent avalanches were sometimes seen through a closed-circuit television system. Ash plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. and drifted NE.
On 9 November CVGHM noted a reduction in intensity of activity from Merapi; one pyroclastic flow occurred in a 6-hour period. Rumbling sounds were accompanied by an ash plume that rose to an altitude of 4.5 km (14,800 ft) a.s.l. and lava-dome incandescence. Ashfall was reported in Selo and lava avalanches traveled 800 m SSE.
Geologic Summary. Merapi, one of Indonesia's most active volcanoes, lies in one of the world's most densely populated areas and dominates the landscape immediately N of the major city of Yogyakarta. The steep-sided modern Merapi edifice, its upper part unvegetated due to frequent eruptive activity, was constructed to the SW of an arcuate scarp cutting the eroded older Batulawang volcano. Pyroclastic flows and lahars accompanying growth and collapse of the steep-sided active summit lava dome have devastated cultivated and inhabited lands on the volcano's western-to-southern flanks and caused many fatalities during historical time. The volcano is the object of extensive monitoring efforts by the Merapi Volcano Observatory (MVO).
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,
Daily Mail http://www.dailymail.co.uk/news/article-1327197/Indonesia-fly-zone-volcano-Mount-Merapi-eruption.html?ito=feeds-newsxml,
Jakarta Globe http://www.thejakartaglobe.com/home/authorities-close-yogyakarta-airport-until-next-monday/405679
SEMERU Eastern Java (Indonesia) 8.108°S, 112.92°E; summit elev. 3676 m
On 4 November, CVGHM reported that from August to October seismic activity at Semeru had increased, and "smoke" and occasional gas plumes rose 400-500 m above the crater. During September incandescent avalanches traveled 400 m SE into the Besuk Kembar drainage on three occasions. Incandescence from the crater was observed in October. Incandescent avalanches traveled 600 m E into Besuk Kembar on 2 November and 4 km into the Besuk Kembar and Besuk Bang (SSE) drainages on 4 November. CVGHM noted that the lava dome in the Jonggring Saloko crater was growing. The Alert Level remained at 2 (on a scale of 1-4).
Geologic Summary. Semeru is the highest volcano on Java and one of its most active. The symmetrical stratovolcano rises abruptly to 3,676 m above coastal plains to the S and lies at the southern end of a volcanic massif extending N to the Tengger caldera. Semeru has been in almost continuous eruption since 1967. Frequent small-to-moderate Vulcanian eruptions have accompanied intermittent lava dome extrusion, and periodic pyroclastic flows and lahars have damaged villages below the volcano. A major secondary lahar on 14 May 1981 caused more than 250 deaths and damaged 16 villages.
Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM) http://www.vsi.esdm.go.id/
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 29 October-5 November and a thermal anomaly over the volcano was observed in satellite imagery. Seismic data on 31 October, and 1 and 4 November suggested that ash plumes rose to an altitude of 5.8 km (19,000 ft) a.s.l. Satellite imagery showed ash plumes drifting 400 km SE on 31 October and 1 November. Fumarolic activity was seen during 1-2 November. Cloud cover prevented observations the other days.
On 1 November, pyroclastic flow deposits from the large explosive eruption on 27 October were detected in satellite imagery on the ESE flank, and had traveled 15 km. Volcanologists inspected the deposits the next day and found that the pyroclastic flow had annihilated a forest in the Bekesh River valley. More than half of the lava dome edifice was destroyed during the eruption. The Aviation Color Code level remained at Orange.
During 4-9 November, the Tokyo VAAC reported that ash plumes from possible eruptions were observed in satellite imagery drifting N, SE, and S at altitudes of km (15,000-25,000 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
CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m
Based on analyses of satellite imagery and web camera footage, the Buenos Aires VAAC reported that an ash plume from Chaitén's lava-dome complex rose to an altitude of 1.8 km (6,000 ft) a.s.l. on 4 November and drifted 25 km NE. Cloud cover prevented clear satellite views of the volcano in subsequent images.
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
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 29 October-5 November. Satellite imagery showed a thermal anomaly over the volcano during 30 October-1 November. Cloud cover prevented observations the other days. 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 3-9 November, 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 between 150 and 160 m below the crater floor. Periodically the lava rose about 20 m above that level, producing nighttime incandescence seen from the Jaggar Museum on the NW caldera rim. A plume from the vent drifted SW and deposited ash nearby.
At the east rift zone, lava continued to flow through the TEB lava-tube system and fed some small lava flows on the coastal plain and the Puhi-o-Kalaikini ocean entry. Some short-lived breakouts of lava occurred from the portion of the lava tube that crosses Highway 130, about 300 m SW of the current County Viewing Area. Incandescence was frequently visible from vents on the N part of the Pu'u 'O'o crater floor.
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/
PAGAN Mariana Islands (Central Pacific) 18.13°N, 145.80°E; summit elev. 570 m
Low-level gas-and-steam plumes from Pagan were observed in satellite imagery during 1-4 November. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory. Pagan is not monitored with ground-based geophysical instrumentation; the only source of information is satellite observation and occasional reports from observers who visit the island.
Geologic Summary. Pagan Island, the largest and one of the most active of the Mariana Islands volcanoes, consists of two stratovolcanoes connected by a narrow isthmus. Both North and South Pagan stratovolcanoes were constructed within calderas, 7 and 4 km in diameter, respectively. The 570-m-high Mount Pagan at the NE end of the island rises above the flat floor of the caldera, which probably formed during the early Holocene. South Pagan is a 548-m-high stratovolcano with an elongated summit containing four distinct craters. Almost all of the historical eruptions of Pagan, which date back to the 17th century, have originated from North Pagan volcano. The largest eruption of Pagan during historical time took place in 1981 and prompted the evacuation of the sparsely populated island.
Source: Emergency Management Office of the Commonwealth of the Mariana Islands, Office of the Governor, United States Geological Survey Volcano Hazards Program http://volcanoes.usgs.gov/nmi/activity/index.php
REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m
Based on a pilot observation, the Washington VAAC reported that on 2 November an ash plume from Reventador rose to an altitude of 4.6 km (15,000 ft) a.s.l. Cloud cover prevented clear satellite observations of the volcano.
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 and pilot observations, the Tokyo VAAC reported that during 3-5 and 7-9 November explosions from Sakura-jima produced ash plumes that rose to altitudes of 1.5-4.3 km (5,000-14,000 ft) a.s.l. and drifted E, ESE, 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
SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m
MVO reported that during 29 October-5 November activity from the Soufrière Hills lava dome was at a low level. The largest pyroclastic flow occurred on 5 November and traveled 1.5 km W down Gages valley. 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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