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SI/USGS Weekly Volcanic Activity Report 3-9 March 2010
From: Sally Kuhn Sennert - kuhns@xxxxxx
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SI/USGS Weekly Volcanic Activity Report
3-9 March 2010
3-9 March 2010
New Activity/Unrest: | Concepción, Nicaragua | Llaima, Central Chile
Ongoing Activity: | Ambrym, Vanuatu (SW Pacific) | Arenal, Costa Rica | Batu Tara, Komba Island (Indonesia) | Kilauea, Hawaii (USA) | Kliuchevskoi, Central Kamchatka (Russia) | Sakura-jima, Kyushu | Santa María, Guatemala | Shiveluch, Central Kamchatka (Russia) | Soufrière Hills, Montserrat | Tungurahua, Ecuador
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
CONCEPCION Nicaragua 11.538°N, 85.622°W; summit elev. 1700? m
Based on information from INETER and analyses of satellite imagery, the Washington VAAC reported that on 8 March an ash plume from Concepción rose to an estimated altitude of 2.1 km (7,000 ft) a.s.l. The plume was last seen in satellite imagery later that day 227 km W.
Geologic Summary. Volcán Concepción is one of Nicaragua's highest volcanoes and is also one of its most active. The symmetrical volcano forms the NW half of the dumbbell-shaped island of Ometepe in Lake Nicaragua. Concepción is connected to neighboring Madera volcano by a narrow isthmus. N-S-trending fractures cutting across the volcano are associated with spatter cones, cinder cones, and maars located on the middle N flank and on the lower S flank down to Lake Nicaragua. Concepción has had frequent moderate explosive eruptions in the past century, most of which have originated from a small summit crater.
Source: Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html
LLAIMA Central Chile 38.692°S, 71.729°W; summit elev. 3125 m
SERNAGEOMIN reported that on 4 March seismicity from Llaima increased. During an overflight that same day, scientists observed emissions of gas and steam from the main crater. Images taken that day were compared to those taken on 21 February and showed no significant changes in morphology. The rate of sulfur dioxide emissions had increased, however. Scientists also noted deposits from a large rockfall along with fracturing of the glacier, especially on the upper N and NW flanks. Those observations in addition to the increased seismicity prompted SERNAGEOMIN to raise the Alert Level to Yellow, Level 4.
Geologic Summary. Llaima, one of Chile's largest and most active volcanoes, contains two main historically active craters, one at the summit and the other to the SE. The massive 3,125-m-high, glacier-covered stratovolcano has a volume of 400 cu km. A Holocene edifice built primarily of accumulated lava flows was constructed over an 8-km-wide caldera that formed about 13,200 years ago, following eruption of the 24 cu km Curacautín Ignimbrite. More than 40 scoria cones dot the volcano's flanks. Following the end of an explosive stage about 7,200 years ago, construction of the present edifice began, characterized by Strombolian, Hawaiian, and infrequent subplinian eruptions. Frequent moderate explosive eruptions with occasional lava flows have been recorded since the 17th century.
Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN) http://www.sernageomin.cl/
Ongoing Activity
AMBRYM Vanuatu (SW Pacific) 16.25°S, 168.12°E; summit elev. 1334 m
Based on pilot observations and analyses of satellite imagery, the Wellington VAAC reported that ash plumes from Ambrym rose to an altitude of 2.4 km (8,000 ft) a.s.l. on 5 March.
Geologic Summary. Ambrym, a large basaltic volcano with a 12-km-wide caldera, is one of the most active volcanoes of the New Hebrides arc. A thick, almost exclusively pyroclastic sequence, initially dacitic, then basaltic, overlies lava flows of a pre-caldera shield volcano. The caldera was formed during a major Plinian eruption with dacitic pyroclastic flows about 1900 years ago. Post-caldera eruptions, primarily from Marum and Benbow cones, have partially filled the caldera floor and produced lava flows that ponded on the caldera floor or overflowed through gaps in the caldera rim. Post-caldera eruptions have also formed a series of scoria cones and maars along a fissure system oriented ENE-WSW. Eruptions have apparently occurred almost yearly during historical time from cones within the caldera or from flank vents. However, from 1850 to 1950, reporting was mostly limited to extra-caldera eruptions that would have affected local populations.
Source: Wellington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/NZ/messages.html
ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m
OVSICORI-UNA reported that during February activity originating from Arenal's Crater C consisted of gas emissions, sporadic Strombolian eruptions, and occasional avalanches. A lava flow traveled down the SW flank. Acid rain and small amounts of ejected pyroclastic material affected the NE and SE flanks. Avalanches from the crater and from lava-flow fronts traveled down the SW, S, and SE flanks, occasionally igniting vegetation. Crater D produced only fumarolic activity.
Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano in Costa Rica and one of its most active. The 1,657-m-high andesitic volcano towers above the eastern shores of Lake Arenal, which has been enlarged by a hydroelectric project. The earliest known eruptions of Arenal took place about 7,000 years ago. Growth of Arenal has been characterized by periodic major explosive eruptions at several-hundred-year intervals and periods of lava effusion that armor the cone. Arenal's most recent eruptive period began with a major explosive eruption in 1968. Continuous explosive activity accompanied by slow lava effusion and the occasional emission of pyroclastic flows has occurred since then from vents at the summit and on the upper western flank.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA) http://www.ovsicori.una.ac.cr/
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 during 8-9 March ash plumes from Batu Tara rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted 45-120 km W and 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
KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m
During 3-9 March, HVO reported an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. The lava surface circulated and both rose and drained through a pit in the cavity floor. A plume from the vent drifted mainly SW, dropping small amounts of ash downwind. Measurements during 4-5 March indicated that the sulfur dioxide emission rate at the summit remained elevated at 700-800 tonnes per day. The 2003-2007 average rate was 140 tonnes per day.
Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed SE through the upper portion of a lava tube system and broke out onto the surface. Thermal anomalies detected by satellite, and visual observations, revealed active lava flows on the pali and on the coastal plain.
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 26 February-5 March seismic activity from Kliuchevskoi was above background levels and lava continued to flow down the NW flank. Strombolian activity periodically ejected material 300 m above the crater, and phreatic explosions occurred from the fronts of the lava flows. Steam-and-gas plumes rose to an altitude of 6.8 km (22,300 ft) a.s.l. most days, and on 3 March one drifted 50 km NE. Satellite imagery revealed a large daily thermal anomaly from the volcano. The Aviation Color Code level 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
SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m
During 3-9 March, the Tokyo VAAC reported multiple explosions from Sakura-jima based on information from JMA. During 3, 5-6, and 8-9 March, plumes rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted NE, E, and SE. Pilots reported on 8 and 9 March that ash plumes rose as high as 3 km (10,000 ft) a.s.l.
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 4 March, INSIVUMEH reported that explosions from Santa María's Santiaguito lava dome complex produced ash plumes that rose to altitudes of 2.7-3 km (8,900-10,000 ft) a.s.l. and drifted E. Ash fell in inhabited areas downwind. The Washington VAAC reported that on 8 March an ash plume was seen in satellite imagery drifting WNW.
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.
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
Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html
SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev. 3283 m
KVERT reported that during 26 February-5 March seismic activity from Shiveluch was above background levels, possibly indicating ash plumes rising to an altitude of 6 km (19,700 ft) a.s.l. Fumarolic activity was occasionally observed. Analyses of satellite imagery revealed a large daily thermal anomaly from the lava dome, and ash plumes that drifted 30 km NE on 26 February and 130 km SE on 28 February. Ash fell in Klyuchi, 50 km SW, on 26 February. On 3 March, a second thermal anomaly on the S flank was noted. Based on information from KVERT and analyses of satellite imagery, the Tokyo VAAC reported that during 5 and 8-9 March ash plumes rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted E and SE. 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.
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
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 26 February-5 March activity from the Soufrière Hills lava dome was at a low level. A swarm of seven relatively large hybrid earthquakes was detected early on 4 March. Later that morning, two small pyroclastic flows descended the Tar River valley and caused ashfall in Salem and Olveston, 6-8 km NW. 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/
TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m
The IG reported that on 2 March an ash plume from Tungurahua rose to an altitude of 8.5 km (28,000 ft) a.s.l. and drifted NW. Although inclement weather often prevented observations of the volcano during 3-9 March, fumarolic activity in the crater was seen on 6 and 8 March. Ash fell in areas to the SW on 3 and 4 March.
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/
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