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SI/USGS Weekly Volcanic Activity Report 17-23 March 2010
From: Sally Kuhn Sennert kuhns@xxxxxx
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SI/USGS Weekly Volcanic Activity Report
17-23 March 2010
17-23 March 2010
New Activity/Unrest: | Eyjafjöll, Southern Iceland
Ongoing Activity: | Batu Tara, Komba Island (Indonesia) | Chaitén, Southern Chile | Dukono, Halmahera | Kilauea, Hawaii (USA) | Kliuchevskoi, Central Kamchatka (Russia) | Sakura-jima, Kyushu | 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
EYJAFJOLL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666 m
The Institute of Earth Sciences and the Icelandic Met Office reported that a fissure eruption from Eyjafjöll (also known as Eyjafjallajökull) began late at night on 20 March. High rates of deformation and increased seismic activity were noted during the previous three weeks; earthquakes were located between 7 and 10 km below the surface. During 19-20 March earthquakes migrated E and became more shallow, at 4-7 km depth. At 22:30 on 20 March seismicity slightly increased and, within the next two hours, reports of a volcanic eruption were received.
The first reports described incandescence reflected from a cloud above the eruption area, a 2-km-wide ice-free pass between Eyjafjöll and Katla volcano (with its overlying Myrdalsjökull ice cap). Lava fountains, seen from the air on 21 March, were ejected from a 500-m-long NE-SW trending fissure on the NE flank of Eyjafjöll at an elevation of about 1,000 m a.s.l. Lava flowed a short distance from the fissure and a minor plume rose 1 km and drifted W. Tephra fall was minor or insignificant. According to news articles, flights in and out of Reykjavík were diverted, delayed, or cancelled. Some local roads were closed and about 500 people living in nearby areas were evacuated. A steam explosion on 22 March generated a steam plume that rose to an altitude of 8 km (26,200 ft) a.s.l. Lava flowed S of the fissure into a canyon causing steam to rise from where the lava interacted with snow and ice. The eruption continued during 23-24 March.
Geologic Summary. Eyjafjöll (also known as Eyjafjallajökull) is located immediately west of Katla volcano. Eyjafjöll consists of an E-W-trending, elongated ice-covered basaltic-andesite stratovolcano with a 2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the eastern and western flanks of the volcano, but are more prominent on the western side. Although the 1666-m-high volcano has erupted during historical time, it has been less active than other volcanoes of Iceland's eastern volcanic zone, and relatively few Holocene lava flows are known. The sole historical eruption of Eyjafjöll, prior to an eruption in 2010, produced intermediate-to-silicic tephra from the central caldera during December 1821 to January 1823.
Sources: Institute of Earth Sciences http://www.earthice.hi.is/,
Icelandic Met Office http://en.vedur.is/,
Iceland Review http://www.icelandreview.com/icelandreview/daily_news/?cat_id=28304&ew_0_a_id=359660,
Iceland Review http://www.icelandreview.com/icelandreview/daily_news/?cat_id=16567&ew_0_a_id=359727,
Iceland Review http://www.icelandreview.com/icelandreview/daily_news/?cat_id=16567&ew_0_a_id=359797
Icelandic Met Office http://en.vedur.is/,
Iceland Review http://www.icelandreview.com/icelandreview/daily_news/?cat_id=28304&ew_0_a_id=359660,
Iceland Review http://www.icelandreview.com/icelandreview/daily_news/?cat_id=16567&ew_0_a_id=359727,
Iceland Review http://www.icelandreview.com/icelandreview/daily_news/?cat_id=16567&ew_0_a_id=359797
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 during 17-18 and 22-23 March ash plumes from Batu Tara rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted about 30-95 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
On 17 March SERNAGEOMIN reported that, during the previous few weeks, growth of Chaitén's lava-dome complex was concentrated in the W part. Gas-and-ash plumes, seen through the video camera located on the rim of the caldera, rose at most 1 km from the central area of the domes. Seismic activity persisted at a low level. The Alert Level remained at Red.
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: Servicio Nacional de Geología y Minería (SERNAGEOMIN) http://www.sernageomin.cl/
DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m
The Darwin VAAC reported that on 22 March an ash plume from Dukono was seen on satellite imagery drifting 45 km SE at an altitude of 2.4 km (8,000 ft) a.s.l.
Geologic Summary. Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less continuous explosive eruptions, sometimes accompanied by lava flows, occurred from 1933 until at least the mid-1990s, when routine observations were curtailed. During a major eruption in 1550, a lava flow filled in the strait between Halmahera and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano presenting a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit crater complex, contains a 700 x 570 m crater that has also been active during historical time.
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 17-23 March, HVO reported incandescence from 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 and spatter downwind. Measurements on 19 March indicated that the sulfur dioxide emission rate at the summit remained elevated at 500 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 above the pali. Incandescence was sometimes seen from a vent low on the S wall of Pu'u 'O'o crater.
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 12-19 March seismic activity from Kliuchevskoi was above background levels. Strombolian activity ejected material 200 m above the crater and lava continued to flow down the flanks. Gas-and-steam plumes rose to altitudes of 5 km (16,400 ft) a.s.l. during 12 and 15-16 March. Satellite imagery revealed a large daily thermal anomaly at the volcano. Based on information from KVERT, the Tokyo VAAC reported that on 21 March an ash plume rose to an altitude of 4.9 km (16,000 ft) a.s.l. and drifted NE. 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.
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
SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m
The Tokyo VAAC reported that during 17-23 March plumes from Sakura-jima identified on satellite imagery, and ash plumes seen by pilots, rose to altitudes of 1.2-3 km (4,000-10,000 ft) a.s.l. and drifted SE 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
SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev. 3283 m
KVERT reported that during 12-19 March seismic activity from Shiveluch was above background levels, possibly indicating ash plumes rising to an altitude of 5.5 km (18,000 ft) a.s.l. Hot avalanches were seen at night. Gas-and-steam plumes sometimes containing ash were seen on 12, 13, 15, and 16 March; plumes seen in satellite imagery on 13 and 16 March drifted 90 km E and SE. Analyses of satellite imagery revealed a large daily thermal anomaly from the lava dome. Based on information from KVERT, the Tokyo VAAC reported that on 21 March an ash plume rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted NE. 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 12-19 March activity from the Soufrière Hills lava dome was at a low level. Small incandescent areas on the dome were visually observed on 14 March. Occasional small pyroclastic flows and rockfalls occurred from the W and S parts of the dome. 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 although inclement weather often prevented observations of Tungurahua during 17-23 March, steam-and-gas plumes were occasionally seen. Explosions were detected by the seismic network and heard in nearby areas on 19 March; the largest explosion generated an ash plume that rose to an altitude of 9 km (29,500 ft) a.s.l. Ashfall was reported in Choglontús, to the SW. On 20 March small lahars affected the Baños-Penipe highway. On 22 March, ashfall was again reported in areas to the SW.
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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