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SI/USGS Weekly Volcanic Activity Report 31 March-6 April 2010
From: Sally Kuhn Sennert kuhns@xxxxxx
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SI/USGS Weekly Volcanic Activity Report
31 March-6 April 2010
Sally Kuhn Sennert - Weekly Report Editor
kuhns@xxxxxx
URL: http://www.volcano.si.edu/reports/usgs/
New Activity/Unrest: | Eyjafjöll, Southern Iceland | Karymsky, Eastern Kamchatka | Kirishima, Kyushu | Redoubt, Southwestern Alaska
Ongoing Activity: | Batu Tara, Komba Island (Indonesia) | Dukono, Halmahera | Kilauea, Hawaii (USA) | Kliuchevskoi, Central Kamchatka (Russia) | Sakura-jima, Kyushu | 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
EYJAFJOLL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666 m
The Icelandic Met Office reported that around 1900 on 31 March a new fissure at Eyjafjöll opened NE of the first fissure that began erupting on 20 March. Activity from the second fissure was not preceded by detectable seismicity. According to a news article, the fissure was about 300 m long, and about 200 m away from the first fissure. At the time of reporting by the Icelandic Met Office on 5 April, lava fountains had remained active from both fissures. Lava mostly accumulated near the new vent but some lava flows had entered the Hruná and Hvanná gullies. News outlets reported that two people had died during the journey back from seeing the eruption. The police estimated that 25,000 people had visited the site since the eruption began.
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: Icelandic Met Office http://en.vedur.is/,
Morgunbladid News http://www.mbl.is/mm/frettir/,
Iceland Review http://icelandreview.com/icelandreview/daily_news/?cat_id=16567&ew_0_a_id=360393,
Iceland Review http://icelandreview.com/icelandreview/daily_news/?cat_id=16567&ew_0_a_id=360280
KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported that during 26 March-2 April seismic activity from Karymsky was above background levels, possibly indicating ash plumes rising to an altitude of 4.1 km (13,500 ft) a.s.l. Satellite imagery revealed an intense daily thermal anomaly from the volcano, and ash plumes that drifted about 250 km generally E during 28-29 and 31 March. The Aviation Color Code level was raised to 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
KIRISHIMA Kyushu 31.931°N, 130.864°E; summit elev. 1700 m
An eruption from Shinmoe-dake (Shinmoe peak), a stratovolcano of the Kirishima volcano group, on 30 March prompted JMA to raise the Alert Level from 1 to 2 (on a scale of 1-5). Ash blanketed the ground to the W of the crater.
Geologic Summary. Kirishima is a large group of more than 20 Quaternary volcanoes located north of Kagoshima Bay. The late-Pleistocene to Holocene volcano group consists of stratovolcanoes, pyroclastic cones, maars, and underlying shield volcanoes located over an area of 20 x 30 km. The larger stratovolcanoes are scattered throughout the field, with the centrally located, 1,700-m-high Karakuni-dake being the highest. Onami-ike and Mi-ike, the two largest maars, are located SW of Karakuni-dake and at its far eastern end, respectively. Holocene eruptions have been concentrated along an E-W line of vents from Mi-ike to Ohachi, and at Shinmoe-dake to the NE. Frequent small-to-moderate explosive eruptions have been recorded since the 8th century.
Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/indexe.html
REDOUBT Southwestern Alaska 60.485°N, 152.742°W; summit elev. 3108 m
AVO reported that a series of small repetitive earthquakes in the vicinity of Redoubt's summit were detected on 5 April. The Volcano Alert Level was raised to Advisory and the Aviation Color Code was raised to Yellow. The next day, the rate of earthquakes decreased markedly.
Geologic Summary. Redoubt is a 3108-m-high glacier-covered stratovolcano with a breached summit crater in Lake Clark National Park about 170 km SW of Anchorage. Next to Mount Spurr, Redoubt has been the most active Holocene volcano in the upper Cook Inlet. Collapse of the summit of Redoubt 10,500-13,000 years ago produced a major debris avalanche that reached Cook Inlet. Holocene activity has included the emplacement of a large debris avalanche and clay-rich lahars that dammed Lake Crescent on the south side and reached Cook Inlet about 3500 years ago. Eruptions during the past few centuries have affected only the Drift River drainage on the north. Historical eruptions have originated from a vent at the north end of the 1.8-km-wide breached summit crater. The 1989-90 eruption of Redoubt had severe economic impact on the Cook Inlet region and affected air traffic far beyond the volcano.
Source: Alaska Volcano Observatory (AVO) http://www.avo.alaska.edu/
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 5 April an ash plume from Batu Tara rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted more than 35 km N.
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
DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m
The Darwin VAAC reported that on 2 April an ash plume from Dukono was seen on satellite imagery drifting 55 km S 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 31 March-6 April, HVO reported incandescence from a 60-m-wide 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 few times the level fluctuated between 235 and 260 m below the surface. Plumes from the vent drifted mainly SW, dropping small amounts of ash downwind. The sulfur dioxide emission rate at the summit on 31 March was 1,400 tonnes per day, the highest recorded in 2010. The rate on 1 and 2 April was 1,000 and 650 tonnes per day, respectively.
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. Lava flows advanced E, and then SE down Pulama pali.
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 March-2 April seismic activity from Kliuchevskoi was above background levels, and gas-and-steam plumes containing small amounts of ash were sometimes seen rising to an altitude of 5.3 km (17,400 ft) a.s.l. Strombolian activity ejected material 300 m above the crater and lava continued to flow down the flanks. Satellite imagery revealed a large daily thermal anomaly from the volcano, and gas-and-steam plumes that drifted about 70 km E on 30 March. 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
The Tokyo VAAC reported that during 31 March-6 April explosions from Sakura-jima sometimes produced plumes identified on satellite imagery. Those plumes, along with ash plumes occasionally seen by pilots, rose to altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l. and drifted SW, SE, E, and NE.
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 26 March-2 April seismic activity from Shiveluch was above background levels, possibly indicating ash plumes rising to an altitude of 4.7 km (15,400 ft) a.s.l. Hot avalanches from the lava dome were seen at night. Satellite imagery revealed a large daily thermal anomaly from the lava dome, and ash plumes that drifted about 40 km SE on 29 March. Based on information from KVERT, the Tokyo VAAC reported that on 5 April an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 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
SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m
MVO reported that during 26 March-2 April activity from the Soufrière Hills lava dome was at a low level. Rockfalls and pyroclastic flows occurred sporadically on the W and S flanks. 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 2 April. Details of possible resulting plumes 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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