************************************************************************
SI/USGS Weekly Volcanic Activity Report 13-19 January 2010
From: Sally Kuhn Sennert - kuhns@xxxxxx
************************************************************************
SI/USGS Weekly Volcanic Activity Report
13-19 January 2010
13-19 January 2010
New Activity/Unrest: | Kharimkotan, Kuril Islands (Russia) | Nyamuragira, Democratic Republic of Congo | Soufrière Hills, Montserrat | Tungurahua, Ecuador | Turrialba, Costa Rica
Ongoing Activity: | Arenal, Costa Rica | Chaitén, Southern Chile | Gaua, Banks Islands (SW Pacific) | Karymsky, Eastern Kamchatka | Kilauea, Hawaii (USA) | Kliuchevskoi, Central Kamchatka (Russia) | Planchón-Peteroa, Central Chile-Argentina border | Rabaul, New Britain | Sakura-jima, Kyushu | Sangay, Ecuador | Shiveluch, Central Kamchatka (Russia) | 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
KHARIMKOTAN Kuril Islands (Russia) 49.12°N, 154.508°E; summit elev. 1145 m
SVERT reported that a thermal anomaly from Kharimkotan's Severgin cone was detected by satellite on 15 January.
Geologic Summary. The 8 x 12 km island of Kharimkotan (also spelled Harimkotan) in the northern Kuriles consists of a stratovolcano cut by two breached depressions on the east and NW sides. These horseshoe-shaped craters were formed by slope failure, which produced debris-avalanche deposits that form large broad peninsulas on the east and NW coasts. Evidence of additional slope failures followed by plinian eruptions are found in sea cliffs of the island. Historical explosive eruptions have occurred since the early 18th century. A central cone, Severgin, was largely destroyed during the 1933 eruption, one of the largest in the Kuril Islands during historical time. Impact of a debris avalanche into the sea from the collapse of Severgin produced a tsunami that swept the island's coast and reached Onekotan and Paramushir Islands, killing two persons. A large lava dome emplaced during the 1933 eruption now fills the head of the eastern crater.
Source: Sakhalin Volcanic Eruption Response Team (SVERT) http://www.imgg.ru/rus/labs_vulcan_hazard.php
NYAMURAGIRA Democratic Republic of Congo 1.408°S, 29.20°E; summit elev. 3058 m
Based on analyses of satellite imagery, the Toulouse VAAC reported that on 18 January sulfur dioxide-and-steam plumes from Nyamuragira possibly contained ash. An ash cloud was visible in satellite imagery the next day.
Geologic Summary. Africa's most active volcano, Nyamuragira (Also spelled Nyamulagira) is a massive basaltic shield volcano N of Lake Kivu and NW of Nyiragongo volcano. Lava flows from Nyamuragira cover 1,500 sq km of the East African Rift. The 3058-m-high summit is truncated by a small 2 x 2.3 km summit caldera that has walls up to about 100 m high. About 40 historical eruptions have occurred since the mid-19th century within the summit caldera and from numerous fissures and cinder cones on the volcano's flanks. A lava lake in the summit crater, active since at least 1921, drained in 1938. Twentieth-century flank lava flows extend more than 30 km from the summit, reaching as far as Lake Kivu.
Source: Toulouse Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/FR/messages.html
SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m
MVO reported that during 8-15 January activity from the Soufrière Hills lava dome increased significantly. One explosion on 8 January and two on 10 January generated ash plumes that rose to altitudes of 5.5-7.6 km (18,000-25,000 ft) a.s.l. Ash fell in occupied areas to the NW, along with lapilli fall on 10 January. The explosions occurred from an area on the NE side of the volcano. Pyroclastic flows from column collapses moved rapidly NE (down Whites Bottom and Tuitts Ghaut), NW (down Tyers Ghaut and Belham Valley), W (down Gages Ghaut), and the SE (down the Tar River Valley). After the explosions activity decreased until 12 January, when cycles of increased numbers of rockfalls, pyroclastic flows, and ash venting were noted.
Observations during 8-15 January revealed that lava-dome growth resumed at the top, central part of the dome. On 18 January, a partial lava-dome collapse generated a pyroclastic flow that traveled W down Gages Valley, into Spring Ghaut, and then WSW down Aymers Ghaut, reaching the sea. Ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted W. Smoke from burning houses in Kinsale was visible after the event. The Hazard Level remained at 4.
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 during 13-14 January explosions from Tungurahua ejected incandescent material 1 km above and 1.5 km away from the crater, onto the flanks. Explosions produced noises resembling "cannon shots" and caused windows and structures to vibrate. Gas-and-ash plumes rose to altitudes of 7-8 km (23,000-26,000 ft) a.s.l. and drifted W and SW, causing ashfall. On 15 January, although meteorological clouds mostly prevented observations, an ash plume was seen rising to an altitude of 6 km (19,700 ft) a.s.l. Cloud cover prevented observations during the next two days. On 17 January, ashfall was reported in areas W and SW. Lahars descended drainages to the W and NW, causing the road to Baños to close. On 18 January, Strombolian activity ejected incandescent blocks and an ash plume rose to an altitude of 6 km (19,700 ft) a.s.l. Explosions caused windows and structures to vibrate. Ashfall was reported in areas W and SW on 18 and 19 January.
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/
TURRIALBA Costa Rica 10.025°N, 83.767°W; summit elev. 3340 m
Based on multiple METAR weather notices during the previous few days, the Washington VAAC reported on 16 January that gas plumes containing some ash rose from Turrialba. Ash was not seen in satellite imagery that day or the next.
Geologic Summary. Turrialba, the easternmost of Costa Rica's Holocene volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano located across a broad saddle NE of Irazú volcano overlooking the city of Cartago. The massive 3340-m-high Turrialba is exceeded in height only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's most voluminous volcanoes. Three well-defined craters occur at the upper SW end of a broad 800 x 2200 m wide summit depression that is breached to the NE. Most activity at Turrialba originated from the summit vent complex, but two pyroclastic cones are located on the SW flank. Five major explosive eruptions have occurred at Turrialba during the past 3500 years. Turrialba has been quiescent since a series of explosive eruptions during the 19th century that were sometimes accompanied by pyroclastic flows. Fumarolic activity continues at the central and SW summit craters.
Source: Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html
Ongoing Activity
ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m
OVSICORI-UNA reported that during December activity originating from Arenal's Crater C consisted of gas emissions, sporadic Strombolian eruptions, and occasional avalanches that traveled down the W and SW flanks. Acid rain and small amounts of ejected pyroclastic material affected the NE and SE flanks. Avalanches from lava-flow fronts traveled down the SW flanks. 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/
CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m
Based on web camera views and analyses of satellite imagery, the Buenos Aires VAAC reported that an ash plume from Chaitén's lava-dome complex drifted NNE on 14 January at an altitude of 1.8 km (6,000 ft) a.s.l. A steam-and-gas plume drifted NE at the same altitude the next day.
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: Buenos Aires Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AG/messages.html
GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m
On 13 January, Vanuatu Geohazards Observatory reported that ash emissions that had become denser and darker on 14 December continued. Ashfall persisted in the W part of the island and satellite imagery showed gas emissions. The Vanuatu Volcano Alert Level (VVAL) remained at 2 (on a scale of 0-4).
Geologic Summary. The roughly 20-km-diameter Gaua Island, also known as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with an 6 x 9 km wide summit caldera. Small parasitic vents near the caldera rim fed Pleistocene lava flows that reached the coast on several sides of the island; several littoral cones were formed where these lava flows reached the sea. Quiet collapse that formed the roughly 700-m-deep caldera was followed by extensive ash eruptions. Construction of the historically active cone of Mount Garat (Gharat) and other small cinder cones in the SW part of the caldera has left a crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat cone is topped by three pit craters. The onset of eruptive activity from a vent high on the SE flank of Mount Garat in 1962 ended a long period of dormancy.
Source: Vanuatu Geohazards Observatory http://www.geohazards.gov.vu/
KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported that during 8-15 January seismic activity from Karymsky was above background levels, possibly indicating that ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. Analyses of satellite imagery revealed an almost daily thermal anomaly over the volcano and ash plumes that drifted 113 km SE on 12 and 13 January. The Level of Concern Color Code 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 13-19 January, 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 occasionally spattered, and both rose and drained through a hole in the cavity floor. A plume from the vent drifted mainly SW, dropping small amounts of ash, and occasionally fresh spatter, downwind. On 14 January, the lava surface suddenly rose to very high levels multiple times; the highest level was about 120 m below the floor of Halema'uma'u crater. Thermal anomalies from the areas above the pali, detected from satellites on the same day, indicated that lava emissions from the TEB vent had resumed. Lava flows were noted during 17-19 January.
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 8-15 January seismic activity from Kliuchevskoi was above background levels and lava continued to flow down the NW flank. Strombolian activity periodically ejected material above the crater. Phreatic explosions were seen from the front of the lava flow, which was about 1.2 km in length. Satellite imagery also revealed a large daily thermal anomaly at the volcano. During 12-14 January, gas-and-steam plumes rose to an altitude of 6.8 km (22,300 ft) a.s.l. and drifted E. The Level of Concern Color Code remained at Orange. Based on information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 18 January an ash plume rose to an altitude of 9 km (30,000 ft) a.s.l. and drifted N.
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
PLANCHON-PETEROA Central Chile-Argentina border 35.240°S, 70.570°W; summit elev. 4107 m
Based on pilot reports and photographs SERNAGEOMIN reported on 13 January that fumarolic plumes from Planchón-Peteroa rose 250 m high on 4, 6, and 7 January. Increased fumarolic activity is common on the warmest days in the summer when snow melts in the crater and more steam is produced.
Geologic Summary. Planchón-Peteroa is an elongated complex volcano along the Chile-Argentina border with several overlapping calderas. Activity began in the Pleistocene with construction of the basaltic-andesite to dacitic Volcán Azufre, followed by formation of basaltic and basaltic-andesite Volcán Planchón, 6 km to the N. About 11,500 years ago, much of Azufre and part of Planchón collapsed, forming the massive Río Teno debris avalanche, which reached Chile's Central Valley. Subsequently, Volcán Planchón II was formed. The youngest volcano, andesitic and basaltic-andesite Volcá Peteroa, consists of scattered vents between Azufre and Planchón. Peteroa has been active into historical time and contains a small steaming crater lake. Historical eruptions from the Planchón-Peteroa complex have been dominantly explosive, although lava flows were erupted in 1837 and 1937.
Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN) http://www.sernageomin.cl/
RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m
Based on a Port Moresby Met Office notice, the Darwin VAAC reported that an ash plume from Rabaul caldera's Tavurvur cone rose 2.4 km (8,000 ft) a.s.l.
Geologic Summary. The low-lying Rabaul caldera on the tip of the Gazelle Peninsula at the NE end of New Britain forms a broad sheltered harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic shield volcano are formed by thick pyroclastic-flow deposits. The 8 x 14 km caldera is widely breached on the E, where its floor is flooded by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul took place as recently as 3,500 and 1,400 years ago. Three small stratovolcanoes lie outside the northern and NE caldera rims. Post-caldera eruptions built basaltic-to-dacitic pyroclastic cones on the caldera floor near the NE and western caldera walls. Several of these, including Vulcan cone, which was formed during a large eruption in 1878, have produced major explosive activity during historical time. A powerful explosive eruption in 1994 occurred simultaneously from Vulcan and Tavurvur volcanoes and forced the temporary abandonment of Rabaul city.
Source: Darwin Volcanic Ash Advisory Centre (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 information from JMA, the Tokyo VAAC reported that during 13-19 January multiple explosions from Sakura-jima often produced plumes that rose to altitudes of 1.5-2.7 km (5,000-9,000 ft) a.s.l. and drifted SE and E. On 16 and 18 January, pilots reported that ash plumes drifted SE at altitudes of 2.4-3 km (8,000-10,000 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
SANGAY Ecuador 2.002°S, 78.341°W; summit elev. 5230 m
Based on pilot observations, the Washington VAAC reported that on 14 January an ash plume from Sangay rose to an altitude of 7.3 km (24,000 ft) a.s.l. Ash was not identified in satellite imagery, although weather clouds were present in the area.
Geologic Summary. The isolated Sangay volcano, located E of the Andean crest, is the southernmost of Ecuador's volcanoes, and its most active. It has been in frequent eruption for the past several centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew within horseshoe-shaped calderas of two previous edifices, which were destroyed by collapse to the E, producing large debris avalanches that reached the Amazonian lowlands. The modern edifice dates back to at least 14,000 years ago. Sangay towers above the tropical jungle on the E side; on the other sides flat plains of ash from the volcano have been sculpted by heavy rains into steep-walled canyons up to 600 m deep. The earliest report of an historical eruption was in 1628. More or less continuous eruptions were reported from 1728 until 1916, and again from 1934 to the present. The more or less constant eruptive activity has caused frequent changes to the morphology of the summit crater complex.
Source: 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 8-15 January seismic activity from Shiveluch was above background levels, possibly indicating ash plumes rising to an altitude of 6.2 km (20,300 ft) a.s.l. Analyses of satellite imagery revealed a large daily thermal anomaly from the lava dome and an ash plume that drifted 8 km SW on 13 January. The Level of Concern Color Code remained at Orange. Based on information from KEMSD, the Tokyo VAAC reported that on 18 January an eruption produced a plume that rose to an altitude of 4.9 km (16,000 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
Tokyo Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html
SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev. 799 m
Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 13 and 16-17 January. Details of possible resulting emissions 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
To contribute to the volcano list, send your message to: volcano@xxxxxxxx Please do not send attachments. ==============================================================
