Smithsonian/USGS Weekly Volcanic Activity Report 12-18 October 2011
From: "Kuhn, Sally" <KUHNS@xxxxxx>
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Smithsonian/USGS Weekly Volcanic Activity Report
12-18 October 2011
Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/
New Activity/Unrest: | Hierro, Canary Islands (Spain) | Katla, Southern Iceland | Shiveluch, Central Kamchatka (Russia) | Tambora, Sumbawa Island (Indonesia)
Ongoing Activity: | Cleveland, Chuginadak Island | Fuego, Guatemala | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Kizimen, Eastern Kamchatka (Russia) | Manam, Northeast of New Guinea (SW Pacific) | Marapi, Sumatra (Indonesia) | Puyehue-Cordón Caulle, Central Chile | Sakura-jima, Kyushu
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
HIERRO Canary Islands (Spain) 27.73°N, 18.03°W; summit elev. 1500 m
Instituto Geográfico Nacional (IGN) reported that tremor, registered by every seismic station on El Hierro Island, continued during 12-18 October. Deformation decreased during this period, with significant inflation-deflation episodes registered by the stations located in the NW part of the island. On 12 October, at about 1430, the amplitude of the tremor signals abruptly decreased and smaller amplitudes persisted during the following days. During the afternoon of 12 October a large light-green colored area was observed in the sea to the S of La Restinga village (at the southernmost point of Hierro); the evolution of this anomaly was observed from land and by helicopter. The extension of the anomaly was controlled by the ocean currents, but a small area was detected as the emission center due to its intense discoloration and concentration. During a helicopter flight on 15 October, steamy lava fragments in this small area were observed. In the same area, during 15-17 October, frequent episodes of emission, forming big turbulent rings of gas and foaming, were observed on the sea surface. Since the night of 17 October, the amplitude of the tremor signal had decreased slowly. On 18 October, deformation further decreased and the sea-surface disruption from gases was not observed.
Geologic Summary. The triangular island of Hierro is the SW-most and least studied of the Canary Islands. The massive Hierro shield volcano is truncated by a large NW-facing escarpment formed as a result of gravitational collapse of El Golfo volcano about 130,000 years ago. The steep-sided 1500-m-high scarp towers above a low lava platform bordering 12-km-wide El Golfo Bay, and three other large submarine landslide deposits occur to the SW and SE. Three prominent rifts oriented NW, NE, and south at 120 degree angles form prominent topographic ridges. The subaerial portion of the volcano consists of flat-lying Quaternary basaltic and trachybasaltic lava flows and tuffs capped by numerous young cinder cones and lava flows. Holocene cones and flows are found both on the outer flanks and in the El Golfo depression. Hierro contains the greatest concentration of young vents in the Canary Islands. Uncertainty surrounds the report of an historical eruption in 1793.
Source: Instituto Geográfico Nacional (IGN) http://www.ign.es/ign/layout/volcaVolcanologia.do
KATLA Southern Iceland 63.63°N, 19.05°W; summit elev. 1512 m
The Iceland Met Office reported increased seismic activity within Katla's caldera. Unrest was first noted in July, when a short-lived glacial flood burst from the Myrdalsjökull glacier that covers Katla occurred in connection with increased seismicity. Since then, several hundred micro-earthquakes had taken place within the area of the caldera. On 5 October an intense earthquake swarm was detected. Most of the earthquakes originated at 5 km depth; the largest one was approximately a M 3.7.
Geologic Summary. Katla volcano, located near the southern end of Iceland's eastern volcanic zone, is hidden beneath the Myrdalsjökull icecap. The subglacial basaltic-to-rhyolitic volcano is one of Iceland's most active and is a frequent producer of damaging jökulhlaups, or glacier-outburst floods. A large 10 x 14 km subglacial caldera with a long axis in a NW-SE direction is up to 750 m deep. Its high point reaches 1380 m, and three major outlet glaciers have breached its rim. Although most historical eruptions have taken place from fissures inside the caldera, the Eldgjá fissure system, which extends about 60 km to the NE from the current ice margin towards Grímsvötn volcano, has been the source of major Holocene eruptions. An eruption from the Eldgjá fissure system about 934 AD produced a voluminous lava flow of about 18 cu km, one of the world's largest known Holocene lava flows. Katla has been the source of frequent subglacial basaltic explosive eruptions that have been among the largest tephra-producers in Iceland during historical time and has also produced numerous dacitic explosive eruptions during the Holocene.
Source: Icelandic Met Office http://en.vedur.is/
SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev. 3283 m
KVERT reported that seismic activity at Shiveluch was moderate during 7-14 October. Ground-based observers noted hot avalanches from the lava dome and that plumes from those avalanches rose to an altitude of 5 km (16,400 ft) a.s.l. An ash explosion on 8 October produced an ash plume that rose to an altitude of 7 km (23,000 ft) a.s.l. Satellite imagery showed a daily thermal anomaly over the lava dome and ash plumes that drifted 160 km E on 6 and 8 October. The Aviation Color Code remained at Orange.
Based on information from KEMSD, the Tokyo VAAC reported that during 15-18 October eruptions produced plumes that rose to altitudes of 6.4-10.4 km (21,000-34,000 ft) a.s.l. An eruption on 16 October noted by KVERT produced a plume that rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted SE.
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
TAMBORA Sumbawa Island (Indonesia) 8.25°S, 118.00°E; summit elev. 2850 m
CVGHM reported that during 22 September-9 October plumes did not rise from Tambora; seismicity fluctuated, but declined overall. Based on visual observations, deformation data, and seismicity, the Alert Level was lowered to 2 (on a scale of 1-4) on 9 October.
Geologic Summary. The massive Tambora stratovolcano forms the entire 60-km-wide Sanggar Peninsula on northern Sumbawa Island. The largely trachybasaltic-to-trachyandesitic volcano grew to about 4000 m elevation before forming a caldera more than 43,000 years ago. Late-Pleistocene lava flows largely filled the early caldera, after which activity changed to dominantly explosive eruptions during the early Holocene. Tambora was the source of history's largest explosive eruption, in April 1815. Pyroclastic flows reached the sea on all sides of the peninsula, and heavy tephra fall devastated croplands, causing an estimated 60,000 fatalities. The eruption of an estimated more than 150 cu km of tephra formed a 6-km-wide, 1250-m-deep caldera and produced global climatic effects. Minor lava domes and flows have been extruded on the caldera floor at Tambora during the 19th and 20th centuries.
Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM) http://www.vsi.esdm.go.id/
Ongoing Activity
CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m
AVO reported that during 12-13 October cloud cover over Cleveland prevented views of the lava dome in the summit crater. Partly cloudy satellite views during 14-18 October showed elevated surface temperatures from the crater indicative of continued growth of the lava dome. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network.
Geologic Summary. Symmetrical Mount Cleveland stratovolcano is situated at the western end of the uninhabited dumbbell-shaped Chuginadak Island in the east-central Aleutians. The 1,730-m-high stratovolcano is the highest of the Islands of Four Mountains group and is one of the most active in the Aleutians. Numerous large lava flows descend its flanks. It is possible that some 18th to 19th century eruptions attributed to Carlisle (a volcano located across the Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In 1944 Cleveland produced the only known fatality from an Aleutian eruption. Recent eruptions from Mt. Cleveland have been characterized by short-lived explosive ash emissions, at times accompanied by lava fountaining and lava flows down the flanks.
Source: Alaska Volcano Observatory (AVO) http://www.avo.alaska.edu/
FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m
INSIVUMEH reported that during 14-15 October explosions from Fuego produced shock waves that were detected nearby, rumbling sounds, and ash plumes that rose 700 m above the crater and drifted S. A small avalanche traveled S in the Santa Teresa drainage. Cloud cover prevented visual observations during 16-18 October; however, explosions and block avalanches were heard.
Geologic Summary. Volcán Fuego, one of Central America's most active volcanoes, is one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N, Acatenango. Construction of Meseta volcano continued until the late Pleistocene or early Holocene, after which growth of the modern Fuego volcano continued the southward migration of volcanism that began at Acatenango. Frequent vigorous historical eruptions have been recorded at Fuego since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows. The last major explosive eruption from Fuego took place in 1974, producing spectacular pyroclastic flows visible from Antigua.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) http://www.insivumeh.gob.gt/inicio.html
KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported that seismic activity continued at a moderate level at Karymsky during 7-14 October and indicated that possible ash plumes rose to an altitude of 2.2 km (7,200 ft) a.s.l. Ash plumes possibly rose to an altitude of 3.8 km (12,500 ft) a.s.l. on 7 October. Satellite imagery showed a thermal anomaly on the volcano on 6 and 8 October. The Aviation 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 12-18 October, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby. At the E rift zone, the fissure that formed on 21 September on the upper E flank of Pu'u 'O'o continued to periodically feed lava flows to the NE and SE of the fissure that did not significantly advance. Vents on the E and W edges of Pu'u 'O'o Crater floor were incandescent.
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/
KIZIMEN Eastern Kamchatka (Russia) 55.130°N, 160.32°E; summit elev. 2376 m
KVERT reported that during 7-14 October the magnitudes of the volcanic earthquakes at Kizimen decreased, as well as the numbers, from 500 to 100. Video data showed that a large lava flow on the NE flank continued to effuse and strong fumarolic activity was observed. A thermal anomaly on the volcano was detected daily in satellite images. The Aviation Color Code remained at Orange.
Geologic Summary. Kizimen is an isolated, conical stratovolcano that is morphologically similar to Mount St. Helens prior to its 1980 eruption. The summit of Kizimen consists of overlapping lava domes, and blocky lava flows descend the flanks of the volcano, which is the westernmost of a volcanic chain north of Kronotsky volcano. The 2,376-m-high Kizimen was formed during four eruptive cycles beginning about 12,000 years ago and lasting 2,000-3,500 years. The largest eruptions took place about 10,000 and 8300-8400 years ago, and three periods of longterm lava-dome growth have occurred. The latest eruptive cycle began about 3,000 years ago with a large explosion and was followed by lava-dome growth lasting intermittently about 1,000 years. An explosive eruption about 1,100 years ago produced a lateral blast and created a 1.0 x 0.7 km wide crater breached to the NE, inside which a small lava dome (the fourth at Kizimen) has grown. A single explosive eruption, during 1927-28, has been recorded in historical time.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php
MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit elev. 1807 m
Based on analysis of satellite imagery, the Darwin VAAC reported that on 18 October ash plumes from Manam rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted 150-170 km NW.
Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the northern coast of mainland Papua New Guinea, is one of the country's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical 1807-m-high basaltic-andesitic stratovolcano to its lower flanks. These "avalanche valleys," regularly spaced 90 degrees apart, channel lava flows and pyroclastic avalanches that have sometimes reached the coast. Two summit craters are present; both are active, although most historical eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE avalanche valley. Frequent historical eruptions, typically of mild-to-moderate scale, have been recorded at Manam since 1616. Occasional larger eruptions have produced pyroclastic flows and lava flows that reached flat-lying coastal areas and entered the sea, sometimes impacting populated areas.
Source: Darwin Volcanic Ash Advisory Centre (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
MARAPI Sumatra (Indonesia) 0.381°S, 100.473°E; summit elev. 2891 m
Based on information from CVGHM, the Darwin VAAC reported that on 12 October an eruption from Marapi produced an ash plume that rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted E.
Geologic Summary. Gunung Marapi, not to be confused with the better known Merapi volcano on Java, is Sumatra's most active volcano. Marapi is a massive complex stratovolcano that rises 2,000 m above the Bukittinggi plain in Sumatra's Padang Highlands. A broad summit contains multiple partially overlapping summit craters constructed within the small 1.4-km-wide Bancah caldera. The summit craters are located along an ENE-WSW line, along which volcanism has migrated to the W. More than 50 eruptions, typically consisting of small-to-moderate explosive activity, have been recorded since the end of the 18th century; no historical lava flows outside the summit craters have been reported.
Source: Darwin Volcanic Ash Advisory Centre (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
PUYEHUE-CORDON CAULLE Central Chile 40.590°S, 72.117°W; summit elev. 2236 m
Based on seismicity during 11-12 October, OVDAS-SERNAGEOMIN reported that the eruption from the Cordón Caulle rift zone, part of the Puyehue-Cordón Caulle volcanic complex, continued at a low level. Plumes visible with an area web camera rose no higher than 4 km above the crater during 11-12 October. On 17 October a white plume rose 4.5 km above the crater and a diffuse ash plume observed in satellite imagery drifted 30 km SE. The next day, a white plume rose 3 km above the crater. Satellite imagery showed a plume drifting 50 km NE, and then later a diffuse ash plume drifting 200 km NE and SE. The Alert Level remained at Red.
According to news articles, several domestic and international flights in Argentina, Brazil, Chile and Uruguay were cancelled on 16 October due to re-suspended ash. OVDAS-SERNAGEOMIN also noted that there was not an increase in volcanic activity, but high winds in the region. Flights resumed the next day.
Geologic Summary. The Puyehue-Cordón Caulle volcanic complex (PCCVC) is a large NW-SE-trending late-Pleistocene to Holocene basaltic-to-rhyolitic transverse volcanic chain SE of Lago Ranco. The 1799-m-high Pleistocene Cordillera Nevada caldera lies at the NW end, separated from Puyehue stratovolcano at the SE end by the Cordón Caulle fissure complex. The Pleistocene Mencheca volcano with Holocene flank cones lies NE of Puyehue. The basaltic-to-rhyolitic Puyehue volcano is the most geochemically diverse of the PCCVC. The flat-topped, 2236-m-high Puyehue volcano was constructed above a 5-km-wide caldera and is capped by a 2.4-km-wide summit caldera of Holocene age. Lava flows and domes of mostly rhyolitic composition are found on the eastern flank of Puyehue. Historical eruptions originally attributed to Puyehue, including major eruptions in 1921-22 and 1960, are now known to be from the Cordón Caulle rift zone. The Cordón Caulle geothermal area, occupying a 6 x 13 km wide volcano-tectonic depression, is the largest active geothermal area of the southern Andes volcanic zone.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN) http://www.sernageomin.cl/,
Associated Press http://www.waaytv.com/news/world/story/Volcanic-ash-delays-weekend-flights/9y5jO6E0kkCjzBTccMUscw.cspx
SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m
Based on information from JMA, the Tokyo VAAC reported that during 12-13 and 15-18 October explosions from Sakura-jima produced plumes that rose to altitudes of 1.8-3.4 km (6,000-11,000 ft) a.s.l. and drifted SE and E. On 18 October a pilot observed an ash plume that rose to an altitude of 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
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Sally Kuhn Sennert
SI/USGS Weekly Volcanic Activity Report Editor
Global Volcanism Program
http://www.volcano.si.edu/reports/usgs/
Smithsonian Institution, National Museum of Natural History
Department of Mineral Sciences, MRC-119
Washington, D.C., 20560
Phone: 202.633.1805
Fax: 202.357.2476
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