VOLCANO: Smithsonian/USGS Weekly Volcanic Activity Report 22-28 June 2011

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Smithsonian/USGS Weekly Volcanic Activity Report 22-28 June 2011
From: "Kuhn, Sally" <KUHNS@xxxxxx>

Smithsonian/USGS Weekly Volcanic Activity Report
22-28 June 2011

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

New Activity/Unrest: | Ambrym, Vanuatu (SW Pacific) | Kirishima, Kyushu | Nabro, Eritrea | Puyehue-Cordón Caulle, Central Chile

Ongoing Activity: | Batu Tara, Komba Island (Indonesia) | Fuego, Guatemala | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Kizimen, Eastern Kamchatka (Russia) | Planchón-Peteroa, Central Chile-Argentina border | Sakura-jima, Kyushu | Shiveluch, Central Kamchatka (Russia)

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

AMBRYM Vanuatu (SW Pacific) 16.25°S, 168.12°E; summit elev. 1334 m

On 27 June, the Vanuatu Geohazards Observatory reported that data collected from Ambrym's monitoring network showed significant degassing daily and occasional explosions in the crater. Field observers noted that the level of the lava lakes was high. During June, villages reported minor ashfall and that acid rain affected vegetables in some areas W, S, and E. The Alert Level remained at 1 (on a scale of 0-4).

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: Vanuatu Geohazards Observatory http://www.geohazards.gov.vu/

KIRISHIMA Kyushu 31.931°N, 130.864°E; summit elev. 1700 m

Based on notifications from JMA, the Tokyo VAAC reported that on 23 June an eruption from Kirishima's Shinmoe-dake (Shinmoe peak) produced a plume that rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted E.

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: Tokyo Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html

NABRO Eritrea 13.37°N, 41.70°E; summit elev. 2218 m

A satellite image of Nabro acquired on 22 June showed a gas-and-ash plume rising from the caldera and drifting W. According to a news article, the eruption resulted in at least seven deaths, injured many, and displaced thousands in Eritrea, and affected about 5,000 Ethiopians living near the border. Two satellite images acquired on 24 June show the erupting vent, plumes and emissions, and lava flows in detail. One false-color image highlighted hot areas throughout the lava flow and flow front, as well as hot material above the vent. Gas emissions rising from the lava flow were also detected. A natural-color image showed fresh but cooled lava flows in the N part of the caldera. A dark ash plume rose from the vent, and at higher altitudes a plume composed of water vapor and sulfur dioxide drifted W and obscured the active lava flow. Black ash deposits covered the landscape to the S and W. During 22-26 June large amounts of sulfur dioxide in the region continued to be detected by satellite images. Based on analyses of satellite imagery, the Toulouse VAAC reported that during 26-27 June plumes rose to altitudes up to 6.1 km (20,000 ft) a.s.l.

Geologic Summary. The 2218-m-high Nabro stratovolcano is the highest volcano in the Danakil depression of northern Ethiopia and Eritrea. Located at the SE end of the Danakil Alps, Nabro lies in the Danakil horst. Nabro is the most prominent and NE-most of three volcanoes with large summit calderas aligned in a NE-SW direction SW of Dubbi volcano. These three volcanoes, along with Sork Ale volcano, collectively comprise the Bidu volcanic complex. The complex Nabro stratovolcano is truncated by nested calderas, 8 and 5 km in diameter. The larger caldera is widely breached to the SW. Nabro was constructed primarily of trachytic lava flows and pyroclastics. Post-caldera rhyolitic obsidian domes and basaltic lava flows were erupted inside the caldera and on its flanks. Some very recent lava flows were erupted from NNW-trending fissures transverse to the trend of the Nabro volcanic range.

Sources: Toulouse Volcanic Ash Advisory Centre (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/FR/messages.html,
NASA Earth Observatory http://earthobservatory.nasa.gov/,
NASA Global Sulfur Dioxide Monitoring http://so2.gsfc.nasa.gov/index.php,
Sudan Tribune http://www.sudantribune.com/Eritrean-opposition-asks-for,39304

PUYEHUE-CORDON CAULLE Central Chile 40.590°S, 72.117°W; summit elev. 2236 m

OVDAS-SERNAGEOMIN reported that the eruption continued from the Cordón Caulle rift zone, part of the Puyehue-Cordón Caulle volcanic complex. During 22 and 24-26 June cameras installed around the volcano recorded ash plumes that rose 2-4 km above the crater and drifted NW, N, and NE. Although meteorological cloud cover prevented camera observations on 23 and 28 June, the Buenos Aires VAAC reported that ash clouds detected in satellite imagery rose to altitudes of 4-4.6 km (13,000-15,000 ft) a.s.l. and drifted E and NE. On 25 June SERNAGEOMIN noted that satellite images showed that the plume drifted 200 km N then an additional 900 km NNE. The next day the plume drifted 250 km N, then turned NNW and drifted 1,450 km. According to news articles, numerous flights in and around Argentina and Chile were cancelled, as well as some flights in Uruguay.

On 27 June satellite images detected a plume that was dense for 300 m then was no longer discernable due to meteorological clouds. News outlets noted that flights in New Zealand had resumed. Ashfall was periodically reported in areas downwind, including in Riñinahue (5-10 mm of ash) Llifen, Futrono, and Curarrehue on 22 June, and Riñinahue, Pucón, and Melipeuco (in the region of Araucanía) on 25 June. Although there were no new aerial observations during 22-27 June, pulses of high-intensity tremor indicated that the lava flow remained active. The Alert Level remained at 6, Red.

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/,
Buenos Aires Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AG/messages.html,
Associated Press http://www.msnbc.msn.com/id/43541842/ns/travel-news/,
Agence France-Presse http://www.gulf-times.com/site/topics/article.asp?cu_no=2&item_no=443284&version=1&template_id=43&parent_id=19,
Big Pond News http://bigpondnews.com/articles/AshCloud/2011/06/27/NZ_flights_resume_as_ash_disperses_630628.html

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 22-25 June ash plumes from Batu Tara rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 35-75 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

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

INSIVUMEH reported that during 23-24 June explosions from Fuego produced ash plumes that rose 150-200 m above the crater and drifted W. Incandescent bursts rose 100 m above the crater. During 23-24 and 27-28 June lava flows traveled 200 m down the Ceniza drainage to the SW and detached blocks reached vegetated areas.

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/

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported moderate seismic activity at Karymsky during 17-24 June and that possible ash plumes rose to an altitude of 3.9 km (12,800 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano during 16-17 June. 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

HVO reported that two lava lakes at Kilauea were active during 22-28 June. The level of the summit lava lake fluctuated deep in the vent inset within the E wall of Halema'uma'u Crater. A gas plume from the vent drifted SW, depositing variable amounts of ash nearby. At Pu'u 'O'o, lava from vents near the NE edge of the perched lava lake in the center of the crater floor continued to fill the lake. The lake level fluctuated and overflowed the edges or flowed through rim breaches, sending lava onto the Pu'u 'O'o crater floor. A small shield had built up against the SW crater wall on the W side of the lake. On 23 June the rim of the perched lava lake was elevated 6-8 m higher than the surrounding crater floor; the crater floor was 35 m below the E crater rim. The preliminary sulfur dioxide emission rate from all east rift zone sources was calculated at 700 tonnes/day that same day.

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 16-24 June seismicity from Kizimen was above background levels and volcanic tremor continued to be detected. Seismic data indicated that possible ash plumes rose to an altitude of 5.2 km (17,000 ft) a.s.l. during 16-17 June. Satellite images showed a thermal anomaly on the volcano during 17-18 and 20-21 June, and gas-and-steam plumes that drifted 200 km NW during 22-23 June. 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

PLANCHON-PETEROA Central Chile-Argentina border 35.240°S, 70.570°W; summit elev. 4107 m

Based on SIGMET notices, the Buenos Aires VAAC reported that during 24-25 June ash plumes from Planchón-Peteroa rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted W, NE, and E. On 27 June satellite imagery showed a gas-and-steam plume, possibly containing ash, drifting 110 km NW.

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: Buenos Aires Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AG/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 on 22, 25, and 28 June plumes from Sakura-jima rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted N and NE. During 27-28 June, pilots observed ash plumes that rose to altitudes of 2.1-3 km (7,000-10,000 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

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev. 3283 m

KVERT reported moderate seismic activity at Shiveluch during 17-24 June. Seismic data indicated that possible ash plumes rose to an altitude of 10 km (32,800 ft) a.s.l. on 19 June and to an altitude of 6 km (19,700 ft) a.s.l. on 18 and 21 June. Satellite imagery showed a thermal anomaly on the lava dome on 18 and 20 June and ash plumes drifting 176 km in multiple directions during 20-21 June. The Aviation Color Code 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.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php


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