Wednesday, October 30, 2013

[ Volcano ] Smithsonian/USGS Weekly Volcanic Activity Report 23-29 October 2013



 
 

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Smithsonian/USGS Weekly Volcanic Activity Report 23-29 October 2013
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Smithsonian/USGS Weekly Volcanic Activity Report

23-29 October 2013

 

Sally Kuhn Sennert - Weekly Report Editor

kuhns@si.edu

URL: http://www.volcano.si.edu/reports/usgs/

 

 

New Activity/Unrest: | Etna, Sicily (Italy) | Kirishima, Kyushu | Kliuchevskoi, Central Kamchatka (Russia) | Sinabung, Sumatra (Indonesia) | Shiveluch, Central Kamchatka (Russia) | Tangkubanparahu, Western Java (Indonesia) | Tungurahua, Ecuador | Zhupanovsky, Eastern Kamchatka

 

Ongoing Activity: | Chirinkotan, Kuril Islands | Chirpoi, Kuril Islands (Russia) | Dukono, Halmahera | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Popocatépetl, México | Sakura-jima, Kyushu | Ubinas, Perú

 

 

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

 

 

ETNA Sicily (Italy) 37.734°N, 15.004°E; summit elev. 3330 m

 

Sezione di Catania - Osservatorio Etneo reported that on 26 October Etna's New Southeast Crater (NSEC) produced a new episode of lava fountaining, six months after the previous paroxysm. A gas plume laden with pyroclastic material rose several kilometers above the summit and drifted SW, affecting population centers as far as the Caltanissetta area. According to a news article a representative from Catania airport noted that the eruption caused the closure of nearby airspace before dawn through the early morning.

 

Lava emitted from the saddle between the two cones of the Southeast Crater advanced S, destroying two wooden shacks at Torre del Filosofo. Another smaller lava flow descended the SE flank of the NSEC cone, partially filling the deep collapse scar formed during the 27 April 2013 paroxysm. At 1019 vigorous ash emissions from the Northeast Crater formed a dark brown plume that rose 1 km; ash emissions from that crater continued through late evening. Lava fountaining from NSEC continued through the late morning and was then followed by a long series of powerful explosions audible to many tens of kilometers away. Strombolian explosions occurred in the late evening. Lava flows continued to advance the next day.

 

Geologic Summary. Mount Etna, towering above Catania, Sicily's second largest city, has one of the world's longest documented records of historical volcanism, dating back to 1500 BC. Historical lava flows cover much of the surface of this massive basaltic stratovolcano, the highest and most voluminous in Italy. Two styles of eruptive activity typically occur at Etna. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more of the three prominent summit craters, the Central Crater, NE Crater, and SE Crater. Flank eruptions, typically with higher effusion rates, occur less frequently and originate from fissures that open progressively downward from near the summit. A period of more intense intermittent explosive eruptions from Etna's summit craters began in 1995. The active volcano is monitored by the Instituto Nazionale di Geofisica e Volcanologia (INGV) in Catania.

 

Sources: INGV Sezione di Catania - Osservatorio Etneo www.ct.ingv.it/,

Kasa http://www.kasa.com/news/international/mount-etna-volcano-erupts-airspace-briefly-closed_2 0373584

 

 

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

 

On 22 October the JMA reported that no eruptions had been detected at Shinmoe-dake (Shinmoe peak), a stratovolcano of the Kirishima volcano group, since the eruption on 7 September 2011. Earthquake activity and sulfur dioxide emissions were both below the detection limit. The Alert Level was lowered to 2 (on a scale of 1-5).

 

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/index.html

 

 

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit elev. 4850 m

 

KVERT reported that at 0100 on 21 October a sharp decrease in seismicity was detected at Kliuchevskoi and only fumarolic activity was observed. The Aviation Color Code was lowered to Orange. Strombolian activity and the effusion of several lava flows continued through 25 October. Satellite images showed aerosol plumes over Canada during 20-23 October.

 

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active volcano. Since its origin about 6000 years ago, the beautifully symmetrical, 4835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. Kliuchevskoi rises above a saddle NE of sharp-peaked Kamen volcano and lies SE of the broad Ushkovsky massif. More than 100 flank eruptions have occurred at Kliuchevskoi during the past roughly 3000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 m and 3600 m elevation. 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 numerous major explosive and effusive eruptions from flank craters.

 

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

 

 

SINABUNG Sumatra (Indonesia) 3.17°N, 98.392°E; summit elev. 2460 m

 

PVMBG reported that after 29 September, the day the Alert Level was lowered to 2 (on a scale of 1-4), seismicity at Sinabung declined but continued to fluctuate through 22 October. White plumes were seen rising 100-300 m from the crater. On 22 October plumes were also grayish and rose 250 m. Vents appeared on the N flank and produced dense white plumes that rose 70 m. On 23 October landslides at two locations were observed, and explosions occurred at 1619 and 1651. Plumes rose from the summit crater and from a fracture formed on 15 October near Lau Kawar. Fog prevented observations for a period after the explosions; once the fog cleared dense gray plumes were observed. A third explosion occurred at 2100. On 24 October an explosion at 0550 generated an ash plume that rose 3 km and caused ashfall in areas S. Another explosion was detected at 0612. According to a news article about 3,300 people that evacuated their homes were mostly from two villages within 3 km of Sinabung, in the Karo district.

 

Based on information from the Indonesian Meteorological Office, the Darwin VAAC reported that an eruption at 1737 on 26 October generated an ash plume that rose to an altitude of 4.9 km (16,000 ft) a.s.l. At 0700 and 1200 on 27 October a webcam showed an ash plume rising to an altitude of 3.7 km (12,000 ft) a.s.l. and drifting over 35 km NE.

 

Geologic Summary. Gunung Sinabung is a Pleistocene-to-Holocene stratovolcano with many lava flows on its flanks.  The migration of summit vents along a N-S line gives the summit crater complex an elongated form.  The youngest crater of this conical, 2460-m-high andesitic-to-dacitic volcano is at the southern end of the four overlapping summit craters.  An unconfirmed eruption was noted in 1881, and solfataric activity was seen at the summit and upper flanks of Sinabung in 1912, although no confirmed historical eruptions were recorded prior to 2010.    

 

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) also known as Center of Volcanology and Geological Hazard Mitigation (CVGHM) http://www.vsi.esdm.go.id/,

Darwin Volcanic Ash Advisory Centre (VAAC) ftp://ftp.bom.gov.au/anon/gen/vaac/,

Associated Press http://www.cbc.ca/news/world/2nd-eruption-of-mount-sinabung-in-indonesia-forces-3-300-peop le-from-homes-1.2223565?cmp=rss

 

 

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

 

Based on visual observations and analyses of satellite data, KVERT reported that during 19-25 October a viscous lava flow effused onto the N and NE flanks of Shiveluch's lava dome, accompanied by hot avalanches, incandescence, ash explosions, and fumarolic activity. A thermal anomaly was detected daily in satellite images.

 

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://ds.data.jma.go.jp/svd/vaac/data/vaac_list.html

 

 

TANGKUBANPARAHU Western Java (Indonesia) 6.77°S, 107.60°E; summit elev. 2084 m

 

PVMBG reported a phreatic eruption from Tangkubanparahu at 0621 on 5 October. The Alert Level was raised to 2 (on a scale of 1-4).

 

Geologic Summary. Tangkubanparahu is a broad shield-like stratovolcano overlooking Indonesia's former capital city of Bandung that was constructed within the 6 x 8 km Pleistocene Sunda caldera. The volcano's low profile is the subject of legends referring to the mountain of the "upturned boat." The rim of Sunda caldera forms a prominent ridge on the western side; elsewhere the caldera rim is largely buried by deposits of Tangkubanparahu volcano. The dominantly small phreatic historical eruptions recorded since the 19th century have originated from several nested craters within an elliptical 1 x 1.5 km summit depression. Tangkubanparahu last erupted in September 1983, when ash rose up to 150 m above the rim of Kawah Ratu.

 

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) also known as Center of Volcanology and Geological Hazard Mitigation (CVGHM) http://www.vsi.esdm.go.id/

 

 

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

 

IG reported that activity at Tungurahua remained high during 23-27 October. Although cloud cover sometimes prevented visual observations of the crater, ash plumes were observed almost daily. During 23-24 October continuous ash emissions produced plumes that rose 3-4 km above the crater and drifted NNE and SW. Ashfall was reported in Penipe (15 km SW), Palitahua (S), Riobamba (30 km S), Tisaleo (29 km NW), El Manzano (8 km SW), and Choglontus (SW). On 25 October blocks were observed rolling down the flanks, and ash fell in El Manzano and Choglontus. The next day continuous ash emissions rose 2 km and drifted SW. Ashfall was noted in Cevallos (23 km NW), Mocha (25 km WNW), Tisaleo, Penipe, El Manzano, and Cloglontus. Ash plumes rose 2 km and drifted W on 27 October. Low-energy gas-and-ash emissions drifted W and SW on 28 October. Ashfall was reported in Palitahua. On 29 October ash plumes rose 4 km and drifted E and NE. Ash fell in Penipe, Mocha, and El Manzano.

 

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/

 

 

ZHUPANOVSKY Eastern Kamchatka 53.59°N, 159.147°E; summit elev. 2958 m

 

KVERT reported that a weak thermal anomaly over Zhupanovsky was detected on 23 October. The next day a phreatic eruption began at about 0300 and generated an ash plume that rose 5 km (16,400 ft) a.s.l. The ash plume was visible in satellite images drifting 40 km SE and S. Ash deposits about 10 cm thick were visible at the summit of the central part of the volcano, and deposits about 1 mm thick covered the Nalychevo Valley. The Aviation Color Code was raised to Orange. Ash plumes at 1635 and 2218 rose to altitudes of 2.5-3 km (8,200-10,000 ft) a.s.l. and drifted 120 km ESE and 25 km S, respectively. At 1134 on 25 October an ash plume rose 3 km (10,000 ft) a.s.l. and drifted 20 km NE. On 27 October KVERT noted that strong fumarolic activity and gas emissions continued, but that the phreatic explosions likely had ceased. The Aviation Color Code was lowered to Yellow, and then lowered again to Green on 29 October.

 

Geologic Summary. The Zhupanovsky volcanic massif consists of four overlapping stratovolcanoes along a WNW-trending ridge. The elongated volcanic complex was constructed within a Pliocene-early Pleistocene caldera whose rim is exposed only on the eastern side. Three of the stratovolcanoes were built during the Pleistocene, the fourth is Holocene in age and was the source of all of Zhupanovsky's historical eruptions. An early Holocene stage of frequent moderate and weak eruptions from 7000 to 5000 years before present (BP) was succeeded by a period of infrequent larger eruptions that produced pyroclastic flows. The last major eruption of Zhupanovsky took place about 800-900 years BP. Historical eruptions have consisted of relatively minor explosions from the third cone.

 

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

 

 

Ongoing Activity

 

 

CHIRINKOTAN Kuril Islands 48.980°N, 153.480°E; summit elev. 724 m

 

SVERT reported that during 21-25 October steam-and-gas emissions from Chirinkotan were detected in satellite images. A thermal anomaly was detected on 24 October. The Aviation Color Code remained at Yellow.

 

Geologic Summary. The small, mostly unvegetated 3-km-wide island of Chirinkotan occupies the far end of an E-W-trending volcanic chain that extends nearly 50 km west of the central part of the main Kuril Islands arc. Chirinkotan is the emergent summit of a volcano that rises 3000 m from the floor of the Kuril Basin. A small 1-km-wide caldera about 300-400 m deep is open to the SE. Lava flows from a cone within the breached crater reached the north shore of the island. Historical eruptions have been recorded at Chirinkotan since the 18th century. Fresh lava flows also descended the SE flank of Chirinkotan during an eruption in the 1880s that was observed by the English fur trader Captain Snow.

 

Source: Sakhalin Volcanic Eruption Response Team (SVERT) http://www.imgg.ru/?id_d=659

 

 

CHIRPOI Kuril Islands (Russia) 46.525°N, 150.875°E; summit elev. 742 m

 

SVERT reported that steam-and-gas emissions from Snow, a volcano of Chirpoi, were detected in satellite images during 22-23 October. The Aviation Color Code remained at Yellow.

 

Geologic Summary. Chirpoi, a small island lying between the larger islands of Simushir and Urup, contains a half dozen volcanic edifices constructed within an 8-9 km wide, partially submerged caldera. The southern rim of the caldera is exposed on nearby Brat Chirpoev Island. Two volcanoes on Chirpoi Island have been historically active. The symmetrical Cherny volcano, which forms the 691 m high point of the island, erupted twice during the 18th and 19th centuries. The youngest volcano, Snow, originated between 1770 and 1810. It is composed almost entirely of lava flows, many of which have reached the sea on the southern coast. No historical eruptions are known from 742-m-high Brat Chirpoev, but its youthful morphology suggests recent strombolian activity.

 

Source: Sakhalin Volcanic Eruption Response Team (SVERT) http://www.imgg.ru/en/home.html

 

 

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

 

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 23 October an ash plume from Dukono rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted 150 km E.

 

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) ftp://ftp.bom.gov.au/anon/gen/vaac/

 

 

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

 

KVERT reported that moderate seismic activity at Karymsky was detected during 18-25 October. Satellite images detected a daily bright thermal anomaly on the volcano possibly indicating weak Vulcanian and Strombolian activity. Ash plumes drifted 170 km SE on 20 and 22 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 23-29 October HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 5.8-km-long Kahauale'a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of a possible minor breakout above the 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/

 

 

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

 

CENAPRED reported that during 23-25 October seismicity at Popocatépetl indicated continuing emissions of water vapor, gas, and occasional small amounts of ash; cloud cover sometimes prevented observations of the crater. On 24 October an explosion at 2111 produced an ash plume that rose 1 km and drifted SW. Eight low-intensity explosions on 26 October increased gas and steam emissions and produced slight amounts of ash. Incandescence from the crater was observed overnight during 26-27 October. An explosion was detected on 27 October; cloud cover prevented visual observations. An ash plume rose 1 km and drifted W on 28 October. The Alert Level remained at to Yellow, Phase Two.

 

Geologic Summary. Popocatépetl, whose name is the Aztec word for smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is North America's second-highest volcano. Frequent historical eruptions have been recorded since the beginning of the Spanish colonial era. A small eruption on 21 December 1994 ended five decades of quiescence. Since 1996 small lava domes have incrementally been constructed within the summit crater and destroyed by explosive eruptions. Intermittent small-to-moderate gas-and-ash eruptions have continued, occasionally producing ashfall in neighboring towns and villages.

 

Source: Centro Nacional de Prevencion de Desastres (CENAPRED) http://www.cenapred.unam.mx/es/

 

 

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

 

Based on information from JMA, the Tokyo VAAC reported that during 24-29 October explosions from Sakura-jima generated plumes that rose to altitudes of 1.8-4.6 km (6,000-15,000 ft) a.s.l. Plumes rose vertically or drifted N, NW, S, and SE. On 29 October a pilot observed an ash plume drifting SE at an altitude of 2.1 km (7,000 ft) a.s.l.

 

JMA reported that 11 explosions from Showa Crater ejected tephra as far as 1,800 m during 25-28 October. Explosions on 28 and 29 October generated ash plumes that rose to altitude of 3.2-3.5 km (10,500-11,500 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.

 

Sources: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/,

Tokyo Volcanic Ash Advisory Center (VAAC) http://ds.data.jma.go.jp/svd/vaac/data/vaac_list.html

 

 

UBINAS Perú 16.355°S, 70.903°W; summit elev. 5672 m

 

IGP reported that a 2-minute-long non-explosive seismic signal indicated gas-and-ash emissions at Ubinas on 22 October. 

 

Geologic Summary. A small, 1.2-km-wide caldera that cuts the top of Ubinas, Peru's most active volcano, gives it a truncated appearance. Ubinas is the northernmost of three young volcanoes located along a regional structural lineament about 50 km behind the main volcanic front of Peru. The upper slopes of the stratovolcano, composed primarily of Pleistocene andesitic lava flows, steepen to nearly 45 degrees. The steep-walled, 150-m-deep summit caldera contains an ash cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-avalanche deposits from the collapse of the SE flank of Ubinas extend 10 km from the volcano. Widespread Plinian pumice-fall deposits from Ubinas include some of Holocene age. Holocene lava flows are visible on the volcano's flanks, but historical activity, documented since the 16th century, has consisted of intermittent minor explosive eruptions.

 

Source: Instituto Geofísico del Perú (IGP) http://www.igp.gob.pe/

 

 

+++++++++++++++++++++++++++++++++++++

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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