Smithsonian/USGS Weekly Volcanic Activity Report 20-26 November 2013
************************************************************************************************
Smithsonian/USGS Weekly Volcanic Activity Report
20-26 November 2013
Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/
New Activity/Unrest: | Etna, Sicily (Italy) | Kliuchevskoi, Central Kamchatka (Russia) | Nishimo-shima, Japan | Sinabung, Sumatra (Indonesia)
Ongoing Activity: | Chirinkotan, Kuril Islands | Chirpoi, Kuril Islands (Russia) | Copahue, Central Chile-Argentina | Fuego, Guatemala | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Sakura-jima, Kyushu | Shiveluch, Central Kamchatka (Russia) | Ulawun, New Britain
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
INGV reported on the morning of 23 November the 17th paroxysm occurred from Etna's New Southeast Crater (NSEC), five days after the previous one. The episode was characterized by a rapid evolution from Strombolian activity to lava fountains, an ash plume that rose several kilometers and drifted NE, and lava flows that were significantly less extensive than those emitted during the 16-17 November paroxysm.
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.
Source: INGV Sezione di Catania - Osservatorio Etneo www.ct.ingv.it/
KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit elev. 4850 m
KVERT reported that at 1235 on 17 November an ash plume from Kliuchevskoi, detected in satellite images, rose to an altitude of 6.5 km (19,700 ft) a.s.l. and drifted 160 km NE. At 1322 an ash plume rose to an altitude of 7km (23,000 ft) a.s.l. and drifted 130 km NE. Video data then showed a high-intensity explosion and Strombolian activity prompting KVERT to raise the Aviation Color Code to Orange.
At 1416 on 19 November seismicity indicated a strong explosion, and observers reported that ash plumes rose to altitudes of 10-12 km (32,800-39,400 ft) a.s.l. and drifted SE. The Aviation Color Code was raised to Red. Later that day the altitudes of the ash plumes were lower; video images showed ash plumes rising to altitudes of 5-5.5 km(16,400-18,000 ft) a.s.l. and drifting NE. The Aviation Color Code was lowered to Orange.
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
NISHIMO-SHIMA Izu, Volcano, and Mariana Islands (Japan) 27.274°N, 140.882°E; summit elev. 38 m
The Japan Coast Guard reported that a Surtseyan eruption 500 m SE from the coast of Nishimo-shima generated a new island called Niijima on 20 November. The island was about 300 x 200 m, and developed a crater 150m wide. Discolored water surrounded the island. Based on satellite images, as well as accounts from the Japan Coast Guard and JMA, the Tokyo VAAC reported that a plume rose 600 m. On 22 November the eruption continued and incandescence within the crater was observed. An ash plume rose 900 m and drifted SE. On 24 November lava flows from the crater extended to the coastline of the island, and bombs continued to be ejected.
Geologic Summary. The small island of Nishino-shima was recently enlarged when it was joined to several new islands that formed during an eruption in 1973-74. Water discoloration has been observed on several occasions since. The 700-m-wide island is the summit of a massive submarine volcano that has prominent satellitic peaks to the south, west, and NE. The summit of the southern cone rises to within 214 m of the sea surface 9 km SSE of Nishino-shima.
Sources: Japan Coast Guard http://www.kaiho.mlit.go.jp/index.html,
Tokyo Volcanic Ash Advisory Center (VAAC) http://ds.data.jma.go.jp/svd/vaac/data/vaac_list.html
SINABUNG Sumatra (Indonesia) 3.17°N, 98.392°E; summit elev. 2460 m
PVMBG reported three explosions from Sinabung on 17 November. The first explosion, at 2024, generated an ash plume that rose 500 m and drifted SW, and a pyroclastic flow that traveled 500 m down the SE flank. At 2152 a dense ash plume from an explosion rose 500 m and drifted SW. Incandescent material was ejected 50 m away from the crater. At 2252 an ash plume rose 1 km and drifted SW. At 0704 on 18 November an explosion generated an ash plume that rose 8 km and drifted SW. A pyroclastic flow also traveled 800 m down the SE flank.
On 19 November at 2155 a dense ash plume rose 10 km, drifted SW, and exhibited lightning. Pyroclastic flows again traveled 500 m SE. Multiple explosions on 20 November (at 0240, 0405, 0529, 0619, and 0641) generated ash plumes that rose to heights between 1 and 3.5 km. An explosion at 1716 was detected by the seismic network but cloud cover prevented observations of possible plumes. White plumes rose 100 m on 21 and 23 November; misty conditions prevented visual observations on 22 November. On 23 November scoria fell in the Sigarang-garang and Desa Kuta villages in the NNE. Two explosions on 24 November, at 0043 and 0232, were detected but not visually observed. Ash plumes rose 8 km and drifted NNE at 0727, rose 1 km at 0812, and rose 3 km at 0855. Since Sinabung's activity continued to increase, PVMBG raised the Alert Level to 4 (on a scale of 1-4) on 24 November. PVMBG noted that residents and tourists were not to approach the crater within a 5-km radius, and that remaining residents in 17 villages around the volcano were to be evacuated. On 25 November Badan Nacional Penanggulangan Bencana (BNPB) reported that 17,713 people, out of the 20,270 residents living within 5 km, had been evacuated to 31 shelters.
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 CVGHM http://www.vsi.esdm.go.id/,
Badan Nacional Penanggulangan Bencana (BNPB) http://www.bnpb.go.id/
Ongoing Activity
CHIRINKOTAN Kuril Islands 48.980°N, 153.480°E; summit elev. 724 m
SVERT reported that on 22 November a thermal anomaly over Chirinkotan was observed. 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 a thermal anomaly from Snow, a volcano of Chirpoi, was detected in satellite images on 21 and 24 November. 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
COPAHUE Central Chile-Argentina border 37.85°S, 71.17°W; summit elev. 2997 m
Based on satellite images, the Buenos Aires VAAC reported that on 22 November a 5-km-wide steam plume possibly containing ash extended over 35 km SE of Copahue. A few hours later the webcam recorded a possible ash plume drifting SE at low altitudes.
Geologic Summary. Volcán Copahue is an elongated composite cone constructed along the Chile-Argentina border within the 6.5 x 8.5 km wide Trapa-Trapa caldera that formed between 0.6 and 0.4 million years ago near the NW margin of the 20 x 15 km Pliocene Caviahue (Del Agrio) caldera. The eastern summit crater, part of a 2-km-long, ENE-WSW line of nine craters, contains a briny, acidic 300-m-wide crater lake (also referred to as El Agrio or Del Agrio) and displays intense fumarolic activity. Acidic hot springs occur below the eastern outlet of the crater lake, contributing to the acidity of the Río Agrio, and another geothermal zone is located within Caviahue caldera about 7 km NE of the summit. Infrequent mild-to-moderate explosive eruptions have been recorded at Copahue since the 18th century. Twentieth-century eruptions from the crater lake have ejected pyroclastic rocks and chilled liquid sulfur fragments.
Source: Buenos Aires Volcanic Ash Advisory Center (VAAC) http://www.smn.gov.ar/vaac/buenosaires/productos.php
FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m
On 21 November INSIVUMEH reported that a recent Strombolian phase at Fuego decreased in intensity. Explosions generated ash plumes that rose 450 m and drifted W and SW. Ashfall was reported in Sangre de Cristo (8 km WSW). During 21-22 November explosions produced ash plumes that rose 450 m and drifted 7 km WNW, as well as loud rumbling sounds heard within 15 km. Lava flows were 300 m long in the Ceniza drainage (SSW). During 25-26 November ash plume from explosions rose 550 m and drifted 10 km W and SW.
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 that moderate seismic activity at Karymsky was detected during 15-22 November. Satellite images detected a daily thermal anomaly on the volcano during 15-19 November, possibly indicating weak Vulcanian and Strombolian activity. 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 20-26 November 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 7.3-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.
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/
SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m
JMA reported that five explosions from Sakura-jima's Showa Crater ejected tephra as far as 800 m during 18-22 November. Incandescence was occasionally detected by a high resolution camera at night. A very small eruption from Minami-dake Crater occurred on 22 November, producing an ash plume that rose 100 m. The Alert Level remained at 3 (on a scale of 1-5).
The Tokyo VAAC reported that during 20-21 and 23-26 November, explosions generated plumes that rose to altitudes of 1.2-4.9 km (4,000-16,000 ft) a.s.l. and drifted N, E, and SE.
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/index.html,
Tokyo Volcanic Ash Advisory Center (VAAC) http://ds.data.jma.go.jp/svd/vaac/data/vaac_list.html
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 15-22 November 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. Explosions generated ash plumes that rose to altitudes of 4-5 km (13,100-16,400 ft) a.s.l. 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://ds.data.jma.go.jp/svd/vaac/data/vaac_list.html
ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m
Based on analyses of satellite imagery, the Darwin VAAC reported that on 26 November an ash plume from Ulawun rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted 30 km NW.
Geologic Summary. The symmetrical basaltic to andesitic Ulawun stratovolcano is the highest volcano of the Bismarck arc, and one of Papua New Guinea's most frequently active. Ulawun rises above the N coast of New Britain opposite Bamus volcano. The upper 1,000 m of the 2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW side of the volcano, and a flank lava-flow complex lies to the S of this valley. Historical eruptions date back to the beginning of the 18th century. Twentieth-century eruptions were mildly explosive until 1967, but after 1970 several larger eruptions produced lava flows and basaltic pyroclastic flows, greatly modifying the summit crater.
Source: Darwin Volcanic Ash Advisory Centre (VAAC) ftp://ftp.bom.gov.au/anon/gen/vaac/
+++++++++++++++++++++++++++++++++++++
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
__._,_.___
No comments:
Post a Comment