Active volcanoes in the world: November 18 - 24, 2015

Active volcanoes in the world: November 18 - 24, 2015

New activity/unrest was observed at 5 volcanoes from November 18 - 24, 2015. During the same period, ongoing activity was reported for 25 volcanoes.

New activity/unrest: Awu, Sangihe Islands (Indonesia) | Ibu, Halmahera (Indonesia) | Kanlaon, Philippines | Telica, Nicaragua | Tengger Caldera, Eastern Java (Indonesia).

Ongoing activity: Asosan, Kyushu (Japan) | Chirinkotan, Kuril Islands (Russia) | Chirpoi, Kuril Islands (Russia) | Colima, Mexico | Copahue, Central Chile-Argentina border | Cotopaxi, Ecuador | Dukono, Halmahera (Indonesia) | Gamkonora, Halmahera (Indonesia) | Hakoneyama, Honshu (Japan) | Karangetang, Siau Island (Indonesia) | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaiian Islands (USA) | Lokon-Empung, Sulawesi (Indonesia) | Marapi, Indonesia | Nishinoshima, Japan | Paluweh, Indonesia | Papandayan, Western Java (Indonesia) | Reventador, Ecuador | Rinjani, Lombok Island (Indonesia) | Semeru, Eastern Java (Indonesia) | Sheveluch, Central Kamchatka (Russia) | Shishaldin, Fox Islands (USA) | Sinabung, Indonesia | Soputan, Sulawesi (Indonesia) | Tungurahua, Ecuador.

New activity/unrest

Awu, Sangihe Islands (Indonesia)
3.67°N, 125.5°E, Elevation 1320 m

PVMBG reported that during 1-24 November the seismic network at Awu detected a significant increase in seismicity, especially in the number of shallow volcanic earthquakes (from a baseline maximum of 4 per day to 74 events on 24 November). The Alert Level was increased to 2 (on a scale of 1-4). Fog prevented visual observations.

Geologic summary: The massive Gunung Awu stratovolcano occupies the northern end of Great Sangihe Island, the largest of the Sangihe arc. Deep valleys that form passageways for lahars dissect the flanks of the 1320-m-high volcano, which was constructed within a 4.5-km-wide caldera. Awu is one of Indonesia's deadliest volcanoes; powerful explosive eruptions in 1711, 1812, 1856, 1892, and 1966 produced devastating pyroclastic flows and lahars that caused more than 8000 cumulative fatalities. Awu contained a summit crater lake that was 1 km wide and 172 m deep in 1922, but was largely ejected during the 1966 eruption.

Ibu, Halmahera (Indonesia)
1.488°N, 127.63°E, Elevation 1325 m

PVMBG reported that during 1-17 November white-to-gray plumes rose as high as 450 m above Ibu’s summit crater. Seismicity was dominated by signals indicating surface or near-surface activity, and the continued growth of the lava dome. The Alert Level remained at 2 (on a scale of 1-4). The public was warned to stay at least 2 km away from the active crater, and 3.5 km away on the N side.

Geologic summary: The truncated summit of Gunung Ibu stratovolcano along the NW coast of Halmahera Island has large nested summit craters. The inner crater, 1 km wide and 400 m deep, contained several small crater lakes through much of historical time. The outer crater, 1.2 km wide, is breached on the north side, creating a steep-walled valley. A large parasitic cone is located ENE of the summit. A smaller one to the WSW has fed a lava flow down the W flank. A group of maars is located below the N and W flanks. Only a few eruptions have been recorded in historical time, the first a small explosive eruption from the summit crater in 1911. An eruption producing a lava dome that eventually covered much of the floor of the inner summit crater began in December 1998.

Kanlaon, Philippines
10.412°N, 123.132°E, Elevation 2435 m

PHIVOLCS reported that the seismic network for Kanlaon detected an explosion-type signal beginning at 0930 on 23 November, culminating with an 8-minute-long steam explosion. Observers reported that a white plume rose 1-1.5 km above the crater and drifted SW, and rumbling was heard in local areas. Only four volcanic earthquakes had been recorded during the previous week, but after the explosion, the network detected volcanic tremor that lasted for five hours. The Alert Level was raised to 1 (on a scale of 0-5). Continuous steam emissions with minor ash content were observed the next morning.

Geologic summary: Kanlaon volcano (also spelled Canlaon), the most active of the central Philippines, forms the highest point on the island of Negros. The massive 2435-m-high andesitic stratovolcano is dotted with fissure-controlled pyroclastic cones and craters, many of which are filled by lakes. The largest debris avalanche known in the Philippines traveled 33 km to the SW from Kanlaon. The summit of Kanlaon contains a 2-km-wide, elongated northern caldera with a crater lake and a smaller, but higher, historically active vent, Lugud crater, to the south. Historical eruptions from Kanlaon, recorded since 1866, have typically consisted of phreatic explosions of small-to-moderate size that produce minor ashfalls near the volcano.

Telica, Nicaragua
12.602°N, 86.845°W, Elevation 1061 m

Based on wind and satellite data, pilot observations, and webcam images, the Washington VAAC reported that on 22 November an ash plume from Telica rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted almost 100 km W. According to news articles, (at least) two explosions, at 0847 and 0848, generated ash plumes that rose 2 km and ejected tephra at least 900 m away. An unstated number of people living within a 900-m-radius evacuated, and residents in Agua Fría (also 900 m away) noted it was the first time variously-sized lapilli and blocks had reached their community. Ash fell in at least 70 communities in the municipalities of Quezalguaque (13 km SW), Posoltega (16 km WSW), Chichigalpa (20 km WSW), and Chinandega (30 km W).

Geologic summary: Telica, one of Nicaragua's most active volcanoes, has erupted frequently since the beginning of the Spanish era. This volcano group consists of several interlocking cones and vents with a general NW alignment. Sixteenth-century eruptions were reported at symmetrical Santa Clara volcano at the SW end of the group. However, its eroded and breached crater has been covered by forests throughout historical time, and these eruptions may have originated from Telica, whose upper slopes in contrast are unvegetated. The steep-sided cone of 1061-m-high Telica is truncated by a 700-m-wide double crater; the southern crater, the source of recent eruptions, is 120 m deep. El Liston, immediately SE of Telica, has several nested craters. The fumaroles and boiling mudpots of Hervideros de San Jacinto, SE of Telica, form a prominent geothermal area frequented by tourists, and geothermal exploration has occurred nearby.

Tengger Caldera, Eastern Java (Indonesia)
7.942°S, 112.95°E, Elevation 2329 m

PVMBG reported that during 1 August-16 November white plumes from Tengger Caldera's Bromo cone rose as high as 150 m above the crater, and an intense sulfur dioxide odor was noted at the Bromo observation post. On 5, 8, and 12 November booming was reported and emissions rose 1.2 km above the crater; diffuse amounts of ash were present in the emissions on 12 November. Seismicity was dominated by tremor, but also included deep and shallow volcanic earthquakes. The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were warned not to approach the crater within a radius of 1 km.

Geologic summary: The 16-km-wide Tengger caldera is located at the northern end of a volcanic massif extending from Semeru volcano. The massive volcanic complex dates back to about 820,000 years ago and consists of five overlapping stratovolcanoes, each truncated by a caldera. Lava domes, pyroclastic cones, and a maar occupy the flanks of the massif. The Ngadisari caldera at the NE end of the complex formed about 150,000 years ago and is now drained through the Sapikerep valley. The most recent of the calderas is the 9 x 10 km wide Sandsea caldera at the SW end of the complex, which formed incrementally during the late Pleistocene and early Holocene. An overlapping cluster of post-caldera cones was constructed on the floor of the Sandsea caldera within the past several thousand years. The youngest of these is Bromo, one of Java's most active and most frequently visited volcanoes.

Ongoing activity

Asosan, Kyushu (Japan)
32.884°N, 131.104°E, Elevation 1592 m

JMA reported that during 16-24 November white plumes rose 400-500 m above the rim of Asosan’s Nakadake Crater. The Alert Level was lowered to 2 (on a scale of 1-5).

Geologic summary: The 24-km-wide Asosan caldera was formed during four major explosive eruptions from 300,000 to 90,000 years ago. These produced voluminous pyroclastic flows that covered much of Kyushu. The last of these, the Aso-4 eruption, produced more than 600 cu km of airfall tephra and pyroclastic-flow deposits. A group of 17 central cones was constructed in the middle of the caldera, one of which, Nakadake, is one of Japan's most active volcanoes. It was the location of Japan's first documented historical eruption in 553 AD. The Nakadake complex has remained active throughout the Holocene. Several other cones have been active during the Holocene, including the Kometsuka scoria cone as recently as about 210 CE. Historical eruptions have largely consisted of basaltic to basaltic-andesite ash emission with periodic strombolian and phreatomagmatic activity. The summit crater of Nakadake is accessible by toll road and cable car, and is one of Kyushu's most popular tourist destinations.

Chirinkotan, Kuril Islands (Russia)
48.98°N, 153.48°E, Elevation 724 m

SVERT reported that on 17 November gas-and-steam emissions from Chirinkotan were detected in satellite images. Cloud cover prevented views of the volcano during 18-23 November. 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.

Chirpoi, Kuril Islands (Russia)
46.525°N, 150.875°E, Elevation 742 m

SVERT reported that satellite images over Snow, a volcano of Chirpoi, detected a thermal anomaly on 17 and 19 November. Cloud cover prevented views of the volcano on the other days during 16-23 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. 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.

Colima, Mexico
19.514°N, 103.62°W, Elevation 3850 m

Based on satellite images, wind data, webcam images, and notices from the Mexico City MWO, the Washington VAAC reported that during 18-20 and 22-23 November ash plumes from Colima rose to altitudes of 4.9-7 km (16,000-23,000 ft) a.s.l. and drifted NW, W, and SW.

Geologic summary: The Colima volcanic complex is the most prominent volcanic center of the western Mexican Volcanic Belt. It consists of two southward-younging volcanoes, Nevado de Colima (the 4320 m high point of the complex) on the north and the 3850-m-high historically active Volcán de Colima at the south. A group of cinder cones of late-Pleistocene age is located on the floor of the Colima graben west and east of the Colima complex. Volcán de Colima (also known as Volcán Fuego) is a youthful stratovolcano constructed within a 5-km-wide caldera, breached to the south, that has been the source of large debris avalanches. Major slope failures have occurred repeatedly from both the Nevado and Colima cones, and have produced a thick apron of debris-avalanche deposits on three sides of the complex. Frequent historical eruptions date back to the 16th century. Occasional major explosive eruptions (most recently in 1913) have destroyed the summit and left a deep, steep-sided crater that was slowly refilled and then overtopped by lava dome growth.

Copahue, Central Chile-Argentina border
37.856°S, 71.183°W, Elevation 2953 m

SERNAGEOMIN reported that at 1930 on 19 November tremor amplitude at Copahue began to oscillate. At 0305 on 20 November crater incandescence was coincident with small explosions that produced ash plumes. The Alert Level remained at Yellow; SERNAGEOMIN recommended no entry into a restricted area within 1.5 km of the crater. ONEMI maintained Level Yellow for the community of Alto Biobío (40 km W) in the Biobío region (since 3 June 2013). 

Based on webcam images, the Buenos Aires VAAC reported continuous emissions of water vapor and gas with minor amounts of ash on 20 November; ash was not detected in satellite images.

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.

Cotopaxi, Ecuador
0.677°S, 78.436°W, Elevation 5911 m

IG reported that during 18-24 November gas, steam, and ash plumes rose almost daily from Cotopaxi, as high as 1.5 km above the crater, and drifted W, and SW. Ashfall was reported in Machachi and Aloasí on 18 November.

Geologic summary: Symmetrical, glacier-clad Cotopaxi stratovolcano is Ecuador's most well-known volcano and one of its most active. The steep-sided cone is capped by nested summit craters, the largest of which is about 550 x 800 m in diameter. Deep valleys scoured by lahars radiate from the summit of the andesitic volcano, and large andesitic lava flows extend as far as the base of Cotopaxi. The modern conical volcano has been constructed since a major edifice collapse sometime prior to about 5000 years ago. Pyroclastic flows (often confused in historical accounts with lava flows) have accompanied many explosive eruptions of Cotopaxi, and lahars have frequently devastated adjacent valleys. The most violent historical eruptions took place in 1744, 1768, and 1877. Pyroclastic flows descended all sides of the volcano in 1877, and lahars traveled more than 100 km into the Pacific Ocean and western Amazon basin. The last significant eruption of Cotopaxi took place in 1904.

Dukono, Halmahera (Indonesia)
1.68°N, 127.88°E, Elevation 1335 m

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 18-24 November ash plumes from Dukono rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 55-165 km in multiple directions.

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 north-flank cone of Gunung Mamuya. This complex volcano presents a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also been active during historical time.

Gamkonora, Halmahera (Indonesia)
1.38°N, 127.53°E, Elevation 1635 m

PVMBG reported that observers at the Gamkonora observation post in Gamsungi (6 km NW), West Halmahera, reported that during 1-15 November diffuse white plumes rose up to 100 m above the crater rim. RSAM values fluctuated; tremor continued to be elevated. The Alert Level remained at 2 (on a scale of 1-4). Residents and tourists were asked not to venture near the crater within a radius of 1.5 km.

Geologic summary: The shifting of eruption centers on Gamkonora, at 1635 m the highest peak of Halmahera, has produced an elongated series of summit craters along a N-S trending rift. Youthful-looking lava flows originate near the cones of Gunung Alon and Popolojo, south of Gamkonora. Since its first recorded eruption in the 16th century, Gamkonora has typically produced small-to-moderate explosive eruptions. Its largest historical eruption, in 1673, was accompanied by tsunamis that inundated villages.

Hakoneyama, Honshu (Japan)
35.233°N, 139.021°E, Elevation 1438 m

According to a news article from 20 November, JMA lowered the Alert Level for Hakoneyama to 1 (on a scale of 1-5) due to continuing low levels of seismicity.

Geologic summary: Hakoneyama volcano is truncated by two overlapping calderas, the largest of which is 10 x 11 km wide. The calderas were formed as a result of two major explosive eruptions about 180,000 and 49,000-60,000 years ago. Scenic Lake Ashi lies between the SW caldera wall and a half dozen post-caldera lava domes that were constructed along a SW-NE trend cutting through the center of the calderas. Dome growth occurred progressively to the south, and the largest and youngest of these, Kamiyama, forms the high point of Hakoneyama. The calderas are breached to the east by the Hayakawa canyon. A phreatic explosion about 3000 years ago was followed by collapse of the NW side of Kamiyama, damming the Hayakawa valley and creating Lake Ashi. The latest magmatic eruptive activity about 2900 years ago produced a pyroclastic flow and a lava dome in the explosion crater, although phreatic eruptions took place as recently as the 12-13th centuries CE. Seismic swarms have occurred during the 20th century. Lake Ashi, along with major thermal areas in the caldera, forms a popular resort area SW of Tokyo.

Karangetang, Siau Island (Indonesia)
2.78°N, 125.4°E, Elevation 1784 m

Based on observations conducted at the Karangetang Volcano Observation Post in the village of Salili, PVMBG reported during 11-18 November that the lava dome was incandescent at night. Variable amounts of white emissions rose as high as 200 m above Main Crater. RSAM values had been stable since 6 November. The Alert Level remained at 3 (on a scale of 1-4); visitors and residents were warned not to approach Karangetang within a 4-km radius.

Geologic summary: Karangetang (Api Siau) volcano lies at the northern end of the island of Siau, north of Sulawesi. The 1784-m-high stratovolcano contains five summit craters along a N-S line. Karangetang is one of Indonesia's most active volcanoes, with more than 40 eruptions recorded since 1675 and many additional small eruptions that were not documented in the historical record (Catalog of Active Volcanoes of the World: Neumann van Padang, 1951). Twentieth-century eruptions have included frequent explosive activity sometimes accompanied by pyroclastic flows and lahars. Lava dome growth has occurred in the summit craters; collapse of lava flow fronts has also produced pyroclastic flows.

Karymsky, Eastern Kamchatka (Russia)
54.049°N, 159.443°E, Elevation 1513 m

KVERT reported that moderate explosive activity at Karymsky continued during 13-20 November. Satellite images detected ash plumes drifting 160 km E during 16-17 November. 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 during the early Holocene. The caldera cuts the south side of the Pleistocene Dvor volcano and is located outside the north margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, located immediately south. The caldera enclosing Karymsky formed about 7600-7700 radiocarbon years ago; construction of the stratovolcano began about 2000 years later. The latest eruptive period began about 500 years ago, following a 2300-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.

Kilauea, Hawaiian Islands (USA)
19.421°N, 155.287°W, Elevation 1222 m

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 18-24 November. Thelava lake continued to circulate and spatter in the Overlook vent. A very long-period earthquake detected at 0230 on 24 November corresponded with the collapse of a very large section of the N rim and wall of the summit vent which caused increased lake spattering and turbulence. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o; a lava flow erupted from a vent on the crater floor on 24 November. The June 27th NE-trending lava flow continued to be active within 1.9-6.1 km NE of Pu'u 'O'o Crater.

Geologic summary: Kilauea volcano, which overlaps the east flank of the massive Mauna Loa shield volcano, has been Hawaii's most active volcano during historical time. Eruptions of Kilauea are prominent in Polynesian legends; written documentation extending back to only 1820 records frequent summit and flank lava flow eruptions that were interspersed with periods of long-term lava lake activity that lasted until 1924 at Halemaumau crater, within the summit caldera. The 3 x 5 km caldera was formed in several stages about 1500 years ago and during the 18th century; eruptions have also originated from the lengthy East and SW rift zones, which extend to the sea on both sides of the volcano. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1100 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.

Lokon-Empung, Sulawesi (Indonesia)
1.358°N, 124.792°E, Elevation 1580 m

Although inclement weather sometimes obscured views of Lokon-Empung's Tompaluan Crater, PVMBG reported that during 12-19 November observers at the post in Kakaskasen Tomohon (North Sulawesi, 4 km from the crater), saw white plumes rising as high as 400 m above the crater. Seismicity fluctuated, but the seismic spectral amplitude measurement (SSAM) showed a gradually increasing trend. The Alert Level remained at 3 (on a scale of 1-4). Residents and tourists were reminded not to approach the crater within a radius of 2.5 km.

Geologic summary: The twin volcanoes Lokon and Empung, rising about 800 m above the plain of Tondano, are among the most active volcanoes of Sulawesi. Lokon, the higher of the two peaks (whose summits are only 2.2 km apart), has a flat, craterless top. The morphologically younger Empung volcano has a 400-m-wide, 150-m-deep crater that erupted last in the 18th century, but all subsequent eruptions have originated from Tompaluan, a 150 x 250 m wide double crater situated in the saddle between the two peaks. Historical eruptions have primarily produced small-to-moderate ash plumes that have occasionally damaged croplands and houses, but lava-dome growth and pyroclastic flows have also occurred.

Marapi, Indonesia
0.381°S, 100.473°E, Elevation 2891 m

PVMBG reported that during 1 August-16 November diffuse white plumes rose as high as 150 m above Marapi, inclement weather prevented observations during October and periodically during the other months. Seismicity fluctuated; the number of tremor, tornillo-type, and signals indicating emissions increased. The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were advised not to enter an area within 3 km of the summit.

Geologic summary: Gunung Marapi, not to be confused with the better-known Merapi volcano on Java, is Sumatra's most active volcano. This massive complex stratovolcano rises 2000 m above the Bukittinggi plain in the 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, with volcanism migrating to the west. More than 50 eruptions, typically consisting of small-to-moderate explosive activity, have been recorded since the end of the 18th century; no lava flows outside the summit craters have been reported in historical time.

Nishinoshima, Japan
27.247°N, 140.874°E, Elevation 25 m

According to a news article from 22 November, recent footage (from the previous week) of Nishinoshima showed that the eruption was ongoing with explosion from the central crater and lava flows. The new island was 1.9 km E to W, 1.95 km N to S, and 100 m high, based on Coast Guard reports.

Geologic summary: The small island of Nishinoshima 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 S, W, and NE. The summit of the southern cone rises to within 214 m of the sea surface 9 km SSE.

Paluweh, Indonesia
8.32°S, 121.708°E, Elevation 875 m

PVMBG reported that observers at a post located in Kampung Ropa, Keliwumbu Village, noted that during 3-17 November diffuse white plumes rose as high as 75 m above Paluweh. Seismicity remained relatively stable, and was characterized by shallow and deep volcanic earthquakes, and signals indicating emissions and avalanches. The Alert Level remained at 2 (on a scale of 1-4). Residents and tourists were reminded not to approach the summit within a radius of 1.5 km.

Geologic summary: Paluweh volcano, also known as Rokatenda, forms the 8-km-wide island of Paluweh north of the volcanic arc that cuts across Flores Island. Although the volcano rises about 3000 m above the sea floor, its summit reaches only 875 m above sea level. The broad irregular summit region contains overlapping craters up to 900 m wide and several lava domes. Several flank vents occur along a NW-trending fissure. The largest historical eruption occurred in 1928, when strong explosive activity was accompanied by landslide-induced tsunamis and lava dome emplacement.

Papandayan, Western Java (Indonesia)
7.32°S, 107.73°E, Elevation 2665 m

PVMBG reported that during 1 September-16 November seismicity at Papandayan was dominated by shallow volcanic earthquakes but also consisted of deep volcanic earthquakes, low-frequency earthquakes, harmonic tremor, and hybrid events. Visual monitoring occurred from the Pakuwon Village post where observers noted white plumes rising at most 35 m above the crater. The Alert Level remained at 2 (on a scale of 1-4); residents and tourists were reminded not to approach the craters within a 1-km radius.

Geologic summary: Papandayan is a complex stratovolcano with four large summit craters, the youngest of which was breached to the NE by collapse during a brief eruption in 1772 and contains active fumarole fields. The broad 1.1-km-wide, flat-floored Alun-Alun crater truncates the summit of Papandayan, and Gunung Puntang to the north gives the volcano a twin-peaked appearance. Several episodes of collapse have given the volcano an irregular profile and produced debris avalanches that have impacted lowland areas beyond the volcano. A sulfur-encrusted fumarole field occupies historically active Kawah Mas ("Golden Crater"). After its first historical eruption in 1772, in which collapse of the NE flank produced a catastrophic debris avalanche that destroyed 40 villages and killed nearly 3000 persons, only small phreatic eruptions had occurred prior to an explosive eruption that began in November 2002.

Reventador, Ecuador
0.077°S, 77.656°W, Elevation 3562 m

During 18-24 November IG reported a high level of seismic activity including explosions, volcano-tectonic events, long-period earthquakes, harmonic tremor, and signals indicating emissions at Reventador; cloud cover often prevented visual observations. Steam, gas, and ash emissions rose 500 m above the crater and drifted W on 20 November. Multiple steam-and-ash plumes rose as high as 2 km and drifted W on 22 November, and ejected incandescent blocks rolled 500 m down the flanks.

Geologic summary: Reventador is the most frequently active of a chain of Ecuadorian volcanoes in the Cordillera Real, well east of the principal volcanic axis. The forested, dominantly andesitic Volcán El Reventador stratovolcano rises to 3562 m above the jungles of the western Amazon basin. A 4-km-wide caldera widely breached to the east was formed by edifice collapse and is partially filled by a young, unvegetated stratovolcano that rises about 1300 m above the caldera floor to a height comparable to the caldera rim. It has been the source of numerous lava flows as well as explosive eruptions that were visible from Quito in historical time. Frequent lahars in this region of heavy rainfall have constructed a debris plain on the eastern floor of the caldera. The largest historical eruption took place in 2002, producing a 17-km-high eruption column, pyroclastic flows that traveled up to 8 km, and lava flows from summit and flank vents.

Rinjani, Lombok Island (Indonesia)
8.42°S, 116.47°E, Elevation 3726 m

Based on satellite and pilot observations, the Darwin VAAC reported that during 18-23 November ash plumes from Rinjani rose to altitudes of 3-4.3 km (10,000-14,000 ft) a.s.l. and drifted as far as 95 km SW, WNW, and W. A thermal anomaly was visible on 18 November; that same day the VAAC noted that activity had continued to decline.

Geologic summary: Rinjani volcano on the island of Lombok rises to 3726 m, second in height among Indonesian volcanoes only to Sumatra's Kerinci volcano. Rinjani has a steep-sided conical profile when viewed from the east, but the west side of the compound volcano is truncated by the 6 x 8.5 km, oval-shaped Segara Anak (Samalas) caldera. The caldera formed during one of the largest Holocene eruptions globally in 1257 CE, which truncated Samalas stratovolcano. The western half of the caldera contains a 230-m-deep lake whose crescentic form results from growth of the post-caldera cone Barujari at the east end of the caldera. Historical eruptions dating back to 1847 have been restricted to Barujari cone and consist of moderate explosive activity and occasional lava flows that have entered Segara Anak lake.

Semeru, Eastern Java (Indonesia)
8.108°S, 112.92°E, Elevation 3676 m

PVMBG reported that during 1 June-15 November both white plumes and gray-to-brownish plumes from Semeru were observed rising as high as 600 m above the crater and drifting in multiple directions; inclement weather sometimes prevented observations. The ash plumes were generated by frequent explosions; 32-74 explosions occurred per month during the June-October interval, although only 7 were counted during the first half of November. A few avalanches traveled 300-500 m S down the Besuk Kembar drainage during July-August. Two incandescent avalanches traveled 500 m down the drainage during 1-15 November. The Alert Level remained at 2 (on a scale from 1-4); visitors and residents were warned to avoid the SE flank within 4 km of the crater.

Geologic summary: Semeru, the highest volcano on Java, and one of its most active, lies at the southern end of a volcanic massif extending north to the Tengger caldera. The steep-sided volcano, also referred to as Mahameru (Great Mountain), rises abruptly to 3676 m above coastal plains to the south. Gunung Semeru was constructed south of the overlapping Ajek-ajek and Jambangan calderas. A line of lake-filled maars was constructed along a N-S trend cutting through the summit, and cinder cones and lava domes occupy the eastern and NE flanks. Summit topography is complicated by the shifting of craters from NW to SE. Frequent 19th and 20th century eruptions were dominated by small-to-moderate explosions from the summit crater, with occasional lava flows and larger explosive eruptions accompanied by pyroclastic flows that have reached the lower flanks of the volcano. Semeru has been in almost continuous eruption since 1967.

Sheveluch, Central Kamchatka (Russia)
56.653°N, 161.36°E, Elevation 3283 m

KVERT reported that during 13-20 November lava-dome extrusion onto Sheveluch’s N flank was accompanied by fumarolic activity, dome incandescence, ashexplosions, and hot avalanches. Satellite images detected a daily thermal anomaly over the dome. The Aviation Color Code remained at Orange.

Geologic summary: The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1300 cu km volcano is one of Kamchatka's largest and most active volcanic structures. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes dot its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large horseshoe-shaped caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. At least 60 large eruptions have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera.

Shishaldin, Fox Islands (USA)
54.756°N, 163.97°W, Elevation 2857 m

AVO reported that no anomalous activity at Shishaldin had been observed in satellite data since weakly elevated surface temperatures were detected on 16 October. In addition, low-amplitude seismic tremor continued but was likely not indicative of a continuing eruption. The Aviation Color Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory.

Geologic summary: The beautifully symmetrical volcano of Shishaldin is the highest and one of the most active volcanoes of the Aleutian Islands. The 2857-m-high, glacier-covered volcano is the westernmost of three large stratovolcanoes along an E-W line in the eastern half of Unimak Island. The Aleuts named the volcano Sisquk, meaning "mountain which points the way when I am lost." A steady steam plume rises from its small summit crater. Constructed atop an older glacially dissected volcano, it is Holocene in age and largely basaltic in composition. Remnants of an older ancestral volcano are exposed on the west and NE sides at 1500-1800 m elevation. There are over two dozen pyroclastic cones on its NW flank, which is blanketed by massive aa lava flows. Frequent explosive activity, primarily consisting of strombolian ash eruptions from the small summit crater, but sometimes producing lava flows, has been recorded since the 18th century.

Sinabung, Indonesia
3.17°N, 98.392°E, Elevation 2460 m

Based on information from PVMBG, the Darwin VAAC reported that on 24 November ash plumes from Sinabung rose to an altitude of 3.3 km (11,000 ft) a.s.l.

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 in 1912. No confirmed historical eruptions were recorded prior to explosive eruptions during August-September 2010 that produced ash plumes to 5 km above the summit.

Soputan, Sulawesi (Indonesia)
1.108°N, 124.73°E, Elevation 1784 m

PVMBG reported that during 3-18 November white plumes were observed rising as high as 200 m above Soputan even though inclement weather sometimes obscured crater views. Seismicity was dominated by emission and avalanche signals, but was also characterized by low-frequency signals and volcanic earthquakes. The Alert Level remained at 2 (on a scale of 1-4). Residents and tourists were advised not to approach the craters within a radius of 1.5 km, or 2.5 km on the WSW flank.

Geologic summary: The small Soputan stratovolcano on the southern rim of the Quaternary Tondano caldera on the northern arm of Sulawesi Island is one of Sulawesi's most active volcanoes. The youthful, largely unvegetated volcano rises to 1784 m and is located SW of Sempu volcano. It was constructed at the southern end of a SSW-NNE trending line of vents. During historical time the locus of eruptions has included both the summit crater and Aeseput, a prominent NE-flank vent that formed in 1906 and was the source of intermittent major lava flows until 1924.

Tungurahua, Ecuador
1.467°S, 78.442°W, Elevation 5023 m

IG reported high seismic activity at Tungurahua during 17-24 November, characterized by long-period events, volcano-tectonic events, explosions, and signals indicating emissions; cloud cover sometimes prevented visual observations. Almost daily ash-and-gas emissions rose as high as 3 km above the crater and drifted SW, W, and NW. Ashfall was reported on most days, in areas including Choglontus (13 km WSW), Manzanó (8 km SW), Cotaló (8 km NW), Bilbao (8 km W), Chontapamba (W), Penipe (15 km SW), Cevallos (23 km NW), Mocha (25 km W), Chacauco (NW), Cusúa (8 km NW), and Píllate (8 km W). Incandescentblocks rolled 500 m down the flanks during 18-19 November.

Geologic summary: Tungurahua, a steep-sided andesitic-dacitic stratovolcano that towers more than 3 km above its northern base, is one of Ecuador's most active volcanoes. Three major edifices have been sequentially constructed since the mid-Pleistocene over a basement of metamorphic rocks. Tungurahua II was built within the past 14,000 years following the collapse of the initial edifice. Tungurahua II itself collapsed about 3000 years ago and produced a large debris-avalanche deposit and a horseshoe-shaped caldera open to the west, inside which the modern glacier-capped stratovolcano (Tungurahua III) was constructed. Historical eruptions have all originated from the summit crater, accompanied by strong explosions and sometimes by pyroclastic flows and lava flows that reached populated areas at the volcano's base. Prior to a long-term eruption beginning in 1999 that caused the temporary evacuation of the city of Baños at the foot of the volcano, the last major eruption had occurred from 1916 to 1918, although minor activity continued until 1925.

Source: GVP

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