Active volcanoes in the world: December 7 - 13, 2016

Active volcanoes in the world: December 7 - 13, 2016

Between December 7 and 13, new activity was reported for 5 volcanoes. Ongoing activity was reported for 10 volcanoes during the same period.

New activity/unrest: Bezymianny, Central Kamchatka (Russia) | Copahue, Central Chile-Argentina border | Ebeko, Paramushir Island (Russia) | Langila, New Britain (Papua New Guinea) | Sheveluch, Central Kamchatka (Russia).

Ongoing activity: Bagana, Bougainville (Papua New Guinea) | Colima, Mexico  | Dukono, Halmahera (Indonesia) | Fuego, Guatemala | Katmai, United States | Kilauea, Hawaiian Islands (USA) | Nevado del Ruiz, Colombia | Sabancaya, Peru | Suwanosejima, Ryukyu Islands (Japan) | Turrialba, Costa Rica.

New activity/unrest

Bezymianny, Central Kamchatka (Russia)
55.972°N, 160.595°E, Summit elev. 2882 m

Based on KBGS RAS (Kamchatka Branch of Geophysical Services, Russian Academy of Sciences) data, KVERT noted that seismicity at Bezymianny began to increase on 18 November. The temperature of a thermal anomaly detected in satellite images increased on 5 December, and then significantly increased on 13 December, which was likely caused by lava-dome extrusion. The Aviation Color Code was raised to Orange.

Geological summary: Prior to its noted 1955-56 eruption, Bezymianny had been considered extinct. The modern volcano, much smaller in size than its massive neighbors Kamen and Kliuchevskoi, was formed about 4700 years ago over a late-Pleistocene lava-dome complex and an ancestral edifice built about 11,000-7000 years ago. Three periods of intensified activity have occurred during the past 3000 years. The latest period, which was preceded by a 1000-year quiescence, began with the dramatic 1955-56 eruption. This eruption, similar to that of St. Helens in 1980, produced a large horseshoe-shaped crater that was formed by collapse of the summit and an associated lateral blast. Subsequent episodic but ongoing lava-dome growth, accompanied by intermittent explosive activity and pyroclastic flows, has largely filled the 1956 crater.

Copahue, Central Chile-Argentina border
37.856°S, 71.183°W, Summit elev. 2953 m

Based on satellite and webcam images, the Buenos Aires VAAC reported that during 7-9 and 11 December diffuse gas, water vapor, and ash plumes from Copahue rose to altitudes of 3-3.3 km (10,000-11,000 ft) a.s.l. and drifted NE, E, ESE, and SW. Inclement weather mostly prevented observations on 10 December.

Geological 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.

Ebeko, Paramushir Island (Russia)
50.686°N, 156.014°E, Summit elev. 1103 m

KVERT reported that, according to observers in Severo-Kurilsk (Paramushir Island) about 7 km E, a gas-and-steam plume containing a small amount of ash rose from Ebeko to an altitude of 1.5 km (4,900 ft) a.s.l., and drifted 6 km N during 8-9 December. The Aviation Color Code was raised to Yellow (the second lowest on a four-color scale). During 9-10 December gas-and-steam plumes with minor amounts of ash rose from two vents, in Sredniy Crater (middle part) and Severny Crater (N part), to altitudes of 1.8-1.9 km (4,900 ft) a.s.l. and drifted 4-5 km NW.

Geological summary: The flat-topped summit of the central cone of Ebeko volcano, one of the most active in the Kuril Islands, occupies the northern end of Paramushir Island. Three summit craters located along a SSW-NNE line form Ebeko volcano proper, at the northern end of a complex of five volcanic cones. Blocky lava flows extend west from Ebeko and SE from the neighboring Nezametnyi cone. The eastern part of the southern crater contains strong solfataras and a large boiling spring. The central crater is filled by a lake about 20 m deep whose shores are lined with steaming solfataras; the northern crater lies across a narrow, low barrier from the central crater and contains a small, cold crescentic lake. Historical activity, recorded since the late-18th century, has been restricted to small-to-moderate explosive eruptions from the summit craters. Intense fumarolic activity occurs in the summit craters, on the outer flanks of the cone, and in lateral explosion craters.

Langila, New Britain (Papua New Guinea)
5.525°S, 148.42°E, Summit elev. 1330 m

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 8-9, 11, and 13 December ash plumes from Langila rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted over 110 km W, WNW, and N.

Geological summary: Langila, one of the most active volcanoes of New Britain, consists of a group of four small overlapping composite basaltic-andesitic cones on the lower eastern flank of the extinct Talawe volcano. Talawe is the highest volcano in the Cape Gloucester area of NW New Britain. A rectangular, 2.5-km-long crater is breached widely to the SE; Langila volcano was constructed NE of the breached crater of Talawe. An extensive lava field reaches the coast on the north and NE sides of Langila. Frequent mild-to-moderate explosive eruptions, sometimes accompanied by lava flows, have been recorded since the 19th century from three active craters at the summit of Langila. The youngest and smallest crater (no. 3 crater) was formed in 1960 and has a diameter of 150 m.

Sheveluch, Central Kamchatka (Russia)
56.653°N, 161.36°E, Summit elev. 3283 m

KVERT reported that during 2-9 December lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed a thermal anomaly over the dome on clear days, and ash plumes drifting 60 km NW on 8 December.

On 10 December explosions generated ash plumes observed in satellite images that rose to altitudes of 10-11 km (32,800-36,000 ft) a.s.l. and drifted 320 km NNE and N. The Aviation Color Code was raised to Red. Satellite images later that day showed a thermal anomaly over the volcano but no ash emissions; the leading edge of the ash plume released earlier was 910 km NNE, drifting at an altitude of 11 km (36,000 ft). The Aviation Color Code was lowered to Orange.

Geological 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.

Ongoing activity

Bagana, Bougainville (Papua New Guinea)
6.137°S, 155.196°E, Summit elev. 1855 m

Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 8-13 December ash plumes from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted W, SW, S, and NE.

Geological summary: Bagana volcano, occupying a remote portion of central Bougainville Island, is one of Melanesia's youngest and most active volcanoes. This massive symmetrical cone was largely constructed by an accumulation of viscous andesitic lava flows. The entire edifice could have been constructed in about 300 years at its present rate of lava production. Eruptive activity is frequent and characterized by non-explosive effusion of viscous lava that maintains a small lava dome in the summit crater, although explosive activity occasionally producing pyroclastic flows also occurs. Lava flows form dramatic, freshly preserved tongue-shaped lobes up to 50 m thick with prominent levees that descend the flanks on all sides.

Colima, Mexico
19.514°N, 103.62°W, Summit elev. 3850 m

Based on webcam and satellite images, and information from the Mexico City MWO, the Washington VAAC reported that ash plumes from Colima rose to altitudes of 4.6-7.3 km (15,000-24,000 ft) a.s.l. during 7-11 December and drifted almost 170 km in multiple directions.

Geological 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.

Dukono, Halmahera (Indonesia)
1.693°N, 127.894°E, Summit elev. 1229 m

Based on analyses of satellite imagery, VONAs issued by the Dukono Volcano Observatory, and model data, the Darwin VAAC reported that during 7-13 December ash plumes from Dukono rose as high as 3 km (10,000 ft) a.s.l. and drifted as far as 305 km NE, E, and SE.

Geological 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.

Fuego, Guatemala
14.473°N, 90.88°W, Summit elev. 3763 m

INSIVUMEH reported that during 6-7 December the number of explosions at Fuego increased to 3-5 per hour. Ash plumes rose 1 km above the crater and drifted 12 km W and SW, causing ashfall in areas downwind including Morelia (9 km SW), Santa Sofía (12 km SW), Panimaché I and II (8 km SW), El Porvenir (8 km ENE), and San Pedro Yepocapa (8 km N). Incandescent block avalanches reached vegetated areas. Activity continued at the same level through 12 December, although 4-6 explosions per hour were detected during 12-13 December. Ash plumes from explosions during 8-12 December rose as high as 1.1 km and drifted 12-15 km W, SW and S. Ash fell in the same areas downwind. During 8-9 and 11-12 December incandescent material was ejected 200 m above the crater, causing avalanches of material in the crater and towards the main ravines.

Geological 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 3763-m-high Fuego and its twin volcano to the north, Acatenango. Construction of Meseta dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at Acatenango. In contrast to the mostly andesitic Acatenango, eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows.

Katmai, United States
58.28°N, 154.963°W, Summit elev. 2047 m

According to NASA's Earth Observatory, a Moderate Resolution Imaging Spectroradiometer (MODIS) satellite image acquired on 2 December of the Katmai area showed a plume of re-suspended ash which had been deposited during the 1912 eruption.

Geological summary: Prior to 1912, Mount Katmai was a compound stratovolcano with four NE-SW-trending summits, most of which were truncated by caldera collapse in that year. Two or more large explosive eruptions took place from Mount Katmai during the late Pleistocene. Most of the two overlapping pre-1912 Katmai volcanoes are Pleistocene in age, but Holocene lava flows from a flank vent descend the SE flank of the SW stratovolcano into the Katmai River canyon. Katmai was initially considered to be the source of the Valley of Ten Thousand Smokes ash flow in 1912. However, the 3 x 4 km wide caldera of 1912 is now known to have formed as a result of the voluminous eruption at nearby Novarupta volcano. The steep walled young caldera has a jagged rim that rises 500-1000 m above the caldera floor and contains a 250-m-deep, still-rising lake. Lake waters have covered a small post-collapse lava dome (Horseshoe Island) that was seen on the caldera floor at the time of the initial ascent to the caldera rim in 1916. Post-1912 glaciers have formed on a bench within Katmai caldera.

Kilauea, Hawaiian Islands (USA)
19.421°N, 155.287°W, Summit elev. 1222 m

During 7-13 December HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lake level rose as high as 9 m below the Halema’uma’u floor. Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta. An active branch of 61G remained active E of Pu'u 'O'o and advanced slowly E at a rate of only a few tens of meters per day.

Geological 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 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.

Nevado del Ruiz, Colombia
4.892°N, 75.324°W, Summit elev. 5279 m

Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that during 6-12 December seismicity at Nevado del Ruiz was characterized by a decrease in the number and magnitude of earthquakes compared to the previous week. Significant amounts of water vapor and gas rose from the crater. On 7 December a low-energy thermal anomaly near Arenas Crater was detected by the MIROVA system. On 9 December gas and water vapor plumes sometimes containing ash rose 2 km above the crater rim and drifted between SW and NW directions. The Alert Level remained at III (Yellow; the second lowest level on a four-color scale).

Geological summary: Nevado del Ruiz is a broad, glacier-covered volcano in central Colombia that covers >200 sq km. Three major edifices, composed of andesitic and dacitic lavas and andesitic pyroclastics, have been constructed since the beginning of the Pleistocene. The modern cone consists of a broad cluster of lava domes built within the caldera of an older edifice. The 1-km-wide, 240-m-deep Arenas crater occupies the summit. The prominent La Olleta pyroclastic cone located on the SW flank may also have been active in historical time. Steep headwalls of massive landslides cut the flanks. Melting of its summit icecap during historical eruptions, which date back to the 16th century, has resulted in devastating lahars, including one in 1985 that was South America's deadliest eruption.

Sabancaya, Peru
15.78°S, 71.85°W, Summit elev. 5967 m

Although weather clouds often prevented webcam and satellite views of Sabancaya, the Buenos Aires VAAC noted that some clear observations during 7-13 December revealed continuous gas-and-water-vapor emissions with sporadic ash puffs which rose to variable heights. Plumes drifted SW, SE, and ENE.

Geological summary: Sabancaya, located in the saddle NE of Ampato and SE of Hualca Hualca volcanoes, is the youngest of these volcanic centers and the only one to have erupted in historical time. The oldest of the three, Nevado Hualca Hualca, is of probable late-Pliocene to early Pleistocene age. The name Sabancaya (meaning "tongue of fire" in the Quechua language) first appeared in records in 1595 CE, suggesting activity prior to that date. Holocene activity has consisted of Plinian eruptions followed by emission of voluminous andesitic and dacitic lava flows, which form an extensive apron around the volcano on all sides but the south. Records of historical eruptions date back to 1750.

Suwanosejima, Ryukyu Islands (Japan)
29.638°N, 129.714°E, Summit elev. 796 m

Based on JMA notices, pilot observations, and satellite-image analyses, the Tokyo VAAC reported that explosions at Suwanosejima on 13 December generated ash plumes that rose to an altitude of 4 km (13,000 ft) a.s.l. and drifted NE.

Geological summary: The 8-km-long, spindle-shaped island of Suwanosejima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two historically active summit craters. The summit of the volcano is truncated by a large breached crater extending to the sea on the east flank that was formed by edifice collapse. Suwanosejima, one of Japan's most frequently active volcanoes, was in a state of intermittent strombolian activity from Otake, the NE summit crater, that began in 1949 and lasted until 1996, after which periods of inactivity lengthened. The largest historical eruption took place in 1813-14, when thick scoria deposits blanketed residential areas, and the SW crater produced two lava flows that reached the western coast. At the end of the eruption the summit of Otake collapsed forming a large debris avalanche and creating the horseshoe-shaped Sakuchi caldera, which extends to the eastern coast. The island remained uninhabited for about 70 years after the 1813-1814 eruption. Lava flows reached the eastern coast of the island in 1884. Only about 50 people live on the island.

Turrialba, Costa Rica
10.025°N, 83.767°W, Summit elev. 3340 m

OVSICORI-UNA reported that after three days of continuous ash emissions at Turrialba activity decreased during the morning of 8 December. Weak and sporadic emissions rising no higher than 200 m above the vent were observed in the afternoon. Events at 0919 and 0934 on 9 December produced ash plumes that rose 500 m and drifted NW. Weak and sporadic ash emissions the rest of the day rose no higher than 500 m. Passive ash emissions on 12 December did not exceed 500 m and drifted NW.

Geological summary: Turrialba, the easternmost of Costa Rica's Holocene volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano located across a broad saddle NE of Irazú volcano overlooking the city of Cartago. The massive 3340-m-high Turrialba is exceeded in height only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's most voluminous volcanoes. Three well-defined craters occur at the upper SW end of a broad 800 x 2200 m summit depression that is breached to the NE. Most activity originated from the summit vent complex, but two pyroclastic cones are located on the SW flank. Five major explosive eruptions have occurred during the past 3500 years. A series of explosive eruptions during the 19th century were sometimes accompanied by pyroclastic flows. Fumarolic activity continues at the central and SW summit craters.

Source: GVP

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