New activity/unrest was observed at 2 volcanoes from January 6 - 12, 2016. During the same period, ongoing activity was reported for 14 volcanoes.
New activity/unrest: Masaya, Nicaragua | Soputan, Sulawesi (Indonesia).
Ongoing activity: Chirpoi, Kuril Islands (Russia) | Colima, Mexico | Copahue, Central Chile-Argentina border | Dukono, Halmahera (Indonesia) | Fuego, Guatemala | Karangetang, Siau Island (Indonesia) | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaiian Islands (USA) | Lokon-Empung, Sulawesi (Indonesia) | Semeru, Eastern Java (Indonesia) | Sheveluch, Central Kamchatka (Russia) | Sinabung, Indonesia | Suwanosejima, Ryukyu Islands (Japan) | Tengger Caldera, Eastern Java (Indonesia).
11.984°N, 86.161°W, Summit elev. 635 m
INETER reported that during 6-8 January the lava lake at Masaya was observed in satellite images and sloshing sounds were noted. Gas emissions rose as high as 400 m above the crater and drifted W and SW. On 8 January very small explosions ejected tephra onto the crater.
Geologic summary: Masaya is one of Nicaragua's most unusual and most active volcanoes. It lies within the massive Pleistocene Las Sierras pyroclastic shield volcano and is a broad, 6 x 11 km basaltic caldera with steep-sided walls up to 300 m high. The caldera is filled on its NW end by more than a dozen vents that erupted along a circular, 4-km-diameter fracture system. The twin volcanoes of Nindirí and Masaya, the source of historical eruptions, were constructed at the southern end of the fracture system and contain multiple summit craters, including the currently active Santiago crater. A major basaltic plinian tephra erupted from Masaya about 6500 years ago. Historical lava flows cover much of the caldera floor and have confined a lake to the far eastern end of the caldera. A lava flow from the 1670 eruption overtopped the north caldera rim. Masaya has been frequently active since the time of the Spanish Conquistadors, when an active lava lake prompted attempts to extract the volcano's molten "gold." Periods of long-term vigorous gas emission at roughly quarter-century intervals cause health hazards and crop damage.
Soputan, Sulawesi (Indonesia)
1.112°N, 124.737°E, Summit elev. 1785 m
On 6 January BNPB reported that several explosions had been detected since the Alert Level for Soputan was raised to 3 (on a scale of 1-4) on 4 January. Strombolian activity that began at 0350 on 5 January ejected incandescent material as high as 250 m above the crater. A booming sound at 0638 was followed by a pyroclastic flow that traveled 2.5 km down the ENE flank. Ash plumes rose 6.5 km above the crater and drifted W. Several villages in the districts of West Langowan (8 km E), Tompaso (11 km NE), and East Ratahan (14 km SE) reported ashfall. Residents and tourists were advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank.
Geologic summary: The 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 Riendengan-Sempu, which some workers have included with Soputan and Manimporok (3.5 km ESE) as a volcanic complex. 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.
Chirpoi, Kuril Islands (Russia)
46.525°N, 150.875°E, Summit elev. 742 m
SVERT reported that satellite images detected a thermal anomaly over Snow, a volcano of Chirpoi, on 9 January. 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.
19.514°N, 103.62°W, Summit elev. 3850 m
Based on satellite images, wind data, webcam images, and notices from the Mexico City MWO, the Washington VAAC reported that during 6-12 January ash plumes from Colima rose to altitudes of 4.6-6.7 km (15,000-22,000 ft) a.s.l. and drifted NE, ENE, and E.
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, Summit elev. 2953 m
Based on satellite and webcam views, the Buenos Aires VAAC reported that on 6 January a gas and steam plume from Copahue with minor amounts of ash rose to an altitude of 4.6 km (15,000 ft) a.s.l.
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.
Dukono, Halmahera (Indonesia)
1.693°N, 127.894°E, Summit elev. 1229 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 6-12 January ash plumes from Dukono rose to altitudes of -3 km (7,000-10,000 ft) a.s.l. and drifted 55-175 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.
14.473°N, 90.88°W, Summit elev. 3763 m
INSIVUMEH reported that white fumarolic plumes rose as high as 350 m above Fuego during 7-12 January. Three weak explosions detected during 9-10 January generated low ash plumes that drifted SE.
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 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.
Karangetang, Siau Island (Indonesia)
2.78°N, 125.4°E, Summit elev. 1784 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 12 January an ash plume from Karangetang rose to an altitude of 5.2 km (17,000 ft) a.s.l. and drifted 65 km NW.
Geologic summary: Karangetang (Api Siau) volcano lies at the northern end of the island of Siau, north of Sulawesi. The stratovolcano contains five summit craters along a N-S line. It 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, Summit elev. 1513 m
KVERT reported that moderate explosive activity at Karymsky continued during 1-8 January. Satellite images detected a thermal anomaly during 1, 3-4, and 6-7 December, and ash plumes drifting as far as 200 km E during 3 and 5-6 January. 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, Summit elev. 1222 m
HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 6-12 January. The lava lake continued to circulate and spatter in the Overlook vent. At 0351 on 8 January a rockfall triggered a small explosion that ejected lava fragments onto the crater rim. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the northeast rim. A short lava flow erupted onto the crater floor on 6 January. The June 27th NE-trending lava flow continued to be active within 6 km NE of Pu'u 'O'o Crater, burning some areas of forest.
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, Summit elev. 1580 m
Although inclement weather sometimes obscured views of Lokon-Empung's Tompaluan Crater, PVMBG reported that during 30 December-7 January observers at the post in Kakaskasen Tomohon (North Sulawesi, 4 km from the crater), saw white plumes rising as high as 250 m above the crater. Seismicity fluctuated, and was dominated by shallow volcanic earthquakes and signals indicating emissions; the number of shallow volcanic earthquakes significantly increased on 3 January. 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 km apart), has a flat, craterless top. The morphologically younger Empung volcano to the NE 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. A ridge extending WNW from Lokon includes Tatawiran and Tetempangan peak, 3 km away.
Semeru, Eastern Java (Indonesia)
8.108°S, 112.92°E, Summit elev. 3676 m
PVMBG reported that during 1 November 2015-4 January 2016 white and gray plumes from Semeru rose as high as 500 m above the crater and drifted E, S, and W; inclement weather sometimes prevented observations. In November nine incandescent avalanches traveled 100-500 m down the flanks. During December 2015-4 January 2016 incandescent material was occasionally ejected above the crater. Seismicity was dominated by signals indicating avalanches and emissions. 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, Summit elev. 3283 m
KVERT reported that during 1-8 January lava-dome extrusion onto Sheveluch’s N flank was accompanied by fumarolic activity, dome incandescence, ash explosions, and hot avalanches. A collapse from the W flank of the lava dome on 3 January produced a hot avalanche, and an ash plume that rose 5.5 km (18,000 ft) a.s.l. and drifted NE. Satellite images detected a daily and intense 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.
3.17°N, 98.392°E, Summit elev. 2460 m
Based on information from PVMBG, ground reports, and satellite images, the Darwin VAAC reported that during 6-12 January ash plumes from Sinabung rose to altitudes of 3.7-4.3 km (12,000-14,000 ft) a.s.l. and drifted 15-40 km SW, W, NW, and 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 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.
Suwanosejima, Ryukyu Islands (Japan)
29.638°N, 129.714°E, Summit elev. 796 m
Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported an explosion at Suwanosejima on 6 January.
Geologic 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.
Tengger Caldera, Eastern Java (Indonesia)
7.942°S, 112.95°E, Summit elev. 2329 m
Based on satellite and webcam images, the Darwin VAAC reported that during 6-12 January ash plumes from Tengger Caldera's Bromo cone rose to an altitude of 3.6 km (12,000 ft) a.s.l. and drifted 30-165 km in multiple directions.
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.