New activity/unrest was observed at 3 volcanoes from January 20 - 26, 2016. During the same period, ongoing activity was reported for 15 volcanoes.
New activity/unrest: Masaya, Nicaragua | Planchon-Peteroa, Zhupanovsky, Eastern Kamchatka (Russia).
Ongoing activity: Chirpoi, Kuril Islands (Russia) | Colima, Mexico | Copahue, Central Chile-Argentina border | Dukono, Halmahera (Indonesia) | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaiian Islands (USA) | Marapi, Indonesia | Momotombo, Nicaragua | Popocatepetl, Mexico | Reventador, Ecuador | Rinjani, Lombok Island (Indonesia) | Semeru, Eastern Java (Indonesia) | Sheveluch, Central Kamchatka (Russia) | Sinabung, Indonesia | Tengger Caldera, Eastern Java (Indonesia).
11.984°N, 86.161°W | Elevation 635 m
INETER reported that during 20-22 January the lava lake in Masaya's Santiago crater continued to be active. Abundant gas emissions rose 350 m above the crater rim on 20 January, and an increase in sound waves from the lava-lake activity was reported. During a field visit that same day, volcanologists noted that the lava lake in the vent on the S part of the crater floor had risen, and that a vent on the NE part of the floor was incandescent. During 21-22 January small gas explosions sounded like gunshots.
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.
Planchon-Peteroa, Central Chile-Argentina border
35.223°S, 70.568°W | Elevation 3977 m
Based on Observatorio Volcanológico de los Andes del Sur (OVDAS) observations, SERNAGEOMIN reported an increase in the number of long-period earthquakes at Planchón-Peteroa beginning on 15 January. On 22 January the Alert Level was raised to Yellow.
Geologic summary: Planchón-Peteroa is an elongated complex volcano along the Chile-Argentina border with several overlapping calderas. Activity began in the Pleistocene with construction of the basaltic-andesite to dacitic Volcán Azufre, followed by formation of basaltic and basaltic-andesite Volcán Planchón, 6 km to the north. About 11,500 years ago, much of Azufre and part of Planchón collapsed, forming the massive Río Teno debris avalanche, which traveled 95 km to reach Chile's Central Valley. Subsequently, Volcán Planchón II was formed. The youngest volcano, andesitic and basaltic-andesite Volcán Peteroa, consists of scattered vents between Azufre and Planchón. Peteroa has been active into historical time and contains a small steaming crater lake. Historical eruptions from the complex have been dominantly explosive, although lava flows were erupted in 1837 and 1937.
Zhupanovsky, Eastern Kamchatka (Russia)
53.589°N, 159.15°E | Elevation 2899 m
Based on visual observations, KVERT reported that on 21 January explosions at Zhupanovsky generated ash plumes that rose to an altitude of 8 km (26,200 ft)a.s.l. and drifted 36 km W. A thermal anomaly was detected in satellite images. The Aviation Color Code remained at Orange (the second highest on a four-color scale).
Geologic summary: The Zhupanovsky volcanic massif consists of four overlapping stratovolcanoes along a WNW-trending ridge. The elongated volcanic complex was constructed within a Pliocene-early Pleistocene caldera whose rim is exposed only on the eastern side. Three of the stratovolcanoes were built during the Pleistocene, the fourth is Holocene in age and was the source of all of Zhupanovsky's historical eruptions. An early Holocene stage of frequent moderate and weak eruptions from 7000 to 5000 years before present (BP) was succeeded by a period of infrequent larger eruptions that produced pyroclastic flows. The last major eruption took place about 800-900 years BP. Historical eruptions have consisted of relatively minor explosions from the third cone.
Chirpoi, Kuril Islands (Russia)
46.525°N, 150.875°E | Elevation 742 m
SVERT reported that satellite images detected a thermal anomaly over Snow, a volcano of Chirpoi, on 18 and 23 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 | Elevation 3850 m
Based on satellite images, wind data, webcam images, and notices from the Mexico City MWO, the Washington VAAC reported that during 20-24 and 26 January ash plumes from Colima rose to altitudes of 4.6-6.7 km (15,000-22,000 ft) a.s.l. and drifted as far as 145 km E, SE, S, and W. Minor ash emissions were observed on 25 January.
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
Based on satellite and webcam views, the Buenos Aires VAAC reported that during 20-23 January almost continuous steam plumes from Copahue contained minor amounts of ash and drifted as far as 150 km W, S, SE, and E.
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)
1.68°N, 127.88°E | Elevation 1335 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 20-24 and 26 January ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 15-120 km W and SW.
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.
Karymsky, Eastern Kamchatka (Russia)
54.049°N, 159.443°E | Elevation 1513 m
KVERT reported that moderate explosive activity at Karymsky continued during 15-22 January. Satellite images detected a thermal anomaly during 15, 18-19, and 21 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 | Elevation 1222 m
HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 20-26 January. The lavalake continued to circulate and spatter in the Overlook vent. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o Crater and high on the northeast rim. 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.
0.381°S, 100.473°E | Elevation 2891 m
PVMBG reported that on most days during periods of clear weather from 1 November 2015 to 19 January 2016 white plumes rose above Marapi as high as 250 m above the crater. A phreatic explosion at 2233 on 14 November generated an ash plume, and ashfall was noted in Panyalaian and Aia Angek on the SW flank. Seismicity fluctuated during 1-18 January; earthquakes indicating emissions, tornillo-type events, and shallow volcanic signals slightly 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.
12.422°N, 86.54°W | Elevation 1297 m
INETER reported that during 20-21 January both RSAM values and emissions at Momotombo were low. Volcanic tremor increased at 0900 on 22 January, causing RSAM values to rise to high levels. There were no changes to emissions. INETER recommended to the public to stay at least 6 km away from the volcano.
Geologic summary: Momotombo is a young, 1297-m-high stratovolcano that rises prominently above the NW shore of Lake Managua, forming one of Nicaragua's most familiar landmarks. Momotombo began growing about 4500 years ago at the SE end of the Marrabios Range and consists of a somma from an older edifice that is surmounted by a symmetrical younger cone with a 150 x 250 m wide summit crater. Young lava flows from Momotombo have flowed down the NW flank into the 4-km-wide Monte Galán caldera. The youthful cone of Momotombito forms a 391-m-high island offshore in Lake Managua. Momotombo has a long record of strombolian eruptions, punctuated by occasional larger explosive activity. The latest eruption, in 1905, produced a lava flow that traveled from the summit to the lower NE base. A small black plume was seen above the crater after an April 10, 1996 earthquake, but later observations noted no significant changes in the crater. A major geothermal field is located on the southern flank of the volcano.
19.023°N, 98.622°W | Elevation 5426 m
CENAPRED reported that during 20-23 and 25 January the seismic network at Popocatépetl recorded 16-68 daily emissions consisting of water vapor, gas, and ash, and 2-5 explosions per day. At 1000 on 23 January an increase in activity was characterized by continuous gas-and-ash emissions, likely related to the destruction of a recently-formed lava dome. Later that night cameras recorded incandescent fragments ejected during periods of emissions. Activity decreased at 0200 on 24 January and then increased again at 0844, with explosions. A series of explosions on 25 January began at 1000 and ended at 1840. Constant steam-and-ash emissions drifted ENE. Another series of explosions occurred during 0218-0600 on 26 January. One of the explosions ejected incandescent fragments 900 m onto the NE flank. The Alert Level remained at Yellow, Phase Two.
Geologic summary: Volcán Popocatépetl, whose name is the Aztec word for smoking mountain, towers to 5426 m 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas to the south. The modern volcano was constructed south of the late-Pleistocene to Holocene El Fraile cone. Three major plinian eruptions, the most recent of which took place about 800 CE, have occurred from Popocatépetl since the mid Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano. Frequent historical eruptions, first recorded in Aztec codices, have occurred since precolumbian time.
0.077°S, 77.656°W | Elevation 3562 m
While in the field on 15 January, IG technicians observed several explosions at Reventador that generated ash plumes which rose 1.5-2 km above the crater. Apyroclastic flow traveled 500 m down the N flank. Pyroclastic flow deposits from the previous three weeks were also noted. Activity during 19-25 January remained high. At 2200 on 19 January a major explosion, heard in El Reventador village, ejected incandescent material onto the SW flank. Gas, steam, and ash emissions rose 0.8-2 km above the crater on most days. During 21-22 January incandescent material traveled 1.2 km down the W flank.
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
PVMBG reported that during 25 October-24 November 2015 white and gray plumes rose as high as 2.6 km above Rinjani's Barujari Crater. Incandescent material was sometimes ejected 30-150 m high. Gray plumes observed during 25 November-24 December rose as high as 2.5 km. During 25 December 2015-18 January 2016 white plumes rose 50 m above the crater. Seismicity had also decreased to background levels. On 20 January the Alert Level was lowered to 1 (on a scale of 1-4), and the public was reminded not to approach the crater.
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 there were 21 explosions recorded at Semeru during 1-17 January, generating dense gray plumes that rose 100-500 m above the crater and drifted E, N, and W. Seismicity was dominated by signals indicating explosions 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 | Elevation 3283 m
KVERT reported that during 15-22 January lava-dome extrusion onto Sheveluch’s N flank was accompanied by fumarolic activity, dome incandescence, ashexplosions, and hot avalanches. 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 | Elevation 2460 m
Based on information from PVMBG and satellite images, the Darwin VAAC reported that during 20-22 and 25 January ash plumes from Sinabung rose to altitudes of 3-3.7 km (10,000-12,000 ft) a.s.l. and drifted W, NW, and N.
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.
Tengger Caldera, Eastern Java (Indonesia)
7.942°S, 112.95°E | Elevation 2329 m
PVMBG reported that during 14-22 January brownish gray plumes from Tengger Caldera's Bromo cone rose as high as 1.8 km above the crater. Seismicity fluctuated; the number of explosion signals increased and some shallow and deep volcanic earthquakes were recorded. The Alert Level remained at 3 (on a scale of 1-4); residents and visitors were reminded not to approach the crater within a radius of 2.5 km.
Based on information from PVMBG and satellite images, the Darwin VAAC reported that during 23 and 25-26 January ash plumes rose to altitudes of 3.6-3.9 km (12,000-13,000 ft) a.s.l. and drifted ENE, E, and SE.
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.