New activity was observed at 2 volcanoes between December 18 and 24. During the same period, ongoing activity was observed at 11 volcanoes.
New activity/unrest: | Kliuchevskoi, Central Kamchatka (Russia) | Palena Volcanic Group, Central Chile
Ongoing activity: | Bagana, Bougainville | Chirinkotan, Kuril Islands | Dukono, Halmahera | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Manam, Northeast of New Guinea (SW Pacific) | Rabaul, New Britain | Sakura-jima, Kyushu | Shiveluch, Central Kamchatka (Russia) | Sinabung, Sumatra (Indonesia) | Ulawun, New Britain
The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 23:00 UTC every Wednesday, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports on various volcanoes are published monthly in the Bulletin of the Global Volcanism Network.
KLIUCHEVSKOI, Central Kamchatka (Russia)
56.057°N, 160.638°E; summit elev. 4850 m
KVERT reported weak seismic activity at Kliuchevskoi during 13-20 December, and video images showed moderate gas-and-steam activity. Satellite images detected daily weak thermal anomalies over the summit and the SW flank. The Aviation Color Code remained at Orange.
Geologic summary: Kliuchevskoi is Kamchatka's highest and most active volcano. Since its origin about 6000 years ago, the beautifully symmetrical, 4835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. Kliuchevskoi rises above a saddle NE of sharp-peaked Kamen volcano and lies SE of the broad Ushkovsky massif. More than 100 flank eruptions have occurred at Kliuchevskoi during the past roughly 3000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 m and 3600 m elevation. The morphology of its 700-m-wide summit crater has been frequently modified by historical eruptions, which have been recorded since the late-17th century. Historical eruptions have originated primarily from the summit crater, but have also included numerous major explosive and effusive eruptions from flank craters.
PALENA VOLCANIC GROUP, Central Chile-Argentina border
43.78°S, 72.47°W; summit elev. 2991 m
Based on a pilot observation and analyses of satellite images, the Buenos Aires VAAC reported that activity at the Palena Volcanic Group began around 1530 on 22 December. Satellite images showed an ash plume drifting SE which dissipated quickly, and diffuse ash, gas, and steam near the source.
Geologic summary: The Palena volcano group consists of five cinder cones oriented along a NNE trend NE of Melimoyu volcano. The youthful volcanoes are named after the middle cone. This is the first confirmed Holocene activity on record.
6.140°S, 155.195°E; summit elev. 1750 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 22 December an ash plume from Bagana rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted 75 km NE.
Geologic summary: Bagana volcano, occupying a remote portion of central Bougainville Island, is one of Melanesia's youngest and most active volcanoes. Bagana is a massive symmetrical lava cone largely constructed by an accumulation of viscous andesitic lava flows. The entire lava cone could have been constructed in about 300 years at its present rate of lava production. Eruptive activity at Bagana is 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 volcano's flanks on all sides.
CHIRINKOTAN, Kuril Islands
48.980°N, 153.480°E; summit elev. 724 m
SVERT reported that a thermal anomaly over Chirinkotan was observed in satellite images on 9, 12, and 15 December. Cloud cover obscured views on the other days during 10-16 December. 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.
1.68°N, 127.88°E; summit elev. 1335 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 18 December a possible ash plume from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted over 35 km E. On 24 December an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 55 km N.
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 N-flank cone of Gunung Mamuya. Dukono is a complex volcano presenting a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit crater complex, contains a 700 x 570 m crater that has also been active during historical time.
KARYMSKY, Eastern Kamchatka (Russia)
54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 13-20 December. Satellite images detected a bright thermal anomaly on the volcano daily, and gas-and-steam plumes that drifted 30 km SW on 18 December. The Aviation Color Code remained at Orange.
Geologic summary: Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon years ago. Construction of the Karymsky stratovolcano began about 2,000 years later. The latest eruptive period began about 500 years ago, following a 2,300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been Vulcanian or Vulcanian-Strombolian with moderate explosive activity and occasional lava flows from the summit crater. Most seismicity preceding Karymsky eruptions has originated beneath Akademia Nauk caldera, which is located immediately S of Karymsky volcano and erupted simultaneously with Karymsky in 1996.
KILAUEA, Hawaii (USA)
19.421°N, 155.287°W; summit elev. 1222 m
During 18-23 December HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. The 7.3-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o; the flow however was most active about 6 km NE of Pu'u 'O'o based on satellite images from 20 December.
Geologic summary: Kilauea, one of five coalescing volcanoes that comprise the island of Hawaii, is one of the world's most active volcanoes. Eruptions at Kilauea originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. About 90% of the surface of Kilauea is formed of lava flows less than about 1,100 years old; 70% of the volcano's surface is younger than 600 years. A long-term eruption from the East rift zone that began in 1983 has produced lava flows covering more than 100 sq km, destroying nearly 200 houses and adding new coastline to the island.
MANAM, Northeast of New Guinea (SW Pacific)
4.080°S, 145.037°E; summit elev. 1807 m
RVO reported that activity at both Manam's Southern Crater and Main Crater was low during 1-15 December; white vapor emissions rose from both craters. Light gray ash clouds rose from Southern Crater during 6, 10, and 13-14 December, and incandescence from the crater was observed during 6-10 and 12-13 December. Incandescence from Main Crater was visible during 11-13 and 15 December, and gray ash plumes rose from the crater during 13-14 December. No plumes from either crater rose more than 100 m during the reporting period.
Geologic summary: The 10-km-wide island of Manam, lying 13 km off the northern coast of mainland Papua New Guinea, is one of the country's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical 1807-m-high basaltic-andesitic stratovolcano to its lower flanks. These "avalanche valleys," regularly spaced 90 degrees apart, channel lava flows and pyroclastic avalanches that have sometimes reached the coast. Two summit craters are present; both are active, although most historical eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE avalanche valley. Frequent historical eruptions, typically of mild-to-moderate scale, have been recorded at Manam since 1616. Occasional larger eruptions have produced pyroclastic flows and lava flows that reached flat-lying coastal areas and entered the sea, sometimes impacting populated areas.
RABAUL, New Britain
4.271°S, 152.203°E; summit elev. 688 m
RVO reported that Rabaul caldera's Tavurvur cone was quiet during 1-15 December. White and occasionally blue vapor plumes rose from the crater, An explosion at 1850 on 15 December generated an ash-poor plume.
Geologic summary: The low-lying Rabaul caldera on the tip of the Gazelle Peninsula at the NE end of New Britain forms a broad sheltered harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic shield volcano are formed by thick pyroclastic-flow deposits. The 8 x 14 km caldera is widely breached on the E, where its floor is flooded by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul took place as recently as 3,500 and 1,400 years ago. Three small stratovolcanoes lie outside the northern and NE caldera rims. Post-caldera eruptions built basaltic-to-dacitic pyroclastic cones on the caldera floor near the NE and western caldera walls. Several of these, including Vulcan cone, which was formed during a large eruption in 1878, have produced major explosive activity during historical time. A powerful explosive eruption in 1994 occurred simultaneously from Vulcan and Tavurvur volcanoes and forced the temporary abandonment of Rabaul city.
31.585°N, 130.657°E; summit elev. 1117 m
JMA reported that on 19 December an explosion from Sakura-jima's Showa Crater ejected tephra as far as 1,300 m. The Alert Level remained at 3 (on a scale of 1-5). The Tokyo VAAC reported that during 18-19 and 21-23 December explosions generated plumes that rose to altitudes of 1.8-3 km (6,000-10,000 ft) a.s.l. and drifted E, SE, and S.
Geologic summary: Sakura-jima, one of Japan's most active volcanoes, is a post-caldera cone of the Aira caldera at the northern half of Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was associated with the formation of the 17 x 23-km-wide Aira caldera about 22,000 years ago. The construction of Sakura-jima began about 13,000 years ago and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kita-dake summit cone ended about 4,850 years ago, after which eruptions took place at Minami-dake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76.
SHIVELUCH, Central Kamchatka (Russia)
56.653°N, 161.360°E; summit elev. 3283 m
Based on visual observations and analyses of satellite data, KVERT reported that during 13-20 December a new lava dome extruded onto the NW part of Shiveluch's older lava dome. Moderate explosions generated ash plumes that rose to altitudes of 4-5 km (13,100-16,400) a.s.l. Lava-dome extrusion was accompanied by hot avalanches, incandescence, and fumarolic activity. A thermal anomaly was detected daily in satellite images. Several strong explosions on 17 December generated ash plumes that rose to altitudes of 5.5-6 km (18,000-19,700 ft) a.s.l. The Aviation Color Code remained at Orange.
Geologic summary: The high, isolated massif of Shiveluch volcano (also spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group and forms one of Kamchatka's largest and most active volcanoes. The currently active Molodoy Shiveluch lava-dome complex was constructed during the Holocene within a large breached caldera formed by collapse of the massive late-Pleistocene Strary Shiveluch volcano. At least 60 large eruptions of Shiveluch have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most recently in 1964, have produced large debris avalanches whose deposits cover much of the floor of the breached caldera. Intermittent explosive eruptions began in the 1990s from a new lava dome that began growing in 1980. The largest historical eruptions from Shiveluch occurred in 1854 and 1964.
SINABUNG, Sumatra (Indonesia)
3.17°N, 98.392°E; summit elev. 2460 m
Based on webcam images, the Darwin VAAC reported that on 22 December an ash plume from Sinabung rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted 55 km W. During 23-24 December ash plumes recorded by the webcam rose to an altitude of 3 km (10,000 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 of Sinabung in 1912, although no confirmed historical eruptions were recorded prior to 2010.
ULAWUN, New Britain
5.05°S, 151.33°E; summit elev. 2334 m
RVO reported that activity at Ulawun was low during 1-15 December; pale gray ash plumes rose from the crater. People between Sena Estate and Noau on the N flank reported ashfall in early December.
Geologic summary: The symmetrical basaltic to andesitic Ulawun stratovolcano is the highest volcano of the Bismarck arc, and one of Papua New Guinea's most frequently active. Ulawun rises above the N coast of New Britain opposite Bamus volcano. The upper 1,000 m of the 2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW side of the volcano, and a flank lava-flow complex lies to the S of this valley. Historical eruptions date back to the beginning of the 18th century. Twentieth-century eruptions were mildly explosive until 1967, but after 1970 several larger eruptions produced lava flows and basaltic pyroclastic flows, greatly modifying the summit crater.