New activity was observed at 2 volcanoes between December 3 and 10. During the same period, ongoing activity was observed at 11 volcanoes.
New activity/unrest: | Kliuchevskoi, Central Kamchatka (Russia) | Shiveluch, Central Kamchatka (Russia)
Ongoing activity: | Bagana, Bougainville | Chirinkotan, Kuril Islands | Chirpoi, Kuril Islands (Russia) | Ibu, Halmahera | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Kizimen, Eastern Kamchatka (Russia) | Pacaya, Guatemala | Rabaul, New Britain | Sakura-jima, Kyushu | Sinabung, Sumatra (Indonesia)
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
On 7 December activity at Kliuchevskoi significantly increased, prompting KVERT to raise the Alert Level to Red. Ash plumes rose to altitudes of 5.5-6 km (18,000-19,700 ft) a.s.l. and drifted more than 212 km NE and over 1,000 km E. According to a news article, a warning to aircraft was issued for the area around the volcano. The next day KVERT lowered the Alert Level to Orange. Ash plumes rose to altitudes of 5-5.5 km (16,400-18,000 ft) a.s.l. and drifted NE.
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.
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 29 November-6 December a new lava dome extruded onto the NW part of Shiveluch's older lava dome. Moderate ash 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. 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.
6.140°S, 155.195°E; summit elev. 1750 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 5-6 December ash plumes from Bagana drifted 55-65 km W. During 9-10 December ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 35-45 km NE and E.
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 weak thermal anomaly over Chirinkotan was observed in satellite images during 2-4 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.
CHIRPOI, Kuril Islands (Russia)
46.525°N, 150.875°E; summit elev. 742 m
SVERT reported that a thermal anomaly over Snow, a volcano of Chirpoi, was detected in satellite images on 3 and 8 December. 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. Two volcanoes on Chirpoi Island have been historically active. 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.
1.488°N, 127.63°E; summit elev. 1325 m
PVMBG reported that during 7 June-9 December white-to-gray plumes rose from Ibu’s craters. Observers in Goin (7 km NNW) noted that the lava dome, which had grown taller than the N crater rim in June, continued to grow; incandescent material from the dome filled the river valley in the direction of the Duono Village, about 5 km NW. Seismicity remained relatively stable. On 10 December the Alert Level was lowered to 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 from the N part.
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 western flank. A group of maars is located below the northern and western flanks of the volcano. Only a few eruptions have been recorded from Ibu 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.
KARYMSKY, Eastern Kamchatka (Russia)
54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported that moderate seismic activity at Karymsky was detected during 29 November-6 December. Vulcanian and Strombolian activity was observed during 2-3 December. Satellite images detected a bright thermal anomaly on the volcano daily. 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 4-10 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 5 km NE of Pu'u 'O'o based on a satellite images from 30 November.
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.
KIZIMEN, Eastern Kamchatka (Russia)
55.130°N, 160.32°E; summit elev. 2376 m
KVERT reported that weak seismic activity at Kizimen continued during 29 November-6 December. Video showed gas-and-steam activity, and satellite images detected a daily weak thermal anomaly. On 9 December the Alert Level was lowered to Green.
Geologic summary: Kizimen is an isolated, conical stratovolcano that is morphologically similar to Mount St. Helens prior to its 1980 eruption. The summit of Kizimen consists of overlapping lava domes, and blocky lava flows descend the flanks of the volcano, which is the westernmost of a volcanic chain north of Kronotsky volcano. The 2,376-m-high Kizimen was formed during four eruptive cycles beginning about 12,000 years ago and lasting 2,000-3,500 years. The largest eruptions took place about 10,000 and 8300-8400 years ago, and three periods of longterm lava-dome growth have occurred. The latest eruptive cycle began about 3,000 years ago with a large explosion and was followed by lava-dome growth lasting intermittently about 1,000 years. An explosive eruption about 1,100 years ago produced a lateral blast and created a 1.0 x 0.7 km wide crater breached to the NE, inside which a small lava dome (the fourth at Kizimen) has grown. A single explosive eruption, during 1927-28, has been recorded in historical time.
14.381°N, 90.601°W; summit elev. 2552 m
INSIVUMEH reported increased Strombolian activity at Pacaya on 5 December. A series of explosions at MacKenney Crater generated ash plumes that rose 2.7 km and drifted 3-5 km, and ejected pyroclastic material that was deposited around the cone. During 8-9 December weak explosions were occurring every 5 seconds, with moderate explosions occurring every minute that ejected bombs and lapilli. Diffuse blue gas plumes drifted SE. During 9-10 December blue gas plumes rose 700 m and drifted W. Tephra was ejected 25 m above the crater.
Geologic summary: Eruptions from Pacaya, one of Guatemala's most active volcanoes, are frequently visible from Guatemala City, the nation's capital. Pacaya is a complex volcano constructed on the southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A cluster of dacitic lava domes occupies the caldera floor. The Pacaya massif includes the Cerro Grande lava dome and a younger volcano to the SW. Collapse of Pacaya volcano about 1,100 years ago produced a debris-avalanche deposit that extends 25 km onto the Pacific coastal plain and left an arcuate somma rim inside which the modern Pacaya volcano (MacKenney cone) grew. During the past several decades, activity at Pacaya has consisted of frequent Strombolian eruptions with intermittent lava flow extrusion on the flanks of MacKenney cone, punctuated by occasional larger explosive eruptions.
31.585°N, 130.657°E; summit elev. 1117 m
The Tokyo VAAC reported that during 4-8 December explosions at Sakura-jima generated plumes that rose to altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l. and drifted E and SE. JMA reported that six explosions from Showa Crater ejected tephra as far as 1,300 m during 6-9 December. Incandescence from the crater was occasionally detected. The Alert Level remained at 3 (on a scale of 1-5).
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.
SINABUNG, Sumatra (Indonesia)
3.17°N, 98.392°E; summit elev. 2460 m
Based on webcam data, wind data, satellite image analysis, and PVMBG, the Darwin VAAC reported that on 4 December an ash plume from Sinabung rose to an altitude of 8.2 km (27,000 ft) a.s.l. and drifted N. Later that day and during 5-6 December ash plumes rose to altitudes of 3-3.7 km (7,000-12,000 ft) a.s.l. and drifted NW. On 10 December an ash plume rose to an altitude of 5.5 km (18,000 ft) a.s.l. and drifted 75 km NW. A few hours later an ash plume rose to an altitude of 11.6 km (38,000 ft) a.s.l. and drifted over 90 km NW.
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.
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