Eruption on Mount Bezymianny in the Russian Far East.

The Tokyo Volcanic Ash Advisory Center and Kamtchatka Volcanic Eruption Response Team reported a major eruption on Mount Bezymianny, a 2882 m stratovolcano (cone shaped volcano made up of layers of ash and lava) on the central part of the Kamchatka Peninsula, which started slightly after 8.20 am local time on Thursday 22 October 2020, which produced an ash column about 9 km high, and formed a cloud roughly 100 km x 200 km in extent. This split into two parts, one of which drifted to the northwest and the other the southeast, travelling over 800 km before dispersing. The following day a satellite passing over the volcano detected a thermal anomaly which is thought likely to be the result of a lava dome forming, but there have been no further eruptions.

 

An ash column over Mount Bezymianny on the Kamchatka Peninsula on 22 October 2020. Siberian Times.

Mount Bezymianny was thought to be extinct until 1955, when it began a volcanic cycle that ended in 1956 with an explosive eruption caused the summit to collapse and created a large horseshoe-shaped crater. This has subsequently been filled in by further eruptive episodes on Bezymianny. The current summit is 2882 m high, but it is overshadowed by the nearby Kamen and Kluchevskaya volcanoes at 4579 m and 4750 m respectively. Bezymianny is thought to have formed about 4700 years ago, on the remains on an older, Pleistocene, volcano active between 11 000 and 7000 years ago. It has undergone three periods of intense activity since its formation, but was apparently inactive for about a thousand years prior to its 1955 reactivation.

Mount Bezymianny is part of the Klyuchevskoi Volcano Group in the Ust-Kamchatka (East Kamchatka) District, along with mounts Klyuchevskoi and Kamen. The Kamchatka Peninsula lies on the eastern edge of the Okhotsk Plate, close to its margin with the Pacific and North American Plates. The Pacific Plate is being subducted along the margin, and as it does so it passes under the southern part of the Kamchatka Peninsula, and as it does so is partially melted by the friction and the heat of the Earth's interior. Some of the melted material then rises through the overlying Okhotsk Plate as magma and fuelling the volcanoes of southern Kamchatka.

 

Simple diagram showing the subduction of the Pacific Plate beneath the Okhotsk Plate along the Kuril Kamchatka Trench. The Kamchatka Peninsula is at the top of the diagram. Auburn University.

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Eruptions on Mount Bezymianny.

The Kamtchatka Volcanic Eruption Response Team reported a thermal anomaly beneath Mount Bezymianny, a 2882 m stratovolcano (cone shaped volcano made up of layers of ash and lava) on the central part of the Kamchatka Peninsula, seen in satellite images between 12 and 15 March 2019, accompanied by intense gas-end-steam emissions from the volcano's crater and avalanches of hot ash on its flanks observed by webcams located around the site. This was followed by a series of eruptions on 15-16 March, which produced ash columns up to 15 km high and drifted to the east and northeast, with ashfalls being reported by communities up to 120 km away.

Thermal image of an eruption on Mount Bezymianny on 15 March 2019. Bright white area represents fragments of hot rock collapsed onto the lava dome and flanks of the volcano. KVERT.

Mount Bezymianny was thought to be extinct until 1955, when it began a volcanic cycle that ended in 1956 with an explosive eruption caused the summit to collapse and created a large horseshoe-shaped crater. This has subsequently been filled in by further eruptive episodes on Bezymianny. The current summit is 2882 m high, but it is overshadowed by the nearby Kamen and Kluchevskaya volcanoes at 4579 m and 4750 m respectively. Bezymianny is thought to have formed about 4700 years ago, on the remains on an older, Pleistocene, volcano active between 11 000 and 7000 years ago. It has undergone three periods of intense activity since its formation, but was apparently inactive for about a thousand years prior to its 1955 reactivation.

 Infrared satellite images of a spreading ash plume from an eruption on Mount Bezymianny starting at 4.10 pm GMT on 16 March 2019. KVERT/VolSatView.

Mount Bezymianny is part of the Klyuchevskoi Volcano Group in the Ust-Kamchatka (East Kamchatka) District, along with mounts Klyuchevskoi and Kamen. The Kamchatka Peninsula lies on the eastern edge of the Okhotsk Plate, close to its margin with the Pacific and North American Plates. The Pacific Plate is being subducted along the margin, and as it does so it passes under the southern part of the Kamchatka Peninsula, and as it does so is partially melted by the friction and the heat of the Earth's interior. Some of the melted material then rises through the overlying Okhotsk Plate as magma and fuelling the volcanoes of southern Kamchatka.

 Simple diagram showing the subduction of the Pacific Plate beneath the Okhotsk Plate along the Kuril Kamchatka Trench. The Kamchatka Peninsula is at the top of the diagram. Auburn University.

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Eruption on Mount Bezymianny, Kamchatka Peninsula.

The Kamtchatka Volcanic Eruption Response Team reported seeing an avalanche of incandescent ashy material on the southeast flank of the lava dome of Mount Bezymianny, a 2882 m stratovolcano (cone shaped volcano made up of layers of ash and lava) on the central part of the Kamchatka Peninsula, on Monday 18 December 2017. This was followed by a brief eruptive episode that started at about 3.55 pm local time on Wednesday 20 December, that produced a column of ash that rose to 10-15 km above sea level, and drifted about 85 km to the northeast. 

Ash column over Mount Bezymianny on 20 December 2017. Yuri Demyanchuk/Institute of Volcanology and Seismology of the Far Eastern Branch of the Russian Academy of Sciences/KVERT.

Mount Bezymianny was thought to be extinct until 1955, when it began a volcanic cycle that ended in 1956 with an explosive eruption caused the summit to collapse and created a large horseshoe-shaped crater. This has subsequently been filled in by further eruptive episodes on Bezymianny. The current summit is 2882 m high, but it is overshadowed by the nearby Kamen and Kluchevskaya volcanoes at 4579 m and 4750 m respectively. Bezymianny is thought to have formed about 4700 years ago, on the remains on an older, Pleistocene, volcano active between 11 000 and 7000 years ago. It has undergone three periods of intense activity since its formation, but was apparently inactive for about a thousand years prior to its 1955 reactivation.

 

The approximate location of Mount Bezmianny. Google Maps.

Mount Bezymianny is part of the Klyuchevskoi Volcano Group in the Ust-Kamchatka (East Kamchatka) District, along with mounts Klyuchevskoi and Kamen. The Kamchatka Peninsula lies on the eastern edge of the Okhotsk Plate, close to its margin with the Pacific and North American Plates. The Pacific Plate is being subducted along the margin, and as it does so it passes under the southern part of the Kamchatka Peninsula, and as it does so is partially melted by the friction and the heat of the Earth's interior. Some of the melted material then rises through the overlying Okhotsk Plate as magma and fuelling the volcanoes of southern Kamchatka.

 Simple diagram showing the subduction of the Pacific Plate beneath the Okhotsk Plate along the Kuril Kamchatka Trench. The Kamchatka Peninsula is at the top of the diagram. Auburn University.

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Eruption on Mount Bezymianny.

Mount Bezymianny is an extremely active stratovolcano on the central part of the Kamchatka Peninsula in the Russian Far East. The volcano was thought to be extinct until 1955, when it began a volcanic cycle that ended in 1956 with an explosive eruption caused the summit to collapse and created a large horseshoe-shaped crater. This has subsequently been filled in by further eruptive episodes on Bezymianny. The current summit is 2882 m high, but it is overshadowed by the nearby Kamen and Kluchevskaya volcanoes at 4579 m and 4750 m respectively.

Mount Bezymianny in 1957 (top) and the late 1980s (bottom) showing the growth of a new summit within the 1956 crater. Top image G.Y. Bogoyavlenskaya/Oregon State University. Bottom image Yuri Doubik/Institute of Volcanology, Petropavlovsk/Oregon State University.

Bezymianny is thought to have formed about 4700 years ago, on the remains on an older, Pleistocene, volcano active between 11 000 and 7000 years ago. It has undergone three periods of intense activity since its formation, but was apparently inactive for about a thousand years prior to its 1955 reactivation.

Bezymianny last erupted in 2011, but underwent a period of seismic activity (earthquakes) in February-March 2012. On 24 August 2012 the  Kamchatka Volcanic Eruption Response Team detected a resumption in seismic activity, followed by the onset of fumarole activity (gas emissions) on 25 August. An explosive eruption occurred on 2 September, causing to an ash cloud rising to a height of 10-12 km, which then drifted 1500 km to the northeast. This was followed on 3 September by lava flows and ash avalanches.

Ash cloud from Mount Bezymianny. Kamchatka Volcanic Eruption Response Team.

See also Seismic activity on Little Sitkin, Eruption on Ivan Grozny, Massive deep Earthquake beneath the Sea of Okhotsk, Earthquake shakes the Kamchatka Peninsula and Volcanoes on Sciency Thoughts YouTube.

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