Bezymianny
Encyclopedia
Bezymianny is an active stratovolcano
in Kamchatka
, Russia
. Prior to its noted 1955-56 eruption, Bezymianny volcano had been considered extinct. The modern Bezymianny volcano, much smaller in size than its massive neighbors Kamen
and Kliuchevskoi, was formed about 4700 years ago over a late-Pleistocene
lava-dome complex and an ancestral volcano that was built between about 11,000-7000 years ago. Three periods of intensified activity have occurred during the past 3000 years. The latest period, which was preceded by a 1000-year quiescence, began with the dramatic 1955-56 eruption. This eruption, similar to that of Mount St. Helens
in 1980, produced a large horseshoe-shaped crater that was formed by collapse of the summit and an associated lateral blast. Subsequent episodic but ongoing lava-dome growth, accompanied by intermittent explosive activity and pyroclastic flow
s, has largely filled the 1956 crater.
Stratovolcano
A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...
in Kamchatka
Kamchatka Peninsula
The Kamchatka Peninsula is a peninsula in the Russian Far East, with an area of . It lies between the Pacific Ocean to the east and the Sea of Okhotsk to the west...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
. Prior to its noted 1955-56 eruption, Bezymianny volcano had been considered extinct. The modern Bezymianny volcano, much smaller in size than its massive neighbors Kamen
Kamen (volcano)
Kamen is a stratovolcano located in the southern part of Kamchatka Peninsula, Russia, flanked by Bezymianny and Kluchevskaya. It is the second highest volcano of Kamchatka....
and Kliuchevskoi, was formed about 4700 years ago over a late-Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
lava-dome complex and an ancestral volcano that was built between about 11,000-7000 years ago. Three periods of intensified activity have occurred during the past 3000 years. The latest period, which was preceded by a 1000-year quiescence, began with the dramatic 1955-56 eruption. This eruption, similar to that of Mount St. Helens
Mount St. Helens
Mount St. Helens is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It is south of Seattle, Washington and northeast of Portland, Oregon. Mount St. Helens takes its English name from the British diplomat Lord St Helens, a...
in 1980, produced a large horseshoe-shaped crater that was formed by collapse of the summit and an associated lateral blast. Subsequent episodic but ongoing lava-dome growth, accompanied by intermittent explosive activity and pyroclastic flow
Pyroclastic flow
A pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...
s, has largely filled the 1956 crater.