Bezymianny

Besymjanny (Russian Безымянный ) is an active stratovolcano on the Kamchatka Peninsula in eastern Russia. The name of the mountain means The Nameless. Besymjanny is located on the southeast flank of the extinct volcano Kamen in the Klyuchevskaya - Sopka - stratovolcano group ( in the literature also in the alternative transcription Kliuchevskoi - Bezymianny - volcanic complex ), which also includes the Sheveluch heard.

The whole volcano group was formed about 4700 years ago on volcanic subsoil.

Volcanic activity

For the past 3,000 years a total of three sections greater activity are based on the volcanic deposits prove: by radiocarbon datings about in the periods 2700-750 BC, from 100 BC to 450 AD and of 800 to 1000 s. Chr.

With the help of Tephrochronologie following outbreaks were dated 2750 ± 500 BC, 1550 ± 500 BC, the year 700 ± 50

Prior to his re- eruption of the volcano in 1955 was considered by its nearly 1,000 -year dormancy to be extinct. After about four weeks of series of earthquakes, however, the volcano on October 22, 1955 broke out again and produced by repeated volcanic explosions from a newly developed summit crater large amounts of volcanic ash.

On 30 May 1956, a large outbreak blew up the eastern flank of the volcano and devastated its environment. The eruption of Besymjanny of 1956 was similar to that of Mount St. Helens on May 18, 1980 in the United States. On Besymjanny plunged large part of the mountainside in a debris avalanche into the valley, about 0.5 cubic kilometers of material, as well as at Mount St. Helens broke the volcano in a large explosive eruption laterally, leaving a horseshoe-shaped crater that for however by later activities has been largely filled again. The eruptions of the activity period 1955/1956 were the mountain about 200 meters back lower than before. The area around the volcano has been greatly changed by the deposition of thick layers of volcanic ash material from pyroclastic flows and other volcanic sediments.

Since then, the volcano is almost constantly active. Other significant outbreaks occurred from 15 October to November 1959 (discharge of 27,000 cubic meters of ash), from 13 to 14 April 1960 ( emissions of 1.2 million cubic meters of ash), from March 25 to 26, 1961 ( thickness: VEI 3, emissions of 7 million cubic meters of ash), 21 May-6 June 1961 18 October to 15 December 1961 21 October-6 November 1962 -May to probably September 1963 June 25th to 20th September 1964, 25 to 26 December 1964 of 9 March 1965 to March 1970 ( thickness: VEI 3, emissions of 42 million cubic meters of lava and 25 million cubic meters of ash), from March 1971 to December 1974.

The mid-1980s came from two major lava flows, and in 1997 led a Plinian eruption in the formation of an approximately 200 -meter summit crater and produced with its Surge a lahar that flowed up to 30 kilometers in the valleys of the rivers Tundrowy Kliuch and Sukhaia Chapiza. The eruption column reached a height of 14 kilometers, which generated widespread pyroclastic flows by their collapse up to 5 kilometers.

In 2008, the ashes of a new outbreak rose to an altitude of 9 km. Finally, it came in June 2010 lead to increased activity.