Report on Bezymianny (Russia) — February 1979
Scientific Event Alert Network Bulletin, vol. 4, no. 2 (February 1979)
Managing Editor: David Squires.
Bezymianny (Russia) Largest explosion since 1956 produces 0.2 km3 of ejecta
Please cite this report as:
Global Volcanism Program, 1979. Report on Bezymianny (Russia) (Squires, D., ed.). Scientific Event Alert Network Bulletin, 4:2. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN197902-300250
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
After a brief period of premonitory seismicity, a series of explosions from Bezymianny began at 1023 on 11 February. The explosions produced what was reported as an agglomerate flow about 10 km long and 10 m thick. They also deposited 2 cm of ash on a town several dozen km from the volcano, and destroyed part of the new cone. Lava flowed several hundred m down the NW flank. The volume of material erupted was about 0.2 km3.
Geological Summary. The modern Bezymianny, much smaller than its massive neighbors Kamen and Kliuchevskoi on the Kamchatka Peninsula, was formed about 4,700 years ago over a late-Pleistocene lava-dome complex and an ancestral edifice built about 11,000-7,000 years ago. Three periods of intensified activity have occurred during the past 3,000 years. The latest period, which was preceded by a 1,000-year quiescence, began with the dramatic 1955-56 eruption. This eruption, similar to that of St. Helens in 1980, produced a large open 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 flows, has largely filled the 1956 crater.
Information Contacts: N. Kozhemyaka, IVP; Tass; Sovetskaya Rossiya Radio, Moscow.