Report on Bezymianny (Russia) — March 1977
Scientific Event Alert Network Bulletin, vol. 2, no. 3 (March 1977)
Managing Editor: David Squires.
Bezymianny (Russia) Explosions in late March send tephra clouds to 15 km altitude
Please cite this report as:
Global Volcanism Program, 1977. Report on Bezymianny (Russia). In: Squires, D. (ed.), Scientific Event Alert Network Bulletin, 2:3. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN197703-300250.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
A column of "stones," ash, and gas was erupted to 6-7 km height on 25 March, following a series of earthquakes the preceding day. Subsequent explosions on 25 and 31 March sent tephra clouds to 15 km altitude and caused heavy ashfall. No damage has occurred to populated areas. The present activity at Bezymianny, which last erupted March 1965-March 1970, is reportedly the strongest since the great eruption of 1955-57.
Further Reference. Bogoyavlenskaya, G.E., Ivanov, B.V., Budnikov, V.A., and Andreev, V.N., 1979, The eruption of Bezymianny volcano in 1977: Byull. Vulkanol. Stn., no. 57, p. 16-25.
Geologic Background. Prior to its noted 1955-56 eruption, Bezymianny had been considered extinct. The modern 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 edifice built 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 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 flows, has largely filled the 1956 crater.
Information Contacts: Tass.