Report on Bezymianny (Russia) — June 1981
Scientific Event Alert Network Bulletin, vol. 6, no. 6 (June 1981)
Managing Editor: Lindsay McClelland.
Bezymianny (Russia) Large tephra cloud and lava flow
Please cite this report as:
Global Volcanism Program, 1981. Report on Bezymianny (Russia). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 6:6. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198106-300250.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
In a report dated 16 June, Tass said that Bezymianny had erupted, ejecting an 8-km-high ash column and extruding a lava flow 400 m wide. NESS personnel inspected early and mid June imagery returned every 3 hours from the GMS satellite, but did not find a large eruption column. Weather is often cloudy over Kamchatka, however, and could have masked evidence of an eruption.
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: E. Hooper, NOAA/NESS; Tass