Report on Bezymianny (Russia) — December 1985
Scientific Event Alert Network Bulletin, vol. 10, no. 12 (December 1985)
Managing Editor: Lindsay McClelland.
Bezymianny (Russia) Possible plumes in December; intense fumarolic activity in early January 1986
Please cite this report as:
Global Volcanism Program, 1985. Report on Bezymianny (Russia). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 10:12. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198512-300250.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
Infrared images from polar-orbiting weather satellites showed plumes from the Kliuchevskoi/Bezymianny area on several days in early December, although weather clouds often obscured the Kamchatka Peninsula. On 2 December at 0237, a NOAA 9 image showed a faint plume emerging from the vicinity of Bezymianny. Two days later at 0216, two weak plumes seemed to be emerging from the area, perhaps one from Kliuchevskoi and one from Bezymianny. On 8 December at 0832, a narrow plume extended about 25-30 km N, probably from Kliuchevskoi. [Kliuchevskoi erupted on 1-2 December.]
[Ivanov reported that in early January 1986] Bezymianny was in a state of intense fumarolic activity.
[Originally included within a Kliuchevskoi report; not in GV 75-85.]
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: S.A. Fedotov and B.V Ivanov, IV; Will Gould, NOAA/NESDIS.