Report on Bezymianny (Russia) — November 1999
Bulletin of the Global Volcanism Network, vol. 24, no. 11 (November 1999)
Managing Editor: Richard Wunderman.
Bezymianny (Russia) Frequent fumarolic plumes, but no seismicity
Please cite this report as:
Global Volcanism Program, 1999. Report on Bezymianny (Russia) (Wunderman, R., ed.). Bulletin of the Global Volcanism Network, 24:11. Smithsonian Institution.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
Fumarolic plumes generally rising 50-300 m above the volcano were often observed during clear weather in August-December 1999, but views were frequently obscured by meteorological clouds. Weak fumarolic activity without a significant plume was detected on a few other occasions during this period. Plumes were observed on the following days: 9-10, 16, and 20-23 August; 2, 12, 22, 26, and 28 September; 22-24, 25-27, and 29-31 October; 1, 5, 11-12, 19, 22-23, 26, and 29 November; 2-3, 24, 25, and 28 December. Depending on local conditions, the plumes often extended 5-10 km downwind, usually E and SE. Others were blown S, NW, or NE. The longest plume during this period was on 26 August when it extended 15 km NE. No seismicity was registered under the volcano from 10 August through the end of December 1999. On October 6, a shallow earthquake was registered under the volcano.
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: Olga Chubarova, Kamchatka Volcanic Eruptions Response Team (KVERT), Institute of Volcanic Geology and Geochemistry, Piip Ave. 9, Petropavlovsk-Kamchatsky, 683006, Russia; Tom Miller, Alaska Volcano Observatory (AVO), a cooperative program of a) U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), b) Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and c) Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA.