Report on Bezymianny (Russia) — August 1996
Bulletin of the Global Volcanism Network, vol. 21, no. 8 (August 1996)
Managing Editor: Richard Wunderman.
Bezymianny (Russia) Lava extrusion, rock avalanches, and increasing seismicity
Please cite this report as:
Global Volcanism Program, 1996. Report on Bezymianny (Russia) (Wunderman, R., ed.). Bulletin of the Global Volcanism Network, 21:8. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199608-300250
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
Scientists doing fieldwork on 23-24 July observed up to six cold rock avalanches that were connected with extrusive block (obelisk) growth on the dome of the volcano. A number of local earthquakes were also recorded at the nearest seismic station (14 km away).
On 20-22 August a weak fumarolic cloud was observed. Seismicity at the volcano during 19-26 August was above background levels, and both the number and energy of earthquakes gradually increased. A viscous lava flow extruded from the top of the dome during 26-28 August and 31 August-1 September, but no ash explosions were observed.
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: Tom Miller, Alaska Volcano Observatory (AVO), 4200 University Drive, Anchorage, AK 99508-4667, USA; Vladimir Kirianov, Kamchatka Volcanic Eruptions Response Team (KVERT), Institute of Volcanic Geology and Geochemistry, Piip Ave. 9, Petropavlovsk-Kamchatsky, 683006, Russia.