Report on Bezymianny (Russia) — August 1994
Bulletin of the Global Volcanism Network, vol. 19, no. 8 (August 1994)
Managing Editor: Richard Wunderman.
Bezymianny (Russia) Gas-and-steam plume seen for the first time since February 1994
Please cite this report as:
Global Volcanism Program, 1994. Report on Bezymianny (Russia). In: Wunderman, R (ed.), Bulletin of the Global Volcanism Network, 19:8. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199408-300250.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
Seismicity remained at background levels from mid-July through early September. However, during 7-14 July, a gas-and-steam plume with a small amount of ash was observed rising ~500 m above the extrusive dome. On 11 July the ash-and-steam plume rose to ~3,000 m asl and drifted generally NE. The gas-and-steam plume extended 150 m above dome through 24 July. During the week of 11-18 August a gas-and-steam plume rose ~200 m above the volcano. A small gas-and-steam plume (to 50-70 m above the volcano) continued during the last 2 weeks of August. On 2-8 September, E. Zhdanova (KVERT) observed a viscous lava flow being "squeezed" from the extrusive dome. A gas-and-ash plume reached 1 km above the volcano and extended >40 km from the volcano. The volcano was obscured by clouds during the next week.
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: V. Kirianov, IVGG.