Report on Bezymianny (Russia) — January 1994
Bulletin of the Global Volcanism Network, vol. 19, no. 1 (January 1994)
Managing Editor: Richard Wunderman.
Bezymianny (Russia) Gas-and-steam plume persists with some ash
Please cite this report as:
Global Volcanism Program, 1994. Report on Bezymianny (Russia). In: Wunderman, R (ed.), Bulletin of the Global Volcanism Network, 19:1. Smithsonian Institution. https://dx.doi.org/10.5479/si.GVP.BGVN199401-300250.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
Seismicity was at background levels from mid-December 1993 through mid-February 1994. On 3 January a large steam-and-gas plume was seen to extend 40 km NE. The next day a large ash-and-gas plume stretched 60 km NE from the crater. One shallow earthquake was recorded on 18 January centered beneath the volcano. Volcanic tremor lasting 30 minutes on 21 January may have been caused by a small explosion from the extrusive summit lava dome. A gas-and-steam plume with a small amount of ash was again observed in early February extending 60 km SE.
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.