Report on Bezymianny (Russia) — 3 September-9 September 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
3 September-9 September 2014
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2014. Report on Bezymianny (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 3 September-9 September 2014. Smithsonian Institution and US Geological Survey.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
KVERT maintained Alert Level Yellow during the week of 5 September for Bezymianny. Weak seismic activity continued, and according to video data, moderate gas and steam activity frequently occurred, although the volcano was obscured by clouds. Satellite data showed a weak thermal anomaly over the volcano during this reporting period.
Geological Summary. 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.