Report on Bezymianny (Russia) — 23 December-29 December 2009
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 23 December-29 December 2009
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2009. Report on Bezymianny (Russia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 23 December-29 December 2009. Smithsonian Institution and US Geological Survey.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
KVERT reported that during 21-23 December a large and intense thermal anomaly from Bezymianny was detected in satellite imagery. During 22-24 December seismic activity was elevated and fumarolic activity was observed. Gas-and-steam plumes rose to an altitude of 4 km (13,100 ft) a.s.l. The Level of Aviation Color Code remained at Yellow.
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.