Report on Bezymianny (Russia) — 2 February-8 February 2011
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 2 February-8 February 2011
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2011. Report on Bezymianny (Russia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 2 February-8 February 2011. 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 28 January-4 February seismicity from Bezymianny did not exceed background levels, however weak volcanic earthquakes were detected. A thermal anomaly over the volcano was observed daily in satellite imagery. Gas and steam activity was observed during 30-31 January and 1-3 February; cloud cover prevented observations on the other days. The Aviation Color Code level remained at Yellow.
Based on information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 4 February an ash plume rose to an altitude of 4.6 km (15,000 ft) a.s.l. drifted NE.
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.