Report on Bezymianny (Russia) — 13 November-19 November 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
13 November-19 November 2002
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2002. Report on Bezymianny (Russia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 13 November-19 November 2002. Smithsonian Institution and US Geological Survey.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
KVERT raised the Concern Color Code at Bezymianny from Green to Yellow on 18 November. A one-pixel thermal anomaly was observed on various satellite imagery on both 16 and 17 November. The closest telemetered seismic stations, located on Kliuchevskoi volcano 13.5 km from Bezymianny's lava dome, only recorded several shallow seismic events at Bezymianny; 13 per month in August and September, and 3 in October. High seismic activity at Kliuchevskoi makes it difficult to distinguish Bezymianny's seismic events.
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.