Report on Bezymianny (Russia) — 14 June-20 June 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
14 June-20 June 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Bezymianny (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 14 June-20 June 2017. Smithsonian Institution and US Geological Survey.
55.972°N, 160.595°E; summit elev. 2882 m
All times are local (unless otherwise noted)
On 15 June KVERT reported that the temperature of a thermal anomaly identified in satellite images had increased, and that the webcam recorded a gas-and-steam plume rising above Bezymianny to 4 km (13,100 ft) a.s.l. and drifted SSE. Hot avalanches of material originated from the lava dome. An explosive event began at 1653 on 16 June, producing an ash cloud 28 x 25 km in size that drifted NE. The Aviation Color Code was raised to Red (the highest level on a four-color scale), but lowered back down to Orange about 5 hours later. At 2110 the ash cloud was 212 x 115 km in size and drifting E; the leading edge of the cloud was about 245 km E.
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.