Report on Bezymianny (Russia) — 12 April-18 April 2023
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 12 April-18 April 2023
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2023. Report on Bezymianny (Russia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 12 April-18 April 2023. 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 the eruption at Bezymianny intensified to a significant explosive phase starting from 1738 on 7 April and ending before 0906 on 8 April (local times). Based on webcam and satellite data ash plumes rose 10-12 km (32,800-39,400 ft) a.s.l. and drifted 2,800 km E. Notable amounts of ash fell at the Apakhonchich station. A daily thermal anomaly from continuing lava effusion was identified in satellite images during 8-14 April. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
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.