Report on Sheveluch (Russia) — 24 February-2 March 2010
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
24 February-2 March 2010
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2010. Report on Sheveluch (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 24 February-2 March 2010. Smithsonian Institution and US Geological Survey.
56.653°N, 161.36°E; summit elev. 3283 m
All times are local (unless otherwise noted)
KVERT reported that during 19-26 February seismic activity from Shiveluch was above background levels, possibly indicating ash plumes rising to an altitude of 5 km (16,400 ft) a.s.l. Fumarolic activity was occasionally observed. Ash and snow fell simultaneously in Klyuchi, 50 km SW, on 21 February. Analyses of satellite imagery revealed a large daily thermal anomaly from the lava dome, and ash plumes that drifted 30 km to the N and E on 23 and 25 February, respectively. Gas-and-steam plumes drifted 60 km N during 18 and 22-25 February. The Aviation Color Code level remained at Orange. Based on information from KVERT, the Tokyo VAAC reported that on 26 February an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted NE.
Geological Summary. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's largest and most active volcanic structures, with at least 60 large eruptions during the Holocene. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes occur on its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large open caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera.