Report on Sheveluch (Russia) — 28 October-3 November 2009
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 28 October-3 November 2009
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2009. Report on Sheveluch (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 28 October-3 November 2009. 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 23-30 October seismic activity from Shiveluch was above background levels and possibly indicated that ash plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. and to an altitude of 6.9 km (22,600 ft) a.s.l. on 29 October. Fumarolic activity was occasionally seen. Analyses of satellite imagery revealed a large thermal anomaly over the lava dome during 22-27 October and an ash plume that drifted 24 km NE on 26 October. Based on information from KEMSD and analyses of satellite imagery, the Tokyo VAAC reported that on 30 October an eruption produced a plume that rose to an altitude of 7 km (23,000 ft) a.s.l. A possible eruption plume rose to an altitude of 6.1 km (20,000 ft) a.s.l. later that day. On 1 November, an eruption produced a plume that rose to an altitude of 4.9 km (16,000 ft) a.s.l.
Geologic Background. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1300 km3 volcano is one of Kamchatka's largest and most active volcanic structures. 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 dot its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large horseshoe-shaped caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. At least 60 large eruptions have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. 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.