Report on Sheveluch (Russia) — 28 March-3 April 2007
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 28 March-3 April 2007
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2007. Report on Sheveluch (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 28 March-3 April 2007. Smithsonian Institution and US Geological Survey.
56.653°N, 161.36°E; summit elev. 3283 m
All times are local (unless otherwise noted)
An explosive event at Shiveluch on 29 March produced an ash plume that rose to an estimated altitude of 9.8 km (32,000 ft) a.s.l. and drifted NE. Based on reports from the Yelizovo Meteorological Watch Office and satellite imagery, the Tokyo VAAC reported that the plume reached an altitude of 11.9 km (39,000 ft) a.s.l. The next day, an explosive event that lasted about 6 minutes produced a plume to altitudes of 10.1-12.2 km (33,000-40,000 ft) a.s.l., based on estimates from AVO, Tokyo VAAC, and the Kamchatkan Branch of Geophysical Services. The plume drifted NE.
According to a news article, a mudflow covered an approximately 900-m-long section of road, about 20 km from Shiveluch on 31 March.
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.