Report on Sheveluch (Russia) — 6 June-12 June 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 6 June-12 June 2012
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on Sheveluch (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 6 June-12 June 2012. 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 1-8 June explosive activity at Shiveluch continued. Ground-based observers and satellite imagery indicated that a viscous lava flow continued to effuse in the active crater, accompanied by fumarolic activity. Observers noted that ash plumes rose to an altitude of 8.5 km (28,000 ft) a.s.l. on 2 June. Satellite imagery showed a thermal anomaly over the lava dome during 31 May and 1-4 June, and ash plumes drifting 152 km S and 250 km S and ENE during 2-3 June. Seismic data indicated that possible ash plumes rose to an altitude of 8 km (26,200 ft) a.s.l. on 5 June. The Aviation Color Code remained at Orange.
Based on analyses of seismic data, the Tokyo VAAC reported that a possible eruption on 6 June produced an ash plume that rose to an altitude of 8.2 km (27,000 ft) a.s.l. Ash was not detected in satellite images.
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.