Report on Sheveluch (Russia) — 18 April-24 April 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
18 April-24 April 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, 18 April-24 April 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 explosive activity at Shiveluch continued during 13-20 April. Ground-based observers and satellite imagery indicated that a viscous lava flow continued to effuse in the crater formed during a 2010 eruption and was accompanied by fumarolic activity. Observers reported that ash plumes rose to altitudes of 6.5-7.5 km (21,300-24,600 ft) a.s.l. during 16-17 April and to altitudes of 4-5 km (13,100-16,400 ft) a.s.l. on the other days. Satellite imagery showed a weak thermal anomaly daily on the lava dome, and ash plumes that drifted 120 km N, NE, and E during 14-15 and 17-18 April. The Aviation Color Code remained at Orange.
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.