Report on Sheveluch (Russia) — 4 April-10 April 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
4 April-10 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, 4 April-10 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 29 March-6 April. Ground-based observers and satellite imagery indicated that a viscous lava flow continued to effuse in the crater formed during a 2010 eruption. Visual observations revealed that ash plumes rose to an altitude of 4 km (13,100 ft) a.s.l. on 30 March and 3 April. Seismic data indicated that ash plumes potentially rose to an altitude of 6.6 km (21,600 ft) a.s.l. every day. Satellite imagery showed a weak thermal anomaly on the lava dome during 29-31 March and 3 April, and ash plumes that drifted 114 km W, E, and NE during 29-30 March and 3 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.