Report on Sheveluch (Russia) — 10 September-16 September 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 10 September-16 September 2014
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2014. Report on Sheveluch (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 10 September-16 September 2014. 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 the explosive and effusive eruption of Shiveluch continued and maintained Alert Level Orange during the week of 12 September. Activity was dominated by lava dome growth on the SE flank, moderate ash explosions, fumarolic activity, and hot avalanches. Satellite data showed a persistent thermal anomaly from the dome region during 4-5, 7 and 11 September. Remobilized ash was observed in a dust plume on 11 September that rose 1-2 km (3,280-6,562 ft) a.s.l. and drifted SE.
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.