Report on Sheveluch (Russia) — 16 April-22 April 2008
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 16 April-22 April 2008
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2008. Report on Sheveluch (Russia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 16 April-22 April 2008. 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 seismic activity at Shiveluch was slightly above background levels during 10-15 April and at background levels on 16 April. According to video footage and visual observations, fumarolic activity from the lava dome occurred during 12-15 April. Based on seismic interpretation, a possible ash plume rose to an altitude of 3 km (9,800 ft) a.s.l. on 14 April. Observations of satellite imagery revealed that a thermal anomaly was present in the crater during 11-14 April. The Level of Concern 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.