Report on Sheveluch (Russia) — 27 July-2 August 2011
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
27 July-2 August 2011
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2011. Report on Sheveluch (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 27 July-2 August 2011. 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 moderate during 22-29 July and indicated that possible ash plumes rose to an altitude of 4.7 km (15,400 ft) a.s.l. during 23 and 25-27 July. Satellite imagery showed a thermal anomaly on the lava dome on 22 July; cloud cover prevented observations on other days. Ground-based observers noted fumarolic activity on 24 July. The Aviation Color Code remained at Orange.
Based on information from KEMSD, the Tokyo VAAC reported that on 1 August an eruption produced a plume that rose to an altitude of 7 km (23,000 ft) a.s.l. and drifted E. Ash was seen in subsequent satellite images that same day.
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.