Report on Sheveluch (Russia) — 1 February-7 February 2012
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 1 February-7 February 2012
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2012. Report on Sheveluch (Russia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 1 February-7 February 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 low levels of seismic activity were detected at Shiveluch during 26 January-3 February. Satellite imagery showed a daily thermal anomaly over the lava dome. Ground-based observers noted that a viscous lava flow continued to effuse in the crater that was formed during a 2010 eruption. Moderate fumarolic activity at the lava dome and occasional hot avalanches were observed all week. Weak ash explosions from the lava dome were reported from the SE flank on 26 January. 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.