Report on Sheveluch (Russia) — 24 September-30 September 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 24 September-30 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, 24 September-30 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 during 19-26 September lava-dome extrusion onto Shiveluch’s N flank was accompanied by ash explosions, incandescence, hot avalanches, and fumarolic activity. Satellite images detected a thermal anomaly over the dome during 18 and 22-25 September. Strong explosions that began at 1238 on 24 September generated ash plumes that rose 11-11.5 km (36,000-37,700 ft) a.s.l. A large ash cloud, 250 by 207 km, drifted NNE. The Aviation Color Code was raised to Red and then lowered back to Orange that same day as the explosive activity subsided.
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.