Report on Sheveluch (Russia) — 27 October-2 November 2010
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 27 October-2 November 2010
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2010. Report on Sheveluch (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 27 October-2 November 2010. 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 from Shiveluch began to increase on 27 October. The magnitude of volcanic tremor then sharply increased on 28 October, indicating a strong explosive eruption. Cloud cover prevented observations of the volcano, but ash plumes possibly rose to an altitude of 10 km (32,800 ft) a.s.l. Ash fell in Ust-Kamchatsk, 85 km SE, a few hours later. The road from Ust-Kamchatsk to Kliuchi, 50 km SW, closed due to poor visibility and darkness. Satellite images indicated that the ash plume rose to an altitude of 12 km (39,400 ft) a.s.l. and drifted E. The Aviation Color Code level was raised to Red. According to news articles, ash from Shiveluch and Kliuchevskoi caused area flight diversions.
On 29 October satellite imagery showed the ash plume drifting 2,500 km E; ash continued to fall in Ust-Kamchatsk. Ash explosions continued on 30 October. Seismic data suggested that ash plumes rose to an altitude of 10 km (32,800 ft) a.s.l. and drifted NE. The Aviation Color Code level was lowered to Orange. Based on analyses of satellite imagery and information from KVERT, the Tokyo VAAC reported that possible eruptions on 31 October and during 1-2 November produced ash plumes that rose to altitudes of 3.7-6.7 km (12,000-22,000 ft) a.s.l. and drifted SE and E. Subsequent notices on 31 October and 1 November stated that ash had dissipated.
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.