Report on Sheveluch (Russia) — 2 October-8 October 2019
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 2 October-8 October 2019
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2019. Report on Sheveluch (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 2 October-8 October 2019. 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 29 September and 1-2 October video and satellite images recorded ash plumes from explosions at Sheveluch rising as high as 9 km (29,500 ft) a.s.l., and a notable pyroclastic flow traveled SE on 1 October. Ash plumes from the events drifted 1,400 km SE and E. On 6 October satellite images showed ash plumes rising to 10 km (32,800 ft) a.s.l. and drifting 430 km NE. The Aviation Color Code was raised to Red (the highest level on a four-color scale). Later that day the ash plumes were visible in satellite images drifting 1,080 km ENE. The Alert Level was lowered back to Orange.
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.