Report on Sheveluch (Russia) — 24 May-30 May 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 24 May-30 May 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Sheveluch (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 24 May-30 May 2017. 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 23-25 May powerful explosions at Sheveluch generated ash plumes that rose 8 km (26,200 ft) a.s.l. and drifted 715 km in different directions. At 0830 on 25 May explosions generated ash plumes that rose 9-10 km (29,500-32,800 ft) a.s.l. and drifted 16 km NE. The Aviation Color Code (ACC) was raised to Red (the highest color on a four-color scale). Around 30 minutes later the ash plume was identified in satellite images drifting 45 km ENE. Strong steam-and-gas emissions rose from the lava dome. The ACC was lowered to Orange. Within the next hour the ash plume drifted 82 km E.
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.