Report on Sheveluch (Russia) — 6 June-12 June 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 6 June-12 June 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Sheveluch (Russia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 6 June-12 June 2001. Smithsonian Institution and US Geological Survey.
56.653°N, 161.36°E; summit elev. 3283 m
All times are local (unless otherwise noted)
On 5 June a gas-and-steam plume rose 450-1,200 m above the volcano and extended 3-5 km W. A thermal anomaly observed in satellite images on 5 June at 1809 had two saturated pixels (49°C) in a background of 15-25°C. On 6 June at 0756 the anomaly consisted of one pixel at 49.3°C in a background of near 4°C. According to reports from the town of Klyuchi, on 7 June at 1630 an ash-and-gas plume rose 600 m above the dome and extended to the W. At 1650 a short-lived explosion sent an ash-and-gas plume 1,500 m above the volcano accompanied by 3- and 2-minute-long, shallow seismic events. A thermal anomaly was observed in satellite images on 7 June at 1745. Three pixels near saturation (at 44-45°C) stood out from a background of pixels 15-25°C, in addition to a steam-and-ash plume extending to the NW about 33 km. The level of Concern Color Code remained at Yellow.
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.