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Report on Sheveluch (Russia) — August 2001


Sheveluch

Bulletin of the Global Volcanism Network, vol. 26, no. 8 (August 2001)
Managing Editor: Richard Wunderman.

Sheveluch (Russia) Eruption on 15 July, pyroclastic flows and explosion on 23 August 2001

Please cite this report as:

Global Volcanism Program, 2001. Report on Sheveluch (Russia) (Wunderman, R., ed.). Bulletin of the Global Volcanism Network, 26:8. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN200108-300270



Sheveluch

Russia

56.653°N, 161.36°E; summit elev. 3283 m

All times are local (unless otherwise noted)


During 14-16 July 2001, spasmodic volcanic tremor increased several times. On 15 July at 1803 a three-pixel anomaly was visible on AVHRR satellite imagery near the SW flank of the volcano and at 2100 a gas-and-steam plume was observed rising to 1.5 km above the dome. A moderate-sized eruption took place on 19 July at 1033. KVERT raised the level of concern from Yellow (volcano is restless; eruption may occur) to Orange (volcano is in eruption or eruption may occur at any time). The eruption produced an ash plume that rose 3 km above the lava dome.

After the eruption through 15 August, seismic activity remained above background levels, with many small earthquakes occurring within the volcano's edifice and many different seismic signals (explosion, avalanche, collapse) recorded locally. Gas-and-steam plumes rose from the summit level to ~2 km above the dome. One- to three-pixel anomalies were occasionally visible on AVHRR imagery near the SW flank of the volcano. The level of continuous spasmodic volcanic tremor increased on 28 and 30 July. On the night of 1 August ash fell in the town of Klyuchi, 46 km S of the volcano. On 11 August several thermal anomalies were recorded on satellite imagery, as well as a gas-and-steam plume that extended 75 km SE. On 15 August volcanic tremor decreased gradually to background levels, but increased again soon after. Pyroclastic flows traveled down the flanks of the volcano following an explosion on 23 August. The volcano remained at concern level Orange throughout August.

Geological Summary. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's largest and most active volcanic structures, with at least 60 large eruptions during the Holocene. 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 occur on its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large open caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. 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.

Information Contacts: Olga Chubarova, Kamchatka Volcanic Eruptions Response Team (KVERT); Institute of Volcanic Geology and Geochemistry, Piip Ave. 9, Petropavlovsk-Kamchatsky, 683006, Russia; Alaska Volcano Observatory (AVO), a cooperative program of a) U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), b) Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and c) Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA; Anchorage Volcanic Ash Advisory Center (VAAC), NOAA Alaska Aviation Weather Unit, 6930 Sand Lake Road, Anchorage, AK 99502-1845, USA (URL: http://vaac.arh.noaa.gov/); Tokyo Volcanic Ash Advisory Center, Tokyo, Japan (URL: http://ds.data.jma.go.jp/svd/vaac/data/).