Report on Sheveluch (Russia) — January 1994
Bulletin of the Global Volcanism Network, vol. 19, no. 1 (January 1994)
Managing Editor: Richard Wunderman.
Sheveluch (Russia) Continued fumarolic activity and plume; variable seismicity
Please cite this report as:
Global Volcanism Program, 1994. Report on Sheveluch (Russia). In: Wunderman, R. (ed.), Bulletin of the Global Volcanism Network, 19:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199401-300270.
56.653°N, 161.36°E; summit elev. 3283 m
All times are local (unless otherwise noted)
Fumarolic activity from the extrusive dome was observed throughout January and into mid-February. The SE part of the extrusive dome continued to grow in mid-February. The persistent gas-and-steam plume rose 400-1,000 m above the crater rim in January. Weak volcanic tremor was recorded for ~0.3 hours/day in late January, a significant decrease from earlier in the month when tremor was recorded for 7-9 hours/day (18:12). Late January temperatures in Kliuchi, 8 km S, were as low as -40°C.
The height of the gas-and-steam plume above the crater rim was estimated to be 800-2,000 m in the first half of February, but only 400 m at mid-month. Weak volcanic tremor (1-5 hours/day) was recorded in late January to early February, and some shallow volcanic earthquakes (average of 1 event/day) were registered. Weak volcanic tremor increased to 3-5.5 hours/day in the second week of February when 1-2 shallow volcanic earthquakes/day were detected. Seismicity increased the following week to 8-12 hours/day of tremor and 1-3 earthquakes/day.
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.
Information Contacts: V. Kirianov, IVGG.