Fumarolic activity from the extrusive dome was observed through mid-March. Growth of the SE part of the dome was observed in mid-February. The height of the gas-and-steam plume in late February through mid-March was usually 300-500 m above the crater rim. However, it was as high as 1.5 km in early March. The amount of weak volcanic tremor varied from 3 to 12 hours/day in late February and early March before dropping to 1.5-6 hours/day at mid-month. During this period, shallow volcanic earthquakes registered at rates of 1-5 events/day.

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: V. Kirianov, IVGG.