[Following notice in early December that seismic stations at Shiveluch and Tolbachik had closed, on 22 December the following message was sent from the Alaska Volcano Observatory (AVO): "KVERT [Kamchatka Volcanic Eruptions Response Team] has informed AVO that, because of a long delay in promised funding from the Ministry of Transportation in Moscow, KVERT must suspend transmittal of information on volcanic activity in Kamchatka. The length of the suspension is unknown at this time.]

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; T. Miller, AVO.