Activity at Shiveluch continued above background levels during 29 December-5 January, with 200 shallow earthquakes occurring daily. Based on seismic interpretation, ash plumes rose to 13.7 km (45,000 ft) a.s.l. According to visual and video data, a large hot avalanche occurred on the SE flank on 4 January. Fumarolic activity was noted during 29-31 December and 2-4 January. The Tokyo VAAC reported eruption plumes to altitudes of 4.3-7.6 km (14,000-25,000 ft) a.s.l. during 5-7 January based on information from the Kamchatkan Experimental and Methodical Seismological Department (KEMSD) and satellite imagery.

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.

Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Kamchatkan Volcanic Eruption Response Team (KVERT)