Based on visual observations and analyses of satellite data, KVERT reported that during 28 September-5 October a viscous lava flow continued to effuse on the NW flank of Shiveluch's lava dome, accompanied by hot avalanches and fumarolic activity. Satellite imagery showed a thermal anomaly on the lava dome on 28 September and during 1-3 October. Based on analyses of satellite imagery, notices from Yelizovo Airport (UHPP), and information from KVERT, the Tokyo VAAC reported that on 5 October ash plumes rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SE. The next day ash plumes rose to an altitude of 7 km (23,000 ft) a.s.l and again drifted SE. The Aviation Color Code remained at Orange.

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