KVERT reported that seismic activity at Shiveluch was moderate during 26 August-1 September, and indicated that possible ash plumes rose to an altitude of 8.6 km (28,200 ft) a.s.l. on 28 August. Ground-based observers noted fumarolic activity during 26, 28, and 30-31 August, and an ash plume that rose to an altitude of 6 km (19,700 ft) a.s.l. on 28 August. A thermal anomaly on the volcano was observed in satellite imagery on 29 and 31 August. The Aviation Color Code remained at Orange.

Based on information from Yelizovo Airport (UHPP) and KVERT, the Tokyo VAAC reported that on 3 September an ash plume rose to an altitude of 5.8 km (19,000 ft) a.s.l. and drifted NE. Subsequent images that day showed that the ash had dissipated.

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)