KVERT reported that seismic activity at Shiveluch was above background levels during 19-26 September. A large number of hot avalanches may have descended the lava dome and produced ash plumes that rose to an altitude of 3.6 km (11,800 ft) a.s.l. Fumaroles on the lava dome were active on 19 September. Analysis of satellite imagery revealed a daily thermal anomaly on the lava dome. According to a news article, video cameras recorded an eruption that produced an ash plume on 26 September. The ash plume rose to an altitude of 4.5 km (14,800 ft) a.s.l. The Level of Concern 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: Itar-Tass News, Kamchatkan Volcanic Eruption Response Team (KVERT)