KVERT reported that during 10-17 July seismic activity from Shiveluch was above background levels. On 14 July, a gas-and-steam plume seen on a video camera rose to an altitude of 4 km (13,100 ft) a.s.l. Based on interpretations of seismic data, ash plumes possibly rose to an altitude of 6.5 km (21,300 ft) a.s.l. during 10, 13-14, and 16 July, and steam-and-gas plumes with some ash content were emitted during the reporting period. Analysis of satellite imagery revealed a daily thermal anomaly over the lava dome, and a steam plume that drifted 19 km SW on 13 July. The Level of Concern Color Code remained at Orange. Based on analyses of satellite imagery and information from KEMSD, the Tokyo VAAC reported that on 17 July an eruption produced a plume that rose to an altitude of 5.5 km (18,000 ft) a.s.l.

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)