KVERT reported that during 24-31 July seismic activity from Shiveluch was above background levels. Based on interpretations of seismic data, ash plumes possibly rose to an altitude of 6.5 km (21,300 ft) a.s.l. Steam-and-gas plumes with some ash content were also noted. Analyses of satellite imagery revealed a large daily thermal anomaly over the lava dome. According to video camera data, ash plumes rose to an altitude of 5 km (16,400 ft) a.s.l. on 23 and 27 July; gas-and-steam plumes rose to an altitude of 2.7 km (8,900 ft) a.s.l. on 24 and 27 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 during 1-2 August eruptions produced plumes that rose to altitudes of 3-5.8 km (10,000-19,000 ft) a.s.l. and drifted E and NE.

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)