KVERT reported that during 19-22 August lava extrusion possibly continued at Sheveluch’s “300 years of RAS” dome on the SW flank of Old Sheveluch and at a new vent or dome that formed during the 17-18 August explosive events. A weak thermal anomaly over the domes was identified in satellite images on 19 and 21 August. Resuspended ash from the S flank rose as high as 3 km (10,000 ft) a.s.l. and drifted 200 km SE during 20-21 August based on webcam and satellite images. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.

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.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)