KVERT reported that seismic activity at Shiveluch continued above background levels during 1-8 June and a thermal anomaly in the crater was detected on satellite imagery. Gas-and-steam plumes rose to altitudes of 4.5 km (14,800 ft) a.s.l. during 1-3 and 5 June. Ash plumes rose to altitudes of 4.5-6 km (14,800-19,700 ft) a.s.l. on 1 and 6 June and were seen on satellite imagery drifting S and SE on 3 and 6 June. Based on seismic interpretation, multiple ash plumes rose to 6.5 km (21,300 ft) a.s.l. during 1-8. The Tokyo VAAC reported that eruption plumes rose to altitudes of 4.3-9.1 km (14,000-30,000 ft) a.s.l. on 9, 11, and 12 June, based on information from KVERT and KEMSD. Ash was not identified on satellite imagery. 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: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)