During 8-14 January, seismicity decreased slightly at Shiveluch but remained above background levels. Seismicity indicated that from 1815 to 1945 on 13 January, several ash explosions up to 5 km a.s.l. and a pyroclastic flow probably occurred. Possible weak ash-and-gas explosions and hot avalanches occurred during 8-14 January. According to visual observations and video data, gas-and-steam plumes rose up to ~2.5-3.4 km a.s.l. during 6-8 January and on 12 January. Shiveluch remained at Concern Color Code Orange.

The Tokyo VAAC reported an eruption of Shiveluch on 17 January at 1625 with a plume that rose to a height of ~4.5 km 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)