KVERT reported that the ongoing eruption at Sheveluch during 12-19 January was generally characterized by explosions, hot avalanches, lava-dome extrusion, and strong fumarolic activity. A daily thermal anomaly was identified in satellite images. Explosions on 19 January produced ash plumes that were identified in satellite images rising as high as 10 km (32,800 ft) a.s.l. and drifting W at 1240 local time. KVERT raised the Aviation Color Code to Red (the highest level on a four-color scale). In a Volcano Observatory Notice for Aviation (VONA) posted at 1635 local time KVERT noted that no additional plumes were identified in satellite images. The Aviation Color Code was lowered to Orange. 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)