KVERT reported that during 14-21 February lava-dome extrusion at Shiveluch was accompanied by ash explosions, incandescence, and fumarolic activity. A thermal anomaly was detected daily in satellite images. On 19 February a gas-and-steam plume containing small amounts of ash rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted about 50 km SSE. On 25 February satellite images detected ash plumes that rose to altitudes of 4-4.5 km (13,100-14,800 ft) a.s.l. and drifted SE. The Aviation 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.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)