KVERT reported that seismic activity at Shiveluch was above background levels during 14-21 December. Based on seismic interpretation, a series of explosions during 18-19 December produced ash plumes that rose to altitudes of 6.5-8.7 km (21,300-29,000 ft) a.s.l. Ash plumes were observed on satellite imagery and drifted more than 130 km W on 18 December and 300 km to the NW and SW on 19 December. Ashfall was reported in the town of Klyuchi, about 30 km SW on 19 December. Large pyroclastic-flow deposits 8-9 km from the lava dome were observed to the S. On 20 December, KVERT reported that the Level of Concern Color Code was raised to Red. On 21 December, the Level of Concern Color Code was lowered back to Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT) – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”