KVERT reported that during 23-24 December gas-and-steam plumes from Koryaksky containing a small amount of ash were detected on satellite images. On 24 December observers from the Nalychevo valley reported that a dark plume rose 200-300 m from a fumarolic vent (about 3 km a.s.l.) on the NW flank of Koryaksky and a boom was heard later that night. Ash plumes detected in satellite imagery on 25 December drifted about 200 km NE. On 28 December, KVERT raised the Alert Level to Orange and reported that a Vulcanian eruption was occurring. Ash plumes rose to an altitude of 4 km (13,200 ft) a.s.l. and drifted NW.
Sources: 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.”