KVERT reported that a thermal anomaly over Kizimen's lava dome was observed in satellite imagery during 29 December-1 January and that an explosive eruption that began on 13 December continued. On 31 December seismicity increased and volcanic tremor was detected. Explosions occurred sporadically for a period of about 20 minutes. Ash plumes detected in satellite imagery rose to an altitude of 8 km (26,200 ft) a.s.l. and drifted SW. Ashfall at least 1 mm thick occurred in multiple areas 225-275 km SSW, including Petropavlovsk-Kamchatsky, Yelizovo, Paratunka, and Nalychevo. On 1 January the Aviation Color Code was raised to Red. Ash plumes at an altitude of 4 km (13,100 ft) a.s.l. drifted 480-500 km SW; ash continued to accumulate in some areas. Seismic data indicated increased activity on 3 January. Explosions continued, and ash plumes drifted more than 200 km SE. A large and bright thermal anomaly was observed in satellite imagery.

Based on analysis of satellite imagery, the Tokyo VAAC reported that possible eruptions during 2-4 January produced plumes that rose to an altitude of 3-4.6 km (10,000-15,000 ft) a.s.l. and drifted S, E, and NE. Subsequent images on those same days showed ash emissions continuing, then dissipating.

Geological Summary. Kizimen is an isolated, conical stratovolcano that is morphologically similar to St. Helens prior to its 1980 eruption. The summit consists of overlapping lava domes, and blocky lava flows descend the flanks of the volcano, which is the westernmost of a volcanic chain north of Kronotsky volcano. The 2334-m-high edifice was formed during four eruptive cycles beginning about 12,000 years ago and lasting 2000-3500 years. The largest eruptions took place about 10,000 and 8300-8400 years ago, and three periods of long-term lava dome growth have occurred. The latest eruptive cycle began about 3000 years ago with a large explosion and was followed by intermittent lava dome growth lasting about 1000 years. An explosive eruption about 1100 years ago produced a lateral blast and created a 1.0 x 0.7 km wide crater breached to the NE, inside which a small lava dome (the fourth at Kizimen) has grown. Prior to 2010, only a single explosive eruption, during 1927-28, had been recorded in historical time.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)