KVERT reported that seismic activity at Karymsky was above background levels on 12 and 18 March; no data was collected during 13-17 March due to technical reasons. According to reports from Yelizovo Airport, pilots saw an ash plume that rose to an altitude of 3.9 km (12,800 ft) a.s.l. and drifted E on 12 March. Analysis of satellite imagery revealed a thermal anomaly on the lava dome during 12-14 and 16-17 March, and ash plumes that drifted 200 km in easterly directions during 12-13 and 16-17 March. The Level of Concern Color Code remained at Orange.

Based on information from the Yelizovo Airport, the Tokyo VAAC reported that on 19 March an ash plume rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted W.

Geological Summary. Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during the early Holocene. The caldera cuts the south side of the Pleistocene Dvor volcano and is located outside the north margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, located immediately south. The caldera enclosing Karymsky formed about 7600-7700 radiocarbon years ago; construction of the stratovolcano began about 2000 years later. The latest eruptive period began about 500 years ago, following a 2300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been vulcanian or vulcanian-strombolian with moderate explosive activity and occasional lava flows from the summit crater.

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