KVERT reported that at 1427 on 16 February a satellite image captured an ash plume from Karymsky drifting 55 km SE at altitudes of 2.5-3 km (8,200-10,000 ft) a.s.l. The Aviation Color Code was raised to Orange (the second highest level on a four-color scale). According to the Tokyo VAAC a possible ash plume on 17 February rose to 3.7 km (12,000 ft) a.s.l. and drifted SE. A weak ash plume drifting 117 km ESE was visible in satellite images on 18 February.

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.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)