KVERT reported that during 4-11 June seismic activity from Karymsky was above background levels, and suggested that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. on 6 June. Satellite imagery revealed a thermal anomaly over the volcano during 4-5 and 8 June. Based on information from KVERT and Yelizovo Airport (UHPP), and analyses of satellite imagery, the Tokyo VAAC reported that on 11 June an eruption produced an ash plume that rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted NE and SE. The Aviation Color Code level remained at Orange.

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)