During 9-16 April, seismicity at Karymsky remained above background with 300-470 earthquakes per day and daily eruptions produced plumes to ~3.5 km a.s.l. During 12-19 April up to 400 small explosions per day produced plumes that rose ~0.5-1.5 km above the vent. According to the Tokyo VAAC, an eruption on 18 April produced a gas-and-ash plume that rose to ~4.6 km a.s.l. and extended SE. Karymsky remains at Concern Color Code 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.

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