KVERT reported weak-to-moderate seismic activity from Karymsky during 24-31 August. Volcanologists working on the flank observed explosive activity; ash plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. on 25 August. Satellite imagery showed a thermal anomaly on the volcano during 23-24, 26, and 28 August. The Aviation Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Geological Summary. Karymsky is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during the early Holocene. The caldera cuts the S side of the Pleistocene Dvor volcano and is located outside the N 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 enclosing caldera formed about 7,600-7,700 radiocarbon years ago; construction of the stratovolcano began about 2,000 years later. The latest eruptive period began about 500 years ago, following a 2,300 years of quiescence. Much of the cone is covered by lava flows less than 200 years old. Recorded eruptions have been Vulcanian or Vulcanian-Strombolian with moderate explosive activity and occasional lava flows from the summit crater.