During 13 October-24 November seismicity remained above background level; low-level Strombolian eruptive activity that has continued since January 1996 (BGVN 21:01) consisted of gas and ash explosions occurring every 20 minutes, sending ash and steam 200-400 m above the crater. During 24 November- 29 December there was elevated seismicity and explosions every 20-30 minutes that sent ash and steam 300-400 m above the crater. On 14 December, the level of concern was downgraded to yellow from orange, indicating that the volcano's activity was less indicative of a major eruption.

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.

Information Contacts: Vladimir Kirianov, Kamchatka Volcanic Eruptions Response Team (KVERT), Institute of Volcanic Geology and Geochemistry; Tom Miller, Alaska Volcano Observatory.