Report on Karymsky (Russia) — 20 September-26 September 2006
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 20 September-26 September 2006
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2006. Report on Karymsky (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 20 September-26 September 2006. Smithsonian Institution and US Geological Survey.
54.049°N, 159.443°E; summit elev. 1513 m
All times are local (unless otherwise noted)
Seismic data and satellite observations reported by KVERT indicate that moderate ash eruptions were continuing from Karymsky during 16-22 September. There have been 40-200 weak shallow earthquakes recorded each day. A thermal anomaly over the crater was noted on 18-19 September. Based on visual observations, volcanologists in the area on 19 September estimated ash explosions to have reached altitudes of 2.3 km (7,500 ft) a.s.l. Ash plumes extending 16-40 km SW and SE were noted at satellite images on 18-19 September.
Geologic Background. 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.