Report on Karymsky (Russia) — 2 April-8 April 2008
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 2 April-8 April 2008
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2008. Report on Karymsky (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 2 April-8 April 2008. Smithsonian Institution and US Geological Survey.
54.049°N, 159.443°E; summit elev. 1513 m
All times are local (unless otherwise noted)
KVERT reported that seismic activity at Karymsky was above background levels during 28-29 March and slightly above background levels during 30 March-4 April. Pilots observed ash plumes to altitudes of 5-7 km (16,400-23,000 ft) a.s.l. during 28-29 March. Based on seismic interpretation, ash plumes possibly rose to an altitude of 2.5 km (8,200 ft) a.s.l. on 2 April and weak ash explosions or avalanches may have occurred daily during the reporting period. Observations of satellite imagery revealed that a thermal anomaly was present in the crater on 28 March and 1, 2, and 3 April; an ash plume drifted S on 3 April. Ash deposits were noted in areas about 20 km E, 70 km SW, and 45-50 km S. The Level of Concern Color Code remained at Orange.
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.