Report on Karymsky (Russia) — 25 February-2 March 2004
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
25 February-2 March 2004
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2004. Report on Karymsky (Russia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 25 February-2 March 2004. Smithsonian Institution and US Geological Survey.
54.049°N, 159.443°E; summit elev. 1513 m
All times are local (unless otherwise noted)
Seismicity remained above background levels at Karymsky during 20-27 February, with 30-100 shallow earthquakes during the week. Based on interpretations of seismic data, several ash explosions during 19-25 may have produced ash plumes to a maximum height of 6.5 km a.s.l. On 20 February an ash plume was seen rising to ~3.5 km a.s.l. Satellite imagery on 20 February showed ash deposits as far away as 35 km S of the volcano. Karymsky remained 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.