Report on Klyuchevskoy (Russia) — 25 April-1 May 2007
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 25 April-1 May 2007
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2007. Report on Klyuchevskoy (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 25 April-1 May 2007. Smithsonian Institution and US Geological Survey.
56.056°N, 160.642°E; summit elev. 4754 m
All times are local (unless otherwise noted)
During 20-27 April, KVERT reported that Strombolian activity occurred at Kliuchevskoi, based on observations and video data. Seismic activity continued above background levels and a thermal anomaly in the crater was detected on satellite imagery. Mudflows and lava flows continued to advance on the NW flank. Phreatic activity and ash plumes from lava-flow fronts were noted. Gas-and-steam plumes containing ash rose to altitudes of 7.2 km (23,600 ft) a.s.l. and were visible on satellite imagery drifting E and SE. Based on satellite imagery and information from KVERT, the Tokyo VAAC reported that ash plumes rose to an altitude of 5.2 (17,000 ft) a.s.l. and drifted E during 25-26 April. The Level of Concern Color Code remained at Orange.
Geologic Background. Klyuchevskoy (also spelled Kliuchevskoi) is Kamchatka's highest and most active volcano. Since its origin about 6000 years ago, the beautifully symmetrical, 4835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. It rises above a saddle NE of sharp-peaked Kamen volcano and lies SE of the broad Ushkovsky massif. More than 100 flank eruptions have occurred during the past roughly 3000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 m and 3600 m elevation. The morphology of the 700-m-wide summit crater has been frequently modified by historical eruptions, which have been recorded since the late-17th century. Historical eruptions have originated primarily from the summit crater, but have also included numerous major explosive and effusive eruptions from flank craters.