Report on Klyuchevskoy (Russia) — January 1987
Scientific Event Alert Network Bulletin, vol. 12, no. 1 (January 1987)
Managing Editor: Lindsay McClelland.
Klyuchevskoy (Russia) Lava flows; directed explosions; plumes on satellite images
Please cite this report as:
Global Volcanism Program, 1987. Report on Klyuchevskoy (Russia). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 12:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198701-300260.
56.056°N, 160.642°E; summit elev. 4754 m
All times are local (unless otherwise noted)
On 26 December, after 5 months of quiet [but see 13:4], two vents from an intracrater scoria cone ejected bombs and ash. Bombs reached 300 m height. Rare gas/steam explosions, mixed with some ash, fed a 1-km eruption column. On 29 December, lava flows poured from a vent near the foot of the scoria cone (last active in July) onto the N and NW flanks. In January, pyroclastic material was ejected obliquely from the crater onto the volcano's flanks. The eruption decreased in intensity on 20 January. Images from the NOAA 9 polar orbiting satellite at 1617 on 21 January showed a 25-km-long plume spreading SW that had grown to 40 km by 0843 the next day.
Weather satellite images showed renewed activity on 17 February with larger plumes late 19 February. Plumes extended as much as 300 km from the volcano (table 1) and were continuing to form as of 20 February. Comparisons of plume temperatures and directions of plume movement with temperature and wind data recorded by radiosondes (launched 15 km to the N) indicated that plumes reached as much as 9 km altitude.[Skip text table]
Date Time Altitude Description 17 Feb 1987 1800 ~9 km 125 km to the SE 2100 ~9 km 250 km to the SSE 18 Feb 1987 0000 --- Small `cold sport' indicating activity 0900 ~3 km 125 km to the SSW 1017 ~3 km 65 km to the SSW, curving SE at its distal end 19 Feb 1987 0000 --- 100 km to the SW 0150 --- 180 km to the SE 1126 --- 180 km to the SSE 1800 --- 190 km to the ESE 2100 --- 250 km long, about 50 km wide 20 Feb 1987 0000 >7.5 km 250 km long 0600 ~7.5 km 300 km ESE
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.
Information Contacts: A. Khrenov and G. Bogoyavlenskaya, IV; M. Matson, S. Kusselson, and W. Gould, NOAA/NESDIS.