Report on Klyuchevskoy (Russia) — 19 April-25 April 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 19 April-25 April 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Klyuchevskoy (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 19 April-25 April 2017. Smithsonian Institution and US Geological Survey.
56.056°N, 160.642°E; summit elev. 4754 m
All times are local (unless otherwise noted)
KVERT reported that a weak thermal anomaly was detected over Klyuchevskoy during 14-17 and 23 April. A steam-and-gas plume that rose to 5 km (16,400 ft) a.s.l. and drifted 125 km SW on 23 April contained some ash, prompting KVERT to raise the Aviation Color Code to Orange. On 24 April satellite images showed an ash plume drifting 72 km SW at an altitude of 7 km (23,000 ft) a.s.l. On 25 April KVERT noted that activity had significantly decreased and only steam-and-gas emissions were observed. The Aviation Color Code was lowered to Yellow. On 25 April ash was again present in a plume; KVERT raised the Aviation Color Code to Orange. The plume rose 3-4 km (9,800-13,100 ft) a.s.l. and drifted 60 km SW.
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.