KVERT reported that a Strombolian and Vulcanian eruption at Klyuchevskoy continued during 27 February-6 March. Explosions generated ash plumes that rose to altitudes of 5-6 km (16,400-19,700 ft) a.s.l. and drifted 400 km E, SE, and NE. Satellite images showed a daily thermal anomaly over the volcano. The magnitude of seismic tremor significantly decreased at 0520 on 9 March, likely signifying the end of the explosive eruption. Only moderate emissions of steam and gas were observed and a thermal anomaly over the summit had been absent for the previous 10 hours. The Aviation Color Code was lowered to Yellow.

Geological Summary. 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.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)