Eruptive activity continued at Kliuchevskoi during 11-18 March. Strombolian explosions occurred intermittently from a cinder cone in the summit crater. Lava flows extended from this cinder cone down the NW flank of the volcano. Occasional vigorous explosions from the summit crater and along the path of the lava flow produced ash plumes that reached as high as 7-8 km (23,000-26,200 ft) a.s.l. and drifted many tens or hundreds of kilometers downwind.

Seismicity was above background levels at Kliuchevskoi during the report period. Ash-and-gas plumes rose to 3.2 km above the crater (~26,300 ft a.s.l.) on 11-12 March. Ash fell in the town of Kozyrevsk on 11 March. Strombolian bursts rose 500-1,000 m (1,600- 3,300 ft) above the summit crater. On 15 March two lava flows were observed on the NW slope of the volcano. Kliuchevskoi remained at Concern Color Code Orange.

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)