Several explosions occurred at Kliuchevskoi during 9-16 May, and seismicity was above background levels. On 14 May KVERT raised the Concern Color Code to Orange from Yellow. An eruption on 14 May at 1120 produced the week's highest rising ash cloud (~8.5 km a.s.l.). During the report period, instruments recorded 26 to 59 earthquakes per day. They were greater than M 1.25 and at depths of ~30 km. A large number of weak shallow earthquakes and tremor also occurred.

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.

Sources: Pravda News, Kamchatkan Volcanic Eruption Response Team (KVERT)