During 22-29 August, seismicity was above background levels at Kliuchevskoi, with 3-8 earthquakes per day of magnitude less than 2.2 occurring at depths around 30 km. On 26 August at 2300 Strombolian activity was seen in the volcano's center crater. Volcanic bombs were hurled to ~200 m above the crater. There were 5-minute intervals between explosions. During 27-28 August, gas-and-steam plumes with minor amounts of ash rose 1.5-2 km above the volcano's crater and drifted SW. 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.

Sources: Associated Press, Kamchatkan Volcanic Eruption Response Team (KVERT)