KVERT reported that during 1100-1150 on 18 February a new vent opened on Klyuchevskoy’s lower NW flank, near Erman glacier at elevations of 2,500-2,700 m, based on satellite images. Snowfall in the area of Klyuchi during 18-19 February inhibited webcam views. Bright incandescence was visible in webcam images beginning at 0323 on 21 February, likely indicating an advancing lava flow. On 23 February the Kamchatka Volcanological Station team reported that lava was flowing from two vents and bombs were being ejected 50 m high. A lahar along the Krutenkaya River was visible in an area 7 km E of Klyuchi Village (30 km NNE). Bright incandescence over the two flank vents was identified in satellite and video images on 24 February. KVERT raised the Aviation Color Code to Orange (the second highest level on a four-color scale).

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: Kamchatkan Volcanic Eruption Response Team (KVERT), Kamchatka Volcanological Station