KVERT reported that the explosive Strombolian eruption at Klyuchevskoy continued 14-21 September. A daily bright thermal anomaly was identified in satellite images. Lava fountaining fed flows that advanced down the Kozyrevsky drainage on the SE flank. Plumes of resuspended ash (deposited on the volcano’s N flanks from Sheveluch’s 10-13 April eruption) drifted 50 km E on 22 September, prompting KVERT to raise the Aviation Color Code to Orange (the third level on a four-color scale). The Aviation Color Code was lowered back to Yellow on 24 September; Strombolian activity continued to feed the lava flow. Dates are based on UTC times; specific events are in local time where noted.

Geological Summary. Klyuchevskoy is the highest and most active volcano on the Kamchatka Peninsula. Since its origin about 6,000 years ago, this symmetrical, basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. It rises above a saddle NE of Kamen volcano and lies SE of the broad Ushkovsky massif. More than 100 flank eruptions have occurred during approximately the past 3,000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 and 3,600 m elevation. Eruptions recorded since the late 17th century have resulted in frequent changes to the morphology of the 700-m-wide summit crater. These eruptions over the past 400 years 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)