KVERT reported that activity at Klyuchevskoy notably decreased, with the eruption likely ending on 8 February. The temperature of the thermal anomaly identified in satellite images abruptly dropped on 7 February, and the magnitude of volcanic tremor decreased during 7-8 February and continued to decline through 12 February. Strombolian activity was not visible at night during 11-12 February. The Aviation Color Code was lowered to Yellow (the second lowest level on a four-color scale) on 12 February.

The Tokyo VAAC reported that re-suspended ash was identified in satellite images during 12-13 February. On 15 February an ash plume rose to 5.2 km (17,000 ft) a.s.l. and drifted NE.

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.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)