KVERT reported that a thermal anomaly over Chikurachki was identified on 21 June and an explosive eruption occurred on 24 June. Explosions recorded during 0730-2100 on 24 June (local time) produced ash plumes that rose to 4.5 km (14,800 ft) a.s.l. A 14 x 30 km ash cloud was visible in satellite images at 0850 drifting 25 km SE, prompting KVERT to raise the Aviation Color Code to Orange (the second highest level on a four-color scale). A VONA issued at 1445 on 25 June (local time) stated that only gas-and-steam emissions were rising from the volcano and that the Aviation Color Code was lowered to Yellow. The ash cloud from the explosive phase had drifted about 790 km SE. Satellite images on 26 June indicated no additional explosions; gas-and-steam emissions persisted. At 1624 (local time) the Aviation Color Code was lowered to Green.

Geological Summary. Chikurachki, the highest volcano on Paramushir Island in the northern Kuriles, is a relatively small cone constructed on a high Pleistocene edifice. Oxidized basaltic-to-andesitic scoria deposits covering the upper part of the young cone give it a distinctive red color. Frequent basaltic Plinian eruptions have occurred during the Holocene. Lava flows have reached the sea and formed capes on the NW coast; several young lava flows are also present on the E flank beneath a scoria deposit. The Tatarinov group of six volcanic centers is located immediately to the south, and the Lomonosov cinder cone group, the source of an early Holocene lava flow that reached the saddle between it and Fuss Peak to the west, lies at the southern end of the N-S-trending Chikurachki-Tatarinov complex. In contrast to the frequently active Chikurachki, the Tatarinov centers are extensively modified by erosion and have a more complex structure. Tephrochronology gives evidence of an eruption around 1690 CE from Tatarinov, although its southern cone contains a sulfur-encrusted crater with fumaroles that were active along the margin of a crater lake until 1959.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)