The Kamchatka Volcanic Eruption Response Team (KVERT) reported that a thermal anomaly over Bezymianny was identified in satellite images during 20-21 and 23-26 September. The volcano was obscured by weather clouds on the other days of the week. On 25 September a plume of resuspended ash lifted from the S flank by strong winds was visible in satellite and webcam images drifting 90 km E. The resuspended ash prompted KVERT to briefly raise the Aviation Color Code from Yellow to Orange (the second highest level on a four-color scale) at 2310; the Aviation Color Code was lowered back to Yellow at 0323 on 26 September.

Geological Summary. The modern Bezymianny, much smaller than its massive neighbors Kamen and Kliuchevskoi on the Kamchatka Peninsula, was formed about 4,700 years ago over a late-Pleistocene lava-dome complex and an edifice built about 11,000-7,000 years ago. Three periods of intensified activity have occurred during the past 3,000 years. The latest period, which was preceded by a 1,000-year quiescence, began with the dramatic 1955-56 eruption. This eruption, similar to that of St. Helens in 1980, produced a large open crater that was formed by collapse of the summit and an associated lateral blast. Subsequent episodic but ongoing lava-dome growth, accompanied by intermittent explosive activity and pyroclastic flows, has largely filled the 1956 crater.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)