Extrusive-effusive eruption at Bezymianny volcano, Kamchatka, Russia intensified on May 28, 2022, with intense paroxysmal episode and pyroclastic flows. As a result, KVERT raised the Aviation Color Code to Red at 07:26 UTC. Bezymianny was considered extinct before it started erupting in 1955 (VEI 5).
According to the Tokyo VAAC, volcanic ash cloud top was reaching 15 km (50 000 feet) above sea level at 08:40 UTC, drifting SE.
The distance of the ash cloud was 365 km (227 miles) SE of the volcano at 07:40 UTC.
The paroxysmal phase of the explosive eruption has ended by 10:00 UTC, but the volcano’s eruptive activity, with the emission of ash up to 5 km (16 400 feet) a.s.l. continued, KVERT said at 10:07 UTC and lowered the Aviation Color Code back to Orange.1https://www.youtube.com/embed/58U1YO9U9-c?feature=oembed
Two ash plumes were observed in the satellite images at 10:00 UTC. The first was reaching a height of 9.5 km (31 200 feet) a.s.l. and extending 212 km (131 miles) southeast of the volcano, while the second extended 650 km (403 miles) southeast of the volcano, according to KVERT.
The Aviation Color Code was raised from Yellow to Orange on May 23 when eruption at the volcano ejected ash up to 5.2 km (17 000 feet) above sea level.2
Activity at the volcano increased on March 14, with new viscous lava flowing out of the dome.3
A gas-steam plume with some amount of ash extended about 90 km (55 miles) to the W of the volcano at 22:00 UTC. By 04:20 UTC on March 15, the cloud was extending about 120 km (75 miles) W of the volcano.
Prior to its noted 1955 – 56 eruption, Bezymianny had been considered extinct. The modern volcano, much smaller in size than its massive neighbors Kamen and Kliuchevskoi, was formed about 4 700 years ago over a late-Pleistocene lava-dome complex and an ancestral 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 horseshoe-shaped crater that was formed by the 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.4
1 VONA/KVERT Information Release, May 28, 2022. KVERT, Institute of Volcanology and Seismology FEB RAS