Bezymianny

Bezymianny (Безымянный Bezymyannyyi, meaning unnamed) is an active stratovolcano in Kamchatka, Russia. Bezymianny volcano had been considered extinct until 1955. Activity started in 1955, culminating in a dramatic eruption on 30 March 1956. This eruption, similar to that of Mount St. Helens in 1980, produced a large horseshoe-shaped 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. The most recent eruption of lava flows occurred in February 2013. An explosive eruption on 20 December 2017 released an ash plume rising to a height of 15 km above sea level, which drifted for 320 km NE. The volcano erupted similarly on 28 May 2022, again spewing an ash plume over 15 km high. On April 7, 2023, Russia reported Bezymianny had erupted explosively again and the Federal Agency for Air Transport, Rosaviatsiya, issued a Notice to Airmen (NOTAM) and raised the aviation Color Code Red. The eruption formed a column of ash that rose to a height of 12 km and was drifting to the southeast slowly. The ash plume stretched out across a distance of 2000 km.

The modern Bezymianny volcano, much smaller than its massive neighbors Kamen and Kliuchevskoi, was formed about 4700 years ago over a late-Pleistocene lava-dome complex and an ancestral volcano that was built between about 11,000–7000 years ago. There have been three periods of intensified activity in the past 3000 years.