Bezymianny is one of the most active volcanoes in Kamchatka and the world. Its previous eruption occurred on March 15, 2019. This paper describes the explosive eruption of the volcano on October 21, 2020, and the events preceding it based on the study of video and various satellite data. Satellite monitoring of the volcano has been carried out using the information system “Remote monitoring of the activity of Kamchatka and Kurile volcanoes” (VolSatView) since 2014. Explosions raised ash up to 10–11 km above sea level, in connection with a cyclone in the Kamchatka region, the eruptive cloud was divided into two, the northern part of which was over the Klyuchevskoy group of volcanoes during October 21–23, and the southern part moved more than 1000 km southeast of the volcano. The main area of the territory where ashfalls were noted at 10:11 GMT on October 22, 2020, was about 111.5 thousand km2, including 60.8 thousand km2 on land. An animated image of the ash cloud movement from the volcano is shown, made according to a series of images of Himawari-8 in the VolSatView (http://kamchatka.volcanoes.smislab.ru/animation/1603972936.webm). The VEI for this eruption is 2.

Bezymianny is one of the most active volcanoes in Kamchatka and in the world. In December 2016, activity of the volcano began to intensify after four years of silence during 2012–2016. In 2017, three, and in 2019, two paroxysmal explosive eruptions of the volcano occurred. The work describes the eruption that occurred on March 15, 2019, as well as the events preceding it, based on the study of video and various satellite data. The volcano was monitored using the information system (IS) “Remote monitoring of the activity of Kamchatka and Kurile volcanoes” (VolSatView). The eruption had been predicted by KVERT (Kamchatkan Volcanic Eruption Response Team) staff 6.5 hours before it began. Explosions raised ash up to 15 km above sea level, the eruptive cloud moved northeast and east of the volcano, the main area of the territory where ashfalls were observed was about 210,410 km2 , including 15,000 km2 on land. An animated image of the ash cloud movement from the volcano is shown, made according to a series of images of Himawari-8 in the IS VolSatView (http://kamchatka.volcanoes.smislab.ru/animation/1584509687.gif). After the eruption, aerosol clouds were recorded in the atmosphere at a distance of up to 4000 km in the northeast of the volcano until March 18, 2019. As a result of the eruption, deposits of pyroclastic flows and pyroclastic surges formed on all slopes of the volcano
(mainly on the eastern and southeastern), the area of which reached about 30 km2.