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.

The first historical eruption of Kambalny volcano began on March 24, 2017 with a powerful ash emission up to 6 km above sea level from the pre-summit crater. According to tephrochronology, it is assumed that the strong eruptions of the volcano occurred 200 (?) and 600 years ago. The maximum intensity of ash emission occurred on 25–26 March: uninterrupted plume laden with ash particles spread over several thousand kilometers, changing the direction of propagation from the volcano from the south-west to the south and south-east. On 27–29 March, the ash plume extended to the west, on 30 March – to the southeast, and on April 02 – to the east of the volcano. On March 31 and April 01, the volcano was relatively quiet. The resumption of the volcano activity after two days of rest was expressed in powerful ash emissions up to 7 km above sea level. A small ash plume was noted on 04 April, and powerful ash emissions up to 7 km above sea level occurred on 09 April. The area of ashes on the land was 1300 km2, the total area covered by ash falls, for example, on 25 March, – 650 thousand km2. To observe the Kambalny volcano eruption we used mainly satellite images of medium resolution available in the information system "Monitoring activity of volcanoes of Kamchatka and Kurile Islands" (VolSatView).