Bezymianny Volcano is one of the most active volcanoes in Kamchatka and in the world. This paper describes the preparation, behavior, products, dynamics, and the geological effect of the March 15, 2019 explosive eruption of the volcano, which was predicted 6.5 h before it began. The sequence of eruptive events was analyzed using data provided by video and satellite-based monitoring of the volcano; the quantitative characteristics for the distribution of pyroclastic deposits were obtained in the information system “Remote Monitoring of Activity of Volcanoes in Kamchatka and the Kurile Islands”. The explosions lifted ash to heights of 15 km above sea level (up to 12 km above the volcano), the eruptive cloud was moving northeastward and east from the volcano, the main ashfall area was 210 400 km2, including 15 000 km2 on land. Apart from tephra, the eruption produced pyroclastic flows and pyroclastic surges covering an area of 30 km2. The total volume of explosive products is estimated as 0.1–0.2 km3. The eruptive rocks are calc-alkaline moderate-K basaltic andesites (SiO2 = 54.84–56.29 wt %), they are the most mafic among all rocks of the current Bezymianny eruption cycle.

A key problem of any video volcano surveillance network is an inconsistent quality and information value of the images obtained. To timely analyze the incoming data, they should be pre-filtered. Additionally, due to the continuous network operation and low shooting intervals, an operative visual analysis of the shots stream is quite difficult and requires the application of various computer algorithms. The article considers the parametric algorithms of image analysis developed by the authors for processing the shots of the volcanoes of Kamchatka. They allow automatically filtering the image flow generated by the surveillance network, highlighting those significant shots that will be further analyzed by volcanologists. A retrospective processing of the full image archive with the methods suggested helps to get a data set, labeled with different classes, for future neural network training.

The early 21st century saw increased eruption activity of major volcanoes in the Northern Group of Kamchatka, namely, Sheveluch, Klyuchevskoy, Bezymianny, and the Tolbachik Fissure Zone. The growth of an extrusive dome on Sheveluch andesitic volcano has occurred, with the dome reaching a height of 600 m after 38 years of nearly uninterrupted eruption activity. An 8-year period of relative quiet was followed by ten summit eruptions and two lateral vent openings on the Klyuchevskoy basaltic volcano. Explosive–effusive eruptions were observed nearly every year on the Bezymianny andesitic volcano. A 36-year quiet period gave way to a new eruption in the Tolbachik regional fissure zone.

Вулкан Безымянный — один из наиболее активных вулканов Камчатки и мира. Предыдущее его извержение произошло 15 марта 2019 г. В настоящей работе описано эксплозивное извержение вулкана 21 октября 2020 г. и предваряющие его события на основании изучения видеоматериалов и различных спутниковых данных. Спутниковый мониторинг вулкана проводился с помощью информационной системы «Дистанционный мониторинг активности вулканов Камчатки и Курил» (VolSatView) с 2014 г. Эксплозии подняли пепел до 10–11 км над уровнем моря, в связи с циклоном в районе Камчатки эруптивное облако было разделено на две части: северная часть в течение 21–23 октября находилась над Ключевской группой вулканов, южная переместилась на расстояние более 1000 км на юго-восток от вулкана. Основная площадь территории, на которой отмечались пеплопады, на 10:11 GMT 22 октября 2020 г. составила около 111,5 тыс. км2, в том числе на суше — 60,8 тыс. км2. Показано анимированное изображение движения пеплового облака от вулкана, выполненное по серии снимков Himawari-8 в VolSatView (http://kamchatka.volcanoes.smislab.ru/animation/1603972936.webm). Для этого извержения VEI равен 2.

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.

Вулкан Безымянный — один из наиболее активных вулканов на Камчатке и в мире. В декабре 2016 г. началась его активизация после четырёхлетнего молчания в течение 2012–2016 гг. В 2017 г. произошло три пароксизмальных эксплозивных извержения вулкана, в 2019 г. — два. В работе дано описание извержения, произошедшего 15 марта 2019 г., а также предваряющих его событий на основании изучения видеоматериалов и различных спутниковых данных. Мониторинг вулкана проводился с помощью информационной системы (ИС) «Дистанционный мониторинг активности вулканов Камчатки и Курил» (VolSatView). Извержение было предсказано сотрудниками KVERT (Kamchatkan Volcanic Eruption Response Team, Камчатская группа реагирования на вулканические извержения) за 6,5 ч до его начала. Эксплозии подняли пепел до 15 км над уровнем моря, эруптивное облако перемещалось на северо-восток и восток от вулкана, основная площадь территории, на которой отмечались пеплопады, составляла около 210 410 км2, в том числе на суше — 15 000  км2. Показано анимированное изображение движения пеплового облака от вулкана, выполненное по серии снимков Himawari-8 в ИС VolSatView (http://kamchatka.volcanoes.smislab.ru/animation/1584509687.gif). Аэрозольные облака после окончания извержения фиксировались в атмосфере на удалении до 4000 км на северо-восток от вулкана до 18 марта 2019 г. В результате извержения на всех склонах вулкана (преимущественно на восточном и юго-восточном) образовались отложения пирокластических потоков и пирокластических волн, площадь которых составила около 30  км2.

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.

В начале XXІ в. наблюдается повышенная эруптивная активность крупнейших вулканов Северной группы Камчатки: Шивелуч, Ключевской, Безымянный и Толбачинской трещинной зоны. Отмечаются особенности роста экструзивного купола андезитового вулкана Шивелуч: за 38 лет почти непрерывной эруптивной деятельности высота купола достигла 600 м. После восьмилетнего периода относительного покоя произошло девять вершинных извержений и два боковых прорыва базальтового вулкана Ключевской. Почти ежегодно наблюдались эксплозивно-эффузивные извержения андезитового вулкана Безымянный. После 36 лет покоя в районе Толбачинской региональной трещинной зоны произошло новое извержение.

At the beginning of the XXI century, increased eruptive activity of the largest volcanoes of the Northern group of Kamchatka is observed: Sheveluch, Klyuchevskoy, Bezymianny and Tolbachinskay fissure zone. The features of growth of andesitic Sheveluch volcano extrusive dome are noted: the height of the dome has reached 600 m during 38 years of almost continuous eruptive activity. After an eight-year period of relative rest, nine terminal eruptions and two lateral breakthroughs of the Klyuchevskoy basalt volcano occurred. Explosive-effusive eruptions of the andesitic Bezymianny volcano were observed almost annually. After 36 years of rest, a new eruption occurred in the Tolbachinsky regional fissure zone.