В статье описано извержение вулкана Чиринкотан с выносом пепла до 4.5 км н.у.м., продолжавшееся с 8 по 23 августа 2021 г. Основные направления перемещения пепловых облаков от вулкана: запад, юго-запад, восток и юго-восток. Активность вулкана во время извержения была опасной для местных авиаперевозок.

В июне 2019 г. на небольшом острове-вулкане Райкоке, расположенном в центральной части Курильской дуги, произошло короткое, но сильное эксплозивное извержение, кульминационная стадия которого продолжалась 3.5 ч, высота пеплового облака достигла 13 км. Анализ серии спутниковых изображений в сочетании с наземными исследованиями позволили охарактеризовать пирокластические отложения извержения и определить масштаб их воздействия на экосистемы острова. Установлено, что извержение имело фреатомагматический субплинианский–плинианский характер.

Karymsky is one of the most active volcanoes of Kamchatka. In the past two years, single powerful explosions with ash removal up to 8–10 km a. s. l. were noted. The explosive event of April 19, with the rise of an ash cloud up to 10 km a. s. l., occurred against the background of a continuous emission of ash from the volcano. Due to the high cyclonic activity near Kamchatka, the ash cloud on April 19–21 stretched into a 1000 km long band from southeast to northeast. The northern part of the eruptive cloud was drawn into the Arctic zone by another cyclone. The area of the ash cloud was over 246 thousand km 2. In addition to the eruptive one, a large cloud of sulfur dioxide was well manifested at the beginning of the eruption. A cloud slightly saturated with sulfur dioxide was observed over the Arctic zone on April 21–22. A detailed description of the explosive event of the volcano and the spread of the ash cloud was performed based on the study of various satellite data in the information system “Remote monitoring of the activity of the volcanoes of the Kamchatka and the Kuriles” (VolSatView, http://kamchatka.volcanoes.smislab.ru).

The first results of tephrachronological researches of the Sarychev Peak volcano, the Matua Island, (Central Kuriles) are represented including the reconstruction of its eruptive history in the Holocene. Based on the study of the distribution of petrogenous oxides and microelements in the tephra sampled layer-by-layer from the reference section of soil-pyroclastic cover of Matua Island, a general trend of the geochemical evolution of the volcano products during the Holocene epoch is traced, their typification was made. The horizons of the transition ashes were identified.

The number of explosive eruptions at Shiveluch Volcano has significantly increased over the past years, which requires close volcanic monitoring using all available techniques. In order to implement a new monitoring technique into integrated methods of volcano monitoring, the authors analyze response to the intensity of the vertical component in the atmospheric electrical field (EZ AEF) during the movement of ash clouds. Two eruptions of different intensity that occurred December 16, 2016 and June 14, 2017 at Shiveluch were selected for study. We used a combination of satellite, seismic, and infrasound data to select signals in the EZ AEF field. Signals with negative polarity that accompanied ashfalls in the EZ AEF dynamics were registered for both eruptions within the closest area (< 50 km). In the former case, the ash cloud was “dry” and thus it caused aerial-electrical structure of the negatively charged cloud. In the latter case, a strong explosion sent into the atmosphere the large volume of ash and volcanic gases (98% in form of vapour) that resulted in the formation of a dipolar aerial-electrical structure caused by eolian differentiation within the closest area. At the distance of more than 100 km we registered a positivegoing signal that is attributive to the aerial-electrical structure of the positively charged type of the cloud.