В статье описана активность вулканов Камчатки и Курильских островов в 2021 г. Эксплозивные события вулкана Карымский представляли опасность для международных и местных авиаперевозок, извержения других вулканов – для местных авиаперевозок.

Chikurachki volcano is located in the northern part of the Karpinsky Ridge on Paramushir Island of the Northern Kuriles. Its eruptive activity is represented by explosive (vulcanian type) and explosive-effusive moderate eruptions; its rock composition is basaltic andesites. Information about fifteen historical eruptions of the volcano is known. The paper describes the eruption in January-February 2022 based on the study of various satellite data in the information system “Remote monitoring activity of Kamchatka and the Kuriles volcanoes” (VolSatView, http://kamchatka.volcanoes.smislab.ru). The explosive eruption continued for three days, the explosions raised ash to 5.5 km above sea level, and ash plumes moved for 260 km mainly to the west, southwest, and southeast of the volcano. The total area of ash falls during the eruption exceeded 28 thousand km2, including 640 km2 on land. Volcanic activity was dangerous for low-flying aircraft.

We present the results of the analysis of the volcanic glasses chemical composition from the products of the summit eruption and G.S. Gorshkov flank vent at Kliuchevskoi volcano in 2020–2021. The data on the chemical and mineral compositions of basaltic andesites produced at initial stage of the G.S. Gorshkov vent activity are given. The compositional variations of the volcanic glasses from summit and subsequent flank eruptions reflect the degree of the tephra particles crystallinity and the successive change of microlite populations during crystallization of a single parental magma. Comparison of the volcanic glasses chemistry from recently eruptions with similar data for the products of the preceding eruptive episodes in 2010 and 2016 shows their complete identity, that indicates the monotonic composition of the basaltic andesite magma feeding the modern volcanic eruptions.

The paper presents the results of remote sensing interpretation of active faults of the Sredinny Range of Kamchatka. The use of remote sensing data allowed us to identify fault scarps and magma-conducting fractures, expressed in the topography by chains of eruption centers. Most of the detected faults are located on volcanic plateaus, what indicates the relation of faulting with thinning of the brittle crust under the volcanic belt, similar to the faults of the Eastern Volcanic Belt. The geometrical characteristics of the most preserved scarps provide an estimate of the magnitude of paleoearthquakes Mw = 5.8±0.2, which significantly exceeds the historical seismicity. The identified faults are located above the northern edge of the subducted portion of the Pacific plate and form a zone oblique to the axis of the Kuril-Kamchatka island-arc system. The strike and normal sense of the faults are consistent with the transverse extension in Kamchatka. These new data provide the northern and western boundaries of the above-subduction extensional setting in Kamchatka.

Впервые представлены результаты испытаний российского авиационного двигателя типа ПД-14 при попадании в его газовоздушный тракт вулканического пепла. Испытания ПД-14 разработки АО «ОДК-Авиадвигатель» проводили в условиях закрытого наземного стенда Ц-17Т ФАУ «ЦИАМ им. П. И. Баранова» согласно требованиям европейского агентства по авиационной безопасности EASA. В качестве вулканического пепла использовали натуральный пепел современных извержений камчатского вулкана Шивелуч. Показано, что попадание пепла в двигатель ПД-14 с максимально допустимой в Европе концентрацией 4 мг/м3 в течение одного часа не приводит к изменению тяговых характеристик ПД-14 и возникновению нежелательных последствий. Особое внимание уделено воздействию вулканического пепла на камеру сгорания и турбину двигателя. Приведены данные рентгеноспектрального анализа стекловидных отложений пепла на элементах турбины. Проведен численный расчет модельной области генерации стекловидных отложений пепла Шивелучa в газовоздушном тракте двигателя ПД-14.

This report presents a brief description of the expeditionary work performed by the staff of the Institute of Volcanology and Seismology, Far Eastern Branch of the Russian Academy of Sciences as part of the research topic and the Russian Science Foundation project on the Kuril Islands in the summer of 2022. In order to study the chemical erosion of volcanic islands and to assess the hydrothermal removal of magmatic volatiles, in addition to the works carried out in 2020 and 2021, hydrological and hydrochemical studies were comducted on the rivers draining the slopes of the volcanic ridges of the Paramushir, Onekotan and Shiashkotan islands. For the first time, with the help of a quadrocopter, sampling of the endorheic Lake Koltsevoe, which occupies the caldera of the Tao-Rusyr volcano (Onekotan Island), was carried out. A detailed hydrochemical testing on the thermal fields of the active volcanoes Sinarka and Kuntomintar (Shiashkotan Island) was performed, a number of regime observations of the Upper Yuryevsk springs (Paramushir Island) were replenished. In order to construct orthophotomaps and determine the boundaries of thermal anomalies, aerial and infrared surveys were carried out at the main study sites in parallel with geochemical sampling. A large number of water and gas samples were taken for further analytical studies during the expedition and the collection of sediments was replenished.

The chemical and isotopic composition of hot springs at the apical part of the active Ebeko volcano (Paramushir Island, Kuril Islands) is characterized based on the data obtained from fieldwork in 2020–2021. Thermal waters discharging from one of the sources of the Kuzminka River are ultra-acid (рН<2) Al-Ca-SO4-Cl type with mineralization up to 5 g/l and temperature up to 70°С. The anionic composition of waters is formed due to the dissolution in groundwater of acidic volcanic gases, partially «purified» in the main reservoir of the volcano's hydrothermal system. The cationic composition of waters, including rare-earth elements, is formed by isochemical dissolution of host rocks in the equivalent of 5 g per 1 liter of water. Differences in the isotopic composition and ratios of macrocomponents (SO4 /Cl, Al+Fe/Ca+Mg/Na+K) of waters of the near the summit  prings and the northwestern slope suggest the presence of different-level aquifers in the hydrothermal system confined to the edifice of the Ebeko volcano.

Based on the results of expeditionary studies (July 2021), geochemical features of thermal waters (natural manifestations and borehole waters) discharging near or directly on the Sea of Okhotsk and Pacific coasts of the central part of Iturup Island were considered: Reidovskie, Lososevye, Cape Konakov, Goryachie Klyuchi, Dachnye, water-recreational complex «Vannochki». The springs (with the exception of Lososevye) belong to subneutral Cl(Cl-HCO3)-Na waters with salinity less than 10 g/l. The Lososevye springs are of the weakly acidic HCO3-SO4-Ca-Na type with salinity of 3 g/l. The spontaneous gas is dominated by CO2 (Dachnye and Vannochki), N2 (Reidovskie and Cape Konakov) and CH4 (Goryachie Klyuchi). Against the background of a general extremely low content of microelements,  thermal waters are enriched with boron and lithium. The springs are characterized by small (0.1 l/s) to insignificant (0.02–0.05 l/s) flow rates, while wells drilled nearby uncover horizons of pressurized waters.