The 2020–2022 field works gave results that were used as a basis for describing the geological structure and whole-rock compositions for Kronotsky Volcano, one of the least known eruption centers in the East Volcanic Belt (EVB), Kamchatka. The stratovolcano edifice was estimated to be 350 km3 in volume, which is much above the respective figures for the other stratovolcanoes in the EVB frontal zone. The rocks are low-K and high-Fe tholeiitic basalts and basaltic andesites (SiO2 = 47.04‒53.15 wt %; K2O = 0.24‒0.65 wt %; FeO*/MgO = 1.2‒2.89). The basalts have extremely low concentrations of silica, potassium, titanium, and phosphorus compared with the rocks of the other frontal volcanoes in Kamchatka. The petrochemical differences thus identified were used to more accurately classify structures situated at the junction between the nearby Kronotsky and Krasheninnikov volcanoes. The acquired data will make the basis for further petrologic and geo-
chemical characterization of the volcano, as well as being possibly used for reconstructing the sequence of volcanic events in the area of study, including a more accurate history of the formation of Lake Kronotsky.

Представлены результаты изучения состава и зональности фено- и субфенокристаллов амфибола в пемзах, изверженных в ходе плинианской фазы извержения вулкана Шивелуч 12 ноября 1964 г. Показано, что зональность субфенокристаллов могла быть сформирована в результате резкой декомпрессии магмы при ее подъеме из предполагаемой области накопления и кристаллизации, расположенной на нижнекоровых глубинах (~15-20 км) в малоглубинную магматическую камеру (~5 км) непосредственно перед извержением.

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.

В марте 2013 г. исполнилось 20 лет с начала деятельности Камчатской группы реагирования на вулканические извержения (KVERT – Kamchatkan Volcanic Eruption Response Team). Группа, созданная коллективными усилиями российских и американских ученых, ведет ежедневный анализ данных, полученных с помощью комплексного (сейсмического, видео-, визуального и спутникового) мониторинга вулканов Камчатки и Северных Курил с целью предупреждения авиакомпаний и всех заинтересованных организаций о возникающей опасности.

Annually in Kamchatka from three to eight volcanoes are in eruptions or in a state of unrest. Multidisciplinary study of each eruption encompassing the history and evaluation of geological effect with the detailed examination of volcanogenic products is needed to assess the dynamics of volcanic activity and hazard to population. The combined efforts of experts from IVS FEB RAS, IKI RAS, CC FEB RAS and FEC FSI RCSH “Planeta” led to the development of the information system called Monitoring of Activity of Kamchatkan Volcanoes (VolSatView, http://volcanoes.smislab.ru). The system allows working with various satellite data of mid to high resolution, meteorological and instrumental information from on-ground observation networks and to conduct combined analyses of diverse data. Currently, the VolSatView features an advanced instrumental base for the analyses of hyperspectral data that could be applied for the examination of volcanic activity. This paper illustrates application of the VolSatView in studying eruptive products of the Northern group of Kamchatka volcanoes (ex. pyroclastic and lava formations) based on hyperspectral satellite data. It is found that spectral reflectivity is indicative of pyroclastic rocks of andesitic composition, whereas spectral brightness is more informative in examination of fresh hot lava. Basaltic and andesitic lavas differ in spectral parameters, for example, in profile configurations of spectral brightness and their values.

Annual Kamchatkan strong explosive eruptions with ash emissions of 8–15 km above the sea level represent a real threat to modern jet aviation. To reduce the risk of aircraft encounters with volcanic ash clouds in the North Pacific region, the KVERT team of the Institute of Volcanology and Seismology of Far Eastern Branch RAS (IVS FEB RAS) conducts daily satellite monitoring of Kamchatkan volcanoes. In 2011, experts of IVS FEB RAS, Space Research Institute RAS, Computing Center of Far Eastern Branch RAS and Far Eastern Center of “Planeta" Research Center for Space Hydrometeorology created and put into trial operation an information service "Monitoring of volcanic activity of Kamchatka and the Kurile Islands" (VolSatView). This service allows working with different satellite data, including hyperspectral data, as well as meteorological and ground information. VolSatView will be able to provide volcanologists with the possibility of continuous monitoring and study of volcanic activity in Kamchatka and the Kurile Islands. The paper presents examples of hyperspectral satellite data use in the VolSatView environment to analyze different volcanic processes.

Эксплозивные извержения вулканов являются наиболее опасными в мире в связи с высокой энергетикой вулканогенного процесса и их непредсказуемостью. Для обеспечения безопасности населения при извержениях необходимо проведение вулканологами комплексного мониторинга вулканов с использованием данных всех доступных видов наблюдений (дистанционных и наземных инструментальных средств, метеоинформации). Созданная в 2011-2015 гг. совместными усилиями специалистов ИВиС ДВО РАН, ИКИ РАН, ВЦ ДВО РАН и ДВ НИЦ Планета ИС “Дистанционный мониторинг активности вулканов Камчатки и Курил (VolSatView)” ориентирована на непрерывный мониторинг вулканической активности Камчатки и Курил и анализ влияния извержений на окружающую среду.

Kamchatka and the Kuril Islands are home to 36 active volcanoes with yearly explosive eruptions that eject ash to heights of 8 to 15 km above sea level, posing hazards to jet planes. In order to reduce the risk of planes colliding with ash clouds in the north Pacific, the KVERT team affiliated with the Institute of Volcanology and Seismology of the Far East Branch of the Russian Academy of Sciences (IV&S FEB RAS) has conducted daily satellite-based monitoring of Kamchatka volcanoes since 2002. Specialists at the IV&S FEB RAS, Space Research Institute of the Russian Academy of Sciences (SRI RAS), the Computing Center of the Far East Branch of the Russian Academy of Sciences (CC FEB RAS), and the Far East Planeta Center of Space Hydrometeorology Research (FEPC SHR) have developed, introduced into practice, and were continuing to refine the VolSatView information system for Monitoring of Volcanic Activity in Kamchatka and on the Kuril Islands during the 2011–2015 period. This system enables integrated processing of various satellite data, as well as of weather and land-based information for continuous monitoring and investigation of volcanic activity in the Kuril–Kamchatka region. No other information system worldwide offers the abilities that the Vol-SatView has for studies of volcanoes. This paper shows the main abilities of the application of VolSatView for routine monitoring and retrospective analysis of volcanic activity in Kamchatka and on the Kuril Islands.