Based on the data of field studies in different years, the macro- and microcomponent composition of the waters of the Zelenoe Lake in the crater of the Troitsky active volcano Maly Semyachik were considered. It is shown that the lake contains ultra-acidic (pH < 1) water of sulfate-chloride composition with mineralization from 8 to 42 g/L, depending on the state of the volcano. The anion composition of the lake is formed by the inflow and subsequent dissolution of acidic volcanic gases in the aquifer located directly under the lake. The cation composition of water is formed by the almost congruent dissolution of the host rocks. After a long period of dormancy, in 2008 a new stage of hydrothermal activation of the volcano began. The activity is ongoing. Against the background of a constantly increasing volume, there is an increase in the concentrations of the main macro components (SO4, Cl, Al, Fe) and in the salinity of water in general.

Significant variations in temperature, water chemistry and volume of the lake in the crater of Maly Semyachik volcano, Kamchatka, in 1965–2020 can be divided in three main stages. The first stage, until about the mid-1980s, was characterized by intense volcanic-hydrothermal activity, high (above 40 °C) temperature, high salinity (up to 40 g/l) and an increase in the level (and volume) of the lake. During the second stage, which lasted 25–30 years, since the mid-1980s until the mid-2000s, the lake cooled down, until freezing in winter, the mineralization decreased (up to 1.6 g/l), and the volume of the lake remained almost constant. After the mid-2000s until present, there is a period of activation of the Maly Semyachik volcano, which is expressed in an increase in temperature, mineralization and a sharp increase in the volume of the crater lake. The water balance of the lake and the input and composition of the thermal acid chloride solution are estimated based on the analysis of changes in chemical and physical parameters over time, using a box model.

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.

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.