Sheveluch volcano is the most active volcano in Kamchatka. The paroxysmal explosive eruption of the volcano that destroyed the lava dome in the volcanic crater continued on April 10–13, 2023. According to various satellite data, the height of the separate eruptive clouds probably exceeded 15 km a. s. l. A powerful cyclone, which dominated the entire Kamchatka Peninsula, pulled the eruptive cloud to the west, turned it to the south, stretched it to the north and directed it to the east from the volcano. The dynamics of the development of ash and aerosol clouds of this eruption is reflected in the animations made from a series of Himawari-9 satellite images in the VolSatView IS from 08:00 UTC (Coordinated Universal Time) on April 10 to 07:50 UTC on April 14 (http://d33.infospace.ru/jr_d33/materials/2023v20n2/283-291/1683110898.webm) and of the Arctica-M1 satellite from 16:00 to 21:30 UTC April 10 (http://d33.infospace.ru/jr_d33/materials/2023v20n2/283-291/1683821166.webm). It was noted that the eruptive column was not vertical: for example, at the initial moment of the eruption on April 10 at 13:20 UTC, it deviated to the north-northeast, on April 11 at 12:00 UTC to the northwest, and on April 12 at 07:00 UTC to the southwest. During the paroxysmal eruption, sulfur dioxide continuously entered the atmosphere, the maximum amount of which was released on April 10–11, as a result of the explosive destruction of the lava dome of the Sheveluch volcano. Ash clouds along with aerosol clouds on April 10–13 were stretched into a strip more than 3500 km long from west to northeast. On April 21–22, the Sheveluch aerosol cloud was observed in the region of the Scandinavian Peninsula. The total area of the territory of Kamchatka and the Pacific Ocean where ash and aerosol plumes and clouds were observed during the April 10–13 eruption was about 3280 thousand km2. The paroxysmal eruption of Sheveluch volcano belongs to the sub-Plinian type because it is characterized by a big height of eruptive cloud and a long event duration. For this eruption, the VEI (Volcanic Explosivity Index) is estimated to be 3–4. A detailed description of the paroxysmal explosive eruption of Sheveluch volcano and the spread of the eruptive cloud was performed based on data from various satellite systems (Himawari-9, NOAA-18/19, GOES-18, Terra, Aqua, JPSS-1, Suomi NPP, Arctica-M1 etc.) in the information system “Remote monitoring of the activity of the volcanoes of the Kamchatka and the Kuriles” (VolSatView, http://kamchatka.volcanoes.smislab.ru).

This is the first petrophysical study of extrusive rocks (dacites to andesites) discharged by Bezymianny Volcano. We provide a comparative description of properties for extrusive rocks in accordance with identified age groups. We show the dynamics in the variation of extrusive rock properties in relation to their ages, with the result that the older a rock the higher are its density, strength, and elastic parameters. Rocks petrophysical features are compared between extrusive domes and lava flows. We argue for petrophysical properties to be applicable for deriving more accurate results for the genesis of rocks having similar petrophysical properties, in particular, rocks of extrusive and effusive origin.

This is the first petrophysical study of extrusive rocks (dacites to andesites) discharged by Bezymianny Volcano. We provide a comparative description of properties for extrusive rocks in accordance with identified age groups. We show the dynamics in the variation of extrusive rock properties in relation to their ages, with the result that the older a rock the higher are its density, strength, and elastic parameters. Rocks petrophysical features are compared between extrusive domes and lava flows. We argue for petrophysical properties to be applicable for deriving more accurate results for the genesis of rocks having similar petrophysical properties, in particular, rocks of extrusive and effusive origin.

Data are presented on a moderate effusive-explosive eruption of the summit crater of Alaid volcano (Atlasov Island, Northern Kuril Islands) observed from September 10 to December 1, 2022. Based on satellite and visual data, it was found that as a result of Strombolian-Volcan activity two lava flows, 2.6 and 1 km long, were poured out on the southern slope of the volcano, and at least 16 emissions occurred to a height of 2.5 to 6 km a.s.l. The ash plumes spread out mainly in the southeast and east-southeast directions, their maximum length reaching 300–500 km. The eruption posed a danger to local airlines. The lava outpouring provoked the formation of lahars that descended the southern slope of the volcano and reached the island coast. The alluvial fan formed from mudflow masses partially deposited beyound the coastline, causing an increase in the island land.

Mineral formations from fumaroles localized in craters and on lava flows were collected by the winter during 1937—1938 eruption of the Klyuchevoskoy volcano (Kamchatka) when a number of adventive craters broke out on its slopes. These were investigated sublimates from craters at different distances from the central core, from their lava flows formed by portions of magma issuing from the core one after another; from flows at various stages of formation and cooling; from fumaroles with wide temperature range. This material allows to get an idea of the distribution of elements in space, time and their depending from temperature. The basaltic magma of the Klyuchevskoy volcano erupted in 1937— 1938 contains the greatest part of the elements Mendeleev’s periodical system, elements characteristic of basic magma as well as those considered as characteristic of acid magma.
During the crystallization of the products of mineral formation from the fumaroles, along with the carrying out of substance from the magma there is taking place an extraction of substance from rocks through which the gases escape, some peculiarities being noticed due to the action of gases of different composition.

В книге проанализированы данные о геологическом строении, возрасте, составе и структурно-тектонических позициях трех разновозрастных групп вулканогенно-кремнистых формаций. Проведенный структурно-формационный анализ в различных тектонических зонах Камчатки и сопоставление закономерностей развития этих зон с данными о строении современных систем островных дуг и глубоководных желобов позволили авторам построить гипотезу развития геосинклиналей и эволюции геосинклинального вулканизма Камчатки.
Книга предназначена для широкого круга геологов