This article reports new data on the chemical and isotopic composition of volcanic gases and the SO2 flux and the soil CO2 flux from the active Ebeko volcano. Within the time interval of 2003–2021 the volcano erupted in 2009, 2010, 2011, October 2016–November 2021. Volcanic gas composition for 2003–2016, 2021 were obtained by direct sampling from fumaroles. The high-temperature gas (420–529°C) has a composition typical of magmatic gases with C/S atomic ratios <1, HCl content 5–7 mmol/mol; isotopic composition of the volcanic vapor δD ~ –24, δ18O = 2.6–4.9. Geochemical precursors of eruptions have been established: an increase in concentrations of CO2, H2, SO2, HCl; a drop in the C/S ratio up to values of <1, which is characteristic of magmatic gases of the Kuriles; an increase in temperature; heavier values of δD and δ18O in the gas condensates; increasing of the total gas output. А high soil CO2 flux was measured using the accumulation chamber method at two thermal fields (up to 10442 g/m2/day), exceeding the visible discharge (~50 t/day versus ~40 t/day). SO2 flux from the active crater was measured by DOAS instruments in 2020 and 2021: they were 99 ± 28 and 9 ± 2.7 t/day in gas plumes, and 747 ± 220 and 450 ± 130 t/day in ash plumes, respectively. A decrease of SO2 output is associated with the rise of degassed magma before the end of the eruption.

The article presents data on two explosive eruptions produced by Ebeko Volcano 19 to 20 October, 2016 and over the period from November 8, 2016 till the end of August 2017. The latter eruption continues. The material was erupted from three vents: one vent is located in the Active funnel and two vents are at the bottom of Middle crater. The authors analyzed the chemical, mineral, and granulometric compositions of tephra. The studied tephra does not contain magmatic components. The authors classify the eruptions as phreatic. The paper provides the assessment of the composition and volume of gas emission. The gross total volume of the erupted material was estimated to exceed 1.5 million tons.

An account is given of magnetostratigraphic studies of Kamchatkan Holocene formations: the cover of soil and pyroclastics and the rocks of the cinder cones from the flank eruptions of Klyuchevskoi Volcano. А study was made of seven sections of the soil and pyroclastics and of samples from 17 cinder cones. А detailed account is given of the data processing procedure. Consideration is given to the reasons for the established incompleteness of the paleomagnetic record in the sections and it is demonstrated that adequately detailed reconstruction of the history of the geomagnetic 1ield is possible only provided that а study is made of а series of рагаllеl sections. The trajесtory of the geomagnetic field vector over the last 4000 years is determined on the basis of the material on radiocarbon datings. Seven cycles of paleosecular variations are distinguished in the age range investigated; each of these cycles has individual features by which they can be recognised and used for stratigraphic correlation. The, features taken were the direction of rotation of the vector, the shape and size of its loops, and the length of the cycles. Correlation of the sections based on paleomagnetic data was found to be in good agreement with the tephrostratigraphic correlation and enabled corrections to be made to the age of some horizons, including the archeological layers of the primitive settlement at Zhupanovo and the cinder cones. The metachronous magnetization present in some tephra layers was found to be an obstacle to any improvement in the accuracy and detail of magnetochronological reconstructions.

The memories about Kamchatkan volcanoes and volcanologists (1964-1989)