Field work in 2020 on the Alaid volcano located on the Atlasov Island in the Kuril island arc was carried out in the coastal zone from Cape Devyatka to Cape Kudryavy. Base camp was located in the site of the former fishing base Devyatka. At the time of the research, the Alaid volcano performed only fumarolic activity. We sampled rocks and fresh water. We also sampled copper, found, as in other slopes of Alaid Volcano, in cracks or in a form of solid covers. We also measured magnetic susceptibility of rocks in their natural manifestations. The unexpected but important outcome of field work was the discovery of a new colony of snails from the Bradybaenidae family, what allows us to confidently say that these snails have survived the eruptions of Alaid Volcano in the XX and XXI centuries.

The second phase of field work in 2020 on the Alaid Volcano, located on Atlasov Island in the north of the Kuril Island Arc, was carried out on October 2. There was no snow in the crater at the time, and this made it possible to study the deep part of the crater and take samples of rocks and snow. The measurements of the temperature of fumarole gases showed that for the tested fumaroles it varied in the range of 35° to 95° C. Rock samples were also taken from the Svechka Rock and at Cape Shtormovoy. It was found that there is currently no water in Yuryev Creek, located in the west-northwest part of Atlasov Island. The studies carried out have made it possible to obtain new unique information, which will undoubtedly be useful to various researchers of active volcanoes in the Kuril island arc.

The paper presents the results of integrated geophysical observations of the Ebeko Volcano’s activity in late 2018 and early 2019. The instrument complex for observation was located at the Severo-Kurilsk seismic station at a distance of 7.2 km far from the volcanic crater. Three types of response in the vertical component of the electric field of the atmosphere have been distinguished during the drift of eruptive clouds from the Ebeko Volcano’s explosions, which gives evidence for various mechanisms of their occurrence. The registration of infrasonic acoustic signals in the near zone made it possible to estimate the trinitrotoluene equivalent for the strongest explosions, which was calculated to be about 100 kg of trinitrotoluene. The authors have revealed certain regularities in the dynamics of the volumetric activity of radon, associated with variations in meteorological values and hydrological features of the registration point. A long period of its activity and the proximity of the observation point to the crater give reason to suggest Ebeko Volcano to be a natural laboratory for studying the mechanisms of eruptions.

Growth of explosive activity of Ebeko volcano in April–June 2020

Klyuchevskoy volcano activity between November 2019 and June 2020

Статья посвящена исследованию генетических связей пород K–Na умеренно-щелочной серии, проявленной в строении вулканического центра Белоголовский расположенного в тыловой части Срединного хребта Камчатки. Дифференцированный ряд пород серии включает в себя трахибазальты, трахиандезиты, трахиты, комендитовые трахиты и комендиты. Проведение расчетов баланса масс и редкоэлементного моделирования показало, что кристаллизационная дифференциация является основным процессом эволюции расплавов изученного вулканического центра, при этом основным фракционирующим минералом является полевой шпат. Методом LA-ICP-MS получены редкоэлементные характеристики породообразующих минералов (Fsp, Cpx, Bt, Ap, Ol), рассчитаны коэффициенты “минерал/порода”, что позволило представить модель эволюции расплавов вулканического центра Белоголовский. Установлены генетические связи между трахиандезитами, трахитами, комендитовыми трахитами и комендитами, тогда как трахибазальты и трахиандезиты не обнаруживают прямых генетических связей.