Sea expedition to the Kuril Islands in summer 2022

This report presents a brief description of the expeditionary work performed by the staff of the Institute of Volcanology and Seismology, Far Eastern Branch of the Russian Academy of Sciences as part of the research topic and the Russian Science Foundation project on the Kuril Islands in the summer of 2022. In order to study the chemical erosion of volcanic islands and to assess the hydrothermal removal of magmatic volatiles, in addition to the works carried out in 2020 and 2021, hydrological and hydrochemical studies were comducted on the rivers draining the slopes of the volcanic ridges of the Paramushir, Onekotan and Shiashkotan islands. For the first time, with the help of a quadrocopter, sampling of the endorheic Lake Koltsevoe, which occupies the caldera of the Tao-Rusyr volcano (Onekotan Island), was carried out. A detailed hydrochemical testing on the thermal fields of the active volcanoes Sinarka and Kuntomintar (Shiashkotan Island) was performed, a number of regime observations of the Upper Yuryevsk springs (Paramushir Island) were replenished. In order to construct orthophotomaps and determine the boundaries of thermal anomalies, aerial and infrared surveys were carried out at the main study sites in parallel with geochemical sampling. A large number of water and gas samples were taken for further analytical studies during the expedition and the collection of sediments was replenished.