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.

Посвящена анализу рельефа вулканических ландшафтов и их изменений в связи с региональными условиями. Рассматриваются процессы, определяющие морфологию вулканических областей и роль глубинных структур в их становлении, излагаются общие закономерности формирования вулканического рельефа. Дается описание морфоструктур новейших вулканических ландшафтов планетарного, глобального, регионального и локального типов на основании представлений о геоморфологических уровнях вулканизма, морфогенетических рядов вулканов и формаций вулканического рельефа. Рассматриваются проявления вулканической деятельности, регулируемой принципом экономии энергии на различных геоморфологических уровнях. На основе геоморфологического анализа расширены представления о телескопированном рифтогенезе, как о модели образования морфоструктур базальтовых покровов второго слоя дна молодых океанов.

The paper presents the results of Brouton Bay (Simushir Island, the Kurile Islands) echo-sounding
investigations had been made in July 2011 during complex scientific and research expedition of FSBSO
Institute of Marine Geology and Geophysics FEB RAS by means of «Lowrance LMS-527cDF iGPS» echo
sounder with oscillator frequency of 50/200 kHz and built-in 12-channel GPS receiver. We worked out
57 km of depth sounding profiles and constructed Brouton Bay bathymetric map and 3D-model. The bay
maximum depth comprised 250 m and the caldera total depth comprised about 700 m. Submarine slopes
of the bay have an angle ~ 15-25° to the depths of 200-220 m, then they have an angle of 5-10°to the vast
nearly flat bottom at the depths of 240-250 m.

We analyzed the bathymetric data obtained during the cruises on the German research vessel “Sonne” using multibeam echosounders within the framework of the Russian-German projects KALMAR (cruise SO201-2, 2009) and BERING (cruise SO249-2, 2016) in the Komandorsky Basin of the Bering Sea. Detailed bathymetric maps of the Piip submarine volcano were constructed. New morphological features of its summit edifices and their age relations are described, hydrothermal activity confined to the edifices is localized, and all side cones and lava flows are mapped. Based on the flank cones and fissure lava flows alignments we determined the tectonic paleostress that existed at the time of their formation, presumably after the Late Miocene-Early Pliocene. It differs from the recent tectonic stress caused by right-lateral displacements along the Bering fault zone.