Methane Flows and Gas Hydrates in the Transition Zone Between the Western Slope of the Kuril Basin and Offshore from Sakhalin Island

The results of integrated studies in the southwestern part of the Sea of Okhotsk obtained during cruise 74 of the R/V Akademik M.A. Lavrentiev in 2016 are presented. Gas hydrates, carbonate crusts and nodules in bottom sediments and more than 100 gas flares in the water column were recognized. Great attention has been paid to the gas composition of the water column and bottom sediments. Anomalous concentrations of hydrocarbon gases, helium, and hydrogen were revealed in the Kuril Basin–Terpeniya Bay transition zone.