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Sources Methane and Gas Hydrate in Okhotsk Sea
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 75th EAGE Conference & Exhibition - Workshops, Jun 2013, cp-349-00023
- ISBN: 978-90-73834-49-1
Abstract
Multidisciplinary surveys were conducted to investigate gas seepage and gas hydrate accumulation on the Northeastern Sakhalin Continental Slope (NSCS), Sea of Okhotsk, during joint Korean–Russian–Japanese expeditions conducted from 2003 to 2012 (CHAOS and SSGH projects). About 500 gas seeps were detected in a 2,000 km2 area of the NESS (between 53º45'N and 54º45'N). Active gas seeps in the gas hydrate system on the NSCS were evident from features in the water column, on the seafloor, and in the subsurface: well- defined hydroacoustic anomalies (gas flares), side-scan sonar structures with high backscatter intensity (seepage structures), bathymetric structures (pockmarks and mounds), gas- and gas-hydrate-related seismic features (bottom-simulating reflectors, gas chimneys, high-amplitude reflectors, and acoustic blanking), high methane concentrations in seawater (10-20mkl/l), and gas hydrates in sediment near the seafloor.