The Umitaka Spur and Joetsu Knoll region,eastern margin of the Japan Sea,has been investigated as the gas hydrate field associated with the occurrence of methane-related/induced activities.Massive to vein-like gas hyd...The Umitaka Spur and Joetsu Knoll region,eastern margin of the Japan Sea,has been investigated as the gas hydrate field associated with the occurrence of methane-related/induced activities.Massive to vein-like gas hydrates are found on/near the seafloor where huge methane plumes,reaching 600-650 m height, have been observed on the echo sounding images around the summits.Columnar chaotic gas-charged sediment structures are observed beneath the gas hydrate occurrences on the seismic images。展开更多
文摘The Umitaka Spur and Joetsu Knoll region,eastern margin of the Japan Sea,has been investigated as the gas hydrate field associated with the occurrence of methane-related/induced activities.Massive to vein-like gas hydrates are found on/near the seafloor where huge methane plumes,reaching 600-650 m height, have been observed on the echo sounding images around the summits.Columnar chaotic gas-charged sediment structures are observed beneath the gas hydrate occurrences on the seismic images。