南海トラフ
The Nankai Trough is located beneath the Pacific Ocean off the southeast coast of Japan, and extends more than 700 km in a southwest-northward trending direction. The Nankai Trough is not only known as an active subduction and earthquake zone, but also for its large clathrate hydrate deposits occurring on the shelf and continental slope. Due to the combination of Japan’s lack of domestic fossil energy sources, along with a projected continued rise in energy consumption, the methane hydrate occurrences in Nankai Trough sedimentary sequences are increasingly the focus of energy resource studies. These resources have the potential to secure a supply of domestic natural gas to meet Japan’s needs for decades to come.