Oceanic trench the level of the surrounding oceanic floor. The greatest ocean depth measured is in the Challenger Deep of the Mariana Trench, at a depth of below sea level. Oceanic lithosphere moves into trenches at a global rate of about 3 km/yr. There are approximately of convergent plate margins, mostly around the Pacific Ocean—the reason for the reference “Pacific-type” margin—but they are also in the eastern Indian Ocean, with relatively short convergent margin segments in the Atlantic Ocean and in the Mediterranean Sea. Globally, there are over 50 major ocean trenches covering an area of 1.9 million km or about 0.5%
Japan Trench Japan Trench The Japan Trench is an oceanic trench part of the Pacific Ring of Fire off northeast Japan. It extends from the Kuril Islands to the northern end of the Izu Islands, and is 8,046 meters (26,398 ft) at its deepest. It links the Kuril-Kamchatka Trench to the north and the Izu-Ogasawara Trench to its south with a length of 800 km (500 miles). This trench is created as the oceanic Pacific plate subducts beneath the continental Okhotsk Plate (a microplate formerly a part of the North American Plate). The subduction process causes bending of the down going plate,