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%
South Sandwich Trench 965 km long and has a maximum depth of 8,428 meters below sea level. This location, at 55°40'S, 025°55'W, is called Meteor Deep. It is 122 km northeast of Zavodovski Island. The southernmost portion of the South Sandwich Trench reaches south of 60°S and therefore into the Southern Ocean, thereby containing the maximum depth of that Ocean at 60°00'S, 024°W, with a depth of 7,235 meters. South Sandwich Trench The South Sandwich Trench is a deep arcuate trench in the South Atlantic Ocean lying 100 km to the east of the South Sandwich Islands. The trench is produced by the