South Sandwich Trench
The South Sandwich Trench is a deep arcuate trench in the South Atlantic Ocean lying around 60 miles to the east of the South Sandwich Islands. The trench is produced by the subduction of the southernmost portion of the South American Plate beneath the small South Sandwich Plate. The South Sandwich Islands constitute a volcanic island arc which results from this active subduction. Several of the mountains of the islands are active or potentially active volcanoes, of which the greatest is Mount Belinda on Montagu Island, which is active.
The South Sandwich Trench is the deepest trench of the Southern Atlantic Ocean, and the second deepest of the Atlantic Ocean, exceeded only by the Puerto Rico Trench.
The trench is 600 miles long and has a maximum depth of 27,651 feet below sea level (5 miles' deep). This location, at 55°40'S 25°55'W, is called Meteor Deep, which is 76 miles northeast of Zavodovski Island.
The southernmost portion of the South Sandwich Trench reaches south of 60°S and therefore deemed part of the Southern Ocean, and contains that ocean's maximum depth also, at 60°00'S 24°W, with a depth of 23,737 feet (4½ miles' depth).