What is the maximum depth of the South Sandwich Trench?

The South Sandwich Trench reaches a maximum depth of 8,266 metres below sea level.

This trench curves east of the South Sandwich Islands in the South Atlantic and extends for roughly 965 kilometres. It is the deepest trench in the southern Atlantic and the second-deepest trench in the Atlantic overall, after the Puerto Rico Trench.

The 8,266-metre figure came from a complete multibeam-sonar survey conducted during the Five Deeps Expedition in February 2019. The measurement carries an uncertainty of roughly 11 to 13 metres, so it should be understood as a scientific survey value rather than a perfectly exact boundary.

The deepest feature is traditionally called Meteor Deep, after the German survey ship Meteor, which first surveyed the region in 1926. The trench forms where the South American Plate is subducted beneath the small South Sandwich Plate, producing the volcanic South Sandwich island arc. Its portion south of 60°S also contains the deepest point of the Southern Ocean.