Map of the Southern Ocean

The Southern Ocean is the fourth-largest of Earth’s five oceans, covering an area of approximately 21,960,000 km² — about 6% of the world’s total ocean area. Its waters reach an average depth of around 3,270 m, the fourth-deepest of the five oceans, and plunge to about 7,236 m at their deepest point, in the South Sandwich Trench. It is bordered by Antarctica.

It encircles Antarctica and carries the Antarctic Circumpolar Current, the largest ocean current on Earth. It was the most recent ocean to be widely recognised as distinct, a status NOAA formally adopted in 2021. By greatest depth it has the fourth-greatest maximum depth of the five oceans, while by surface area it ranks 4th. By surface area it is about 13% the size of the Pacific, the largest ocean.

Oceans are the largest bodies of water on the planet and together cover the majority of its surface. Under the five-ocean model used on this site, the global ocean is divided into the Pacific, Atlantic, Indian, Southern and Arctic oceans. The figures above are widely cited approximate values (CIA World Factbook / NOAA); exact measurements vary with how each basin’s boundaries are drawn. Use the interactive map to pan across the Southern Ocean and the coasts that frame it, or compare it with the other oceans.