Overview
The Southern Ocean, also known as the Antarctic Ocean, is the fourth-largest of Earth's five oceans, covering approximately 20 million square kilometers. It surrounds the continent of Antarctica and extends north to 60 degrees south latitude, where it meets the Atlantic, Pacific, and Indian Oceans.
Geography and Physical Features
The Southern Ocean has an average depth of about 3,270 meters, with its deepest point in the South Sandwich Trench at roughly 7,236 meters. Its defining feature is the Antarctic Circumpolar Current, the strongest ocean current in the world, which flows eastward around Antarctica and isolates the continent's cold waters from warmer northern waters.
Significance
The Southern Ocean plays a critical role in the global climate system, absorbing large amounts of carbon dioxide and heat. The Antarctic Circumpolar Current drives global ocean circulation and helps maintain the deep cold of the Antarctic environment. The ocean was officially recognized as a distinct fifth ocean by the International Hydrographic Organization in 2000.
Notable Facts
The Southern Ocean is home to vast populations of krill, which form the base of the Antarctic food web and support whales, penguins, and seals. Massive icebergs, some larger than small countries, regularly calve from Antarctica's ice shelves into its waters. Sea ice in the Southern Ocean roughly doubles the size of Antarctica each winter.