ted a fifth world ocean - the Southern Ocean
- from the southern portions of the Atlantic Ocean, Indian Ocean, and
Pacific Ocean. The Southern Ocean extends from the coast of Antarctica
north to 60 degrees south latitude, which coincides with the Antarctic
Treaty Limit. The Southern Ocean is now the fourth largest of the world's
five oceans (after the Pacific Ocean, Atlantic Ocean, and Indian Ocean,
but larger than the Arctic Ocean).

Geography Southern Ocean

Location: body of water between 60 degrees south latitude and Antarctica

Geographic coordinates: 65 00 S, 0 00 E (nominally), but the Southern
Ocean has the unique distinction of being a large circumpolar body of
water totally encircling the continent of Antarctica; this ring of water
lies between 60 degrees south latitude and the coast of Antarctica,
and encompasses 360 degrees of longitude

Map references: Antarctic Region

Area: total: 20.327 million sq km note: includes Amundsen Sea,
Bellingshausen Sea, part of the Drake Passage, Ross Sea, a small part
of the Scotia Sea, Weddell Sea, and other tributary water bodies

Area - comparative: slightly more than twice the size of the US

Coastline: 17,968 km

Climate: sea temperatures vary from about 10 degrees Celsius to -2
degrees Celsius; cyclonic storms travel eastward around the continent
and frequently are intense because of the temperature contrast between
ice and open ocean; the ocean area from about latitude 40 south to the
Antarctic Circle has the strongest average winds found anywhere on Earth;
in winter the ocean freezes outward to 65 degrees south latitude in the
Pacific sector and 55 degrees south latitude in the Atlantic sector,
lowering surface temperatures well below 0 degrees Celsius; at some
coastal points intense persistent drainage winds from the interior keep
the shoreline ice-free throughout the winter

Terrain: the Southern Ocean is deep, 4,000 to 5,000 meters over most
of its extent with only limited areas of shallow water; the Antarctic
continental shelf is generally narrow and unusually deep - its edge
lying at depths of 400 to 800 meters (the global mean is 133 meters);
the Antarctic icepack grows from an average minimum of 2.6 million square
kilometers in March to about 18.8 million square kilometers in September,
better than a sixfold increase in area; the Antarctic Circumpolar Current
(21,000 km in length) moves perpetually eastward; it is the world's
largest ocean cu