If you had to draw the boundaries of the Earth's oceans on a map, would you be able to? The answer is no—because there is really only one "world ocean." Oceanographers have divided the world ocean into four principal areas, or basins: the Pacific, Atlantic, Indian, and Arctic Ocean basins. The Atlantic, Indian, and Pacific Ocean basins merge into icy waters around Antarctica. Some oceanographers define this as a fifth ocean, usually called the Antarctic or Southern Ocean basin.


This video focuses on the Antarctic Ocean basin and is taken from the interactive online game, My Ocean. Test your ocean knowledge and learn about the different basins of the world ocean by playing here.

  • If Antarctica's ice sheets melted, the world's ocean would rise by over 61 meters (200 feet).
  • Antarctica is pushed into the earth by the weight of its ice sheets. If they melted, the land would rebound or "spring back" about 495 meters (1,625 feet). This process would happen very slowly over the next 10,000 years. Scotland and Scandinavia are still rebounding today after the last ice age at the rate of roughly 0.5 meters (1.6 feet) a century!
  • During the feeding season in Antarctica, a full grown blue whale can eat four to eight million krill, or four to eight tons, every day for six months. This daily intake would feed a human for at least four years!
  • Winter temperature on the East Antarctic ice sheet averages -60°C (-140°F), much colder than a freezer! The lowest temperature ever recorded was -89.6°C (-193.3°F) at the Russian Vostok station.
  • The Antarctic Convergence is an invisible climate boundary in the ocean between the Antarctic region and the rest of the ocean, where warm and cold water meet. Since it arose around 20 million years ago, there has been very little exchange of marine life across the convergence.

Earth's fifth-largest continental landmass.

Antarctic Circumpolar Current (ACC)

most powerful surface ocean current in the world, which rotates clockwise around the continent of Antarctica. Also called the West Wind Drift.


group of organisms linked in order of the food they eat, from producers to consumers, and from prey, predators, scavengers, and decomposers.


small marine crustacean, similar to shrimp.


bird native to the Antarctic.


marine mammal with flippers and a sleek coat.

Southern Ocean

ocean surrounding Antarctica, considered by some scientists as a fifth ocean.