
Animated map exhibiting the world's
oceanic waters. A continuous body of water encircling the
Earth, the World Ocean is divided into a number of principal areas with relatively free interchange among them. Five oceanic divisions are usually reckoned:
Pacific,
Atlantic,
Indian,
Arctic, and
Southern; the last two listed are sometimes consolidated into the first three.
The 'World Ocean', 'world ocean', or 'global ocean' is the interconnected system of the
Earth's
oceanic (or
marine)
waters, and comprises the bulk of the
hydrosphere.
The unity and continuity of the World Ocean, with relatively free interchange among its parts, is of fundamental importance to
oceanography.
[1] Customarily, it is divided into a number of principal oceanic areas that are delimited by the
continents and various oceanographic features: these divisions are the '
Atlantic Ocean', '
Arctic Ocean' (sometimes considered a
sea of the Atlantic), '
Indian Ocean', '
Pacific Ocean', and '
Southern Ocean' (sometimes reckoned instead as just the southern portions of the Atlantic, Indian, and Pacific Oceans). In turn, oceanic waters are interspersed by many smaller seas and other bodies of water.
A global ocean has existed in one form or another on Earth for eons, and the notion dates back to
classical antiquity (in the form of
Oceanus). The contemporary concept of the ''World Ocean'' was coined by the
Russian
oceanographer Yuly Shokalsky in the early
20th century to describe what is basically a solitary, continuous ocean that covers and encircles most of the Earth.
While continuous, the World Ocean can be visualized as being centered on the Southern Ocean. The Atlantic, Indian, and Pacific Oceans can be seen as
bays or lobes extending northward from the Southern Ocean. Further north, the Atlantic opens into the Arctic Ocean, which is connected to the Pacific by the
Bering Strait:
★ The Southern Ocean is the ocean surrounding
Antarctica, dominated by the
Antarctic Circumpolar Current, generally the ocean south of sixty degrees south latitude. The Southern Ocean is partially covered in
sea ice, the extent of which varies according to the season. The Southern Ocean is the second smallest of the five named oceans.
★ The Atlantic Ocean, the second largest, extends from the Southern Ocean between
South America,
Africa,
North America and
Europe, to the Arctic Ocean. The Atlantic meets the Indian Ocean south of Africa at
Cape Agulhas.
★ The Indian Ocean extends northward from the Southern Ocean to
India, between Africa and
Australia. The Indian Ocean joins the Pacific Ocean to the west, near Australia.
★ The Pacific Ocean, the largest of all, also reaches northward from the Southern Ocean to the Arctic Ocean. It spans the gap between Australia,
Asia, North America and
Oceania. The Pacific Ocean meets the Atlantic south of South America at
Cape Horn.
★ The Arctic Ocean is the smallest of the five. It joins the Atlantic near
Greenland and
Iceland, and joins the Pacific at the
Bering Strait. It overlies the
North Pole, touching North America in the
Western hemisphere and
Scandinavia and Asia in the
Eastern hemisphere. The Arctic Ocean is partially covered in sea ice, the extent of which varies according to the season. Some authorities do not consider the Arctic Ocean a ''bona fide'' ocean, because it is largely surrounded by land with only limited exchange of water with the other oceans. Consequently, it is considered by some to be a
sea of the Atlantic, referred to as the ''Arctic Mediterranean Sea'' or ''Arctic Sea''.
The approximate shape of the World Ocean can for most purposes be treated as constant, although in fact it is not:
continental drift continually changes its structure.
See also
★
Sea
★
Plate tectonics
★
Superocean
★
World Ocean Atlas
★
Seven Seas
Sources
1. Spilhaus, Athelstan F. 1942 (Jul.). "Maps of the whole world ocean." ''Geographical Review'' (American Geographical Society). Vol. 32 (3): pp. 431-5.
★ Chekin, L. 2002. "
The world ocean in medieval cartography". Moscow: S. I. Vavilov Institute of the History of Science and Technology of the Russian Academy of Sciences; thesis for
Museum of the World Ocean congress.
★ "
Ocean". ''The Columbia Encyclopedia'', 6th ed. 2003. New York: Columbia University Press; also,
★ Danabasoglu, Gokhan ; McWilliams, James C.; & Gent, Peter R. 1994. "
The role of mesoscale tracer transports in the global ocean circulation". ''
Science'': vol. 264. (no. 5162), pp. 1123-1126.
★ "
The world ocean".
Infoplease.com. 2005. Pearson Education.
★ Levitus, Sydney; Antonov, John I.; Boyer, Timothy P.; and Stephens, Cathy. 2000. "Warming of the world ocean":
abstract,
article. ''Science'': vol. 287. (no. 5461), pp. 2225-2229.
★ "
All about oceans".
LiveScience.com. 2007. Imaginova Corp.
★ Spilhaus, Athelstan F. 1942. "Maps of the whole world ocean." ''
Geographical Review'': vol. 32 (no. 3), pp. 431-5.
★ ''
UN Atlas of the Oceans'':
★
★ "
Distribution of land and water on the planet", "
Origins of the oceans and continents"