Borders of the oceans

Smaller regions of the oceans are called seas, gulfs, bays, straits, and other terms.

[1][2] This concept of a continuous body of water with relatively free interchange among its parts is of fundamental importance to oceanography.

[3] The major oceanic divisions are defined in part by the continents, various archipelagos, and other criteria.

Smaller regions of the oceans are called seas, gulfs, bays, straits, and other terms.

Oceanic crust is the thin layer of solidified volcanic basalt that covers the Earth's mantle.

A complete hierarchy showing which seas belong to which oceans, according to the International Hydrographic Organization (IHO), is available at the European Marine Gazetteer website.

[5] In turn, oceanic waters are interspersed by many smaller seas, gulfs, and bays.

Farther north, the Atlantic opens into the Arctic Ocean, which is connected to the Pacific by the Bering Strait, forming a continuous expanse of water.

The International Hydrographic Organization (IHO) defines the limits of the Arctic Ocean (excluding the seas it contains) as follows:[9]: Art.

The Antarctic Continent.Note that these definitions exclude any marginal waterbodies that are separately defined by the IHO (such as the Bay of Biscay and Gulf of Guinea), though these are usually considered to be part of the Atlantic Ocean.

)[11] While the name "Southern Ocean" is frequently used, some geographic authorities such as the 10th edition of the World Atlas from the U.S. National Geographic Society generally show the Atlantic, Indian, and Pacific Oceans continuing to Antarctica.

The 3rd edition, currently in force, of the International Hydrographic Organization's (IHO) Limits of Oceans and Seas defines the limits of the Indian Ocean (excluding the seas it contains) as follows:[9] Note that this definition excludes any marginal waterbodies that are separately defined by the IHO (such as the Bay of Bengal and Arabian Sea), though these are usually considered to be part of the Indian Ocean.

)[11] While the name "Southern Ocean" is frequently used, some geographic authorities such as the 10th edition of the World Atlas from the U.S. National Geographic Society generally show the Atlantic, Indian, and Pacific Oceans continuing to Antarctica.

The 3rd edition, currently in force, of the International Hydrographic Organization's (IHO) Limits of Oceans and Seas defines the limits of the North Pacific Ocean (excluding the seas it contains) as follows:[9] The 3rd edition, currently in force, of the International Hydrographic Organization's (IHO) Limits of Oceans and Seas defines the limits of the South Pacific Ocean (excluding the seas it contains) as follows:[9] Note that these definitions exclude any marginal waterbodies that are separately defined by the IHO (such as the Gulf of Alaska and Coral Sea), though these are usually considered to be part of the Pacific Ocean.

)[11] While the name "Southern Ocean" is frequently used, some geographic authorities such as the 10th edition of the World Atlas from the U.S. National Geographic Society generally show the Atlantic, Indian, and Pacific Oceans continuing to Antarctica.

The Southern Ocean then extended from Antarctica northwards to latitude 40° south between Cape Agulhas in Africa (long.

[16] The Southern Ocean did not appear in the 1953 third edition because "...the northern limits ... are difficult to lay down owing to their seasonal change ... Hydrographic Offices who issue separate publications dealing with this area are therefore left to decide their own northern limits.

Instead, in the IHO 1953 publication, the Atlantic, Indian and Pacific Oceans were extended southward, the Indian and Pacific Oceans (which had not previously touched pre 1953, as per the first and second editions) now abutted at the meridian of South East Cape, and the southern limits of the Great Australian Bight and the Tasman Sea were moved northwards.

The 4th edition of Limits of Oceans and Seas has yet to be published due to "areas of concern" by several countries relating to various naming issues around the world.

Despite this, the 4th edition definition has de facto usage by many organisations, scientists and nations – even at times by IHO committees.

[9] Other sources, such as the National Geographic Society, show the Atlantic, Pacific and Indian Oceans as extending to Antarctica, although articles on the National Geographic web site have begun to reference the Southern Ocean.

Coastal maps of Tasmania and South Australia label the sea areas as Southern Ocean,[20] while Cape Leeuwin in Western Australia is described as the point where the Indian and Southern Oceans meet.

Rotating series of maps showing alternate divisions of the oceans
Maps exhibiting the world's oceanic waters. A continuous body of water encircling Earth , the World/Global Ocean is divided into a number of principal areas. Five oceanic divisions are usually recognized: Pacific , Atlantic , Indian , Arctic , and Southern/Antarctic ; the last two listed are sometimes consolidated into the first three.
The borders of the Arctic Ocean , according to the CIA World Factbook [ 6 ] (blue area), and as defined by the IHO (black outline – excluding marginal waterbodies)
The Atlantic Ocean, according to the CIA World Factbook [ 10 ] (blue area), and as defined by the IHO (black outline – excluding marginal waterbodies)
The Indian Ocean, according to the CIA World Factbook [ 12 ] (blue area), and as defined by the IHO (black outline – excluding marginal waterbodies)
The Pacific Ocean according to the CIA World Factbook [ 13 ] (blue area), and as defined by the IHO (black outline – excluding marginal waterbodies)
The Southern Ocean according to the CIA World Factbook [ 14 ]
Map showing the proposal presented by the thesis entitled " Natural delimitation between the Pacific and South Atlantic oceans by the Shackleton fracture zone ".