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Difference between revisions of "Southern Ocean"
Source content drawn from Wikipedia article on the Southern Ocean.
Westarctica (talk | contribs) (Created page with "thumb|200px|right|Map of the Southern Ocean The '''Southern Ocean''', also known as the '''Antarctic Ocean''' comprises the southernmost waters...") |
Westarctica (talk | contribs) (Source content drawn from Wikipedia article on the Southern Ocean.) |
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==Geography== | ==Geography== | ||
[[File:Old Antarctica map.jpg|thumb|350px|right|1906 map of the Antarctica showing the unknown boundries of the continent]] | |||
The Southern Ocean, geologically the youngest of the oceans, was formed when [[Antarctica]] and South America moved apart, opening the Drake Passage, roughly 30 million years ago. The separation of the continents allowed the formation of the Antarctic Circumpolar Current. | The Southern Ocean, geologically the youngest of the oceans, was formed when [[Antarctica]] and South America moved apart, opening the Drake Passage, roughly 30 million years ago. The separation of the continents allowed the formation of the Antarctic Circumpolar Current. | ||
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===Natural resources=== | ===Natural resources=== | ||
[[File:Maganese Nodule.jpg|thumb|right|Manganese nodule]] | |||
The Southern Ocean probably contains large, and possibly giant, oil and gas fields on the continental margin. Placer deposits, accumulation of valuable minerals such as gold, formed by gravity separation during sedimentary processes are also expected to exist in the Southern Ocean. | The Southern Ocean probably contains large, and possibly giant, oil and gas fields on the continental margin. Placer deposits, accumulation of valuable minerals such as gold, formed by gravity separation during sedimentary processes are also expected to exist in the Southern Ocean. | ||
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===Natural hazards=== | ===Natural hazards=== | ||
[[File:Iceberg Moving.jpg|thumb|right|Three ships moving an iceberg to clear shipping lanes in the Southern Ocean]] | |||
Icebergs can occur at any time of year throughout the ocean. Some may have drafts up to several hundred meters; smaller icebergs, iceberg fragments and sea-ice (generally 0.5 to 1 m thick) also pose problems for ships. The deep continental shelf has a floor of glacial deposits varying widely over short distances. | Icebergs can occur at any time of year throughout the ocean. Some may have drafts up to several hundred meters; smaller icebergs, iceberg fragments and sea-ice (generally 0.5 to 1 m thick) also pose problems for ships. The deep continental shelf has a floor of glacial deposits varying widely over short distances. | ||
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==Physical oceanography== | ==Physical oceanography== | ||
===Antarctic Circumpolar Current and Antarctic Convergence=== | ===Antarctic Circumpolar Current and Antarctic Convergence=== | ||
[[File:Circumpolar.jpg|thumb|right|Antarctic Circumpolar Current]] | |||
The Antarctic Circumpolar Current moves perpetually eastward – chasing and joining itself, and at 21,000 km (13,000 mi) in length – it comprises the world's longest ocean current, transporting 130 million cubic meters per second of water – 100 times the flow of all the world's rivers. | The Antarctic Circumpolar Current moves perpetually eastward – chasing and joining itself, and at 21,000 km (13,000 mi) in length – it comprises the world's longest ocean current, transporting 130 million cubic meters per second of water – 100 times the flow of all the world's rivers. | ||
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===Upwelling=== | ===Upwelling=== | ||
[[File:Antarctic bottom.png|thumb|right|Water mass bodies of the Southern Ocean]] | |||
Large-scale upwelling is found in the Southern Ocean. Strong westerly (eastward) winds blow around Antarctica, driving a significant flow of water northwards. This is actually a type of coastal upwelling. Since there are no continents in a band of open latitudes between South America and the tip of the Antarctic Peninsula, some of this water is drawn up from great depths. In many numerical models and observational syntheses, the Southern Ocean upwelling represents the primary means by which deep dense water is brought to the surface. Shallower, wind-driven upwelling is also found off the west coasts of North and South America, northwest and southwest Africa, and southwest and southeast Australia, all associated with oceanic subtropical high pressure circulations. | Large-scale upwelling is found in the Southern Ocean. Strong westerly (eastward) winds blow around Antarctica, driving a significant flow of water northwards. This is actually a type of coastal upwelling. Since there are no continents in a band of open latitudes between South America and the tip of the Antarctic Peninsula, some of this water is drawn up from great depths. In many numerical models and observational syntheses, the Southern Ocean upwelling represents the primary means by which deep dense water is brought to the surface. Shallower, wind-driven upwelling is also found off the west coasts of North and South America, northwest and southwest Africa, and southwest and southeast Australia, all associated with oceanic subtropical high pressure circulations. | ||
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===Ross and Weddell Gyres=== | ===Ross and Weddell Gyres=== | ||
[[File:Antarctic frontal.png|thumb|right|Oceanographic frontal systems in the Southern Ocean]] | |||
The Ross Gyre and Weddell Gyre are two gyres (a large system of circulating currents) that exist within the Southern Ocean. The gyres are located in the Ross Sea and Weddell Sea respectively, and both rotate clockwise. The gyres are formed by interactions between the Antarctic Circumpolar Current and the Antarctic Continental Shelf. | The Ross Gyre and Weddell Gyre are two gyres (a large system of circulating currents) that exist within the Southern Ocean. The gyres are located in the Ross Sea and Weddell Sea respectively, and both rotate clockwise. The gyres are formed by interactions between the Antarctic Circumpolar Current and the Antarctic Continental Shelf. | ||
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==Economic activity== | ==Economic activity== | ||
[[File:Antarctic krill.jpg|thumb|right|Antarctic krill]] | |||
Between 1 July 1998 and 30 June 1999, fisheries landed 119,898 tonnes, of which 85% consisted of [[krill]] and 14% of Patagonian toothfish. International agreements came into force in late 1999 to reduce illegal, unreported, and unregulated fishing, which in the 1998–99 season landed five to six times more Patagonian toothfish than the regulated fishery. | Between 1 July 1998 and 30 June 1999, fisheries landed 119,898 tonnes, of which 85% consisted of [[krill]] and 14% of Patagonian toothfish. International agreements came into force in late 1999 to reduce illegal, unreported, and unregulated fishing, which in the 1998–99 season landed five to six times more Patagonian toothfish than the regulated fishery. | ||
[[Category:Geography of Westarctica]] | [[Category:Geography of Westarctica]] | ||
[[Category:Seas]] | [[Category:Seas]] | ||