South Atlantic Ocean

South Atlantic Ocean
Name	South Atlantic Ocean
Caption	Map showing the South Atlantic Ocean.
Area	Approximately 41,100,000 km²
Max-depth	South Sandwich Trench (~8,428 m)
Islands	Ascension Island, Saint Helena, Tristan da Cunha, Falkland Islands

South Atlantic Ocean. It is the portion of the Atlantic Ocean that lies south of the Equator, extending to the continent of Antarctica. Bordered by South America to the west and Africa to the east, it connects to the Southern Ocean in the south. Major features include the Mid-Atlantic Ridge and significant currents like the Brazil Current and the Benguela Current.

Geography and boundaries

The northern boundary is defined by the Equator, from the coast of Brazil near São Roque Cape eastward to Liberia. Its western limit follows the coastlines of nations such as Argentina, Uruguay, and Brazil to Cape Horn. To the east, it borders countries including South Africa, Namibia, and Angola, extending to Cape Agulhas. The southern boundary is often set at the 60°S parallel, where it meets the Southern Ocean adjacent to Antarctica. Key marginal seas include the Rio de la Plata and the Gulf of Guinea, while notable islands are the Falkland Islands, Ascension Island, and Saint Helena.

Geology and ocean floor

The seafloor is dominated by the Mid-Atlantic Ridge, a divergent tectonic boundary responsible for seafloor spreading between the South American Plate and the African Plate. This creates a rugged underwater mountain range with a central rift valley. Deeper areas include basins like the Argentina Basin and the Cape Basin, while the South Sandwich Trench, near the Scotia Plate, is its deepest point. Volcanic activity along the ridge has formed islands such as Tristan da Cunha and Bouvet Island, and the region features extensive abyssal plains.

Climate and hydrology

The climate is influenced by the South Atlantic High, a semi-permanent high-pressure system. Prevailing winds include the southeast trade winds in the north and the Westerlies in the south, which drive major ocean currents. The warm Brazil Current flows southward along the coast of South America, while the cold, nutrient-rich Benguela Current moves northward along southwestern Africa. These currents meet the Antarctic Circumpolar Current in the south. The region experiences tropical cyclones, such as Hurricane Catarina which struck Brazil in 2004.

Marine life and ecosystems

The cold, upwelling waters of the Benguela Current support one of the world's most productive marine ecosystems, with abundant phytoplankton fueling large fisheries for species like anchovy and sardine. The Patagonian Shelf near Argentina is another rich area, known for squid and hake. The open ocean hosts migratory species including southern right whale, albatross, and bluefin tuna. Unique island ecosystems, like those on Gough Island, are critical breeding grounds for seabirds. Deep-sea vents along the Mid-Atlantic Ridge harbor specialized chemosynthetic life.

Human history and exploration

Early crossings were made by Portuguese explorers like Bartolomeu Dias, who rounded the Cape of Good Hope in 1488, and Ferdinand Magellan, who traversed the strait now bearing his name in 1520. The ocean became a vital route for the Atlantic slave trade between Africa and the Americas. Key historical events include the Battle of the River Plate in 1939 and the Falklands War in 1982. Scientific expeditions, such as those by HMS Challenger and the German Meteor expedition, have extensively studied its depths.

Economic importance

It is a major route for global shipping, connecting economies via the Cape Route and passages like the Strait of Magellan. Significant offshore oil and gas fields are located near Brazil, Angola, and Nigeria. The Benguela Current and Patagonian Shelf regions support lucrative commercial fishing industries. Islands like Ascension Island and Saint Helena have strategic and telecommunications importance. The ocean also holds potential for deep-sea mining of polymetallic nodules and for marine biotechnology research.

Category:Atlantic Ocean Category:Oceans