TheAntarctic Convergence orAntarctic Polar Front is a marine belt encirclingAntarctica, varying in latitude seasonally, where cold, northward-flowing Antarctic waters meet the relatively warmer waters of thesub-Antarctic. The line separates theclockwiseAntarctic circumpolar current from other oceans.[1] Antarctic waters predominantly sink beneath the warmer subantarctic waters, while associated zones of mixing andupwelling create a zone very high in marine productivity, especially forAntarctic krill.
This line, like theArctic tree line, is a natural boundary rather than an artificial one, such as theborders ofnations andtime zones. It not only separates twohydrological regions, but also separates areas of distinctivemarine life andclimates.
TheArctic has no similar boundary because of the large bodies of landcontiguous with the northern polar region.
The Antarctic Convergence was first crossed byAnthony de la Roché in 1675[2] andEdmond Halley in 1700,[3] and first described by the BritishDiscovery Investigations and the GermanMeteor Expedition in 1925–1927.[4]
The Antarctic Convergence is a zone approximately 32 to 48 km (20 to 30 mi) wide, varying in latitude seasonally and in differentlongitudes, extending across theAtlantic,Pacific, andIndianoceans between the48th and61st parallels of south latitude. Although the northern boundary varies, for the purposes of the Convention on the Conservation of Antarctic Marine Living Resources 1980, it is defined as "50°S, 0°; 50°S, 30°E; 45°S, 30°E; 45°S, 80°E; 55°S, 80°E; 55°S, 150°E; 60°S, 150°E; 60°S, 50°W; 50°S, 50°W; 50°S, 0°."[5] Although this zone is a mobile one, it usually does not stray more than half a degree of latitude from its mean position. The precise location at any given place and time is made evident by the sudden drop in seawater temperature from north to south of, on average, 2.8 °C (5.0 °F) from 5.6 °C (42.1 °F) to below 2 °C (36 °F).
Amsterdam Island (France)Crozet Islands (France)
Diego Ramírez Islands (Chile)
Falkland Islands (United Kingdom)
Isla de los Estados (Argentina)
Macquarie Island (Australia)
NZ Subantarctic Islands (New Zealand)Chatham Islands (New Zealand)
Prince Edward Islands (South Africa)Saint Paul Island (France) /Tierra del Fuego (Argentina /Chile)
Tristan da Cunha (United Kingdom)
Bouvet Island (Norway)
Heard Island and McDonald Islands (Australia)Kerguelen Islands (France)
South Georgia and the South Sandwich Islands (United Kingdom)
Balleny Islands (Antarctic Treaty System)Peter I Island (Antarctic Treaty System)Scott Island (Antarctic Treaty System)South Orkney Islands (Antarctic Treaty System)South Shetland Islands (Antarctic Treaty System)
This article incorporatespublic domain material from"Antarctic Convergence".Geographic Names Information System.United States Geological Survey.
