Scotia Sea
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The Scotia Sea is a sub-Antarctic sea where the Southern Ocean and the South Atlantic Ocean meet. It extends between Tierra del Fuego off the southern tip of the South American continent and the British territories of South Georgia, the South Sandwich Islands, the South Orkney Islands and the Antarctic Peninsula. Its western end is the Drake Passage between the Tierra Del Fuego and Graham Land.
The Scotia Sea covers an area of about 350,000 square miles, about half of the sea standing above the continental shelf.
The icy isles of South Georgia, the South Sandwich Islands, the South Orkney Islands all sit on top of the Scotia Ridge, which frames the Scotia Sea to the north, east, and south.
History
Named in about 1932 after the Scotia, the expedition ship used in these waters by the Scottish National Antarctic Expedition (1902–04) under William S Bruce. The most famous traverse of this frigid sea was made in 1916 by Sir Ernest Shackleton and five others in the adapted lifeboat James Caird when they left Elephant Island and reached South Georgia two weeks later.
On 20 August 2006 an earthquake with a magnitude of 7.0 struck at 1:41 a.m. local time (0341 GMT). The exact location was 61.011°S, 34.375°W at a depth of 6 miles with a USGS event ID of "usrqal".[1]
Flora and fauna
Despite the harsh conditions the islands do support vegetation and have been described as the Scotia Sea Islands tundra ecoregion, which includes South Georgia, the volcanic South Sandwich Islands and the South Orkneys in the Scotia Sea as well as the remote South Shetland Islands near the Antarctic Peninsula and the small isolated volcano Bouvet Island. All these islands lie in the cold seas below the Antarctic convergence. These areas support tundra vegetation consisting of mosses, lichen and algae, while seabirds, penguins and seals feed in the surrounding waters.
Seabirds include four species of albatross: Black-browed Albatross (Diomedea melanophris), Grey-headed Albatross (Thalassarche chrysostoma), Light-mantled Albatross (Phoebetria palpebrata), and Wandering Albatross (Diomedea exulans). There are only five species of bird that remain on land on the islands, and these include two endemic species: a race of the Yellow-billed Pintail duck(Anas georgica) and South Georgia Pipit (Anthus antarcticus).
Penguin species found here include large numbers of King Penguins on South Georgia especially, as well as Chinstrap Penguin, Macaroni Penguin, Gentoo penguin, Adelie Penguin, and Rockhopper Penguin (Eudyptes chrysocome).
Seals include the Antarctic Fur Seal (Arctocephalus gazella) and Sub-Antarctic Fur Seal (Arctocephalus tropicalis) in large numbers, Leopard Seal (Hydrurga leptonyx), Weddell Seal (Leptonychotes weddellii), the huge Southern Elephant Seal (Mirounga leonina), and Crabeater Seal (Lobodon carcinophagus).[2]
Threats and preservation
Although the islands have a harsh climate and have never been permanently occupied they have long been used as a base for fishing and seal-hunting. Wildlife on these remote islands is threatened by introduced species, especially on South Georgia, where even large animals including reindeer have been brought to the islands. Further damage to ecosystems results from overfishing. South Georgia, the South Sandwich Islands and Bouvet Island are protected as nature reserves, and Bird Island, South Georgia is a site of special scientific interest. The seals are further protected by international agreements and Fur Seal populations are recovering.
South Scotia Ridge
South Scotia Ridge 60°S 46°30'W) is an undersea ridge named in association with the Scotia Sea.
References
- ↑ event "usrqal", according to the USGS
- ↑ [1]