|South polar region (Antarctica) |
The southern parts of the great oceans form the ring of the South Polar Sea, where cold water masses, driven by the west wind drift and practically unhindered by land bridges, flow around the continent as far as the Antarctic convergence (roughly at the position of the 10 °C February air temperature isotherm). There the cold Antarctic water sinks along a narrow zone, with only minor seasonal fluctuations, beneath the warmer water masses from lower latitudes, heated in the tropics. As a result the surface water temperature falls towards the pole by 4 °C in a short distance.
Climate and Habitat
The extent of the sea ice in the South Polar Sea fluctuates widely with the seasons. The average annual temperature at the South Pole station at a height of 2,800 metres is minus 50 °C. At the Mirny coastal station it is only minus 11.5 °C, and annual precipitation there reaches 427 millimetres. Even less precipitation remains lying on the inland ice: 20 grams of ice per square centimetre and year, or 5 to 50 millimetres of water equivalent. At the Russian Vostok research station in East Antarctica, at a height of 3,488 metres, a world cold record of minus 89.2 °C was measured in July 1983.
In contrast to the North Pole, at the South Pole there is thick inland ice reaching heights of up to 4,300 metres above sea level. Thus the average height of the Antarctic is 2,040 metres, while the average height of the other continents is only some 730 metres. Beside the East Antarctic Shield the ice holds together the archipelago of West Antarctica, from which only a few individual mountain ranges break through the ice (nunataks) and only a few of the coasts are free of ice. But even just the 2 to 3 percent of periglacial regions, which lie without ice cover at the periphery of the glaciers, when taken together amount to a territory that is larger than Germany. The highest peak in the Antarctic is the Vinson Massif in the Transantarctic Mountains with a height of 4,897 metres at the root of the Filchner-Ronne Ice Shelf.
Despite the inhospitable living conditions for humans, the coasts and oceans are an ecologically rich habitat for adapted species such as whales, seals, penguins, fish, krill and others. Raw materials have also been discovered in many places, but their exploitation although technically possible would currently be uneconomic. Furthermore, it is in any case prohibited at least until 2042. In the deep Antarctic seas, especially in the Pacific sector, rich fields of manganese nodules have been proved at a depth of 1,000 to 5,000 metres beneath the sea.
The inland ice is the most important fresh water repository in the Earth's water supply. The natural annual iceberg export of some 1,200 km³, which mainly takes place by calving from the shelf ice, could be economically used for the production of fresh water. Technical developments in this direction have already been discussed and experiments have been carried out.
Research and Conservation
Today the Antarctic is the subject of research programmes in international cooperation. It is protected by the SCAR Treaty (Scientific Committee on Antarctic Research; Antarctic Treaty), concluded in 1959, which was initially signed by twelve countries and was prolonged in 1991. Out of the 46 member states that have now acceded, 28 including Germany have consultative status which also gives them the right to install a research station. For the duration of the treaty, military uses are banned and claims of sovereignty are frozen.
The first Agreed Measures for the Conservation of Antarctic Fauna and Flora entered into force in 1964, followed by the Convention for the Conservation of Antarctic Seals in 1978 and the Convention for the Conservation of Antarctic Marine Living Resources in 1982. A provisional agreement on raw materials exploration with a view to environmental protection was signed in 1988. In a Protocol to the Antarctic Treaty in 1992, all activities relating to mineral resources are prohibited for the time being except for scientific purposes, and the status of the Antarctic as a nature reserve is stipulated, initially for a period of 50 years.
Following the disastrous and irresponsible whaling campaigns that began in the Arctic in the 17th century and in the Antarctic in the 19th century, the International Whaling Commission (IWC) was set up in 1932 with the purpose of regulating the stocks of the marine mammals by means of conservative catch quotas. Until the 1960s up to 40,000 whales were still being caught annually. From 1965, those species that were under threat of extinction were placed under protection. Today, commercial whaling is prohibited with the exception of minke whales. Only whaling for scientific purposes is permitted.
Initially the Soviet Union and Japan objected to the IWC whaling ban. In the 1985/86 season the Japanese still caught 1,941 minke whales with four whalers and a factory ship, and the Soviet Union as many as 3,028 with five whalers and a factory ship. Both countries ceased hunting provisionally after the 1987/88 season. Meanwhile however, Japan has resumed whaling officially only for "scientific purposes" and is the only country in the world apart from Norway that continues to conduct commercial whaling more or less openly. Norway catches nearly 400 whales per year in the North Atlantic. In addition to this, Iceland and Korea also operate "scientific whaling", and the "traditional catches" of the Greenlanders and Eskimos are also tolerated. In 1994 a 21 million square kilometre whale protection area was set up around the Antarctic, initially for a period of 50 years.
But it is not only whales that are hunted by commercial methods. Since the 1970s up to 300,000 tons of fish have been caught annually in the Antarctic Ocean, especially by the Soviet Union or Russia as well as Japan and Poland. Fishing is now severely restricted under the Antarctic Treaty.
V. Hochschild; Ü: J. Attfield
Keywords: Antarctic climate diagram drift ice fishing ground glacier habitat ice inland ice krill mineral resources pack ice polar circle polar zone raw material shelf ice south pole volcano west wind drift
View the map frame in Google Earth. open
Map frame in Google Maps
View the map frame in Google Maps. open