Antarctica

history:

More than 170 million years ago, the land areas of Antarctica were part of the landmass of the supercontinent Gondwana and lay south of Africa. After the breakup of Gondwana, Antarctica was slowly moved southward, causing progressive cooling.

The first ice fields worth mentioning appeared about 30 million years ago. About 25 million years ago, the Drake Strait opened between Antarctica and South America. The formation of the circumpolar current triggered by this intensified the icing process. The continent has been almost completely covered by a thick layer of ice for around 5 million years.

Natural space:

East Antarctica consists of a number of small, very old continent blocks. These are embedded in large, mostly Proterozoic structures of metamorphic rocks. This Precambrian base is overlaid by flat, in places very thick, Devonian to Jurassic sedimentary rocks and volcanic rocks. The Transantarctic Mountains were formed during orogeny 500 to 480 million years ago, the uplift took place about 50 million years ago.

In West Antarctica, the essential components are younger and only emerged during the course of the disintegration of the supercontinent Gondwana. Mesozoic to Tertiary folded chain mountains are characteristic over a base of Pre-Devonian basement. These run through the Antarctic Peninsula and are orogenically related to the Andes of Patagonia.

Climate:

Antarctica has the coldest climate on earth. The mean annual temperatures in the interior are well below - 30 °C. Summer mean temperatures exceed 0 °C only in parts of the Antarctic Peninsula.

The Russian station Vostok (3,488 m above sea level) in East Antarctica is considered the absolute cold pole on earth, where a temperature of - 89.2 °C was measured on July 21, 1983. At the maritime edge and on the sub-Antarctic islands, temperatures are significantly milder. Precipitation falls exclusively as snow.

The edge of the continent is marked by a lively atmospheric circulation. East to south-easterly katabatic winds blow from the continent into the sub-Antarctic depression. Storms with wind speeds of 150 to 200 km/h are not uncommon (Adélieland, for example, records 340 storm days a year). Offshore downdrafts and deep-water upwelling are the main causes of extensive ice-free oceans off the continent.

Vegetation and wildlife:

The flora of Antarctica is largely limited to mosses, lichens and land algae, which grow on coastal areas that are occasionally snow-free, on steep rock faces and scree slopes, as well as bacteria and fungi living in the soil. Only in the outskirts of Antarctica have two types of seed plants been found.

The animal world consists of insects, mites and aphids in the interior of the continent, and mainly seabirds and marine mammals in the coastal area. The organisms living in the Antarctic sea area sometimes show special adaptations to the icy water temperatures that prevail here. For example, a glycolic protein has been isolated from some fish, which protects cells and body fluids from the cold like an antifreeze.

Many Antarctic icefish are the only vertebrates that have no or very few red blood cells. Nevertheless, their oxygen supply is sufficient, since the total material turnover is greatly reduced as a result of the low temperatures.

Despite high concentrations of dissolved nutrient salts, the Southern Ocean is one of the least productive seas. If the nutrient-rich water gets a little further north and warms up slightly, highly productive waters develop, such as the Benguela Current off the west coast of southern Africa, which are of great importance for global fishing.

Population:

The continent is not really populated, but about 4000 people live in the more than 80 research stations in summer and about 1000 people in winter, whereby the exact number varies greatly.

Economy:

The increasing demand for food and raw materials and the shortage of various energy sources have increased interest in the economic use of the continent. For a long time only sea creatures were caught here, especially the whale stocks have declined dramatically due to excessive fishing. Whaling officially ended in 1986, but Japan continued to capture minke whales for research.

The mining of mineral raw materials (coal, iron, non-ferrous metal and uranium ore) has so far not been economical, which is not least due to the extremely difficult external conditions. Useful deposits of crude oil and natural gas have not yet been found. The Antarctic Treaty was extended by various agreements to regulate the use of mineral resources.