Antarctic Continent
Antarctic Continent - continent situated at the very South of Earth, the center of the Antarctic Continent approximately coincides with the south geographic pole. The Antarctic Continent is washed by the waters of the South Ocean (in Russia this ocean is often considered as the south parts of the Indian, Pacific, and Atlantic oceans). The square of the continent is about 14.4 m. sq. km (1.6 m. sq. km from the total area are the ice shelves).
The Antarctic Continent was discovered in the 19th century (28th of January) 1820 by a Russian expedition under the guidance of Faddey Bellinsgauzen and Mikhail Lazarev, who came to it on the ship's boats "Vostok" and "Mirnyy" at the point of 69°21` SL 2°14` WL. (a district of a modern ice shelf of Bellinsgauzen).
The first who came to the continent on the 24th of January 1895 included the captain of the Norwegian ship "Antarctic" Kristensen and a teacher of natural sciences Karlsten Borkhgreving.
 Geological structure of the eastern Antarctic Continent
The eastern Antarctic Continent presents the ancient Pre-Cambrian continental platform (craton), which coincides with the platforms of the India, Brazil, Africa, and Australia. All of these cratons formed after the disruption of a super Gondwana continent. The age of the rocks of the crystal base is 2.5-2.8 billion years, in which the most ancient rocks are the rocks of Enderby Land - more than 3 billion years.
The base is covered with more recent sedimentary cover that formed 350-190 million years ago and which is basically of marine origin. The 320-280 million year old layers contain the glacial drifts, however, the more recent ones contain the fossils of plants and animals including ichthyosaurus and dinosaurs, which proves the strong difference in the climate of that time and the modern one. The finds of heat-loving reptiles and filical flora were made by the first researchers on the Antarctic Continent and were evidence of the large-scale horizontal movement of the platforms.
 Geological structures of the western Antarctic Continent
The western Antarctic continent is a more recent and divided area that was formed during the last 500 million years because of an addition to the Antarctic platform's smaller continental fragment micro platforms. The largest of them are Elsvort's mountain, the Antarctic Peninsula and the Land of Mary Berd. The collision of these micro platforms with the Antarctic platform led to the formation of the mountains of the western Antarctic Continent.
The Antarctic glaciers are the greatest in the world. About 30 million cubic kilometers of ice are hidden in the south plateau-glacier of earth.
If all this ice were to melt, the level of the world's ocean would rise 100 meters. Most glaciers could be called water floods because they don't have any clear limits. At the place where the glacier flows into the bay reaching the coast, the ice becomes an ice shelf. The largest ice shelf is Ross's ice shelf. And the thickest one is Retford's ice shelf. Its thickness is more than 1.6 kilometers and right here the heavy drifted glaciers form.
The most immense of all the history of observations on the Antarctic Continent iceberg is called "B15". It was locked in the Ross's sea for two and half years. Its size can be compared to Jamaica. It is approx. 11,000 square kilometers. When the Antarctic spring arrived it split into nine parts.
Some time later on, one more gigantic iceberg, which its length was more than 200 kilometers, separated from the continental part of Antarctic Continent and started as an ice- drift. One specialist's opinion is that it poses a hazard to navigation in the South latitudes. With the help of satellites another gigantic glacier was discovered, but of a smaller size, in which its length is "only" 75 kilometers.
Gigantic icebergs become a fatal barrier for approaching ice-breakers and freighters to the Antarctic continent. The debris of the giants - numerous small icebergs pose even more danger. The observation of the ice-floe with the help of satellites is retained for 26 years. But in the last three years in the South Seas, icebergs of a record size have appeared and the amount of the small icebergs, which could destroy ships, arrived into the South latitudes, which is a sizeable increase.
The simplest thing is to connect the appearance of iceberg-destruction with the general climate warming. It is the reason for all disasters: abnormally hot year in 2007 in Ukraine, droughts in Spain, floods in Germany, intensely cold weather in the European part of Russia, and fires in the Asiatic one. - The most serious approach to this problem of the increase of ice-floes is being addressed by American scientists. |
