Antarctica referat

Antarctica, fifth largest of the earth’s seven continents. The southernmost, coldest, windiest, highest, most remote, and most recently discovered continent, it surrounds the South Pole, the point at the southern end of the earth’s axis. Almost completely covered by ice, Antarctica has no permanent human population. The continent is ringed by the Southern, or Antarctic, Ocean, a body of water made up of the southern portions of the Atlantic, Pacific, and Indian oceans but sometimes considered a separate ocean due to its lower temperature and salt concentration. The entire area south of the Antarctic Convergence, the zone where the Southern Ocean meets the other oceans, is referred to as the Antarctic region. Antarctica means 'opposite to the Arctic,' the earth’s northernmost region.

The continent is shaped somewhat like a comma, with a round body surrounding the pole and a tail curving toward South America. The round portion, lying mainly in the eastern hemisphere, makes up East Antarctica. The tail and its thickened base, located entirely in the western hemisphere, form West Antarctica. Antarctica lies about 1000 km (about 600 mi) from South America, its nearest neighbor; about 4000 km (about 2500 mi) from Africa; and about 2500 km (about 1600 mi) from Australia. Antarctica’s latitude (location in relation to the equator) and high elevations make it the coldest continent. Air temperatures of the high inland regions fall below –80° C (-110° F) in winter and rise only to about –30° C (about –20° F) in summer. The warmest coastal regions reach the freezing point in summer but drop well below in winter.

The last continent to be discovered, Antarctica remained hidden behind barriers of fog, storm, and sea ice until it was first sighted in the early 19th century. Because of the extreme cold and the lack of native peoples, forests, land animals, and obvious natural resources, the continent remained largely neglected for decades after discovery. Scientific expeditions and seal hunters had explored only fragments of its coasts by the end of the 19th century, while the interior remained unknown. Explorers first reached the South Pole in 1911, and the first permanent settlements—scientific stations—were established in the early 1940s. From that time the pace of exploration accelerated rapidly. Scientists continue to conduct research in Antarctica, and in recent years increasing numbers of tourists have visited Antarctica to appreciate the region’s majestic scenery and wildlife.

Seven nations—Argentina, Australia, Britain, Chile, France, New Zealand, and Norway—claim territory in Antarctica. Other nations, including the United States and Russia, do not acknowledge these claims and make no claims of their own, but reserve rights to claim territory in the future. Since 1961 the continent has been administered under the Antarctic Treaty, an international agreement to preserve the continent for peaceful scientific study.

Mineral Resources Although only about 1 percent of the continent’s ice-free areas have been surveyed for minerals, evidence indicates that Antarctica contains rich mineral deposits. The Transantarctic Mountains contain huge deposits of coal as well as copper, lead, zinc, silver, tin, and gold. The Prince Charles Mountains of East Antarctica are rich in iron ore; the Antarctic Peninsula contains copper and molybdenum ores; and the Dufek Massif includes ores of chromium, platinum, copper, and nickel. It is also believed that deposits of petroleum and natural gas exist in the continental shelf regions, such as the area under the Ross Sea. Although Antarctica has prospects for mineral development, there are concerns about the potential environmental and political impacts of this development. In 1991 the signatory nations of the Antarctic Treaty agreed to a 50-year moratorium on commercial mining activity. The only mineral resources currently used are sand, gravel, and crushed rocks for constructing airstrips and building foundations at the scientific stations.

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