Antarctica is the Earth's southernmost continent. It is on the South Pole. It is almost entirely south of the Antarctic Circle. Around Antarctica is the Southern Ocean. At 14.0 million km2 (5.4 million sq mi), it is the fifth-largest continent in area after Asia, Africa, North America, and South America. About 98% of Antarctica is covered by ice. This ice averages at least 1.6 kilometers (1.0 mi) in thickness.
Antarctica, on average, is the coldest, driest, and windiest continent. It is also the highest of all the continents. Antarctica is considered a desert. It has yearly precipitation of only 200 mm (8 inches) near the sea and far less inland. No humans live in Antarctica permanently. However, about 1,000 to 5,000 people live through the year at the research stations in Antarctica. Only plants and animals that can bear cold live there. The animals include penguins, seals, nematodes, tardigrades and mites. Plant life includes some grass and shrubs, algae, lichen, fungi, and bacteria.
The first known sighting of the continent was in 1820. Antarctica was mostly forgotten for the rest of the 19th century. This was because of its hostile environment, few resources, and isolation. The first official use of the name Antarctica as a continental name in the 1890s is said to have been used by Scottish cartographer John George Bartholomew.
The Antarctic Treaty was signed in 1959 by 12 countries. More countries have signed the treaty since then. So far, 46 countries have signed the treaty. The treaty declares that military activities and mineral mining are against the law. However, it supports scientific research. It also helps the continent's ecozone. More than 4,000 scientists from different nations and different interests experiment together.
Geography and geology [change]
Antarctica is covered by an ice sheet about four kilometres thick. Under the ice it is mostly land, except at places such as the Ross ice shelf, which has no land underneath. Antarctica has some important features hidden by the ice. One is Lake Vostok, which has been covered by ice for at least 15 million years. The lake is 250 km long and 50 km wide. Another is the huge Gamburtsev mountain chain, which are the size of the Alps, yet entirely buried under the ice. The Gamburtsev range has a nearby massive rift valley similar to the East African Great Rift Valley. It is called the Lambert system. Scientists used radar that can work under ice to survey the whole of Antarctica.
Life in Antarctica [change]
Most plants that grow on the land in Antarctica are moss, lichen and algae. This is because Antarctica does not have much moisture (water), sunlight, good soil, or a warm temperature. Plants usually only grow for a few weeks in the summer. The most important organisms in Antarctica are the plankton which grow in the ocean.
One important source of food in the Antarctic is the krill, which is a general term for the small shrimp-like marine crustaceans. Krill are near the bottom of the food chain: they feed on phytoplankton and to a lesser extent zooplankton. Krill are a food form suitable for the larger animals for whom krill makes up the largest part of their diet. So whales, penguins, seals, and even some of the birds that live in the Antarctic, depend on krill.
Whales are the largest animals in the ocean, and in Antarctica. They are mammals, not fish. That means that they breathe air and do not lay eggs. Many different kinds of whales live in the oceans around Antarctica. The whales that eat krill do not have teeth. Instead they have in their mouths. Baleen is long, hard strips that act like a strainer. The whale takes in a mouthful of water, and it goes through the baleen. Any krill in the water is trapped and swallowed, while the water goes back out.
Penguins only live south of the equator. Several different kinds live in and around Antarctica. The biggest ones can stand nearly 4 feet tall and can weigh almost 100 pounds. The smallest kinds are only about one foot tall. Penguins are large birds that swim very well but cannot fly. They have black backs and wings with white fronts. They look rather like fat, little men in suits as they waddle over the ice. The penguins have a thick layer of blubber that keeps them warm. Their feathers are very tightly packed and they are on top of each other to make another thick cover. They also have a layer of woolly down under the feathers. The feathers themselves are coated with a type of oil that makes them waterproof. The penguins eat fish and are at home in the ocean. They come up on the land or ice to lay their eggs and raise the chicks. The animals nest together in a huge group.
History of its discovery [change]
For a long time, people had believed that there was a great continent in the far south of Earth. They thought this Terra Australis would "balance" the lands in the north like Europe, Asia and North Africa. People have believed this from the times of Ptolemy (1st century AD). He suggested this idea to keep the balance of all known lands in the world. Pictures of a large land in the south were common in maps. In the late 17th century, people discovered that South America and Australia were not part of the mythical "Antarctica". However, geographers still believed that Antarctica was much bigger than it really was.
European maps continued to show this unknown land until Captain James Cook's ships, HMS Resolution and Adventure, crossed the Antarctic Circle on 17 January 1773, in December 1773. They crossed it again in January 1774. In fact, Cook did come within about 75 miles (121 km) of the Antarctic coast. However, he was forced to go back because of ice in January 1773. The first confirmed sighting of Antarctica were by three different men. According to different organizations (the National Science Foundation, NASA, the University of California, San Diego, and other sources), ships captained by three men saw Antarctica in 1820. Fabian Gottlieb von Bellingshausen (a captain in the Russian Imperial Navy), Edward Bransfield (a captain in the Royal Navy), and Nathaniel Palmer (an American seal hunter out of Stonington, Connecticut). Von Bellingshausen saw Antarctica on 27 January 1820. This was three days before Bransfield saw land, and ten months before Palmer did so in November 1820. On that day the two-ship journey led by Von Bellingshausen and Mikhail Petrovich Lazarev reached a point within 32 kilometers (20 mi) of the Antarctic and saw ice fields there. The first recorded landing on mainland Antarctica was by the American sealer John Davis. He landed in West Antarctica on 7 February 1821. However, some historians are not sure about this claim.
People began discovering different parts of Antarctica and mapping them. This was slow work because they could only work in the summer. At last a map was made, and people began to talk about exploring the land, not only the sea. However, this would have been very hard work. They would have to break through the ice that was around Antarctica. Then they would have to land on it and bring in enough things to live on while they explored the land.
The first man to begin more serious exploration of the Antarctic land was a person named Robert Falcon Scott, the most well known from all of the explorers. He wanted to be the very first man to reach the South Pole. At the same time, another team from Norway lead by Roald Amundsen had started. They both raced each other to the North Pole, but in the end Amundsen won because he had made a good use of the animals, by using using sleigh dogs. Scott had used ponies and motor sleds, but he had not succeeded and when he got to the North Pole he was greeted by the message from Amundsen, showing that he had beaten Scott.
On his way back, Scott and three companions met a blizzard and froze to death while waiting for it to finish. The people who found him eight months later also found his records and diary, which he had written to the day he died.
People of the Antarctic live in there for a short time to learn more about Antarctica, so most of the people who live there are scientists. They study the weather, animals, glaciers, and the air around our earth. Some scientists drill into the ice to find out about the weather long ago. People who work in the Antarctic must be very careful, because a blizzard can start any time and any where. When they go far away from their shelter, they must always take lots of food just in case.
Today people explore Antarctica using snowmobiles, which are faster than dogs and can pull heavier loads. Many come to Antarctica just for a short visit, as a trip. There are companies in South America that have vacations to Antarctica, so people pay to take a ship down there. Some people may just take their own boats.
Related pages [change]
- "Antarctica - The World Factbook". United States Central Intelligence Agency. 2007-03-08. https://www.cia.gov/library/publications/the-world-factbook/geos/ay.html#People. Retrieved 2007-03-14.
- "National Geophysical Data Center". National Satellite, Data, and Information Service. http://www.ngdc.noaa.gov/mgg/image/relief_slides2.html. Retrieved 9 June 2006. Choose the South Pole view.
- Campbell I.B. and Claridge G.G.C. 1987. Antarctia:soils, weathering, processes and environment p4 Elsevier, Amsterdam, Netherlands. ISBN 0-444-42784-8
- C. Alan Joyce (2007-01-18). "The World at a glance: surprising facts". The World Almanac. http://www.worldalmanac.com/blog/2007/01/the_world_at_a_glance_surprisi.html. Retrieved 2009-02-07.
- "Mystery of Antarctica's 15-million year-old lake". The Daily Galaxy. 2007-12-04. http://www.dailygalaxy.com/my_weblog/2007/12/secret-life-o-1.html. Retrieved 2009-07-01.
- Amos, Jonathan 2011. Gamburtsev 'ghost mountains mystery solved'. BBC News Science & Environment 
- Fausto Ferraccioli et al. 2011. East Antarctic rifting triggers uplift of the Gamburtsev Mountains. Nature 479 388-392. 
- Jonathan Amos 2011. Antarctic's hidden world revealed. BBC News Science/Environment. 
- Buskey, Theresa. Alan Christopherson, M.S.. ed (in English). History and Geography. L.I.F.E.P.A.C.. Alpha Omega Publications, Inc. ISBN 978-1-58095-156-2.
- The Mariners' Museum. "Age of Exploration: John Cook". http://www.mariner.org/educationalad/ageofex/cook.php. Retrieved 12 February 2006.
- James Cook, The Journals, edited by Philip Edwards. Penguin Books, 2003, p. 250.
- U.S. Antarctic Program External Panel of the National Science Foundation. "Antarctica—Past and Present" (PDF). http://www.nsf.gov/pubs/1997/antpanel/antpan05.pdf. Retrieved 6 February 2006.
- Guy G. Guthridge. "Nathaniel Brown Palmer, 1799-1877". NASA, U.S. Government. http://quest.arc.nasa.gov/antarctica/background/NSF/palmer.html. Retrieved 2006-02-06.
- "Palmer Station". Archived from the original on 2006-02-10. http://web.archive.org/web/20060210005949/http://arcane.ucsd.edu/pstat.html. Retrieved 2008-03-03.
- "An Antarctic Time Line: 1519–1959". south-pole.com. http://www.south-pole.com/p0000052.htm. Retrieved 2006-02-12.
- "Antarctic Explorers Timeline: Early 1800s". http://ku-prism.org/polarscientist/timeline/antarcticexplorers1800.html. Retrieved 2006-02-12.
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