Antarctica facts for kids
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| Area |
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| Population | 0 (about 1000 people living temporarily) |
| Dependencies |
8
• Australian Antarctic Territory
• Ross Dependency • Queen Maud Land • Peter I Island • Adélie Land • British Antarctic Territory • Chilean Antarctic Territory • Argentine Antarctica |
| Time zones | None |
| Internet TLD | .aq |
Antarctica is the Earth's southernmost continent. It is on the South Pole. It's 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 science stations in Antarctica. Only plants and animals that can live in 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.
Contents
Geography
Positioned asymmetrically around the South Pole and largely south of the Antarctic Circle (one of the five major circles of latitude that mark maps of the world), Antarctica is surrounded by the Southern Ocean. Rivers exist in Antarctica; the longest is the Onyx. Antarctica covers more than 14.2 million km2 (5,500,000 sq mi), almost double the area of Australia, making it the fifth-largest continent. Its coastline is almost 18,000 km (11,200 mi) long: as of 1983[update], of the four coastal types, 44% of the coast is floating ice in the form of an ice shelf, 38% consists of ice walls that rest on rock, 13% is ice streams or the edge of glaciers, and the remaining 5% is exposed rock.
The lakes that lie at the base of the continental ice sheet occur mainly in the McMurdo Dry Valleys or various oases. Lake Vostok, discovered beneath Russia's Vostok Station, is the largest subglacial lake globally and one of the largest lakes in the world. It was once believed that the lake had been sealed off for millions of years, but scientists now estimate its water is replaced by the slow melting and freezing of ice caps every 13,000 years. During the summer, the ice at the edges of the lakes can melt, and liquid moats temporarily form. Antarctica has both saline and freshwater lakes.
Antarctica is divided into West Antarctica and East Antarctica by the Transantarctic Mountains, which stretch from Victoria Land to the Ross Sea. The vast majority of Antarctica is covered by the Antarctic ice sheet, which averages 1.9 km (1.2 mi) in thickness. The ice sheet extends to all but a few oases, which, with the exception of the McMurdo Dry Valleys, are located in coastal areas. Several Antarctic ice streams flow to one of the many Antarctic ice shelves, a process described by ice-sheet dynamics.
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East Antarctica comprises Coats Land, Queen Maud Land, Enderby Land, Mac. Robertson Land, Wilkes Land, and Victoria Land. All but a small portion of the region lies within the Eastern Hemisphere. East Antarctica is largely covered by the East Antarctic Ice Sheet. There are numerous islands surrounding Antarctica, most of which are volcanic and very young by geological standards. The most prominent exceptions to this are the islands of the Kerguelen Plateau, the earliest of which formed around 40 Ma.
Vinson Massif, in the Ellsworth Mountains, is the highest peak in Antarctica at 4,892 m (16,050 ft). Mount Erebus on Ross Island is the world's southernmost active volcano and erupts around 10 times each day. Ash from eruptions has been found 300 kilometres (190 mi) from the volcanic crater. There is evidence of a large number of volcanoes under the ice, which could pose a risk to the ice sheet if activity levels were to rise. The ice dome known as Dome Argus in East Antarctica is the highest Antarctic ice feature, at 4,091 metres (13,422 ft). It is one of the world's coldest and driest places—temperatures there may reach as low as −90 °C (−130 °F), and the annual precipitation is 1–3 cm (0.39–1.18 in).
Climate
Antarctica is the coldest of Earth's continents. It used to be ice-free until about 34 million years ago, when it became covered with ice. The coldest natural air temperature ever recorded on Earth was −89.2 °C (−128.6 °F) at the Soviet (now Russian) Vostok Station in Antarctica on 21 July 1983.
Antarctica is a frozen desert with little rain; the South Pole itself receives less than 10 cm (4 in) per year, on average. Temperatures reach a minimum of between −80 °C (−112 °F) and −89.2 °C (−128.6 °F) in the interior in winter and reach a maximum of between 5 °C (41 °F) and 15 °C (59 °F) near the coast in summer.
Sunburn is often a health issue as the snow surface reflects almost all of the ultraviolet light falling on it. Given the latitude, long periods of constant darkness or constant sunlight create climates unfamiliar to human beings in much of the rest of the world.
East Antarctica is colder than its western counterpart because of its higher elevation. Weather fronts rarely penetrate far into the continent, leaving the centre cold and dry. Despite the lack of rain over the central portion of the continent, ice there lasts for extended periods. Heavy snowfalls are common on the coastal portion of the continent, where snowfalls of up to 1.22 metres (48 in) in 48 hours have been recorded.
At the edge of the continent, strong katabatic winds off the polar plateau often blow at storm force. In the interior, wind speeds are typically moderate. During clear days in summer, more solar radiation reaches the surface at the South Pole than at the equator because of the 24 hours of sunlight each day at the Pole.
Antarctica is colder than the Arctic for three reasons. First, much of the continent is more than 3,000 m (9,800 ft) above sea level, and temperature decreases with elevation in the troposphere. Second, the Arctic Ocean covers the north polar zone: the ocean's relative warmth is transferred through the icepack and prevents temperatures in the Arctic regions from reaching the extremes typical of the land surface of Antarctica. Third, the Earth is at aphelion in July (i.e., the Earth is farthest from the Sun in the Antarctic winter), and the Earth is at perihelion in January (i.e., the Earth is closest to the Sun in the Antarctic summer). The orbital distance contributes to a colder Antarctic winter (and a warmer Antarctic summer) but the first two effects have more impact.
The aurora australis, commonly known as the southern lights, is a glow observed in the night sky near the South Pole created by the plasma-full solar winds that pass by the Earth. Another unique spectacle is diamond dust, a ground-level cloud composed of tiny ice crystals. It generally forms under otherwise clear or nearly clear skies, so people sometimes also refer to it as clear-sky precipitation. A sun dog, a frequent atmospheric optical phenomenon, is a bright "spot" beside the true sun.
Life in Antarctica
Plants
Few land plants grow in Antarctica. 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. However, moss, lichen and algae do grow. The most important organisms in Antarctica are the plankton which grow in the ocean.
Animals
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. Whalers have hunted whales for hundreds of years, for meat and blubber. Nowadays most whaling is done in the Antarctic area.
Penguins only live south of the equator. Several different kinds live in and around Antarctica. The biggest ones can stand nearly 4 feet (1.2m) tall and can weigh almost 100 pounds (40 kg). The smallest kinds are only about one foot (30 cm) tall. Penguins are large birds that swim very well but cannot fly. They have black backs and wings with white fronts. 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
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, ships captained by three men saw Antarctica in 1820. The three men were Fabian 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). The first recorded landing on mainland Antarctica was by the American sealer John Davis. He landed on 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 serious exploration of the Antarctic land was the Nimrod Expedition led by Ernest Shackleton in 1907–09. They were the first to climb Mount Erebus and to reach the South Magnetic Pole. Shackleton himself and three other members of his expedition made several firsts in December 1908 – February 1909. They were the first humans to cross the Ross Ice Shelf, and the Transantarctic Mountain Range (via the Beardmore Glacier). They were the first to set foot on the South Polar Plateau.
Robert Falcon Scott, the most well known of all of the explorers, wanted to be the first man to reach the South Pole. At the same time, another team from Norway lead by Roald Amundsen started. They both raced each other to the South Pole, but in the end Amundsen won because he had made a good use of his sleigh dogs. Scott had used ponies and motor sleds, but when he got to the South Pole he found a 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.
Climate change and global warming are showing effects in Antarctica, particularly the Antarctic Peninsula.
People
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. Most are in national science stations on the coast. Some bases are far from the sea, for example at the South pole. They study the weather, animals, glaciers, and the earth's atmosphere. Some scientists drill ice cores to find out about the weather long ago. People who work in the Antarctic must be 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 go there in a ship. Some people may just take their own boats.
Related pages
Images for kids
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A speculative representation of Antarctica labelled as 'Terra Australis Incognita' on Jan Janssonius's Zeekaart van het Zuidpoolgebied (1657), Het Scheepvaartmuseum
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Glossopteris sp. leaf from the Permian of Antarctica
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Pine Island Glacier, photographed in November 2011
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Image of the largest hole in the ozone layer recorded, in September 2006
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Emperor penguins with juveniles
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Orange lichen (Caloplaca) growing on the Yalour Islands, Wilhelm Archipelago
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Refuse littering the shoreline at Bellingshausen Station on King George Island, photographed in 1992
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A whale in the Southern Ocean Whale Sanctuary
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Adélie Land, depicted by Jules Dumont d'Urville in his Voyage au Pôle Sud (1846)
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The Nimrod Expedition of 1907–1909 (left to right): Frank Wild, Ernest Shackleton, Eric Marshall and Jameson Adams
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The "ceremonial" South Pole, at Amundsen–Scott Station
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The cruise ship Silver Cloud in Wilhelmina Bay
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An aerial view of McMurdo Station, the largest research station in Antarctica
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See also
In Spanish: Antártida para niños
