Introduction
The southernmost continent in the world, Antarctica surrounds the South Pole. Its name means “opposite to the Arctic” (the Arctic is the region around the North Pole). Antarctica has no permanent human population.
Geography
An ice sheet covers nearly all of Antarctica. At its thickest point the ice sheet is 15,670 feet (4,776 meters) deep. Its average elevation is estimated at between 7,000 and 8,000 feet (2,100 to 2,400 meters) above sea level. The continent covers about 5.4 million square miles (14 million square kilometers). Its ice sheet contains 90 percent of the world's ice and 70 percent of the world's fresh water.
The continent has two unequal parts. The larger is generally known as East Antarctica while the smaller is West Antarctica. The Transantarctic Mountains separate East and West Antarctica. Other mountain ranges include the Prince Charles Mountains and smaller ranges near the coasts. Mountains with only their peaks showing through the ice, known as nunataks, are found in some areas. Several active volcanoes are located near the Antarctic Peninsula and in the Transantarctic Mountains.
West Antarctica includes the Antarctic Peninsula, an 800-mile (1,300-kilometer) extension of the continent that juts northward towards the southern tip of South America. The Antarctic Peninsula has many mountain ranges. It includes the Vinson Massif. At 16,066 feet (4,897 meters) above sea level, the Vinson Massif is the highest peak in Antarctica.
Surrounding Antarctica are the southern parts of the Pacific, the Atlantic, and the Indian oceans. Around the coast of the continent, glaciers continually “calve,” or break off, icebergs into the sea. These icebergs float north until they reach warm water, break into pieces, and melt. In some places, however, the floating glaciers stay attached to the land and continue to grow until they become ice shelves. The Ross Ice Shelf is one example. It averages 1,000 feet (300 meters) thick.
About 2 percent of Antarctica is ice-free. These unusual land areas, called oases, are mostly found near the coast. They include the dry valleys of southern Victoria Land and the Bunger Oasis in Wilkes Land.
Antarctica does not have 24-hour periods divided into days and nights. At the South Pole the sun rises on about September 21 and moves in a circular path upward until December 21. Then it circles downward until it sets on about March 22. This “day,” or summer, is six months long. From March 22 until September 21 the South Pole is dark, and Antarctica has its “night,” or winter.
Climate
Antarctica is the coldest continent. The world's record low temperature (-128.6° F ; -89.2° C) was recorded in this region. The average annual temperature in the interiors is -70° F (-57° C). The coast is, however, warmer. Along the Antarctic Peninsula temperatures can rise up to 59° F (15° C).
Antarctica's interior is one of the world's major cold deserts. Rainfall on the continent averages only 1 to 2 inches (2.5 to 5 centimeters) a year.
Plants and animals
The extremely cold climate of Antarctica has kept the continent almost empty of life. The exceptions in terms of plants are mosses and liverworts that grow in some ice-free areas along the coast and two species of flowering plants that grow on the peninsula.
Native land animals are limited to certain species of arthropods, or insect-like animals. Nearly all the species discovered on the continent are found only in Antarctica. These include springtails, midges, and mites.
About 45 species of birds live on the continent. The emperor and the Adélie penguins are found in large numbers around the entire coastline. Gentoo and chinstrap penguins occupy the Antarctic Peninsula coasts and some islands. Four species of seals breed in the Antarctic. They are the Weddell seal, the crabeater seal, the leopard seal, and the Ross seal. Other Antarctic species include the fur seal and the huge elephant seal.
Fishes limited to the Antarctic include the Antarctic cod and the icefish. The Antarctic waters are also home to the killer whale, sperm whale, and rare bottle-nosed, or beaked, whale, and the pygmy right whale. Seven species of baleen, or whalebone, whales also inhabit the waters.
The most important single member of the food chain in the Antarctic is the krill. It looks like a small shrimp and exists in huge numbers; some biologists think that there may be 5 billion or more of krills. They eat small marine plants and animals and in turn are eaten in great numbers by squid, birds, seals, and whales.
Economy
Little economic development has taken place on the icy continent. Whalers and sealers first arrived in 1778, and seal hunters began catching Antarctic seals for oil and fur in the early 1790s.
Whaling began in Antarctic waters in the 19th century but declined by the 1960s. In 1994 the 40-nation International Whaling Commission permanently banned whaling there.
The Soviet Union began commercial fishing operations in 1967. Today fleets of other nations, mainly Japan and Norway, also fish in these waters.
Such minerals such as antimony, chromium, copper, gold, lead, tin, uranium, and zinc have been discovered in small quantities. Large mineral deposits of iron ore and coal have been found in the Prince Charles and Transantarctic Mountains, respectively.
Commercial tourist visits to Antarctica began in the 1950s. By the end of the century, tourism had increased to about 13,000 visitors per year.
International relations
Because it has never had permanent human settlements, Antarctica has had an unusual political history. Seven nations have claimed sections of territory centering on the South Pole. Three of the claimed areas overlap on the Antarctic Peninsula. Some parts of the continent are unclaimed. Most other nations do not recognize the claims.
The international claims were fueled by scientific interest in the continent. Widespread scientific investigation of Antarctica began during the International Geophysical Year (IGY) in 1957–58. During the IGY many nations cooperated in an effort to explore different areas of the world. In Antarctica it led to the establishment of year-round research stations. To continue the spirit of cooperation after the IGY, 12 nations signed the Antarctic Treaty in 1959. Argentina, Australia, Belgium, Chile, France, Japan, New Zealand, Norway, South Africa, the United Kingdom, the United States, and the Soviet Union agreed, among other concerns, to reserve the continent for peaceful purposes, encourage cooperation in science, call for environmental protection, and allow inspections of each country's installations. By 2000, 44 nations had signed the Antarctic Treaty, and every year hundreds of researchers travel to Antarctica to conduct experiments.
History
The first expedition to come close to Antarctica took place in 1772–75. English navigator James Cook sailed around the continent and came within 100 miles (160 kilometers) of it.
The first recorded landing on Antarctica was on Cape Adare in 1895. The first group to spend a winter on the continent did so in a ship that was caught in ice at Cape Adare during the period from March 1898 to March 1899.
Englishmen Robert F. Scott and Ernest Henry Shackleton led three expeditions between 1901 and 1913. They pioneered routes into the interior of Antarctica, and the research they conducted provided a base for present-day scientific programs. On December 14, 1911, Roald Amundsen of Norway became the first person to reach the South Pole.
Many other expeditions followed. In 1990 a six-man international expedition led by American Will Steger completed a 221-day trek across Antarctica, from west to east using dogsleds. It was the longest dogsled trek as well as the first time that the crossing was made without the help of motorized vehicles.
