Antarctica

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Antarctica

Image:Flag of Antarctica.svg

Image:LocationAntarctica.png

Area 14,000,000 km² (280,000 km² ice-free, 13,720,000 km² ice-covered)
Population ~1000 (none permanent)
Government None, governed by the Antarctic Treaty System
Partial Territorial claims Template:ARG
Template:AUS
Template:CHL
Template:FRA
Template:NZL
Template:NOR
Template:GBR
Internet TLD .aq
Calling Code +672

Antarctica is the continent at the extreme southern latitudes of the Earth, containing the South Pole. It is surrounded by the Southern Ocean and divided in two by the Transantarctic Mountains. On average, it is the coldest, driest, windiest, and highest of all the continents. With 98% of it covered in ice, Antarctica, at 14 million km², is the third-smallest continent (after Europe and Australia). Because there is little precipitation, the entire continent is technically a desert and is thus the largest in the world. There are no permanent human residents and only cold-adapted plants and animals survive there, including penguins, fur seals, mosses, lichens, and many types of algae. The name "Antarctica" comes from the Greek ανταρκτικός (antarktikos), meaning "opposite the Arctic."<ref>{{cite web

| author=Liddell, Henry George and Scott, Robert
| work=A Greek-English Lexicon
| publisher=Clarendon Press
| title=Template:Polytonic
| year=1940
| url=http://www.perseus.tufts.edu/cgi-bin/ptext?doc=Perseus:text:1999.04.0057:entry=%239514
| accessdate=12 February
| accessyear=2006

}}</ref>

Although myths and speculation about a Terra Australis ("Southern Land") go back to antiquity, the first sighting of the continent is commonly accepted to have occurred in 1821 by the Russian expedition of Mikhail Lazarev and Fabian Gottlieb von Bellingshausen. The continent was largely neglected in the 19th century because of its hostile environment, lack of resources, and isolated location.

Antarctica is not under the political sovereignty of any nation, although seven countries (Argentina, Australia, Chile, France, New Zealand, Norway and the United Kingdom) maintain territorial claims. Most other countries do not recognize these claims, and the claims of Argentina, Chile and the United Kingdom all overlap. Also, the United States and Russia reserve the right to territorial claims. Human activity on the continent is regulated by the Antarctic Treaty, which was signed in 1959 by 12 countries and prohibits any military activity, supports scientific research, and protects the continent's ecozone. Ongoing experiments are conducted by more than 4000 scientists of many different nationalities and with many different research interests.

Contents

Exploration

Image:Orpheus-Gate-2.jpg Image:Port-Lockroy.jpg Template:Main

Belief in the existence of a Terra Australis—a vast continent located in the far south of the globe to "balance" the northern lands of Europe, Asia and north Africa—had existed since Ptolemy suggested the idea in order to preserve symmetry of landmass in the world. Depictions of a large southern landmass were common in maps such as the early 16th century Turkish Piri Reis map. Even in the late 17th century, after explorers had found that South America and Australia were not part of "Antarctica," geographers believed that the continent was much larger than its actual size. However, as Antarctica has no indigenous population, it was mostly unknown and unexplored until the 19th century.

European maps continued to show this land until Captain James Cook's ships, Resolution and Adventure, crossed the Antarctic Circle on January 17, 1773 and again in 1774.<ref>{{cite web

| author=The Mariners' Museum
| title=Age of Exploration: John Cook
| url=http://www.mariner.org/educationalad/ageofex/cook.php
| accessdate=12 February
| accessyear=2006

}}</ref>

The first confirmed sighting of Antarctica can be narrowed down to the crews of ships captained by two individuals. According to various organizations (the National Science Foundation,<ref>{{cite web

| author=U.S. Antarctic Program External Panel of the National Science Foundation
| title=Antarctica—Past and Present
| url=http://www.nsf.gov/pubs/1997/antpanel/antpan05.pdf
| accessdate=6 February
| accessyear=2006

}}</ref> NASA,<ref>NASA, U.S. Government Palmer biography Retrieved February 6 2006.</ref> the University of California, San Diego,<ref>University of California, San Diego Palmer Station Retrieved February 5 2006.</ref> and other sources<ref>South-Pole An Antarctic Time Line : 1519 - 1959. Retrieved February 12 2006</ref><ref>Polar Radar for Ice Sheet Measurements. Antarctic Explorers Timeline: Early 1800s. Retrieved February 12 2006.</ref>), ships captained by three men sighted Antarctica in 1820: Fabian von Bellingshausen (a captain in the Russian Imperial Navy), Edward Bransfield (a captain in the British Navy), and Nathaniel Palmer (an American sealer out of Stonington, Connecticut). Von Bellingshausen supposedly saw Antarctica on January 27, 1820, three days before Bransfield sighted land, and ten months before Palmer did so in November 1820. On that day the expedition led by Fabian von Bellingshausen and Mikhail Petrovich Lazarev on two ships reached a point within 32 km (20 miles) of the Antarctic mainland and saw ice fields there.

In 1841, explorer James Clark Ross sailed through what is now known as the Ross Sea and discovered Ross Island. He sailed along a huge wall of ice that was later named the Ross Ice Shelf. Mount Erebus and Mount Terror are named after two ships from his expedition: HMS Erebus and HMS Terror.<ref>James Clark Ross South-Pole - Exploring Antarctica. Retrieved February 12 2006.</ref> Image:Shackleton expedition.jpg During an expedition led by Ernest Shackleton, parties led by T. W. Edgeworth David became the first to climb Mount Erebus and to reach the South Magnetic Pole.<ref>Australian Antarctic Division. Tannatt William Edgeworth David Retrieved February 7 2006.</ref> On December 14, 1911, a party led by Norwegian polar explorer Roald Amundsen from the ship Fram became the first to reach the South Pole, using a route from the Bay of Whales and up the Axel Heiberg Glacier. This area previously colonized by the famous "Claus Expedition"<ref>South-pole Roald Amundsen South-Pole - Exploring Antarctica. Retrieved February 9 2006.</ref>

Richard Evelyn Byrd led several voyages to the Antarctic by plane in the 1930s and 1940s. He is credited with implementing mechanized land transport and conducting extensive geological and biological research.<ref>70South. Richard Byrd. Retrieved February 12 2006.</ref> However, it was not until October 31, 1956 that anyone set foot on the South Pole again; on that day a U.S. Navy group led by Rear Admiral George Dufek successfully landed an aircraft there.<ref>U.S. Navy. Dates in American Naval History: October. Retrieved February 12 2006.</ref>


Geography

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Image:Antarctica satellite orthographic.jpg Image:Maritime-Antarctica.jpg The continent of Antarctica is located mostly south of the Antarctic Circle, surrounded by the Southern Ocean. It is the southernmost land mass, comprising more than 14 million km², making it the fifth-largest continent. The coastline measures 17 968 km (11,160 miles) and is mostly characterized by ice formations, as the following table shows:

Coastal types around Antarctica
(from Drewry, 1983)
Type Frequency
Ice shelf (floating ice front) 44%
Ice walls (resting on ground) 38%
Ice stream/outlet glacier (ice front or ice wall) 13%
Rock 5%
Total 100%


Physically, it is divided in two by the Transantarctic Mountains close to the neck between the Ross Sea and the Weddell Sea. The portion west of the Weddell Sea and east of the Ross Sea is called Western Antarctica and the remainder Eastern Antarctica, because they correspond roughly to the Eastern and Western Hemispheres relative to the Greenwich meridian.

About 98% of Antarctica is covered by the Antarctic ice sheet. The ice sheet is, on average, 2.5 kilometers (1.6 miles) thick. Despite its zero precipitation in some areas, the continent has approximately 90% of the world's fresh water, in the form of ice.<ref name="cia">Central Intelligence Agency Factbook Retrieved February 6 2006.</ref> Western Antarctica is covered by the West Antarctic Ice Sheet. The West Antarctic Ice Sheet has been of recent concern because of the possibility, real though small, of its collapse. If it does break down, ocean levels would rise by several meters in a relatively short period of time. Several Antarctic ice streams, which account to about 10% of the ice sheet, flows to one of the many Antarctic ice shelves.

Image:Mt erebus.jpg Vinson Massif, the highest peak in Antarctica at 4892 meters (16,050 feet), is located in the Ellsworth Mountains. Although Antarctica is home to many volcanoes, only Deception Island and Mt. Erebus are active. Mount Erebus, located in Ross Island, is the southernmost active volcano. Minor eruptions are frequent and lava flow has been observed in recent years. Other dormant volcanoes may potentially be active.<ref>British Antarctic Survey. Volcanoes. Retrieved February 13 2006.</ref> In 2004, an underwater volcano was found in the Antarctic Peninsula by American and Canadian researchers. Recent evidence shows this unnamed volcano may be active.<ref>National Science Foundation. Scientists Discover Undersea Volcano Off Antarctica. Retrieved February 13 2006</ref>

Antarctica is home to more than 70 lakes that lie thousands of metres under the surface of the continental ice sheet. Lake Vostok, discovered beneath Russia's Vostok Station in 1996, is the largest of these subglacial lakes. It is believed that the lake has been sealed off for 35 million years. There is some evidence that Vostok's waters may contain microbial life. Due to the lake's similarity to Europa, a moon of Jupiter, confirming that life can survive in Lake Vostok might strengthen the argument for the possibility of life on Europa.<ref>National Science Foundation Lake Vostok Retrieved February 6 2006.</ref><ref>NASA Lake Vostok may teach us about Europa Retrieved February 4 2006.</ref>

Template:Seealso

Geology

Geological history and paleontology

More than 170 million years ago, Antarctica was part of the supercontinent Gondwana. Over time Gondwana broke apart and Antarctica as we know it today was formed around 25 million years ago.

Paleozoic era (540-250 Mya)

Image:Survey-Route.jpg During the Cambrian period Gondwana had a mild climate. West Antarctica was partially in the northern hemisphere, and during this period large amounts of sandstones, limestones and shales were deposited. East Antarctica was at the equator, where sea-floor invertebrates and trilobites flourished in the tropical seas. By the start of the Devonian period (416 Mya) Gondwana was in more southern latitudes and the climate was cooler, though fossils of land plants are known from this time. Sand and silts were laid down in what is now the Ellsworth, Horlick and Pensacola Mountains. Glaciation began at the end of the Devonian period (360 Mya) as Gondwana became centered around the South Pole and the climate cooled, though flora remained. During the Permian period the plant life became dominated by fern-like plants such as Glossopteris, which grew in swamps. Over time these swamps became deposits of coal in the Transantarctic Mountains. Towards the end of the Permian period continued warming led to a dry, hot climate over much of Gondwana.<ref name="Stonehouse">{{cite book

| editor = Stonehouse, B. (ed.)
| title = Encyclopedia of Antarctica and the Southern Oceans
| year = 2002
| month = June
| publisher = John Wiley & Sons
| id = ISBN 0-471-98665-8

}}</ref>

Mesozoic era (250-65 Mya)

As a result of continued warming, the polar ice caps melted and much of Gondwana became a desert. In East Antarctica the seed fern became established, and large amounts of sandstones and shales were laid down at this time. The Antarctic Peninsula began to form during the Jurassic period (206-146 Mya), and islands gradually rose out of the ocean. Ginkgo trees and cycads were plentiful during this period, as were reptiles such as Lystrosaurus. In West Antarctica conifer forests dominated through the entire Cretaceous period (146-65 Mya), though Southern beech began to take over at the end of this period. Ammonites were common in the seas around Antarctica, and dinosaurs were also present, though only two Antarctic dinosaur species (Cryolophosaurus and Antarctopelta) have been described to date. It was during this period that Gondwana began to break up.

Gondwana breakup (160-23 Mya)

Africa separated from Antarctica around 160 Mya, followed by India in the early Cretaceous (about 125 Mya). About 65 Mya, Antarctica (then connected to Australia) still had a tropical to subtropical climate, complete with a marsupial fauna. About 40 Mya Australia-New Guinea separated from Antarctica and the first ice began to appear. Around 23 Mya, the Drake Passage between Antarctica and South America resulted in the Antarctic Circumpolar Current. The ice spread, replacing the forests that then covered the continent. Since about 15 Mya, the continent has been mostly covered with ice.<ref name="Trewby">{{cite book

| editor = Trewby, Mary (ed.)
| title = Antarctica: An Encyclopedia from Abbott Ice Shelf to Zooplankton
| year = 2002
| month = September
| publisher = Firefly Books
| id = ISBN 1-55297-590-8

}}</ref>

Geology of present-day Antarctica

Image:AntarcticaRockSurface.jpg The geological study of Antarctica has been greatly hindered by the fact that nearly all of the continent is permanently covered with a thick layer of ice. However, newer techniques such as remote sensing have begun to reveal the structures beneath the ice.

West Antarctica closely resembles the Andes of South America.<ref name="Stonehouse" /> The Antarctic Peninsula was formed by uplift and metamorphism of sea-bed sediments during the late Paleozoic and the early Mesozoic eras. This sediment uplift was accompanied by igneous intrusions and volcanism. The most common rocks in West Antarctica are andesite and rhyolite volcanics formed during the Jurassic Period. There is also evidence of volcanic activity, even after the ice sheet had formed, in Marie Byrd Land and Alexander Island. The only anomalous area of West Antarctica is the Ellsworth Mountains region, where the stratigraphy is more similar to the eastern part of the continent.

East Antarctica is geologically very old, dating from the Precambrian era, with some rocks formed more than 3 billion years ago. It is composed of a metamorphic and igneous platform which is the basis of the continental shield. On top of this base are various more modern rocks, such as sandstones, limestones, coal and shales laid down during the Devonian and Jurassic periods to form the Transantarctic Mountains. In coastal areas some faulting has occurred, for example in the Shackleton Range and in Victoria Land.

The main mineral resource known on the continent is coal.<ref name="Trewby" /> It was first recorded near the Beardmore Glacier by Frank Wild on the Nimrod Expedition, and now low-grade coal is known across many parts of the Transantarctic Mountains. The Prince Charles Mountains contain significant deposits of iron ore. The most valuable resources of Antarctica lie offshore, namely the oil and natural gas fields found in the Ross Sea in 1973. Exploitation of all mineral resources is banned until 2048 by the Protocol on Environmental Protection to the Antarctic Treaty.


Climate

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Image:Lake Fryxell.jpg Antarctica is the coldest place on Earth. It has little precipitation, with the South Pole getting almost none, making it a frozen desert. Temperatures reach a minimum of between −85 °C and −90 °C (−121 °F and −130 °F) in the winter and about 30 degrees higher in the summer months. Sunburn is often a health issue as the snow surface reflects over 90% of the sunlight falling on it.<ref name="weather">British Antarctic Survey. Weather in the Antarctic Retrieved February 9 2006.</ref> Eastern Antarctica is colder than its western counterpart because of its higher elevation. Weather fronts rarely penetrate far into the continent, leaving the center cold and dry. Despite the lack of precipitation over the central portion of the continent, ice there lasts for extended time periods. Heavy snowfalls are not uncommon on the coastal portion of the continent, where snowfalls of up to 1.22 meters (48 inches) in 48 hours have been recorded. Image:Friesland-St-Boris.jpg At the edge of the continent, strong katabatic winds off the polar plateau often blow at storm force. In the interior, however, wind speeds are often moderate. During summer more solar radiation reaches the surface at the South Pole than is received at the equator in an equivalent period.<ref name="cia" />

Antarctica is colder than the Arctic for two reasons. First, much of the continent is more than 3 km above sea level, and temperature decreases with elevation. 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.

Depending on the latitude, long periods of constant darkness or constant sunlight mean that climates familiar to humans are not generally present on the continent. The aurora australis, commonly known as the southern lights, is a glow observed in the night sky near the South Pole. 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 sundog, a frequent atmospheric optical phenomenon, is a bright "spot" beside the true sun.<ref name="weather" />

Image:Iceberg09.jpg

Population

Template:Seealso Although Antarctica has no permanent residents, a number of governments maintain permanent research stations throughout the continent. The population of persons doing and supporting science on the continent and its nearby islands varies from approximately 4000 in summer to 1000 in winter. Many of the stations are staffed around the year.

Image:Antarctic researchers.jpg The first settlers of Antarctica (the world region situated south of the Antarctic Convergence) were English and American sealers who used to spend a year or more on South Georgia, from 1786 onward. During the whaling era, which lasted until 1966, the population of that island varied from over 1000 in the summer (over 2000 in some years) to some 200 in the winter. Most of the whalers were Norwegian, with an increasing proportion of Britons. The settlements included Grytviken, Leith Harbour, King Edward Point, Stromness, Husvik, Prince Olav Harbour, Ocean Harbour and Godthul. Managers and other senior officers of the whaling stations often lived together with their families. Among them was the founder of Grytviken, Captain Carl Anton Larsen, a prominent Norwegian whaler and explorer who adopted British citizenship in 1910. His family included his wife, three daughters and two sons.

Image:Fieldwork-Melnik.jpgThe first child born in the southern polar region was Norwegian girl Solveig Gunbjörg Jacobsen, born in Grytviken on 8 October 1913, and her birth registered by the resident British Magistrate of South Georgia. She was a daughter of Fridthjof Jacobsen, the assistant manager of the whaling station, and of Klara Olette Jacobsen. Jacobsen arrived on the island in 1904 to become the manager of Grytviken, serving from 1914 to 1921; two of his children were born on the island<ref>R.K. Headland, The Island of South Georgia, Cambridge University Press, 1984.</ref>.

Emilio Marcos Palma was the first person born on the Antarctic mainland, at Base Esperanza in 1978, his parents being sent there along with seven other families by the Argentinean government to determine if family life was suitable in the continent. In 1986 Juan Pablo Camacho was born at the Presidente Eduardo Frei Montalva Base, becoming the first Chilean born in Antarctica. Several bases are now home to families with children attending schools at the station.<ref>The Antarctic Sun Questions and answers Retrieved February 9 2006.</ref>

Flora and fauna

Template:Seealso

Flora

Image:Lichen squamulose.jpg Template:Main The climate of Antarctica does not allow much vegetation to exist. A combination of freezing temperatures, poor soil quality, lack of moisture and sunlight limit the chances for plants to exist. As a result, plant life is limited to mostly mosses and liverworts. The autotrophic community is made up of mostly protists. The flora of the continent largely consists of lichens, bryophytes, algae, and fungi. Growth generally occurs in the summer, and only for a few weeks at most.

There are more than 200 species of lichens and approximately 50 species of bryophytes, such as mosses. Seven hundred species of algae exist, most of which are phytoplankton. Multicolored snow algae and diatoms are especially abundant in the coastal regions during the summer. There are two species of flowering plants found in the Antarctic Peninsula: Antarctic hair grass and Antarctic pearlwort.<ref>Australian Antarctic Division Antarctic Wildlife Retrieved February 5 2006.</ref>

Fauna

Land fauna is completely invertebrate. Such invertebrate life includes microscopic mites, lice, nematodes, and springtails. The midge, just 12 mm in size, is the largest land animal in Antarctica (other than humans). The Snow Petrel is one of only three birds that breed exclusively in Antarctica and have been seen at the South Pole.

Image:Emperor penguin.jpg

A variety of marine animals exists, and they rely, directly or indirectly, on the phytoplankton. Antarctic sea life includes penguins, blue whales, and fur seals. More specifically, the Emperor penguin is the only penguin that breeds during the winter in Antarctica. The Adélie Penguin breeds further south than any other penguin. The Rockhopper penguin has distinctive feathers around the eyes; one could call them elaborate eyelashes. King penguins, Chinstrap penguins and Gentoo Penguins also breed in the Antarctic. The Antarctic fur seal was very heavily hunted in the 18th and 19th centuries for its pelt by sealers from the United States and the United Kingdom. The Weddell Seal, a "true seal", is named after Sir James Weddell, commander of British sealing expeditions in the Weddell Sea. Antarctic krill, which congregates in large schools, is the keystone species of the ecosystem of the Southern Ocean, and is an important food organism for whales, seals, leopard seals, fur seals, squid, icefish, penguins, albatrosses and many other birds.<ref>Creatures of Antarctica Retrieved February 6 2006.</ref>

The passing of the Antarctic Conservation Act brought several restrictions to the continent. The introduction of alien plants or animals can bring a criminal penalty, as can the extraction of any indigenous species. The overfishing of krill, which plays a large role in the Antarctic ecosystem, led officials to enact regulations on fishing. The Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR), a treaty that came into force in 1980, requires that regulations managing all Southern Ocean fisheries consider potential effects on the entire Antarctic ecosystem.<ref name="cia" /> Despite these new acts, unregulated and illegal fishing, particularly of Patagonian toothfish, remains a serious problem. The illegal fishing of toothfish has been increasing, with estimates of 32,000 tonnes in 2000.<ref>BBC News. Toothfish at risk from illegal catches. Retrieved February 11 2006.</ref><ref>Australian Antarctic Division. Toothfish. Retrieved February 11 2006.</ref>

Politics

Image:Logistic-Support.jpg As the only uninhabited continent, Antarctica has no government and belongs to no country. Various countries claim areas of it, but most other countries do not recognize those claims. The area between 90°W and 150°W is the only part of Antarctica not claimed by any country.<ref name="cia" />

Since 1959, claims on Antarctica have been suspended and the continent is considered politically neutral. Its status is regulated by the 1959 Antarctic Treaty and other related agreements, collectively called the Antarctic Treaty System. For the purposes of the Treaty System, Antarctica is defined as all land and ice shelves south of 60°S. The treaty was signed by 12 countries, including the Soviet Union and the United States. It set aside Antarctica as a scientific preserve, established freedom of scientific investigation, environmental protection, and banned military activity on that continent. This was the first arms control agreement established during the Cold War.

The Antarctic Treaty prohibits any military activity in Antarctica, such as the establishment of military bases and fortifications, the carrying out of military manoeuvres, or the testing of any type of weapon. Military personnel or equipment are only permitted for scientific research or for any other peaceful purposes.<ref>Scientific Committee on Antarctic Research. Antarctic Treaty Retrieved February 9 2006.</ref> The only documented large-scale land military maneuver was "Operación 90", undertaken ten years before the Antarctic Treaty by the Argentinian military.<ref>Antarctica Institute of Argentina. Argentina in Antarctica Retrieved February 9 2006.</ref>

The United States military issues the Antarctica Service Medal to military members or civilians who perform research duty on the Antarctica continent. The medal includes a "wintered over" bar issued to those who remain on the continent for two complete six-month seasons.<ref>U.S. Navy Antarctic Service Medal Retrieved February 9 2006.</ref>

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Antarctic territories

Image:Antarctica.jpg Template:Main

Flag Territory Claimant Claim limits Date
Image:Flag of France.svg Adelie Land France Template:Coor dm Antarctic to Template:Coor dm Antarctic 1924
Image:Flag of Argentina.svg Argentine Antarctica Argentina Template:Coor d Antarctic to Template:Coor d Antarctic 1943
Image:Flag of Australia.svg Australian Antarctic Territory Australia Template:Coor d Antarctic to Template:Coor dm Antarctic and Template:Coor dm Antarctic to Template:Coor dm Antarctic 1933
Image:Flag of Chile.svg Antártica Chilena Province Chile Template:Coor d Antarctic to Template:Coor d Antarctic 1940
Image:Flag of the United Kingdom.svg British Antarctic Territory United Kingdom Template:Coor d Antarctic to Template:Coor d Antarctic 1908
Image:Flag of Norway.svg Dronning Maud Land Norway Template:Coor dm Antarctic to Template:Coor d Antarctic 1939
Peter I Island Template:Coor dm 1929
Image:Flag of New Zealand.svg Ross Dependency New Zealand Template:Coor d Antarctic to Template:Coor d Antarctic 1923

The Argentinean, British and Chilean claims all overlap.

Germany also maintained a claim to Antarctica, known as New Swabia, between 1939 and 1945. It was situated from Template:Coor d Antarctic to Template:Coor d Antarctic, overlapping Norway's claim.

Economy

Template:Main Image:Antarctic cod.jpg

Although coal, hydrocarbons, iron ore, platinum, copper, chromium, nickel, gold and other minerals have been found, they exist in quantities too small to exploit. The 1991 Protocol on Environmental Protection to the Antarctic Treaty prevents such struggle for resources. In 1998 a compromise agreement was reached to add a 50-year ban on mining until the year 2048, further limiting economic development and exploitation. The primary agricultural activity is the capture and offshore trading of fish. Antarctic fisheries in 2000-01 reported landing 112,934 tonnes.<ref name="cia"><ref>Santa Barbara City College Biological Sciences Importance of Antarctica Retrieved February 5 2006.</ref>

Image:Antarctic-Postal-Services.jpg Small-scale tourism has existed since 1957 and is currently self-regulated by International Association of Antarctic Tour Operators (IAATO). However, not all vessels have joined the IAATO. Several ships transport people into Antarctica for specific scenic locations. A total of 27,950 tourists visited in the 2004-05 Antarctic summer with nearly all of them coming from commercial ships. The number is predicted to increase to over 80,000 by 2010.<ref>International association of Antarctica Tour Operators. Tourism Statistics. Retrieved March 4 2006.</ref><ref>Politics of Antarctica Retrieved February 5 2006.</ref> There has been some recent concern over the adverse effect done to the environment and ecosystem by this influx of visitors. A call for stricter regulations for ships and a tourism quota have been made by environmentalists and scientists alike.<ref>Telegraph UK. Tourism threatens Antarctic. Retrieved March 4 2006.</ref> Antarctic sight seeing flights (which did not land) operated out of Australia and New Zealand until the fatal crash of Air New Zealand Flight 901 in 1979 on Mount Erebus.

Research

Image:Amundsen-Scott marsstation ray h edit.jpg Template:Seealso

Each year, scientists from 27 different nations conduct experiments not reproducible in any other place in the world but the Antarctic. In the summer more than 4000 scientists operate research stations; this number decreases to nearly 1000 in the winter.<ref name="cia" /> The McMurdo Station is capable of housing more than 1000 scientists, visitors, and tourists.

Researchers include biologists, geologists, oceanographers, physicists, astronomers, glaciologists, and meteorologists. Geologists tend to study plate tectonics in the Arctic region, meteorites from the outer space, and resources from the breakup of the supercontinent Gondwanaland. Glaciologists in Antarctica are concerned with the study of the history and dynamics of floating ice, seasonal snow, glaciers, and ice sheets. Biologists, in addition to examining the wildlife, are interested in how harsh temperatures and the presence of people affect adaptation and survival strategies in a wide variety of organisms. Medical physicians have made discoveries concerning the spreading of viruses and the body's response to extreme seasonal temperatures. Astrophysicists in Amundsen-Scott South Pole Station are able to study the celestial dome and cosmic microwave background radiation because of the ozone hole and the location's dry, cold environment. Antarctic ice serves as both the shield and the detection medium for the largest neutrino telescope in the world, built 2 km below Amundsen-Scott station. <ref>Antarctic Connection Science in Antarctica Retrieved February 4 2006.</ref>

Since the 1970s an important focus of study has been the ozone layer in the atmosphere above Antarctica. In 1985 3 British Scientests working on data they had gathered at Halley Station on the Brunt Ice Shelf discovered the exitence of a hole in this layer. In 1998 NASA satellite data showed that the Antarctic ozone hole was the largest on record, covering 27 million square kilometers. In 2002 significant areas of ice shelves disintegrated in response to regional warming.<ref name="cia" />

Image:ALH84001.jpg

Meteorites from Antarctica are a relatively recent resource for study of the material formed early in the solar system; most are thought to come from asteroids, but some may have originated on larger planets. The first meteorites found in Antarctica were in 1912. In 1969 the Japanese discovered nine meteorites in Antarctica. Most of these meteorites have fallen onto the ice sheet in the last million years. Motion of the ice sheet tends to concentrate the meteorites at blocking locations such as mountain ranges, with wind erosion bringing them to the surface after centuries beneath accumulated snowfall. Compared with meteorites collected in more temperate regions on Earth, the Antarctic meteorites are relatively well preserved.<ref name="meteorite">NASA Meteorites from Antarctica Retrieved February 9 2006.</ref>

This large collection of meteorites allows a better understanding of the abundance of meteorite types in the solar system and how meteorites relate to asteroids and comets. New types of meteorites and rare meteorites have been found. Among these meteorites are pieces blasted off the moon, and probably Mars, by impacts. These specimens, particularly ALH84001 discovered by ANSMET, are at the center of the controversy about possible evidence of microbial life on Mars. Because meteorites in space absorb and record cosmic radiation, the time elapsed since the meteorite hit the Earth can be determined from laboratory studies. The elapsed time since fall, or terrestrial residence age, of a meteorite represents more information that might be useful in environmental studies of Antarctic ice sheets.<ref name="meteorite" />

See also

Footnotes

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External links

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Commercial

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