Antarctica

Antarctica

Overview



| style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top;" | 14000000 sqkm
280000 sqkm
13720000 sqkm
|-
! style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top; text-align: left;" | Population
(permanent)
(non-permanent)
| style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top;" | 7th 
0
approx.
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| style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top;" | 14000000 sqkm
280000 sqkm
13720000 sqkm
|-
! style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top; text-align: left;" | Population
(permanent)
(non-permanent)
| style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top;" | 7th 
0
approx. 1,000
|-
! style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top; text-align: left;" | Dependencies
| style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top;" |
|-
! style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top; text-align: left;" | Official Territorial claims
| style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top;" | Antarctic Treaty System
Antarctic Treaty System
The Antarctic Treaty and related agreements, collectively called the Antarctic Treaty System or ATS, regulate international relations with respect to Antarctica, Earth's only continent without a native human population. For the purposes of the treaty system, Antarctica is defined as all of the land...


|-
! style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top; text-align: left;" | Reserved the right to make claims
| style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top;" |
|-
! style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top; text-align: left;" | Time Zones
| style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top;" | None
UTC-03:00 (Graham Land
Graham Land
Graham Land is that portion of the Antarctic Peninsula which lies north of a line joining Cape Jeremy and Cape Agassiz. This description of Graham Land is consistent with the 1964 agreement between the British Antarctic Place-names Committee and the US Advisory Committee on Antarctic Names, in...

 only)

|-
! style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top; text-align: left;" | Internet Top-level domain
Top-level domain
A top-level domain is one of the domains at the highest level in the hierarchical Domain Name System of the Internet. The top-level domain names are installed in the root zone of the name space. For all domains in lower levels, it is the last part of the domain name, that is, the last label of a...


| style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top;" | .aq
.aq
.aq is the Internet country code top-level domain for Antarctica. It is reserved for organizations that conduct work in Antarctica or promote the Antarctic and Southern Ocean regions...


|-
! style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top; text-align: left;" | Calling Code
| style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top;" | Dependent on the parent country of each base. (One such is +672.)
|}

Antarctica is Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

's southernmost continent
Continent
A continent is one of several very large landmasses on Earth. They are generally identified by convention rather than any strict criteria, with seven regions commonly regarded as continents—they are : Asia, Africa, North America, South America, Antarctica, Europe, and Australia.Plate tectonics is...

, encapsulating the South Pole
South Pole
The South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is one of the two points where the Earth's axis of rotation intersects its surface. It is the southernmost point on the surface of the Earth and lies on the opposite side of the Earth from the North Pole...

. It is situated in the Antarctic
Antarctic
The Antarctic is the region around the Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica and the ice shelves, waters and island territories in the Southern Ocean situated south of the Antarctic Convergence...

 region of the Southern Hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...

, almost entirely south of the Antarctic Circle
Antarctic Circle
The Antarctic Circle is one of the five major circles of latitude that mark maps of the Earth. For 2011, it is the parallel of latitude that runs south of the Equator.-Description:...

, and is surrounded by the Southern Ocean
Southern Ocean
The Southern Ocean comprises the southernmost waters of the World Ocean, generally taken to be south of 60°S latitude and encircling Antarctica. It is usually regarded as the fourth-largest of the five principal oceanic divisions...

. At 14.0 million km2 (5.4 million sq mi), it is the fifth-largest continent in area after Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

, Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

, North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

. For comparison, Antarctica is nearly twice the size of Australia. About 98% of Antarctica is covered by ice
Ice
Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...

 that averages at least 1.6 kilometre (0.994196378639691 mi) in thickness.

Antarctica, on average, is the coldest, driest, and windiest continent, and has the highest average elevation
Elevation
The elevation of a geographic location is its height above a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface ....

 of all the continents. Antarctica is considered a desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...

, with annual precipitation
Precipitation (meteorology)
In meteorology, precipitation In meteorology, precipitation In meteorology, precipitation (also known as one of the classes of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation...

 of only 200 mm (8 inches) along the coast and far less inland. The temperature in Antarctica has reached −89 °C (−129 °F). There are no permanent human residents, but anywhere from 1,000 to 5,000 people reside throughout the year at the research stations scattered across the continent. Only cold-adapted organisms survive there, including many types of algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

, animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...

s (for example mite
Mite
Mites, along with ticks, are small arthropods belonging to the subclass Acari and the class Arachnida. The scientific discipline devoted to the study of ticks and mites is called acarology.-Diversity and systematics:...

s, nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...

s, penguin
Penguin
Penguins are a group of aquatic, flightless birds living almost exclusively in the southern hemisphere, especially in Antarctica. Highly adapted for life in the water, penguins have countershaded dark and white plumage, and their wings have become flippers...

s, seals
Pinniped
Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...

 and tardigrade
Tardigrade
Tardigrades form the phylum Tardigrada, part of the superphylum Ecdysozoa. They are microscopic, water-dwelling, segmented animals with eight legs. Tardigrades were first described by Johann August Ephraim Goeze in 1773...

s), bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

, fungi
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...

, plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

s, and protist
Protist
Protists are a diverse group of eukaryotic microorganisms. Historically, protists were treated as the kingdom Protista, which includes mostly unicellular organisms that do not fit into the other kingdoms, but this group is contested in modern taxonomy...

a. Vegetation where it occurs is tundra
Tundra
In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...

.

Although myths and speculation about a Terra Australis
Terra Australis
Terra Australis, Terra Australis Ignota or Terra Australis Incognita was a hypothesized continent appearing on European maps from the 15th to the 18th century...

("Southern Land") date back to antiquity, the first confirmed sighting of the continent is commonly accepted to have occurred in 1820 by the Russian expedition of Fabian Gottlieb von Bellingshausen
Fabian Gottlieb von Bellingshausen
Fabian Gottlieb Thaddeus von Bellingshausen was an officer in the Imperial Russian Navy, cartographer and explorer, who ultimately rose to the rank of Admiral...

 and Mikhail Lazarev. The continent, however, remained largely neglected for the rest of the 19th century because of its hostile environment, lack of resources, and isolation.
The Antarctic Treaty
Antarctic Treaty System
The Antarctic Treaty and related agreements, collectively called the Antarctic Treaty System or ATS, regulate international relations with respect to Antarctica, Earth's only continent without a native human population. For the purposes of the treaty system, Antarctica is defined as all of the land...

 was signed in 1959 by 12 countries; to date, 47 countries have signed the treaty. The treaty prohibits military activities and mineral mining, prohibits nuclear explosions and nuclear power, supports scientific research, and protects the continent's ecozone
Ecozone
An ecozone is the broadest biogeographic division of the Earth's land surface, based on distributional patterns of terrestrial organisms.Ecozones delineate large areas of the Earth's surface within which organisms have been evolving in relative isolation over long periods of time, separated from...

. Ongoing experiments are conducted by more than 4,000 scientists of multiple nationalities.

Etymology


The first formal use of the name "Antarctica" as a continental name in the 1890s is attributed to the Scottish cartographer
Cartography
Cartography is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively.The fundamental problems of traditional cartography are to:*Set the map's...

 John George Bartholomew
John George Bartholomew
John George Bartholomew FRSE was a British cartographer and geographer. As a holder of a royal warrant, he used the title "Cartographer to the King"; for this reason he was sometimes known by the epithet "the Prince of Cartography".Bartholomew's longest lasting legacy is arguably naming the...

. The name Antarctica is the romanized version of the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 compound word ἀνταρκτική (antarktiké), feminine of ἀνταρκτικός (antarktikos), meaning "opposite to the Arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

", "opposite to the north".

History


Belief in the existence of a Terra Australis – a vast continent in the far south of the globe to "balance" the northern lands of Europe, Asia and North Africa
North Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...

 – has existed since the times of Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

 (1st century AD), who suggested the idea to preserve the symmetry
Symmetry
Symmetry generally conveys two primary meanings. The first is an imprecise sense of harmonious or aesthetically pleasing proportionality and balance; such that it reflects beauty or perfection...

 of all known landmass
Landmass
A landmass is a contiguous area of land surrounded by ocean. Although it may be most often written as one word to distinguish it from the usage "land mass"—the measure of land area—it is also used as two words.Landmasses include:*supercontinents...

es in the world. Even in the late 17th century, after explorers had found that South America and Australia were not part of the fabled "Antarctica", geographers believed that the continent was much larger than its actual size.

European maps continued to show this hypothetical land until Captain James Cook
James Cook
Captain James Cook, FRS, RN was a British explorer, navigator and cartographer who ultimately rose to the rank of captain in the Royal Navy...

's ships, HMS Resolution
HMS Resolution (Cook)
HMS Resolution was a sloop of the Royal Navy, and the ship in which Captain James Cook made his second and third voyages of exploration in the Pacific...

 and Adventure
HMS Adventure (1771)
HMS Adventure was a barque of the Royal Navy that sailed with Resolution on James Cook's second expedition to the Pacific in 1772–1775. She was the first ship to circumnavigate the globe from west to east....

, crossed the Antarctic Circle on 17 January 1773, in December 1773 and again in January 1774. Cook came within about 75 miles (120.7 km) of the Antarctic coast before retreating in the face of field ice in January 1773. The first confirmed sighting of Antarctica can be narrowed down to the crews of ships captained by three individuals. According to various organizations (the National Science Foundation
National Science Foundation
The National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...

, NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

, the University of California, San Diego
University of California, San Diego
The University of California, San Diego, commonly known as UCSD or UC San Diego, is a public research university located in the La Jolla neighborhood of San Diego, California, United States...

, and other sources), ships captained by three men sighted Antarctica in 1820: Fabian Gottlieb von Bellingshausen
Fabian Gottlieb von Bellingshausen
Fabian Gottlieb Thaddeus von Bellingshausen was an officer in the Imperial Russian Navy, cartographer and explorer, who ultimately rose to the rank of Admiral...

 (an Estonia
Estonia
Estonia , officially the Republic of Estonia , is a state in the Baltic region of Northern Europe. It is bordered to the north by the Gulf of Finland, to the west by the Baltic Sea, to the south by Latvia , and to the east by Lake Peipsi and the Russian Federation . Across the Baltic Sea lies...

n-born captain in the Imperial Russian Navy
Imperial Russian Navy
The Imperial Russian Navy refers to the Tsarist fleets prior to the February Revolution.-First Romanovs:Under Tsar Mikhail Feodorovich, construction of the first three-masted ship, actually built within Russia, was completed in 1636. It was built in Balakhna by Danish shipbuilders from Holstein...

), Edward Bransfield
Edward Bransfield
Edward Bransfield was a master of the British Royal Navy and considered the discoverer of the continent of Antarctica.-Early life:...

 (an Irish
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

-born captain in the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

), and Nathaniel Palmer
Nathaniel Palmer
Nathaniel Brown Palmer was an American seal hunter, explorer, sailing captain, and ship designer. He was born in Stonington, Connecticut.-Sealing career and Antarctic exploration:...

 (an American sealer
Seal hunting
Seal hunting, or sealing, is the personal or commercial hunting of seals. The hunt is currently practiced in five countries: Canada, where most of the world's seal hunting takes place, Namibia, the Danish region of Greenland, Norway and Russia...

 out of Stonington, Connecticut
Stonington, Connecticut
The Town of Stonington is located in New London County, Connecticut, in the state's southeastern corner. It includes the borough of Stonington, the villages of Pawcatuck, Lords Point, Wequetequock, the eastern halves of the villages of Mystic and Old Mystic...

). Von Bellingshausen saw Antarctica on 27 January 1820, three days before Bransfield sighted land, and ten months before Palmer did so in November 1820. On that day the two-ship expedition led by Von Bellingshausen and Mikhail Lazarev reached a point within 32 km (19.9 mi) of the Antarctic mainland and saw ice fields there. The first documented landing on mainland Antarctica was by the American sealer John Davis
John Davis (sealer)
Captain John Davis was a seal hunter from Connecticut, USA who captained men who may have been the first to have set foot on Antarctica on 7 February 1821 shortly after the first sightings of the new continent by Fabian von Bellingshausen, Mikhail Petrovich Lazarev, Edward Bransfield and Nathaniel...

 in West Antarctica
West Antarctica
West Antarctica, or Lesser Antarctica, one of the two major regions of Antarctica, is the part of the continent that lies within the Western Hemisphere including the Antarctic Peninsula.-Location and description:...

 on 7 February 1821, although some historians dispute this claim.

In December 1839, as part of the United States Exploring Expedition
United States Exploring Expedition
The United States Exploring Expedition was an exploring and surveying expedition of the Pacific Ocean and surrounding lands conducted by the United States from 1838 to 1842. The original appointed commanding officer was Commodore Thomas ap Catesby Jones. The voyage was authorized by Congress in...

 of 1838–42 conducted by the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 (sometimes called the "Ex. Ex.", or "the Wilkes Expedition"), an expedition sailed from Sydney, Australia, into the Antarctic Ocean, as it was then known, and reported the discovery "of an Antarctic continent west of the Balleny Islands
Balleny Islands
The Balleny Islands are a series of uninhabited islands in the Southern Ocean extending from 66°15' to 67°35'S and 162°30' to 165°00'E. The group extends for about in a northwest-southeast direction. The islands are heavily glaciated and are of volcanic origin. Glaciers project from their slopes...

". That part of Antarctica was later named "Wilkes Land
Wilkes Land
Wilkes Land is a large district of land in eastern Antarctica, formally claimed by Australia as part of the Australian Antarctic Territory, though the validity of this claim has been placed for the period of the operation of the Antarctic Treaty, to which Australia is a signatory...

", a name it maintains to this day.


Explorer James Clark Ross
James Clark Ross
Sir James Clark Ross , was a British naval officer and explorer. He explored the Arctic with his uncle Sir John Ross and Sir William Parry, and later led his own expedition to Antarctica.-Arctic explorer:...

 passed through what is now known as the Ross Sea
Ross Sea
The Ross Sea is a deep bay of the Southern Ocean in Antarctica between Victoria Land and Marie Byrd Land.-Description:The Ross Sea was discovered by James Ross in 1841. In the west of the Ross Sea is Ross Island with the Mt. Erebus volcano, in the east Roosevelt Island. The southern part is covered...

 and discovered Ross Island
Ross Island
Ross Island is an island formed by four volcanoes in the Ross Sea near the continent of Antarctica, off the coast of Victoria Land in McMurdo Sound.-Geography:...

 (both of which were named for him) in 1841. He sailed along a huge wall of ice that was later named the Ross Ice Shelf
Ross Ice Shelf
The Ross Ice Shelf is the largest ice shelf of Antarctica . It is several hundred metres thick. The nearly vertical ice front to the open sea is more than 600 km long, and between 15 and 50 metres high above the water surface...

. Mount Erebus
Mount Erebus
Mount Erebus in Antarctica is the southernmost historically active volcano on Earth, the second highest volcano in Antarctica , and the 6th highest ultra mountain on an island. With a summit elevation of , it is located on Ross Island, which is also home to three inactive volcanoes, notably Mount...

 and Mount Terror
Mount Terror (Antarctica)
Mount Terror is a large shield volcano that forms the eastern part of Ross Island, Antarctica. It has numerous cinder cones and domes on the flanks of the shield and is mostly under snow and ice. It is the second largest of the four volcanoes which make up Ross Island and is somewhat overshadowed...

 are named after two ships from his expedition: HMS Erebus
HMS Erebus (1826)
HMS Erebus was a Hecla-class bomb vessel designed by Sir Henry Peake and constructed by the Royal Navy in Pembroke dockyard, Wales in 1826. The vessel was named after the dark region in Hades of Greek mythology called Erebus...

 and Terror
HMS Terror (1813)
HMS Terror was a bomb vessel designed by Sir Henry Peake and constructed by the Royal Navy in the Davy shipyard in Topsham, Devon. The ship, variously listed as being of either 326 or 340 tons, carried two mortars, one and one .-War service:...

. Mercator Cooper
Mercator Cooper
Mercator Cooper was a ship's captain who is credited with the first formal American visit to Tokyo, Japan and the first formal landing on the mainland East Antarctica....

 landed in East Antarctica
East Antarctica
East Antarctica, also called Greater Antarctica, constitutes the majority of the Antarctic continent, lying on the Indian Ocean side of the Transantarctic Mountains...

 on 26 January 1853.

During the Nimrod Expedition
Nimrod Expedition
The British Antarctic Expedition 1907–09, otherwise known as the Nimrod Expedition, was the first of three expeditions to the Antarctic led by Ernest Shackleton. Its main target, among a range of geographical and scientific objectives, was to be first to the South Pole...

 led by Ernest Shackleton
Ernest Shackleton
Sir Ernest Henry Shackleton, CVO, OBE was a notable explorer from County Kildare, Ireland, who was one of the principal figures of the period known as the Heroic Age of Antarctic Exploration...

 in 1907, parties led by Edgeworth David
Edgeworth David
Sir Tannatt William Edgeworth David KBE, DSO, FRS, was a Welsh Australian geologist and Antarctic explorer. A household name in his lifetime, David's most significant achievements were discovering the major Hunter Valley coalfield in New South Wales and leading the first expedition to reach the...

 became the first to climb Mount Erebus and to reach the South Magnetic Pole
South Magnetic Pole
The Earth's South Magnetic Pole is the wandering point on the Earth's surface where the geomagnetic field lines are directed vertically upwards...

. Douglas Mawson
Douglas Mawson
Sir Douglas Mawson, OBE, FRS, FAA was an Australian geologist, Antarctic explorer and Academic. Along with Roald Amundsen, Robert Falcon Scott, and Ernest Shackleton, Mawson was a key expedition leader during the Heroic Age of Antarctic Exploration.-Early work:He was appointed geologist to an...

, who assumed the leadership of the Magnetic Pole party on their perilous return, went on to lead several expeditions until retiring in 1931. In addition, Shackleton himself and three other members of his expedition made several firsts in December 1908 – February 1909: they were the first humans to traverse the Ross Ice Shelf
Ross Ice Shelf
The Ross Ice Shelf is the largest ice shelf of Antarctica . It is several hundred metres thick. The nearly vertical ice front to the open sea is more than 600 km long, and between 15 and 50 metres high above the water surface...

, the first to traverse the Transantarctic Mountain Range (via the Beardmore Glacier
Beardmore Glacier
The Beardmore Glacier in Antarctica is one of the largest glaciers in the world, with a length exceeding 160 km . The glacier is one of the main passages from the Ross Ice Shelf through the Queen Alexandra and Commonwealth ranges of the Transantarctic Mountains to the Antarctic Plateau, and was one...

), and the first to set foot on the South Polar Plateau. An expedition led by Norwegian polar explorer Roald Amundsen
Amundsen's South Pole expedition
The first expedition to reach the geographic South Pole was led by the Norwegian explorer Roald Amundsen. He and four others arrived at the pole on 14 December 1911, five weeks ahead of a British party led by Robert Falcon Scott...

 from the ship Fram
Fram
Fram is a ship that was used in expeditions of the Arctic and Antarctic regions by the Norwegian explorers Fridtjof Nansen, Otto Sverdrup, Oscar Wisting, and Roald Amundsen between 1893 and 1912...

became the first to reach the geographic South Pole on 14 December 1911, using a route from the Bay of Whales
Bay of Whales
The Bay of Whales is a natural ice harbor, or iceport, indenting the front of Ross Ice Shelf just north of Roosevelt Island. It is the southernmost point of open ocean not only of the Ross Sea, but worldwide...

 and up the Axel Heiberg Glacier
Axel Heiberg Glacier
The Axel Heiberg Glacier is a valley glacier, long, descending from the high-elevations of the Antarctic Plateau into the Ross Ice Shelf between the Herbert Range and Mount Don Pedro Christophersen in the Queen Maud Mountains....

. One month later, the doomed Scott Expedition
Terra Nova Expedition
The Terra Nova Expedition , officially the British Antarctic Expedition 1910, was led by Robert Falcon Scott with the objective of being the first to reach the geographical South Pole. Scott and four companions attained the pole on 17 January 1912, to find that a Norwegian team led by Roald...

 reached the pole.

Richard E. Byrd led several voyages to the Antarctic by plane in the 1930s and 1940s. He is credited with implementing mechanized land transport on the continent
Transport in Antarctica
Transport in Antarctica has transformed from explorers crossing the isolated remote area of Antarctica by foot to a more open area due to human technologies enabling more convenient and faster transport, predominantly by air and water, as well as land....

 and conducting extensive geological and biological research. However, it was not until 31 October 1956 that anyone set foot on the South Pole again; on that day a U.S. Navy group led by Rear Admiral George J. Dufek
George J. Dufek
George John Dufek was an American naval officer, naval aviator, and Arctic expert. He served in World War II and the Korean War and in the 1940s and 1950s spent much of his career in the Antarctic, first with Admiral Byrd and later as supervisor of U.S. programs in the South Polar regions...

 successfully landed an aircraft there.

The first person to sail single-handed to Antarctica was the New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

er David Henry Lewis
David Henry Lewis
David Henry Lewis, DCNZM was a sailor, adventurer, doctor, and Polynesian scholar. He is best known for his studies on the traditional systems of navigation used by the Pacific Islanders...

, in a 10-meter steel sloop Ice Bird.

Geography


Centered asymmetrically around the South Pole
South Pole
The South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is one of the two points where the Earth's axis of rotation intersects its surface. It is the southernmost point on the surface of the Earth and lies on the opposite side of the Earth from the North Pole...

 and largely south of the Antarctic Circle, Antarctica is the southernmost continent and is surrounded by the Southern Ocean
Southern Ocean
The Southern Ocean comprises the southernmost waters of the World Ocean, generally taken to be south of 60°S latitude and encircling Antarctica. It is usually regarded as the fourth-largest of the five principal oceanic divisions...

; alternatively, it may be considered to be surrounded by the southern Pacific
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

, Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

, and Indian Oceans, or by the southern waters of the World Ocean
World Ocean
The World Ocean, world ocean, or global ocean, is the interconnected system of the Earth's oceanic waters, and comprises the bulk of the hydrosphere, covering almost 71% of the Earth's surface, with a total volume of 1.332 billion cubic kilometres.The unity and continuity of the World Ocean, with...

. It covers more than 14000000 km² (5,405,430.2 sq mi), making it the fifth-largest continent, about 1.3 times as large as Europe. The coastline measures 17968 km (11,165 mi) and is mostly characterized by ice formations, as the following table shows:
Coastal types around Antarctica
Type Frequency
Ice shelf
Ice shelf
An ice shelf is a thick, floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Ice shelves are only found in Antarctica, Greenland and Canada. The boundary between the floating ice shelf and the grounded ice that feeds it is called...

 (floating ice front)
44%
Ice walls (resting on ground) 38%
Ice stream/outlet glacier (ice front or ice wall) 13%
Rock 5%
Total 100%


Antarctica is divided in two by the Transantarctic Mountains
Transantarctic Mountains
The three largest mountain ranges on the Antarctic continent are the Transantarctic Mountains , the West Antarctica Ranges, and the East Antarctica Ranges. The Transantarctic Mountains compose a mountain range in Antarctica which extend, with some interruptions, across the continent from Cape Adare...

 close to the neck between the Ross Sea and the Weddell Sea
Weddell Sea
The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha Coast, Queen Maud Land. To the east of Cape Norvegia is...

. The portion west of the Weddell Sea and east of the Ross Sea is called West Antarctica and the remainder East Antarctica, because they roughly correspond to the Western and Eastern Hemispheres relative to the Greenwich meridian.

About 98% of Antarctica is covered by the Antarctic ice sheet
Antarctic ice sheet
The Antarctic ice sheet is one of the two polar ice caps of the Earth. It covers about 98% of the Antarctic continent and is the largest single mass of ice on Earth. It covers an area of almost 14 million square km and contains 30 million cubic km of ice...

, a sheet of ice
Ice sheet
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² , thus also known as continental glacier...

 averaging at least 1.6 km (0.994196378639691 mi) thick. The continent has about 90% of the world's ice (and thereby about 70% of the world's fresh water
Fresh Water
Fresh Water is the debut album by Australian rock and blues singer Alison McCallum, released in 1972. Rare for an Australian artist at the time, it came in a gatefold sleeve...

). If all of this ice were melted, sea levels would rise about 60 m (196.9 ft). In most of the interior of the continent, precipitation
Precipitation (meteorology)
In meteorology, precipitation In meteorology, precipitation In meteorology, precipitation (also known as one of the classes of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation...

 is very low, down to 20 mm (0.78740157480315 in) per year; in a few "blue ice
Blue ice (glacial)
Blue ice occurs when snow falls on a glacier, is compressed, and becomes part of a glacier that winds its way toward a body of water . During its travels, air bubbles that are trapped in the ice are squeezed out, and the size of the ice crystals increases, making it clear...

" areas precipitation is lower than mass loss by sublimation and so the local mass balance is negative. In the dry valleys
McMurdo Dry Valleys
The McMurdo Dry Valleys are a row of snow-free valleys in Antarctica located within Victoria Land west of McMurdo Sound. The region is one of the world's most extreme deserts, and includes many interesting features including Lake Vida and the Onyx River, Antarctica's longest river.-Climate:The Dry...

 the same effect occurs over a rock base, leading to a desiccated landscape.

West Antarctica
West Antarctica
West Antarctica, or Lesser Antarctica, one of the two major regions of Antarctica, is the part of the continent that lies within the Western Hemisphere including the Antarctic Peninsula.-Location and description:...

 is covered by the West Antarctic Ice Sheet
West Antarctic Ice Sheet
The West Antarctic Ice Sheet is the segment of the continental ice sheet that covers West Antarctica, the portion of Antarctica on the side of the Transantarctic Mountains which lies in the Western Hemisphere. The WAIS is classified as a marine-based ice sheet, meaning that its bed lies well...

. The sheet has been of recent concern because of the real, if small, possibility of its collapse. If the sheet were to break down, ocean levels would rise by several metres in a relatively geologically short period of time, perhaps a matter of centuries. Several Antarctic ice stream
Ice stream
An ice stream is a region of an ice sheet that moves significantly faster than the surrounding ice. Ice streams are a type of glacier. They are significant features of the Antarctic where they account for 10% of the volume of the ice...

s, which account for about 10% of the ice sheet, flow
Ice sheet dynamics
Ice sheet dynamics describe the motion within large bodies of ice, such those currently on Greenland and Antarctica. Ice motion is dominated by the movement of glaciers, whose gravity-driven activity is controlled by two main variable factors: the temperature and strength of their bases...

 to one of the many Antarctic ice shelves.

East Antarctica lies on the Indian Ocean side of the Transantarctic Mountains
Transantarctic Mountains
The three largest mountain ranges on the Antarctic continent are the Transantarctic Mountains , the West Antarctica Ranges, and the East Antarctica Ranges. The Transantarctic Mountains compose a mountain range in Antarctica which extend, with some interruptions, across the continent from Cape Adare...

 and comprises Coats Land
Coats Land
Coats Land is a region in Antarctica which lies westward of Queen Maud Land and forms the eastern shore of the Weddell Sea, extending in a general northeast-southwest direction between 20º00´W and 36º00´W. The northeast part was discovered from the Scotia by William S. Bruce, leader of the Scottish...

, Queen Maud Land
Queen Maud Land
Queen Maud Land is a c. 2.7 million-square-kilometre region of Antarctica claimed as a dependent territory by Norway. The territory lies between 20° west and 45° east, between the British Antarctic Territory to the west and the Australian Antarctic Territory to the east. The latitudinal...

, Enderby Land
Enderby Land
Enderby Land is a projecting land mass of Antarctica, extending from Shinnan Glacier at to William Scoresby Bay at .Enderby Land was discovered in February 1831 by John Biscoe in the whaling brig Tula, and named after the Enderby Brothers of London, owners of the Tula, who encouraged their...

, Mac. Robertson Land
Mac. Robertson Land
Mac. Robertson Land is the portion of Antarctica lying southward of the coast between William Scoresby Bay and Cape Darnley. Mac. Robertson Land is located at . In the east, Mac. Robertson Land includes the Prince Charles Mountains. Mac...

, Wilkes Land
Wilkes Land
Wilkes Land is a large district of land in eastern Antarctica, formally claimed by Australia as part of the Australian Antarctic Territory, though the validity of this claim has been placed for the period of the operation of the Antarctic Treaty, to which Australia is a signatory...

 and Victoria Land
Victoria Land
Victoria Land is a region of Antarctica bounded on the east by the Ross Ice Shelf and the Ross Sea and on the west by Oates Land and Wilkes Land. It was discovered by Captain James Clark Ross in January 1841 and named after the UK's Queen Victoria...

. All but a small portion of this region lies within the Eastern Hemisphere
Eastern Hemisphere
The Eastern Hemisphere, also Eastern hemisphere or eastern hemisphere, is a geographical term for the half of the Earth that is east of the Prime Meridian and west of 180° longitude. It is also used to refer to Europe, Asia, Africa, and Australasia, vis-à-vis the Western Hemisphere, which includes...

. East Antarctica is largely covered by the East Antarctic Ice Sheet
East Antarctic Ice Sheet
The East Antarctic Ice Sheet is one of two large ice sheets in Antarctica, and the largest on the entire planet. The EAIS lies between 45° West and 168° East longitudinally....

.

Vinson Massif
Vinson Massif
Vinson Massif is the highest mountain of Antarctica, lying in the Sentinel Range of the Ellsworth Mountains, which stand above the Ronne Ice Shelf near the base of the Antarctic Peninsula. The massif is located about from the South Pole and is about long and wide. At the highest point is Mount...

, the highest peak in Antarctica at 4892 m (16,050 ft), is located in the Ellsworth Mountains
Ellsworth Mountains
The Ellsworth Mountains are the highest mountain ranges in Antarctica, forming a long and wide chain of mountains in a north to south configuration on the western margin of the Ronne Ice Shelf. They are bisected by Minnesota Glacier to form the northern Sentinel Range and the southern Heritage...

. Antarctica contains many other mountains, both on the main continent and the surrounding islands. Located on Ross Island
Ross Island
Ross Island is an island formed by four volcanoes in the Ross Sea near the continent of Antarctica, off the coast of Victoria Land in McMurdo Sound.-Geography:...

, Mount Erebus is the world's southernmost active volcano. Another well-known volcano is found on Deception Island, which is famous for a giant eruption in 1970. Minor eruptions are frequent and lava flow has been observed in recent years. Other dormant volcanoes may potentially be active. In 2004, an underwater volcano was found in the Antarctic Peninsula
Antarctic Peninsula
The Antarctic Peninsula is the northernmost part of the mainland of Antarctica. It extends from a line between Cape Adams and a point on the mainland south of Eklund Islands....

 by American and Canadian researchers. Recent evidence shows this unnamed volcano may be active.

Antarctica is home to more than 70 lakes that lie at the base of the continental ice sheet. Lake Vostok
Lake Vostok
Lake Vostok is the largest of more than 140 subglacial lakes found under the surface of Antarctica. The overlying ice provides a continuous paleoclimatic record of 400,000 years, although the lake water itself may have been isolated for 15 to 25 million years. The lake is named after the...

, discovered beneath Russia's Vostok Station
Vostok Station
Vostok Station was a Russian Antarctic research station. It was at the southern Pole of Cold, with the lowest reliably measured natural temperature on Earth of −89.2 °C . Research includes ice core drilling and magnetometry...

 in 1996, is the largest of these subglacial lake
Subglacial lake
A subglacial lake is a lake under a glacier, typically an ice cap or ice sheet. There are many such lakes, with Lake Vostok in Antarctica being by far the largest known at present.-Characteristics:...

s. It was once believed that the lake had been sealed off for 500,000 to one million years but a recent survey suggests that, every so often, there are large flows of water from one lake to another.

There is some evidence, in the form of ice core
Ice core
An ice core is a core sample that is typically removed from an ice sheet, most commonly from the polar ice caps of Antarctica, Greenland or from high mountain glaciers elsewhere. As the ice forms from the incremental build up of annual layers of snow, lower layers are older than upper, and an ice...

s drilled to about 400 m (1,312.3 ft) above the water line, that Lake Vostok's waters may contain microbial life
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...

. The frozen surface of the lake shares similarities with Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

's moon Europa
Europa (moon)
Europa Slightly smaller than Earth's Moon, Europa is primarily made of silicate rock and probably has an iron core. It has a tenuous atmosphere composed primarily of oxygen. Its surface is composed of ice and is one of the smoothest in the Solar System. This surface is striated by cracks and...

. If life is discovered in Lake Vostok, this would strengthen the argument for the possibility of life on Europa. On 7 February 2008, a NASA team embarked on a mission to Lake Untersee
Lake Untersee
Lake Untersee is the largest surface freshwater lake in the interior of the Gruber Mountains of central Queen Maud Land in East Antarctica. It is situated to the southwest of the Schirmacher Oasis. The lake is approximately long and wide, with a surface area of , and a maximum depth of...

, searching for extremophile
Extremophile
An extremophile is an organism that thrives in physically or geochemically extreme conditions that are detrimental to most life on Earth. In contrast, organisms that live in more moderate environments may be termed mesophiles or neutrophiles...

s in its highly alkaline waters. If found, these resilient creatures could further bolster the argument for extraterrestrial life in extremely cold, methane-rich environments.

Geological history and paleontology


More than 170 million years ago, Antarctica was part of the supercontinent
Supercontinent
In geology, a supercontinent is a landmass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a supercontinent today.-History:...

 Gondwana
Gondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...

. Over time, Gondwana gradually broke apart and Antarctica as we know it today was formed around 25 million years ago.

Paleozoic era (540–250 Ma)


During the Cambrian period
Cambrian
The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...

, Gondwana had a mild climate. West Antarctica was partially in the Northern Hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...

, and during this period large amounts of sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

s, limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

s and shale
Shale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...

s were deposited. East Antarctica was at the equator, where sea floor invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

s and trilobite
Trilobite
Trilobites are a well-known fossil group of extinct marine arthropods that form the class Trilobita. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period , and they flourished throughout the lower Paleozoic era before...

s flourished in the tropical seas. By the start of the Devonian period
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...

 (416 Ma), Gondwana was in more southern latitudes and the climate was cooler, though fossils of land plants are known from this time. Sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

 and silt
Silt
Silt is granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in a surface water body...

s were laid down in what is now the Ellsworth
Ellsworth Mountains
The Ellsworth Mountains are the highest mountain ranges in Antarctica, forming a long and wide chain of mountains in a north to south configuration on the western margin of the Ronne Ice Shelf. They are bisected by Minnesota Glacier to form the northern Sentinel Range and the southern Heritage...

, Horlick
Horlick Mountains
The Horlick Mountains are a mountain range in the Transantarctic Mountains of Antarctica, lying eastward of Reedy Glacier and including the Wisconsin Range, Long Hills and Ohio Range....

 and Pensacola Mountains
Pensacola Mountains
The Pensacola Mountains are a large group of mountain ranges and peaks in Antarctica, extending 450 km in a NE-SW direction, comprising the Argentina Range, Forrestal Range, Dufek Massif, Cordiner Peaks, Neptune Range, Patuxent Range, Rambo Nunataks and Pecora Escarpment...

. Glaciation began at the end of the Devonian period (360 Ma), as Gondwana became centered around the South Pole and the climate cooled, though flora
Antarctic flora
The Antarctic flora is a distinct community of vascular plants which evolved millions of years ago on the supercontinent of Gondwana, and is now found on several separate areas of the Southern Hemisphere, including southern South America, southernmost Africa, New Zealand, Australia and New Caledonia...

 remained. During the Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...

 period, the plant life became dominated by fern
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...

-like plants such as Glossopteris
Glossopteris
Glossopteris is the largest and best-known genus of the extinct order of seed ferns known as Glossopteridales ....

, which grew in swamps. Over time these swamps became deposits of coal in the Transantarctic Mountains
Transantarctic Mountains
The three largest mountain ranges on the Antarctic continent are the Transantarctic Mountains , the West Antarctica Ranges, and the East Antarctica Ranges. The Transantarctic Mountains compose a mountain range in Antarctica which extend, with some interruptions, across the continent from Cape Adare...

. Towards the end of the Permian period, continued warming led to a dry, hot climate over much of Gondwana.

Mesozoic era (250–65 Ma)



As a result of continued warming, the polar ice caps melted and much of Gondwana became a desert. In Eastern Antarctica, the seed fern became established, and large amounts of sandstone and shale were laid down at this time. Synapsid
Synapsid
Synapsids are a group of animals that includes mammals and everything more closely related to mammals than to other living amniotes. They are easily separated from other amniotes by having an opening low in the skull roof behind each eye, leaving a bony arch beneath each, accounting for their name...

s, commonly known as "mammal-like reptiles", were common in Antarctica during the Late Permian and Early Triassic
Early Triassic
The Early Triassic is the first of three epochs of the Triassic period of the geologic timescale. It spans the time between 251 ± 0.4 Ma and 245 ± 1.5 Ma . Rocks from this epoch are collectively known as the Lower Triassic, which is a unit in chronostratigraphy...

 and included forms such as Lystrosaurus
Lystrosaurus
Lystrosaurus was a genus of Late Permian and Early Triassic Period dicynodont therapsids, which lived around 250 million years ago in what is now Antarctica, India, and South Africa...

. The Antarctic Peninsula began to form during the Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 period (206–146 Ma), and islands gradually rose out of the ocean. Ginkgo
Ginkgo
Ginkgo , also spelled gingko and known as the Maidenhair Tree, is a unique species of tree with no close living relatives...

 trees and cycad
Cycad
Cycads are seed plants typically characterized by a stout and woody trunk with a crown of large, hard and stiff, evergreen leaves. They usually have pinnate leaves. The individual plants are either all male or all female . Cycads vary in size from having a trunk that is only a few centimeters...

s were plentiful during this period. In West Antarctica, coniferous forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...

s dominated through the entire Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 period (146–65 Ma), though Southern beech
Nothofagus
Nothofagus, also known as the southern beeches, is a genus of 35 species of trees and shrubs native to the temperate oceanic to tropical Southern Hemisphere in southern South America and Australasia...

 began to take over at the end of this period. Ammonite
Ammonite
Ammonite, as a zoological or paleontological term, refers to any member of the Ammonoidea an extinct subclass within the Molluscan class Cephalopoda which are more closely related to living coleoids Ammonite, as a zoological or paleontological term, refers to any member of the Ammonoidea an extinct...

s were common in the seas around Antarctica, and dinosaurs were also present, though only three Antarctic dinosaur genera
Genera
Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...

 (Cryolophosaurus
Cryolophosaurus
Cryolophosaurus was a large theropod dinosaur, with a crest on its head that looked like a Spanish comb. Due to the resemblance of this feature to Elvis Presley's pompadour haircut from the 1950s, this dinosaur was at one point informally known as "Elvisaurus".Cryolophosaurus was excavated from...

and Glacialisaurus
Glacialisaurus
Glacialisaurus is a genus of massospondylid sauropodomorph dinosaur. It lived during the Early Jurassic period in what is now central Transantarctic Mountains of Antarctica. It is known from the holotype FMNH PR1823, a partial hind limb and from the referred material FMNH PR1822, a left...

, from the Hanson Formation
Mount Kirkpatrick Formation
The Mount Kirkpatrick Formation is one of only two major dinosaur-bearing rock formations yet found on the continent of Antarctica; the other is the Santa Marta Formation from the Late Cretaceous...

, and Antarctopelta
Antarctopelta
Antarctopelta was a genus of ankylosaurian dinosaur with one known species, A. oliveroi, which lived in Antarctica during the Late Cretaceous Period. It was a medium-sized ankylosaur, reaching no more than 4 meters in length, and showed characteristics of two different families, making more...

) have been described to date. It was during this period that Gondwana began to break up.

Gondwanaland breakup (160–23 Ma)


The cooling of Antarctica occurred stepwise, as the continental spread changed the oceanic currents from longitudinal equator-to-pole temperature-equalizing currents to latitudinal currents that preserved and accentuated latitude temperature differences.

Africa separated from Antarctica around 160 Ma, followed by the Indian subcontinent
Indian subcontinent
The Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...

, in the early Cretaceous (about 125 Ma). About 65 Ma, Antarctica (then connected to Australia) still had a tropical to subtropical climate, complete with a marsupial
Marsupial
Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...

 fauna
Fauna
Fauna or faunæ is all of the animal life of any particular region or time. The corresponding term for plants is flora.Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess shale fauna"...

. About 40 Ma Australia-New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...

 separated from Antarctica, so that latitudinal currents could isolate Antarctica from Australia, and the first ice began to appear. During the Eocene-Oligocene extinction event
Eocene-Oligocene extinction event
The transition between the end of the Eocene and the beginning of the Oligocene, called the Grande Coupure in Europe, occurring 33.9 ± 0.1 Ma, is marked by large-scale extinction and floral and faunal turnover .Most of the affected organisms were marine or aquatic in nature...

 about 34 million years ago, CO2 levels have been found to be about 760 ppm and had been decreasing from earlier levels in the thousands of ppm. Around 23 Ma, the Drake Passage
Drake Passage
The Drake Passage or Mar de Hoces—Sea of Hoces—is the body of water between the southern tip of South America at Cape Horn, Chile and the South Shetland Islands of Antarctica...

 opened between Antarctica and South America, resulting in the Antarctic Circumpolar Current
Antarctic Circumpolar Current
The Antarctic Circumpolar Current is an ocean current that flows from west to east around Antarctica. An alternative name for the ACC is the West Wind Drift. The ACC is the dominant circulation feature of the Southern Ocean and, at approximately 125 Sverdrups, the largest ocean current...

 that completely isolated the continent. Models of the changes suggest that declining CO2 levels became more important. The ice began to spread, replacing the forests that then covered the continent. Since about 15 Ma, the continent has been mostly covered with ice, with the Antarctic ice cap reaching its present extension around 6 Ma.

Neogene Period (23–0.05 mya)


In 1986, Peter Webb and a team of paleontologists at Ohio State University
Ohio State University
The Ohio State University, commonly referred to as Ohio State, is a public research university located in Columbus, Ohio. It was originally founded in 1870 as a land-grant university and is currently the third largest university campus in the United States...

 discovered the remains of an extensive temperate forest that flourished 400 miles (643.7 km) from the South Pole 3 million years ago.

Geology of present-day Antarctica


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, new techniques such as remote sensing
Remote sensing
Remote sensing is the acquisition of information about an object or phenomenon, without making physical contact with the object. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth by means of propagated signals Remote sensing...

, ground-penetrating radar
Ground-penetrating radar
Ground-penetrating radar is a geophysical method that uses radar pulses to image the subsurface. This nondestructive method uses electromagnetic radiation in the microwave band of the radio spectrum, and detects the reflected signals from subsurface structures...

 and satellite imagery
Satellite imagery
Satellite imagery consists of photographs of Earth or other planets made by means of artificial satellites.- History :The first images from space were taken on sub-orbital flights. The U.S-launched V-2 flight on October 24, 1946 took one image every 1.5 seconds...

 have begun to reveal the structures beneath the ice.

Geologically, West Antarctica closely resembles the Andes
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...

 mountain range of South America. The Antarctic Peninsula
Antarctic Peninsula
The Antarctic Peninsula is the northernmost part of the mainland of Antarctica. It extends from a line between Cape Adams and a point on the mainland south of Eklund Islands....

 was formed by uplift and metamorphism
Metamorphism
Metamorphism is the solid-state recrystallization of pre-existing rocks due to changes in physical and chemical conditions, primarily heat, pressure, and the introduction of chemically active fluids. Mineralogical, chemical and crystallographic changes can occur during this process...

 of sea bed sediments during the late Paleozoic
Paleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...

 and the early Mesozoic
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...

 eras. This sediment uplift was accompanied by igneous intrusions and volcanism
Volcanism
Volcanism is the phenomenon connected with volcanoes and volcanic activity. It includes all phenomena resulting from and causing magma within the crust or mantle of a planet to rise through the crust and form volcanic rocks on the surface....

. The most common rocks in West Antarctica are andesite
Andesite
Andesite is an extrusive igneous, volcanic rock, of intermediate composition, with aphanitic to porphyritic texture. In a general sense, it is the intermediate type between basalt and dacite. The mineral assemblage is typically dominated by plagioclase plus pyroxene and/or hornblende. Magnetite,...

 and rhyolite
Rhyolite
This page is about a volcanic rock. For the ghost town see Rhyolite, Nevada, and for the satellite system, see Rhyolite/Aquacade.Rhyolite is an igneous, volcanic rock, of felsic composition . It may have any texture from glassy to aphanitic to porphyritic...

 volcanics formed during the Jurassic period. There is also evidence of volcanic activity, even after the ice sheet had formed, in Marie Byrd Land
Marie Byrd Land
Marie Byrd Land is the portion of West Antarctica lying east of the Ross Ice Shelf and the Ross Sea and south of the Pacific Ocean, extending eastward approximately to a line between the head of the Ross Ice Shelf and Eights Coast. It stretches between 158°W and 103°24'W...

 and Alexander Island
Alexander Island
Alexander Island or Alexander I Island or Alexander I Land or Alexander Land is the largest island of Antarctica, with an area of lying in the Bellingshausen Sea west of the base of the Antarctic Peninsula, from which it is separated by Marguerite Bay and George VI Sound. Alexander Island lies off...

. The only anomalous area of West Antarctica is the Ellsworth Mountains
Ellsworth Mountains
The Ellsworth Mountains are the highest mountain ranges in Antarctica, forming a long and wide chain of mountains in a north to south configuration on the western margin of the Ronne Ice Shelf. They are bisected by Minnesota Glacier to form the northern Sentinel Range and the southern Heritage...

 region, where the stratigraphy
Stratigraphy
Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....

 is more similar to the eastern part of the continent.

East Antarctica is geologically varied, dating from the Precambrian
Precambrian
The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...

 era, with some rocks formed more than 3 billion years ago. It is composed of a metamorphic
Metamorphic rock
Metamorphic rock is the transformation of an existing rock type, the protolith, in a process called metamorphism, which means "change in form". The protolith is subjected to heat and pressure causing profound physical and/or chemical change...

 and igneous platform which is the basis of the continental shield
Shield (geology)
A shield is generally a large area of exposed Precambrian crystalline igneous and high-grade metamorphic rocks that form tectonically stable areas. In all cases, the age of these rocks is greater than 570 million years and sometimes dates back 2 to 3.5 billion years...

. On top of this base are various modern rocks, such as sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

s, limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

s, coal and shale
Shale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...

s laid down during the Devonian and Jurassic periods to form the Transantarctic Mountains
Transantarctic Mountains
The three largest mountain ranges on the Antarctic continent are the Transantarctic Mountains , the West Antarctica Ranges, and the East Antarctica Ranges. The Transantarctic Mountains compose a mountain range in Antarctica which extend, with some interruptions, across the continent from Cape Adare...

. In coastal areas such as Shackleton Range
Shackleton Range
The Shackleton Range is a mountain range in Antarctica. Rising to , it extends in an east-west direction for about between the Slessor and Recovery glaciers....

 and Victoria Land
Victoria Land
Victoria Land is a region of Antarctica bounded on the east by the Ross Ice Shelf and the Ross Sea and on the west by Oates Land and Wilkes Land. It was discovered by Captain James Clark Ross in January 1841 and named after the UK's Queen Victoria...

 some faulting
Geologic fault
In geology, a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement along the fractures as a result of earth movement. Large faults within the Earth's crust result from the action of tectonic forces...

 has occurred.

The main mineral resource known on the continent is coal. It was first recorded near the Beardmore Glacier
Beardmore Glacier
The Beardmore Glacier in Antarctica is one of the largest glaciers in the world, with a length exceeding 160 km . The glacier is one of the main passages from the Ross Ice Shelf through the Queen Alexandra and Commonwealth ranges of the Transantarctic Mountains to the Antarctic Plateau, and was one...

 by Frank Wild
Frank Wild
Commander John Robert Francis Wild CBE, RNVR, FRGS , known as Frank Wild, was an explorer...

 on the Nimrod Expedition
Nimrod Expedition
The British Antarctic Expedition 1907–09, otherwise known as the Nimrod Expedition, was the first of three expeditions to the Antarctic led by Ernest Shackleton. Its main target, among a range of geographical and scientific objectives, was to be first to the South Pole...

, and now low-grade coal is known across many parts of the Transantarctic Mountains. The Prince Charles Mountains
Prince Charles Mountains
Prince Charles Mountains is a major group of mountains in Mac. Robertson Land in Antarctica, including the Athos Range, the Porthos Range, and the Aramis Range. The highest peak is Mount Menzies . Other prominent peaks are Mount Izabelle and Mount Stinear...

 contain significant deposits of iron ore. The most valuable resources of Antarctica lie offshore, namely the oil
Oil field
An oil field is a region with an abundance of oil wells extracting petroleum from below ground. Because the oil reservoirs typically extend over a large area, possibly several hundred kilometres across, full exploitation entails multiple wells scattered across the area...

 and natural gas field
Natural gas field
Oil and natural gas are produced by the same geological process according fossil fuel suggestion: anaerobic decay of organic matter deep under the Earth's surface. As a consequence, oil and natural gas are often found together...

s found in the Ross Sea in 1973. Exploitation of all mineral resources is banned
Ban (law)
A ban is, generally, any decree that prohibits something.Bans are formed for the prohibition of activities within a certain political territory. Some see this as a negative act and others see it as maintaining the "status quo"...

 until 2048 by the Protocol on Environmental Protection to the Antarctic Treaty
Protocol on Environmental Protection to the Antarctic Treaty
The Protocol on Environmental Protection to the Antarctic Treaty, also known as the Antarctic-Environmental Protocol, or the Madrid Protocol, is part of the Antarctic Treaty System...

.

Climate



Antarctica is the coldest place on Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

. The coldest natural temperature ever recorded on Earth was −89.2 C at the Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

n Vostok Station
Vostok Station
Vostok Station was a Russian Antarctic research station. It was at the southern Pole of Cold, with the lowest reliably measured natural temperature on Earth of −89.2 °C . Research includes ice core drilling and magnetometry...

 in Antarctica on 21 July 1983. For comparison, this is 11 °C (20 °F) colder than subliming dry ice
Dry ice
Dry ice, sometimes referred to as "Cardice" or as "card ice" , is the solid form of carbon dioxide. It is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue...

. Antarctica is a frozen desert with little precipitation
Precipitation (meteorology)
In meteorology, precipitation In meteorology, precipitation In meteorology, precipitation (also known as one of the classes of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation...

; the South Pole itself receives less than 10 cm (4 in) per year, on average. Temperatures reach a minimum of between −80 C and −90 C 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.

East Antarctica is colder than its western counterpart because of its higher elevation. Weather front
Weather front
A weather front is a boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena. In surface weather analyses, fronts are depicted using various colored lines and symbols, depending on the type of front...

s 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 metres (48 in) in 48 hours have been recorded.

At the edge of the continent, strong katabatic wind
Katabatic wind
A katabatic wind, from the Greek word katabatikos meaning "going downhill", is the technical name for a drainage wind, a wind that carries high density air from a higher elevation down a slope under the force of gravity. Such winds are sometimes also called fall winds...

s off the polar plateau often blow at storm force. In the interior, however, wind speeds are typically moderate. During summer, more solar radiation reaches the surface during clear days at the South Pole than at the equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....

 because of the 24 hours of sunlight each day at the Pole.


Antarctica is colder than the Arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

 for two reasons. First, much of the continent is more than 3 kilometres (2 mi) 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. 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.

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 wind
Solar wind
The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...

s that pass by the Earth. Another unique spectacle is diamond dust
Diamond dust
Diamond dust is a ground-level cloud composed of tiny ice crystals. This meteorological phenomenon is also referred to simply as ice crystals and is reported in the METAR code as IC. Diamond dust generally forms under otherwise clear or nearly clear skies, so it is sometimes referred to as...

, 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
Sun dog
A sun dog or sundog, scientific name parhelion ; , also called a mock sun or a phantom sun, is an atmospheric phenomenon that creates bright spots of light in the sky, often on a luminous ring or halo on either side of the sun.Sundogs may appear as a colored patch of light to the left or right of...

, a frequent atmospheric optical phenomenon
Optical phenomenon
An optical phenomenon is any observable event that results from the interaction of light and matter. See also list of optical topics and optics. A mirage is an example of an optical phenomenon....

, is a bright "spot" beside the true sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

.

Population


Antarctica has no permanent residents, but a number of governments maintain permanent manned research station
Research station
A research station is a station built for the purpose of conducting scientific research. Research station sites might include outer space and oceans. Many nations have research stations in Antarctica; Showa Station, Halley and Troll are examples...

s throughout the continent. The number of people conducting and supporting scientific research and other work on the continent and its nearby islands varies from about 1,000 in winter to about 5,000 in the summer. Many of the stations are staffed year-round, the winter-over personnel typically arriving from their home countries for a one-year assignment. An Orthodox church, Trinity Church
Trinity Church, Antarctica
Trinity Church is a small Russian Orthodox church on King George Island near Russian Bellingshausen Station in Antarctica. It is the southernmost Eastern Orthodox church in the world....

, opened in 2004 at the Russian Bellingshausen Station
Bellingshausen Station
thumb|right|Bellingshausen is one of Antarctica's most polluted places. Old vehicles, rusting barrels and other refuse litter the shorelinethumb|right|Muddy scene around the base. On the hilltop an orthodox church was built in 2004...

 is also manned year-round by one or two priests, who are similarly rotated every year.

The first semi-permanent inhabitants of regions near Antarctica (areas situated south of the Antarctic Convergence
Antarctic Convergence
The Antarctic Convergence is a curve continuously encircling Antarctica where cold, northward-flowing Antarctic waters meet the relatively warmer waters of the subantarctic. Antarctic waters predominantly sink beneath subantarctic waters, while associated zones of mixing and upwelling create a zone...

) were British and American sealers who used to spend a year or more on South Georgia, from 1786 onward. During the whaling
Whaling
Whaling is the hunting of whales mainly for meat and oil. Its earliest forms date to at least 3000 BC. Various coastal communities have long histories of sustenance whaling and harvesting beached whales...

 era, which lasted until 1966, the population of that island varied from over 1,000 in the summer (over 2,000 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
Grytviken
Grytviken is the principal settlement in the British territory of South Georgia in the South Atlantic. It was so named in 1902 by the Swedish surveyor Johan Gunnar Andersson who found old English try pots used to render seal oil at the site. It is the best harbour on the island, consisting of a...

, Leith Harbour
Leith Harbour
Leith Harbour , also known as Port Leith, was a whaling station up on the northeast coast of South Georgia, established and operated by Christian Salvesen Ltd, Edinburgh. The station was in operation from 1909 until 1965. It was the largest of seven whaling stations, situated near the mouth of...

, King Edward Point
King Edward Point
King Edward Point is a promontory and settlement with port facilities on the northeastern coast of the island of South Georgia. It is located at in Cumberland East Bay...

, Stromness
Stromness (South Georgia)
Stromness is a former whaling station on the northern coast of South Georgia Island in the South Atlantic. Its historical significance is that it represents the destination of Ernest Shackleton's epic rescue journey in 1916. See also Stromness Bay...

, Husvik
Husvik
Husvik is a former whaling station on the north-central coast of South Georgia Island. It was one of three such stations in Stromness Bay, the other two being Stromness and Leith Harbour. Husvik initially began as a floating, offshore factory site in 1907. In 1910, a land station was constructed...

, Prince Olav Harbour
Prince Olav Harbour
Prince Olav Harbour is small harbour in the south west portion of Cook Bay, entered between Point Abrahamsen and Sheep Point, along the north coast of South Georgia.-Background:...

, Ocean Harbour
Ocean Harbour
Ocean Harbour is a deeply indented bay on the north coast of South Georgia which is entered west-northwest of Tijuca point. It was an active whaling station between 1909–1920...

 and Godthul
Godthul
Godthul is a bay long entered between Cape George and Long Point, on the north coast of South Georgia, between Cumberland East Bay and Ocean Harbour...

. 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
Carl Anton Larsen
Carl Anton Larsen was a Norwegian Antarctic Explorer, who made important contributions to the exploration of Antarctica, the most significant being the first discovery of fossils, for which he received the Back Grant from the Royal Geographical Society...

, a prominent Norwegian whaler and explorer who, along with his family, adopted British citizenship in 1910.

The first child born in the southern polar region
Antarctic Convergence
The Antarctic Convergence is a curve continuously encircling Antarctica where cold, northward-flowing Antarctic waters meet the relatively warmer waters of the subantarctic. Antarctic waters predominantly sink beneath subantarctic waters, while associated zones of mixing and upwelling create a zone...

 was Norwegian girl Solveig Gunbjørg Jacobsen, born in Grytviken on 8 October 1913, and her birth was 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.

Emilio Marcos Palma was the first person born south of the 60th parallel south
60th parallel south
The 60th parallel south is a circle of latitude that is 60 degrees south of the Earth's equatorial plane. No land lies on the parallel—it crosses nothing but ocean...

 (the continental limit according to the Antarctic Treaty), as well as the first one born on the Antarctic mainland, in 1978 at Base Esperanza
Esperanza Base
-References:*Antarctica. Sydney: Reader's Digest, 1985, p. 156-157.*Child, Jack. Antarctica and South American Geopolitics: Frozen Lebensraum. New York: Praeger Publishers, 1988, p. 73....

, on the tip of the Antarctic Peninsula; his parents were sent there along with seven other families by the Argentine
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

 government to determine if family life was suitable on the continent. In 1984, Juan Pablo Camacho was born at the Frei Montalva Station, becoming the first Chilean born in Antarctica. Several bases are now home to families with children attending schools at the station. As of 2009, eleven children were born in Antarctica (south of the 60th parallel south): eight at the Argentinean Esperanza Base
Esperanza Base
-References:*Antarctica. Sydney: Reader's Digest, 1985, p. 156-157.*Child, Jack. Antarctica and South American Geopolitics: Frozen Lebensraum. New York: Praeger Publishers, 1988, p. 73....

 and three at the Chilean Frei Montalva Station.

Biodiversity




Few terrestrial vertebrates live in Antarctica. Invertebrate life includes microscopic
Microscopic
The microscopic scale is the scale of size or length used to describe objects smaller than those that can easily be seen by the naked eye and which require a lens or microscope to see them clearly.-History:...

 mite
Mite
Mites, along with ticks, are small arthropods belonging to the subclass Acari and the class Arachnida. The scientific discipline devoted to the study of ticks and mites is called acarology.-Diversity and systematics:...

s like the Alaskozetes antarcticus
Alaskozetes antarcticus
Alaskozetes antarcticus is a species of non-parasitic mite, known for its ability to survive in subzero temperatures.This animal's name derives from its habitat: Alasko, meaning "from Alaska", and antarcticus, in connection with frigid conditions in which the mite lives...

, lice, nematodes, tardigrade
Tardigrade
Tardigrades form the phylum Tardigrada, part of the superphylum Ecdysozoa. They are microscopic, water-dwelling, segmented animals with eight legs. Tardigrades were first described by Johann August Ephraim Goeze in 1773...

s, rotifer
Rotifer
The rotifers make up a phylum of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John Harris in 1696, and other forms were described by Anton van Leeuwenhoek in 1703...

s, krill
Krill
Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world...

 and springtail
Springtail
Springtails form the largest of the three lineages of modern hexapods that are no longer considered insects...

s. The flightless midge
Midge (insect)
Midges comprise many kinds of very small two-winged flies found world-wide. The term does not encapsulate a well-defined taxonomic group, but includes animals in several families of Nematoceran Diptera. While some midges are vectors for disease, many others play useful roles as prey items for...

 Belgica antarctica
Belgica antarctica
Belgica antarctica is a species of flightless midge endemic to the continent of Antarctica. At 2–6 mm long, it is the largest purely terrestrial animal on the continent, as well as its only true insect. Its flightlessness may be an adaptation to prevent wind from blowing it into inhospitable sites...

, up to 6 millimetre (0.236220472440945 in) in size, is the largest purely terrestrial animal in Antarctica. The Snow Petrel
Snow Petrel
The Snow Petrel is the only member of the genus Pagodroma. It is one of only three birds that breed exclusively in Antarctica and has been seen at the South Pole. It has the most southerly breeding distribution of any bird.-Taxonomy:...

 is one of only three birds that breed exclusively in Antarctica.

A variety of marine animals exist and rely, directly or indirectly, on the phytoplankton. Antarctic sea life includes penguin
Penguin
Penguins are a group of aquatic, flightless birds living almost exclusively in the southern hemisphere, especially in Antarctica. Highly adapted for life in the water, penguins have countershaded dark and white plumage, and their wings have become flippers...

s, blue whales, orca
Orca
The killer whale , commonly referred to as the orca, and less commonly as the blackfish, is a toothed whale belonging to the oceanic dolphin family. Killer whales are found in all oceans, from the frigid Arctic and Antarctic regions to tropical seas...

s, colossal squid
Colossal Squid
The colossal squid , sometimes called the Antarctic or giant cranch squid, is believed to be the largest squid species in terms of mass. It is the only known member of the genus Mesonychoteuthis...

s and fur seal
Fur seal
Fur seals are any of nine species of pinnipeds in the Otariidae family. One species, the northern fur seal inhabits the North Pacific, while seven species in the Arctocephalus genus are found primarily in the Southern hemisphere...

s. The Emperor penguin
Emperor Penguin
The Emperor Penguin is the tallest and heaviest of all living penguin species and is endemic to Antarctica. The male and female are similar in plumage and size, reaching in height and weighing anywhere from . The dorsal side and head are black and sharply delineated from the white belly,...

 is the only penguin that breeds during the winter in Antarctica, while the Adélie Penguin
Adelie Penguin
The Adélie Penguin, Pygoscelis adeliae, is a species of penguin common along the entire Antarctic coast. They are among the most southerly distributed of all seabirds, as are the Emperor Penguin, the South Polar Skua, the Wilson's Storm Petrel, the Snow Petrel, and the Antarctic Petrel...

 breeds farther south than any other penguin. The Rockhopper penguin
Rockhopper penguin
The rockhopper penguins are three closely related taxa of crested penguins that have been traditionally treated as a single species and are sometimes split into two or three species. Not all experts agree on the classification of these penguins...

 has distinctive feathers around the eyes, giving the appearance of elaborate eyelashes. King penguin
King Penguin
The King Penguin is the second largest species of penguin at about , second only to the Emperor Penguin. There are two subspecies—A. p. patagonicus and A. p...

s, Chinstrap penguin
Chinstrap Penguin
The Chinstrap Penguin is a species of penguin which is found in the South Sandwich Islands, Antarctica, the South Orkneys, South Shetland, South Georgia, Bouvet Island and Balleny...

s, and Gentoo Penguin
Gentoo penguin
The Gentoo Penguin , Pygoscelis papua, is easily recognized by the wide white stripe extending like a bonnet across the top of its head and its bright orange-red bill. The gentoo penguin has pale whitish-pink webbed feet and a fairly long tail - the most prominent tail of all penguins. Chicks have...

s also breed in the Antarctic.

The Antarctic fur seal
Antarctic Fur Seal
The Antarctic fur seal is one of eight seals in the genus Arctocephalus, and one of nine fur seals in the subfamily Arctocephalinae. As its name suggests, the Antarctic fur seal is distributed in Antarctic waters. Around 95% of the world population breeds at the Island of South Georgia...

 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
Weddell Seal
The Weddell seal , is a relatively large and abundant true seal with a circumpolar distribution surrounding Antarctica. Weddell seals have the most southerly distribution of any mammal, with a habitat that extends as far south as McMurdo Sound...

, a "true seal", is named after Sir James Weddell
James Weddell
James Weddell was a British sailor, navigator and seal hunter who in the early Spring of 1823 sailed to latitude of 74°15' S and into a region of the Southern Ocean that later became known as the Weddell Sea.-Early life:He entered the merchant service very...

, commander of British sealing expeditions in the Weddell Sea
Weddell Sea
The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha Coast, Queen Maud Land. To the east of Cape Norvegia is...

. Antarctic krill
Antarctic krill
Antarctic krill, Euphausia superba, is a species of krill found in the Antarctic waters of the Southern Ocean. It is a shrimp-like crustacean that lives in large schools, called swarms, sometimes reaching densities of 10,000–30,000 individual animals per cubic metre...

, which congregates in large schools
Shoaling and schooling
In biology, any group of fish that stay together for social reasons are said to be shoaling , and if, in addition, the group is swimming in the same direction in a coordinated manner, they are said to be schooling . In common usage, the terms are sometimes used rather loosely...

, is the keystone species
Keystone species
A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. Such species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and...

 of the ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

 of the Southern Ocean
Southern Ocean
The Southern Ocean comprises the southernmost waters of the World Ocean, generally taken to be south of 60°S latitude and encircling Antarctica. It is usually regarded as the fourth-largest of the five principal oceanic divisions...

, and is an important food organism for whales, seals, leopard seal
Leopard Seal
The leopard seal , also referred to as the sea leopard, is the second largest species of seal in the Antarctic...

s, fur seals, squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...

, icefish
Notothenioidei
The Antarctic icefish belong to the perciform suborder Notothenioidei and are the largely endemic, dominant fish taxa in the cold continental shelf waters surrounding Antarctica. At present, the suborder includes 8 families with 43 genera and 122 species...

, penguins, albatross
Albatross
Albatrosses, of the biological family Diomedeidae, are large seabirds allied to the procellariids, storm-petrels and diving-petrels in the order Procellariiformes . They range widely in the Southern Ocean and the North Pacific...

es and many other birds.

A census of sea life carried out during the International Polar Year
International Polar Year
The International Polar Year is a collaborative, international effort researching the polar regions. Karl Weyprecht, an Austro-Hungarian naval officer, motivated the endeavor, but died before it first occurred in 1882-1883. Fifty years later a second IPY occurred...

 and which involved some 500 researchers was released in 2010. The research is part of the global Census of Marine Life
Census of Marine Life
The Census of Marine Life was a global network of researchers in more than 80 nations engaged in a 10-year scientific initiative to assess and explain the diversity, distribution, and abundance of life in the oceans...

 (CoML) and has disclosed some remarkable findings. More than 235 marine organisms live in both polar regions, having bridged the gap of 12000 km (7,456 mi). Large animals such as some cetaceans and birds make the round trip annually. More surprising are small forms of life such as mudworms, sea cucumbers and free-swimming snails found in both polar oceans. Various factors may aid in their distribution – fairly uniform temperatures of the deep ocean at the poles and the equator which differ by no more than 5 °C, and the major current systems or marine conveyor belt
Thermohaline circulation
The term thermohaline circulation refers to a part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes....

 which transport egg and larvae stages.


The climate of Antarctica does not allow extensive vegetation. A combination of freezing temperatures, poor soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

 quality, lack of moisture, and lack of sunlight inhibit plant growth. As a result, the diversity of plant life is very small and limited in distribution. Excluding organisms which are not plants (algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

 and fungi, including lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...

-forming species), the flora
Flora
Flora is the plant life occurring in a particular region or time, generally the naturally occurring or indigenous—native plant life. The corresponding term for animals is fauna.-Etymology:...

 of the continent largely consists of bryophyte
Bryophyte
Bryophyte is a traditional name used to refer to all embryophytes that do not have true vascular tissue and are therefore called 'non-vascular plants'. Some bryophytes do have specialized tissues for the transport of water; however since these do not contain lignin, they are not considered to be...

s (there are about 100 species of moss
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...

es and 25 species of liverwort
Marchantiophyta
The Marchantiophyta are a division of bryophyte plants commonly referred to as hepatics or liverworts. Like other bryophytes, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information....

s), with only two species of flowering plants, both found in the Antarctic Peninsula: Deschampsia antarctica
Deschampsia antarctica
Deschampsia antarctica is one of two flowering plants native to Antarctica, the other being Colobanthus quitensis ....

(Antarctic hair grass) and Colobanthus quitensis
Colobanthus quitensis
Colobanthus quitensis is one of the two flowering plants found in the Antarctic region. It occurs on the continental edge, as well as the South Orkney Islands and the South Shetland Islands...

(Antarctic pearlwort). Growth generally occurs in the summer, and only for a few weeks at most.

About 1150 species of fungi have been recorded from Antarctica, of which about 750 are non-lichen-forming and 400 are lichen-forming. Some of these species are cryptoendoliths as a result of evolution under extreme conditions. Seven hundred species of algae exist, most of which are phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...

. Multicolored snow algae and diatom
Diatom
Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons , fans , zigzags , or stellate colonies . Diatoms are producers within the food chain...

s are especially abundant in the coastal regions during the summer. Recently ancient ecosystems consisting of several types of bacteria have been found living trapped deep beneath glaciers. The autotroph
Autotroph
An autotroph, or producer, is an organism that produces complex organic compounds from simple inorganic molecules using energy from light or inorganic chemical reactions . They are the producers in a food chain, such as plants on land or algae in water...

ic community is made up of mostly protist
Protist
Protists are a diverse group of eukaryotic microorganisms. Historically, protists were treated as the kingdom Protista, which includes mostly unicellular organisms that do not fit into the other kingdoms, but this group is contested in modern taxonomy...

s.

Conservation



The Protocol on Environmental Protection to the Antarctic Treaty (also known as the Environmental Protocol or Madrid Protocol) came into force in 1998, and is the main instrument concerned with conservation and management of biodiversity in Antarctica. The Antarctic Treaty Consultative Meeting is advised on environmental and conservation issues in Antarctica by the Committee for Environmental Protection. A major concern within this committee is the risk to Antarctica from unintentional introduction of non-native species from outside the region.

The passing of the Antarctic Conservation Act
Antarctic Conservation Act
The Antarctic Conservation Act, enacted in 1978 by the 95th United States Congress , and amended by , is a United States federal law that addresses the issue of environmental conservation on the continent of Antarctica...

 (1978) in the U.S. brought several restrictions to U.S. activity on Antarctica. The introduction of alien plants or animals can bring a criminal penalty, as can the extraction of any indigenous species. The overfishing
Overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....

 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. Despite these new acts, unregulated and illegal fishing, particularly of Patagonian toothfish
Patagonian toothfish
The Patagonian toothfish, Dissostichus eleginoides , is a fish found in the cold, temperate waters of the southern Atlantic, southern Pacific, Indian, and Southern Oceans on seamounts and continental shelves around most sub-Antarctic islands.A close relative, the Antarctic toothfish , is found...

 (marketed as Chilean Sea Bass in the U.S.), remains a serious problem. The illegal fishing of toothfish has been increasing, with estimates of 32,000 tonnes (35,300 short tons) in 2000.

Politics



Antarctica has no government, although various countries claim sovereignty in certain regions. While a few of these countries have mutually recognised each other's claims, the validity of these claims is generally not recognised universally.

New claims on Antarctica have been suspended since 1959 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
Antarctic Treaty System
The Antarctic Treaty and related agreements, collectively called the Antarctic Treaty System or ATS, regulate international relations with respect to Antarctica, Earth's only continent without a native human population. For the purposes of the treaty system, Antarctica is defined as all of the land...

. Antarctica is defined as all land and ice shelves
Ice shelf
An ice shelf is a thick, floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Ice shelves are only found in Antarctica, Greenland and Canada. The boundary between the floating ice shelf and the grounded ice that feeds it is called...

 south of 60° S for the purposes of the Treaty System. The treaty was signed by twelve countries including the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 (and later Russia), the United Kingdom, Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

, Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

, Australia, and the United States. It set aside Antarctica as a scientific preserve, established freedom of scientific investigation and environmental protection, and banned military activity on the continent. This was the first arms control
Arms control
Arms control is an umbrella term for restrictions upon the development, production, stockpiling, proliferation, and usage of weapons, especially weapons of mass destruction...

 agreement established during the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

.

In 1983, the Antarctic Treaty Parties began negotiations on a convention to regulate mining in Antarctica. A coalition of international organisations launched a public pressure campaign to prevent any minerals development in the region, led largely by Greenpeace International which established its own scientific station–World Park Base
World Park Base
World Park Base was a non-governmental year-round Antarctic base located at Cape Evans on Ross Island in the Ross Dependency. The international environmental organization Greenpeace established World Park Base in 1987 in order to press its demand for the Antarctic Treaty nations to declare all of...

–in the Ross Sea region and conducted annual expeditions to document environmental effects of humans on the continent. In 1988, the Convention on the Regulation of Antarctic Mineral Resources (CRAMRA) was adopted. The following year, however, Australia and France announced that they would not ratify the convention, rendering it dead for all intents and purposes. They proposed instead that a comprehensive regime to protect the Antarctic environment be negotiated in its place. The Protocol on Environmental Protection to the Antarctic Treaty (the ‘Madrid Protocol’) was negotiated as other countries followed suit and on 14 January 1998 it entered into force. The Madrid Protocol bans all mining in Antarctica, designating the continent as a ‘natural reserve devoted to peace and science’.


The Antarctic Treaty prohibits any military activity in Antarctica
Military activity in the Antarctic
As Antarctica has never been permanently settled by humans, there has historically been little military activity in the Antarctic. While the Antarctic Treaty, which came into effect on June 23, 1961, bans military activity in Antarctica, military personnel and equipment may be used for scientific...

, including the establishment of military bases and fortifications, military manoeuvers, and weapons testing. Military personnel or equipment are permitted only for scientific research or other peaceful purposes. The only documented military land manoeuvre was Operation NINETY
Operación 90
Operación 90 was the first Argentine ground expedition to the South Pole, conducted in 1965, by ten soldiers of the Argentine Army under then-Colonel Jorge E. Leal. It was performed to attempt to cement Argentina's claims to a portion of Antarctica, as well as for scientific reasons and to perfect...

 by the Argentine military
Military of Argentina
The Armed Forces of the Argentine Republic, in Spanish Fuerzas Armadas de la República Argentina, are controlled by the Commander-in-Chief and a civilian Minister of Defense...

.

The United States military issues the Antarctica Service Medal
Antarctica Service Medal
The Antarctica Service Medal was established by the United States Congress on July 7, 1960 under Public Law 600 of the 86th Congress. The medal was intended as a military award to replace several commemorative awards which had been issued for previous Antarctica expeditions from 1928 to 1941...

 to military members or civilians who perform research duty in Antarctica. The medal includes a "wintered over" bar issued to those who remain on the continent for 2 six-month seasons.

Antarctic territories



Date Country Territory Claim limits Map
1908  United Kingdom  British Antarctic Territory 20°W to 80°W
1923  New Zealand   Ross Dependency
Ross Dependency
The Ross Dependency is a region of Antarctica defined by a sector originating at the South Pole, passing along longitudes 160° east to 150° west, and terminating at latitude 60° south...

150°W to 160°E
1924  Early Modern France   Adélie Land
Adélie Land
Adélie Land is the portion of the Antarctic coast between 136° E and 142° E , with a shore length of 350 km and with its hinterland extending as a sector about 2,600 km toward the South Pole. It is claimed by France as one of five districts of the French Southern and Antarctic Lands, although not...

142°2'E to 136°11'E
1929  Norway   Peter I Island
Peter I Island
Peter I Island is an uninhabited volcanic island in the Bellingshausen Sea, from Antarctica. It is claimed as a dependency of Norway, and along with Queen Maud Land and Bouvet Island comprises one of the three Norwegian dependent territories in the Antarctic and sub-Antarctic. Peter I Island is ...

68°50′S 90°35′W
1933  Australia   Australian Antarctic Territory
Australian Antarctic Territory
The Australian Antarctic Territory is a part of Antarctica. It was claimed by the United Kingdom and placed under the authority of the Commonwealth of Australia in 1933. It is the largest territory of Antarctica claimed by any nation...

160°E to 142°2'E and
136°11'E to 44°38'E
1939  Norway   Queen Maud Land
Queen Maud Land
Queen Maud Land is a c. 2.7 million-square-kilometre region of Antarctica claimed as a dependent territory by Norway. The territory lies between 20° west and 45° east, between the British Antarctic Territory to the west and the Australian Antarctic Territory to the east. The latitudinal...

44°38'E to 20°W
1940  Chile   Antártica
Antártica
The Chilean Antarctic Territory is the territory in Antarctica claimed by Chile. The Chilean Antarctic Territory ranges from 53°W to 90°W and from the South Pole to 60°S, partially overlapping Argentine and British Antarctic claims...

53°W to 90°W
1943  Argentina  Argentine Antarctica 25°W to 74°W
None Unclaimed territory
(Marie Byrd Land
Marie Byrd Land
Marie Byrd Land is the portion of West Antarctica lying east of the Ross Ice Shelf and the Ross Sea and south of the Pacific Ocean, extending eastward approximately to a line between the head of the Ross Ice Shelf and Eights Coast. It stretches between 158°W and 103°24'W...

)
90°W to 150°W
(except Peter I Island
Peter I Island
Peter I Island is an uninhabited volcanic island in the Bellingshausen Sea, from Antarctica. It is claimed as a dependency of Norway, and along with Queen Maud Land and Bouvet Island comprises one of the three Norwegian dependent territories in the Antarctic and sub-Antarctic. Peter I Island is ...

)


The Argentine, British, and Chilean claims all overlap, and have caused friction. The areas shown as Australia's
Australian Antarctic Territory
The Australian Antarctic Territory is a part of Antarctica. It was claimed by the United Kingdom and placed under the authority of the Commonwealth of Australia in 1933. It is the largest territory of Antarctica claimed by any nation...

 and New Zealand's
Ross Dependency
The Ross Dependency is a region of Antarctica defined by a sector originating at the South Pole, passing along longitudes 160° east to 150° west, and terminating at latitude 60° south...

 claims were British territory until they were handed over following the countries' independence. Australia currently claims the largest area. The claims of Britain, Australia, New Zealand, France and Norway are all recognised by each other.

Other countries participating as members of Antarctic Treaty have a territorial interest in the Antarctic continent but the provisions of the Treaty do not allow them to make their claims while it is in force.
has a designated 'zone of interest
Brazilian Antarctica
Brazilian Antarctica is the name of the Antarctic territory south of 60°S, and from 28°W to 53°W, proposed as 'Zone of Interest' by geopolitical scholar Therezinha de Castro...

' that is not an actual claim. has formally reserved its right to make a claim. has inherited the Soviet Union's right to claim territory under the original Antarctic Treaty. has formally reserved its right to make a claim. reserved its right to make a claim in the original Antarctic Treaty.

Economy



Although coal, hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....

s, iron ore, platinum
Platinum
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...

, copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

, chromium
Chromium
Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...

, nickel, gold and other minerals have been found, they have not been in large enough quantities to exploit. The 1991 Protocol on Environmental Protection to the Antarctic Treaty
Protocol on Environmental Protection to the Antarctic Treaty
The Protocol on Environmental Protection to the Antarctic Treaty, also known as the Antarctic-Environmental Protocol, or the Madrid Protocol, is part of the Antarctic Treaty System...

 also restricts a struggle for resources. In 1998, a compromise agreement was reached to place an indefinite ban on mining, to be reviewed in 2048, further limiting economic development and exploitation. The primary economic activity is the capture and offshore trading of fish. Antarctic fisheries in 2000–01 reported landing 112,934 tonnes.

Small-scale "expedition tourism" has existed since 1957 and is currently subject to Antarctic Treaty and Environmental Protocol provisions, but in effect self-regulated by the International Association of Antarctica Tour Operators
International Association of Antarctica Tour Operators
The International Association of Antarctic Tour Operators was originally founded in 1991 by seven companies. The primary goal of the association is to promote the "safe and environmentally responsible" travel. Since the group's inception membership has grown to over 100 members...

 (IAATO). Not all vessels associated with Antarctic tourism are members of IAATO, but IAATO members account for 95% of the tourist activity. Travel is largely by small or medium ship, focusing on specific scenic locations with accessible concentrations of iconic wildlife. A total of 37,506 tourists visited during the 2006–07 Austral summer
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...

 with nearly all of them coming from commercial ships. The number is predicted to increase to over 80,000 by 2010.

There has been some concern over the potential adverse environmental and ecosystem effects caused by the influx of visitors. A call for stricter regulations for ships and a tourism quota has been made by some environmentalists and scientists. The primary response by Antarctic Treaty Parties has been to develop, through their Committee for Environmental Protection and in partnership with IAATO, "site use guidelines" setting landing limits and closed or restricted zones on the more frequently visited sites. 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
Air New Zealand Flight 901
Air New Zealand Flight 901 was a scheduled Air New Zealand Antarctic sightseeing flight that operated between 1977 and 1979, from Auckland Airport to Antarctica and return via Christchurch...

 in 1979 on Mount Erebus, which killed all 257 aboard. Qantas
Qantas
Qantas Airways Limited is the flag carrier of Australia. The name was originally "QANTAS", an initialism for "Queensland and Northern Territory Aerial Services". Nicknamed "The Flying Kangaroo", the airline is based in Sydney, with its main hub at Sydney Airport...

 resumed commercial overflights to Antarctica from Australia in the mid-1990s.

Research



Each year, scientists from 28 different nations conduct experiment
Experiment
An experiment is a methodical procedure carried out with the goal of verifying, falsifying, or establishing the validity of a hypothesis. Experiments vary greatly in their goal and scale, but always rely on repeatable procedure and logical analysis of the results...

s not reproducible in any other place in the world. In the summer more than 4,000 scientists operate research station
Research station
A research station is a station built for the purpose of conducting scientific research. Research station sites might include outer space and oceans. Many nations have research stations in Antarctica; Showa Station, Halley and Troll are examples...

s; this number decreases to just over 1,000 in the winter. McMurdo Station
McMurdo Station
McMurdo Station is a U.S. Antarctic research center located on the southern tip of Ross Island, which is in the New Zealand-claimed Ross Dependency on the shore of McMurdo Sound in Antarctica. It is operated by the United States through the United States Antarctic Program, a branch of the National...

, which is the largest research station in Antarctica, is capable of housing more than 1,000 scientists, visitors, and tourists.

Researchers include biologists
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...

, geologists
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...

, oceanographers
Oceanography
Oceanography , also called oceanology or marine science, is the branch of Earth science that studies the ocean...

, physicists
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

, astronomers
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

, glaciologists
Glaciology
Glaciology Glaciology Glaciology (from Middle French dialect (Franco-Provençal): glace, "ice"; or Latin: glacies, "frost, ice"; and Greek: λόγος, logos, "speech" lit...

, and meteorologists
Meteorology
Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...

. Geologists tend to study plate tectonics
Plate tectonics
Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...

, meteorites from outer space
Outer space
Outer space is the void that exists between celestial bodies, including the Earth. It is not completely empty, but consists of a hard vacuum containing a low density of particles: predominantly a plasma of hydrogen and helium, as well as electromagnetic radiation, magnetic fields, and neutrinos....

, and resources from the breakup of the supercontinent Gondwanaland. Glaciologists in Antarctica are concerned with the study of the history and dynamics
Ice sheet dynamics
Ice sheet dynamics describe the motion within large bodies of ice, such those currently on Greenland and Antarctica. Ice motion is dominated by the movement of glaciers, whose gravity-driven activity is controlled by two main variable factors: the temperature and strength of their bases...

 of floating ice, seasonal snow
Snow
Snow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by...

, glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

s, and ice sheet
Ice sheet
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² , thus also known as continental glacier...

s. 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 at Amundsen-Scott South Pole Station
Amundsen-Scott South Pole Station
The Amundsen–Scott South Pole Station is the American scientific research station on the high plateau of Antarctica. This station is located at the southernmost place on the Earth, the Geographic South Pole, at an elevation of 2,835 meters above sea level.The original Amundsen-Scott Station was...

 study the celestial dome and cosmic microwave background radiation
Cosmic microwave background radiation
In cosmology, cosmic microwave background radiation is thermal radiation filling the observable universe almost uniformly....

. Many astronomical observations are better made from the interior of Antarctica than from most surface locations because of the high elevation, which results in a thin atmosphere, low temperature, which minimizes the amount of water vapour in the atmosphere, and absence of light pollution
Light pollution
Light pollution, also known as photopollution or luminous pollution, is excessive or obtrusive artificial light.The International Dark-Sky Association defines light pollution as:...

, thus allowing for a view of space clearer than anywhere else on Earth. Antarctic ice serves as both the shield and the detection medium for the largest neutrino telescope in the world, built 2 km (1.2 mi) below Amundsen-Scott station.

Since the 1970s, an important focus of study has been the ozone layer
Ozone layer
The ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone . This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which is potentially damaging to the life forms on Earth...

 in the atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...

 above Antarctica. In 1985, three British Scientists working on data they had gathered at Halley Station on the Brunt Ice Shelf
Brunt Ice Shelf
The Brunt Ice Shelf borders the Antarctic coast of Coats Land between Dawson-Lambton Glacier and Stancomb-Wills Glacier Tongue. It was the location of the base of the Royal Society Expedition, 1955–59 which was taken over as the British Halley Research Station...

 discovered the existence of a hole in this layer. It was eventually determined that the destruction of the ozone was caused by chlorofluorocarbon
Chlorofluorocarbon
A chlorofluorocarbon is an organic compound that contains carbon, chlorine, and fluorine, produced as a volatile derivative of methane and ethane. A common subclass are the hydrochlorofluorocarbons , which contain hydrogen, as well. They are also commonly known by the DuPont trade name Freon...

s emitted by human products. With the ban of CFCs in the Montreal Protocol
Montreal Protocol
The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances believed to be responsible for ozone depletion...

 of 1989, it is believed that the ozone hole will close up by around 2065. In September 2006, NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

 satellite data showed that the Antarctic ozone hole was the largest on record, covering 27.5 million km2 (10.6 million sq mi).

On 6 September 2007, Belgian-based International Polar Foundation unveiled the Princess Elisabeth station
Princess Elisabeth Base
Princess Elisabeth Base, located on Utsteinen Nunatak in Dronning Maud Land is a Belgian polar station, taken into use on February 15, 2009. The station is the first polar base that combines eco-friendly construction materials, clean and efficient energy use, optimization of the station's energy...

, the world's first zero-emissions polar science station in Antarctica to research
Research
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...

 climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...

. Costing $16.3 million, the prefabricated station, which is part of International Polar Year
International Polar Year
The International Polar Year is a collaborative, international effort researching the polar regions. Karl Weyprecht, an Austro-Hungarian naval officer, motivated the endeavor, but died before it first occurred in 1882-1883. Fifty years later a second IPY occurred...

, was shipped to the South Pole from Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

 by the end of 2008 to monitor the health
Health
Health is the level of functional or metabolic efficiency of a living being. In humans, it is the general condition of a person's mind, body and spirit, usually meaning to be free from illness, injury or pain...

 of the polar region
Polar region
Earth's polar regions are the areas of the globe surrounding the poles also known as frigid zones. The North Pole and South Pole being the centers, these regions are dominated by the polar ice caps, resting respectively on the Arctic Ocean and the continent of Antarctica...

s. Belgian polar explorer Alain Hubert stated: "This base will be the first of its kind to produce zero emissions, making it a unique model of how energy should be used in the Antarctic." Johan Berte is the leader of the station design team and manager of the project which conducts research in climatology
Climatology
Climatology is the study of climate, scientifically defined as weather conditions averaged over a period of time, and is a branch of the atmospheric sciences...

, glaciology
Glaciology
Glaciology Glaciology Glaciology (from Middle French dialect (Franco-Provençal): glace, "ice"; or Latin: glacies, "frost, ice"; and Greek: λόγος, logos, "speech" lit...

 and microbiology
Microbiology
Microbiology is the study of microorganisms, which are defined as any microscopic organism that comprises either a single cell , cell clusters or no cell at all . This includes eukaryotes, such as fungi and protists, and prokaryotes...

.

In January 2008, the British Antarctic Survey
British Antarctic Survey
The British Antarctic Survey is the United Kingdom's national Antarctic operation and has an active role in Antarctic affairs. BAS is part of the Natural Environment Research Council and has over 400 staff. It operates five research stations, two ships and five aircraft in and around Antarctica....

 (BAS) scientists, led by Hugh Corr and David Vaughan, reported (in the journal Nature Geoscience
Nature Geoscience
Nature Geoscience is a monthly, peer reviewed, scientific journal published by Nature Publishing Group. The Chief Editor is Heike Langenberg. The first issue was published in January 2008.-Scope:...

) that 2,200 years ago, a volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

 erupted under Antarctica's ice sheet (based on airborne survey
Aerial survey
Aerial survey is a geomatics method of collecting information by using aerial photography, LiDAR or from remote sensing imagery using other bands of the electromagnetic spectrum, such as infrared, gamma, or ultraviolet. It can also refer to the chart or map made by analysing a region from the air...

 with radar images). The biggest eruption in Antarctica in the last 10,000 years, the volcanic ash was found deposited on the ice surface under the Hudson Mountains
Hudson Mountains
The Hudson Mountains is a group of parasitic cones forming nunataks just above the Antarctic ice sheet in west Ellsworth Land. They lie just east of Cranton Bay and Pine Island Bay at the eastern extremity of Amundsen Sea, and are bounded on the north by Cosgrove Ice Shelf and on the south by Pine...

, close to Pine Island Glacier
Pine Island Glacier
- Ice sheet drainage :The Antarctic ice sheet is the largest mass of ice on earth, containing a volume of water equivalent to of global sea level. The ice sheet forms from snow which falls onto the continent and compacts under its own weight. The ice then moves under its own weight toward the...

.

Meteorites



Meteorite
Meteorite
A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...

s from Antarctica are an important area of study of material formed early in the solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...

; most are thought to come from asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

s, but some may have originated on larger planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...

s. The first meteorites were found in 1912. In 1969, a Japanese expedition discovered nine meteorites. 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 well-preserved.

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 are pieces blasted off the Moon, and probably Mars, by impacts. These specimens, particularly ALH84001
ALH84001
Allan Hills 84001 is a meteorite that was found in Allan Hills, Antarctica on December 27, 1984 by a team of U.S. meteorite hunters from the ANSMET project. Like other members of the group of SNCs , ALH 84001 is thought to be from Mars. However, it does not fit into any of the previously...

 discovered by ANSMET
ANSMET
ANSMET is a program funded by the Office of Polar Programs of the National Science Foundation that looks for meteorites in the Transantarctic Mountains. This geographical area serves as a collection point for meteorites that have originally fallen on the extensive high-altitude ice fields...

, 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.

In 2006, a team of researchers from Ohio State University
Ohio State University
The Ohio State University, commonly referred to as Ohio State, is a public research university located in Columbus, Ohio. It was originally founded in 1870 as a land-grant university and is currently the third largest university campus in the United States...

 used gravity measurements by NASA's GRACE
Gravity Recovery and Climate Experiment
The Gravity Recovery And Climate Experiment , a joint mission of NASA and the German Space Agency, has been making detailed measurements of Earth's gravity field since its launch in March 2002....

 satellites to discover the 300 miles (482.8 km)-wide Wilkes Land crater
Wilkes Land crater
Wilkes Land crater is an informal term that may apply to two separate cases of conjectured giant impact craters hidden beneath the ice cap of Wilkes Land, East Antarctica...

, which probably formed about 250 million years ago.

Ice mass and global sea level


Due to its location at the South Pole, Antarctica receives relatively little solar radiation. This means that it is a very cold continent where water is mostly in the form of ice. Precipitation is low (most of Antarctica is a desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...

) and almost always in the form of snow, which accumulates and forms a giant ice sheet which covers the land. Parts of this ice sheet form moving glaciers known as ice streams, which flow towards the edges of the continent. Next to the continental shore are many ice shelves
Ice shelf
An ice shelf is a thick, floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Ice shelves are only found in Antarctica, Greenland and Canada. The boundary between the floating ice shelf and the grounded ice that feeds it is called...

. These are floating extensions of outflowing glaciers from the continental ice mass. Offshore, temperatures are also low enough that ice is formed from seawater
Seawater
Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% . This means that every kilogram of seawater has approximately of dissolved salts . The average density of seawater at the ocean surface is 1.025 g/ml...

 through most of the year. It is important to understand the various types of Antarctic ice to understand possible effects on sea levels and the implications of global warming.

Sea ice extent expands annually in the Antarctic winter and most of this ice melts in the summer. This ice is formed from the ocean water and floats in the same water and thus does not contribute to rise in sea level. The extent of sea ice
Sea ice
Sea ice is largely formed from seawater that freezes. Because the oceans consist of saltwater, this occurs below the freezing point of pure water, at about -1.8 °C ....

 around Antarctica has remained roughly constant in recent decades, although the thickness changes are unclear.

Melting of floating ice shelves (ice that originated on the land) does not in itself contribute much to sea-level rise (since the ice displaces only its own mass of water). However it is the outflow of the ice from the land to form the ice shelf which causes a rise in global sea level. This effect is offset by snow falling back onto the continent. Recent decades have witnessed several dramatic collapses of large ice shelves around the coast of Antarctica, especially along the Antarctic Peninsula. Concerns have been raised that disruption of ice shelves may result in increased glacial outflow from the continental ice mass.

On the continent itself, the large volume of ice present stores around 70% of the world's fresh water. This ice sheet is constantly gaining ice from snowfall and losing ice through outflow to the sea. West Antarctica is currently experiencing a net outflow of glacial ice, which will increase global sea level over time. A review of the scientific studies looking at data from 1992 to 2006 suggested that a net loss of around 50 gigatonnes of ice per year was a reasonable estimate (around 0.14 mm of sea level rise). Significant acceleration of outflow glaciers in the Amundsen Sea Embayment may have more than doubled this figure for 2006.

East Antarctica is a cold region with a ground base above sea level
Above mean sea level
The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach...

 and occupies most of the continent. This area is dominated by small accumulations of snowfall which becomes ice and thus eventually seaward glacial flows. The mass balance of the East Antarctic Ice Sheet
East Antarctic Ice Sheet
The East Antarctic Ice Sheet is one of two large ice sheets in Antarctica, and the largest on the entire planet. The EAIS lies between 45° West and 168° East longitudinally....

 as a whole is thought to be slightly positive (lowering sea level) or near to balance. However, increased ice outflow has been suggested in some regions.

Effects of global warming


Some of Antarctica has been warming up; particularly strong warming has been noted on the Antarctic Peninsula. A study by Eric Steig published in 2009 noted for the first time that the continent-wide average surface temperature trend of Antarctica is slightly positive at >0.05 °C (0.09 °F) per decade from 1957 to 2006. This study also noted that West Antarctica has warmed by more than 0.1 °C (0.2 °F) per decade in the last 50 years, and this warming is strongest in winter and spring. This is partly offset by fall cooling in East Antarctica. There is evidence from one study that Antarctica is warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

 as a result of human carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

 emissions. However, the small amount of surface warming in West Antarctica is not believed to be directly affecting the West Antarctic Ice Sheet
West Antarctic Ice Sheet
The West Antarctic Ice Sheet is the segment of the continental ice sheet that covers West Antarctica, the portion of Antarctica on the side of the Transantarctic Mountains which lies in the Western Hemisphere. The WAIS is classified as a marine-based ice sheet, meaning that its bed lies well...

's contribution to sea level. Instead the recent increases in glacier outflow are believed to be due to an inflow of warm water from the deep ocean, just off the continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...

. The net contribution to sea level from the Antarctic Peninsula is more likely to be a direct result of the much greater atmospheric warming there.

In 2002 the Antarctic Peninsula's Larsen-B ice shelf collapsed. Between 28 February and 8 March 2008, about 570 square kilometres (220.1 sq mi) of ice from the Wilkins Ice Shelf
Wilkins Sound
Wilkins Sound is a seaway in Antarctica that is largely occupied by the Wilkins Ice Shelf. It is located on the southwest side of the Antarctic Peninsula between the concave western coastline of Alexander Island and the shores of Charcot Island and Latady Island farther to the west.Its northern...

 on the southwest part of the peninsula collapsed, putting the remaining 15000 km² (5,791.5 sq mi) of the ice shelf at risk. The ice was being held back by a "thread" of ice about 6 km (4 mi) wide, prior to its collapse on 5 April 2009. According to NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

, the most widespread Antarctic surface melting of the past 30 years occurred in 2005, when an area of ice comparable in size to California briefly melted and refroze; this may have resulted from temperatures rising to as high as 5 °C (41 °F).

Ozone depletion



Each year a large area of low ozone concentration or "ozone hole" grows over Antarctica. This hole covers the whole continent and is at its largest in September. 2008 saw the longest lasting hole on record, which remained until the end of December. The hole was detected by scientists in 1985 and has tended to increase over the years of observation. The ozone hole is attributed to the emission of chlorofluorocarbon
Chlorofluorocarbon
A chlorofluorocarbon is an organic compound that contains carbon, chlorine, and fluorine, produced as a volatile derivative of methane and ethane. A common subclass are the hydrochlorofluorocarbons , which contain hydrogen, as well. They are also commonly known by the DuPont trade name Freon...

s or CFCs into the atmosphere, which decompose the ozone
Ozone
Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope...

 into other gases.

Some scientific studies suggest that ozone depletion may have a dominant role in the recent climate changes in Antarctica (and a wider area of the Southern Hemisphere). Ozone absorbs large amounts of ultraviolet radiation in the stratosphere
Stratosphere
The stratosphere is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. It is stratified in temperature, with warmer layers higher up and cooler layers farther down. This is in contrast to the troposphere near the Earth's surface, which is cooler...

. Ozone depletion over Antarctica can cause a cooling of around 6 °C in the local stratosphere. This cooling has the effect of intensifying the westerly winds which flow around the continent (the polar vortex
Polar vortex
A polar vortex is a persistent, large-scale cyclone located near one or both of a planet's geographical poles. On Earth, the polar vortices are located in the middle and upper troposphere and the stratosphere...

) and thus prevents outflow of the cold air near the South Pole. As a result, the continental mass of the East Antarctic ice sheet is held at lower temperatures, and the peripheral areas of Antarctica, especially the Antarctic Peninsula, are subject to higher temperatures, which promote accelerated melting. Recent models also suggest that the ozone depletion/enhanced polar vortex effect also accounts for the recent increase in sea-ice just offshore of the continent.

See also


  • Flag of Antarctica
    Flag of Antarctica
    Antarctica has no official flag as it is not a nation nor is it ruled by a single government or body. The Antarctic Treaty Organization adopted a flag in 2002 and is used as an unofficial symbol of the continent...

  • Mammals of Antarctica
  • Soviet Antarctic Expedition
    Soviet Antarctic Expedition
    The Soviet Antarctic Expedition was part of the Arctic and Antarctic Research Institute of the Soviet Committee on Antarctic Research of the Academy of Sciences of the USSR....


External links