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Arctic From Wikipedia, the free encyclopedia Arctic http://en.wikipedia.org/wiki/Arctic
For the ships, see MV Arctic, SS Arctic, USS Arctic
The red line indicates the 10°C isotherm in July, sometimes used to define the Arctic region border
Artificially coloured topographical map of the Arctic region
The Arctic (/ɑɹktɪk/, /ɑɹtɪk/) is the region around the Earth's North Pole, opposite the Antarctic region around the South Pole. The Arctic includes the Arctic Ocean (which overlies the North Pole) and parts of Canada, Greenland (a territory of Denmark), Russia, the United States (Alaska), Iceland, Norway, Sweden and Finland.
Arctic shrinkage is currently taking place due to global warming. This is leading to fears of a catastrophic Arctic methane release, and prompting calls for Arctic geoengineering to prevent it.
The word Arctic comes from the Greek αρκτικός (arktikos), "near the Bear, arctic, northern"[1] and that from the word άρκτος (arktos), which means bear [2]. The name refers to the constellation Ursa Major, the "Great Bear", which is prominent in the northern portion of the celestial sphere.
There are many definitions of the Arctic region. The boundary is generally considered to be north of the Arctic Circle (66° 33’N), which is the approximate limit of the midnight sun and the polar night. Other definitions are based on climate and ecology, such as the 10 °C (50 °F) July isotherm, which roughly corresponds to the tree line in most of the Arctic. Socially and politically, the Arctic region includes the northern territories of the eight Arctic states, including Sapmi, although by natural science definitions much of this territory is considered subarctic.
The Arctic region consists of a vast ice-covered ocean (which is sometimes considered to be a northern arm of the Atlantic Ocean) surrounded by treeless permafrost. In recent years the extent of the sea ice has declined. Life in the Arctic includes organisms living in the ice,[3] zooplankton and phytoplankton, fish and marine mammals, birds, land animals, plants, and human societies.
The Arctic region is a unique area among Earth's ecosystems. The cultures in the region and the Arctic indigenous peoples have adapted to its cold and extreme conditions.
Contents
[hide]
* 1 Nature
o 1.1 Climate
o 1.2 Plants
o 1.3 Animals
o 1.4 Natural resources
o 1.5 Paleo-history
* 2 Indigenous population
* 3 International cooperation and politics
o 3.1 Territorial claims
o 3.2 Scientific exploration
o 3.3 Pollution
* 4 Climate change
* 5 Arctic waters
* 6 Arctic lands
* 7 See also
* 8 References
* 9 External links
[edit] Nature
[edit] Climate
Main article: Climate of the Arctic
The Arctic's climate is characterized by cold winters and cool summers. Precipitation mostly comes in the form of snow. The Arctic's annual precipitation is low, with most of the area receiving less than 50 centimetres (20 in). High winds often stir up snow, creating the illusion of continuous snowfall. Average winter temperatures can be as low as −40 °C (−40 °F), and the coldest recorded temperature is approximately −68 °C (−90 °F). Coastal Arctic climates are moderated by oceanic influences, having generally warmer temperatures and heavier snowfalls than the colder and drier interior areas.
[edit] Plants
Arctic vegetation is composed of plants such as dwarf shrubs, graminoids, herbs, lichens and mosses, which all grow relatively close to the ground, forming tundra. As one moves northward, the amount of warmth available for plant growth decreases considerably. In the northernmost areas, plants are at their metabolic limits, and small differences in the total amount of summer warmth make large differences in the amount of energy available for maintenance, growth and reproduction. Colder summer temperatures cause the size, abundance, productivity and variety of plants to decrease. Trees cannot grow in the Arctic, but in its warmest parts, shrubs are common and can reach 2 m (6 ft 7 in) in height; sedges, mosses and lichens can form thick layers. In the coldest parts of the Arctic, much of the ground is bare; nonvascular plants such as lichens and mosses predominate, along with a few scattered grasses and forbs (like the Arctic poppy).
[edit] Animals
Muskox
Herbivores on the Tundra include the Arctic hare, lemming, muskox, and caribou. They are preyed on by the Arctic fox and wolf. The polar bear is also a predator, though it prefers to hunt for marine life from the ice. There are also many birds and marine species endemic to the colder regions. Other land animals include wolverines, ermines, and arctic ground squirrels. Marine mammals include seals, walrus, and several species of cetacean—baleen whales and also narwhals and belugas.
[edit] Natural resources
See also: Petroleum exploration in the Arctic
The Arctic includes sizable natural resources (oil, gas, minerals, forest—if the subarctic is included—and fish) to which modern technology and the economic opening up of Russia have given significant new opportunities. The interest of the tourism industry is also on the increase.
The Arctic is one of the last and most extensive continuous wilderness areas in the world, and its significance in preserving biodiversity and genotypes is considerable. The increasing presence of humans fragments vital habitats. The Arctic is particularly susceptible to the abrasion of groundcover and to the disturbance of the rare reproduction places of the animals that are characteristic to the region. The Artctic also holds 1/5 of the Earth water supply, which means that if the temperature goes up, the Artic will melt and will flood many countries.
[edit] Paleo-history
Marine fossils in Canadian Arctic
During the Cretaceous, the Arctic still had seasonal snows, though only a light dusting and not enough to permanently hinder plant growth.[citation needed] Animals such as Chasmosaurus, Hypacrosaurus, Troodon, and Edmontosaurus may have all migrated north to take advantage of the summer growing season, and migrated south to warmer climes when the winter came. A similar situation may also have been found amongst dinosaurs that lived in Antarctic regions, such as Muttaburrasaurus of Australia.
[edit] Indigenous population
Main article: Circumpolar peoples
Further information: Circumpolar religion, Indigenous peoples of Siberia, and Inuit Circumpolar Council
The Inuit are the descendants of what anthropologists call the Thule culture, a nomadic people who emerged from western Alaska around 1000 CE and spread eastwards across the Arctic, displacing the related Dorset culture (in Inuktitut, the Tuniit). Inuit legends speak of the Tuniit as "giants", people who were taller and stronger than the Inuit, but who were easily scared off and retreated from the advancing Inuit. Researchers believe that the Dorset culture lacked dogs, boats and other technologies that gave the expanding Inuit society a large advantage over them. By 1300, the Inuit had settled west Greenland, and finally moved into east Greenland over the following century.
The Tuniit survived in Aivilik, Southampton and Coats Islands, until the beginning of the 20th century. They were known as Sadlermiut (Sallirmiut in the modern spelling). Their population had been ravaged by diseases brought by contact with Europeans, and the last of them fell in a flu epidemic caught from a passing whaler in 1902. The area has since been resettled by Inuit. Genetic research suggests that there was little or no intermarriage between the Tuniit and the Inuit over the thousand years of contact in the Canadian Arctic.
[edit] International cooperation and politics
The Arctic region is a focus of international political interest. International Arctic cooperation got underway on a broad scale well over ten years ago. The International Arctic Science Committee (IASC), hundreds of scientists and specialists of the Arctic Council, the Barents Euro-Arctic Council and its regional cooperation have compiled high quality information on the Arctic.
[edit] Territorial claims
Main article: Territorial claims in the Arctic
No country owns the North Pole or the region of the Arctic Ocean surrounding it. The surrounding Arctic states, the United States, Canada, Russia, Norway and Denmark (via Greenland), are limited to a 370 kilometre (200 nautical mile) economic zone around their coasts.
Upon ratification of the United Nations Convention on the Law of the Sea, a country has ten years to make claims to extend its 200 mile zone.[4] Due to this, Norway (ratified the convention in 1996[5]), Russia (ratified in 1997[5]), Canada (ratified in 2003[5]) and Denmark (ratified in 2004[5]) launched projects to establish claims that certain Arctic sectors should belong to their territories.
On August 2, 2007, two Russian bathyscaphes, MIR-1 and MIR-2, for the first time in history descended to the Arctic seabed beneath the North Pole and placed there a Russian flag made of rust-proof titanium alloy. The mission was a scientific expedition, but the flag-placing raised concerns of a race for control of the Arctic's vast petroleum resources[6](See 2007 Russian North Pole expedition)
Foreign Ministers and other officials representing Canada, Denmark, Norway, Russia, and the United States met in Ilulissat, Greenland on May 28, 2008 at the Arctic Ocean Conference and announced the Ilulissat Declaration.[7][8]
[edit] Scientific exploration
Since 1937 the whole Arctic region was extensively explored by the Soviet and Russian manned drifting ice stations. Scientific settlements that were established on the drift ice were carried thousands of kilometers by the ice flow.[9]
[edit] Pollution
Long-range pollution pathways to the Arctic
The Arctic is comparatively clean, although there are certain ecologically difficult localized pollution problems that present a serious threat to people’s health living around these pollution sources. Due to the prevailing worldwide sea and air currents, the Arctic area is the fallout region for long-range transport pollutants, and in some places the concentrations exceed the levels of densely populated urban areas. An example of this is the phenomenon of Arctic haze, which is commonly blamed on long-range pollutants. Another example is with the bioaccumulation of PCB's (polychlorinated biphenyls) in Arctic wildlife and people.
[edit] Climate change
Main articles: Arctic shrinkage and Arctic methane release
Arctic sea ice coverage as of 2007 compared to 2005 and also compared to 1979-2000 average
The Arctic is especially vulnerable to the effects of global warming as has become apparent in the melting sea ice in recent years. Climate models predict much greater warming in the Arctic than global average.[10] This fact has garnered significant international attention to the region. In particular, there are concerns that Arctic shrinkage, a consequence of melting glaciers and other ice in Greenland, could soon contribute to a substantial rise in sea levels worldwide.[11] A recent study by a research group at Naval Postgraduate School, Monterey, California working with members of NASA and the Institute of Oceanology at the Polish Academy of Sciences estimate that the Arctic sea could be ice-free in the summer as soon as 2013.[12][13] The Arctic sea ice melted at an unprecedented rate, well ahead of the estimates generated by climate models, in 2007.
In September of 2008, the extent of the summer Arctic ice cap was at a near-record low, only 9 percent greater than the record low in 2007, and 33.6 percent below the average extent of sea ice from 1979 to 2000. [14]
The current Arctic shrinkage is leading to widespread fears of a potentially catastrophic Arctic methane release. Release of methane stored in clathrates and permafrost could have a devastating effect on the Earth's atmosphere and could cause abrupt and severe global warming[15], as methane is a potent greenhouse gas. Similar methane release events have been linked to the great dying (a mass extinction event) and the Paleocene-Eocene thermal maximum (an abrupt climate change event). This process of Arctic methane release may cause positive feedback effects which rapidly accelerate global warming, due to the clathrate gun effect.[16]
Apart from concerns regarding the detrimental effects of warming in the Arctic, some potential opportunities have gained attention as well. However, it should be noted that these advantages are relatively minor compared to the risk of runaway global warming. The melting of the ice is making the so-called Northwest passage, the shipping routes through the northern-most latitudes, more navigable, raising the possibility that the Arctic region will become a prime trade route.[17] In addition, it is believed that the Arctic seabed may contain substantial oil fields which may become accessible if the ice covering them melts.[18] These factors have led to recent international debates as to which nations can claim sovereignty or ownership over the waters of the Arctic.[19][20][21].
NOAA's Arctic Report Card [22] presents annually-updated, peer-reviewed information on recent observations of environmental conditions in the Arctic relative to historical records. In 2008, there continues to be widespread and, in some cases, dramatic evidence of an overall warming of the Arctic system.
[edit] Arctic waters
* Arctic Ocean
* Baffin Bay
* Beaufort Sea
* Barents Sea
* Bering Sea
* Bering Strait
* Chukchi Sea
* Davis Strait
* Denmark Strait
* East Siberian Sea
* Greenland Sea
* Hudson Bay
* Kara Sea
* Laptev Sea
* Nares Strait
* Norwegian Sea
[edit] Arctic lands
* Alaska (USA)
* Aleutian Islands (USA)
* Bear Island (Norway)
* Canadian Arctic Archipelago
* Diomede Islands (Russia/USA)
* Franz Josef Land (Russia)
* Newfoundland and Labrador (Canada)
* New Siberian Islands (Russia)
* Northwest Territories (Canada)
* Novaya Zemlya (Russia)
* Nunavik (northern Québec, Canada)
* Nunavut (Canada)
* Finnmark (Norway)
* Greenland (Denmark)
* Iceland (majority of island south of arctic circle)
* Jan Mayen (Norway)
* Russian Arctic islands
* Severnaya Zemlya (Russia)
* Siberia (Russia)
* Svalbard (Norway)
* Yukon (Canada)
* Wrangel Island (Russia)
[edit] See also
* Arctic Climate Impact Assessment (ACIA)
* Arctic Haze
* Arctic National Wildlife Refuge (ANWR) (in Alaska in the US)
* Arctic Ocean
* Arctic Refuge drilling controversy
* Arctic Cordillera
* Arctic Research Office (ARO) (of the US)
* Explorers of the Arctic (Category)
* Exploration of the Arctic (Category)
* Extreme points of the Arctic
* Nordicity
* Polar climate
* Polar ice packs
[edit] References
1. ^ Arktikos, Henry George Liddell, Robert Scott, A Greek-English Lexicon, at Perseus
2. ^ Arktos, Henry George Liddell, Robert Scott, A Greek-English Lexicon, at Perseus
3. ^ http://www.arctic.noaa.gov/essay_krembsdeming.html
4. ^ "United Nations Convention on the Law of the Sea (Annex 2, Article 4)". Retrieved on 2007-07-26.
5. ^ a b c d http://www.un.org/Depts/los/reference_files/status2007.pdf
6. ^ The Battle for the Next Energy Frontier: The Russian Polar Expedition and the Future of Arctic Hydrocarbons, by Shamil Midkhatovich Yenikeyeff and Timothy Fenton Krysiek, Oxford Institute for Energy Studies, August 2007
7. ^ "Conference in Ilulissat, Greenland: Landmark political declaration on the future of the Arctic", Ministry of Foreign Affairs of Denmark (2008-05-28). Retrieved on 6 June 2008.
8. ^ "The Ilulissat Declaration". um.dk (2008-05-28). Retrieved on 2008-06-06.
9. ^ North Pole drifting stations (1930s-1980s)
10. ^ ACIA, Impacts of a Warming Arctic: Arctic Climate Impact Assessment, Cambridge University Press, 2012. [1]
11. ^ Study: Glaciers contributing more to rising seas,2007[2]
12. ^ Arctic summers ice-free 'by 2013' Jonathan Amos BBC News December 12, 2007 Retrieved February 11, 2008
13. ^ Arctic ice melt worse than predicted: scientists Barbara Miller, www.abc.net.au, December 13, 2007 Retrieved February 9, 2008
14. ^ Global Sea Ice Extent and Concentration: What sensors on satellites are telling us about sea ice "National Snow and Ice Data Center" Retrieved January 24, 2009
15. ^ http://www.sciencedaily.com/releases/2008/09/080918192943.htm
16. ^ http://www.nationmaster.com/encyclopedia/Clathrate-gun-hypothesis
17. ^ Will ice melt open fabled Northwest Passage?, CNN.com, 29 Aug, 2002[3]
18. ^ The great Arctic Circle oil rush, CNN.com, 8 Aug, 2007[4]
19. ^ New patrol ships will reassert northern sovereignty: PM, Victoria Times Colonist, 9 July, 2007[5]
20. ^ Russia stakes its claim on North Pole in underwater search for oil, Times Online, 28 July, 2007[6]
21. ^ "Arctic melt stuns scientists", CBS News (2007-10-09).
22. ^ NOAA Arctic Report Card - Updated annually
* Arctic Centre, Rovaniemi Arctic research
* WordReference.com Dictionary Etymology
* CIA World Factbook 2002 - Arctic Region Large version of the Arctic region map
* Arctic Theme Page Comprehensive Arctic Resource from NOAA.
* Bering Sea Climate and Ecosystem Current state of the Bering Sea Climate and Ecosystem. Comprehensive resource on the Bering Sea with viewable oceanographic, atmospheric, climatic, biological and fisheries data with ecosystem relevance, recent trends, essays on key Bering Sea issues, maps, photos, animals and more. From NOAA.
* Arctic time series: The Unaami Data collection Viewable interdisciplinary, diverse collection of Arctic variables from different geographic regions and data types.
* Arctic exploration and history
* Arctic research
[edit] External links
* The Canadian Museum of Civilization - The Story of the Canadian Arctic Expedition of 1913-1918
* The Battle for the Next Energy Frontier: The Russian Polar Expedition and the Future of Arctic Hydrocarbons, by Shamil Midkhatovich Yenikeyeff and Timothy Fenton Krysiek, Oxford Energy Comment, Oxford Institute for Energy Studies, August 2007
* UNEP/GRID-Arendal Maps and Graphics library Information resources from the UN Environment programme
* Arctic Institute of North America Digital Library Over 8000 photographs dating from the late 1800s through the 1900s.
* euroarctic.com News service from the Barents region provided by Norwegian Broadcasting Corp (NRK), Swedish Radio (SR) and STBC Murman.
* WWF International Arctic Programme Arctic environment and conservation information
* International Polar Foundation
* Arctic Council
* NOAA Arctic Theme Page
* Arctic Environmental Atlas Circum-Arctic interactive map, with multiple layers of information
* GLOBIO Human Impact maps Report on human impacts on the Arctic
* International Arctic Research Center
* Vital Arctic Graphics Overview and case studies of the Arctic environment and the Arctic Indigenous Peoples.
* Arctic and Taiga Canadian Atlas
* Summary
* PolarTREC PolarTREC-Teachers and Researchers Exploring and Collaborating
* NOAA State of the Arctic Report 2006
* UN Environment Programme Key Polar Centre at UNEP/GRID-Arendal
* Arctic Geobotanical Atlas, University of Alaska Fairbanks
* AMAP - the Arctic Monitoring and Assessment Programme
* Polar Discovery
* Arctic Transform Transatlantic Policy Options for Supporting Adaptation in the Marine Arctic
[hide]
v • d • e
Regions of the world
Location of Africa Africa North (Maghreb) · Central · South · West · East Location of the Middle East Middle East Arabian Peninsula · Caucasus · Levant · Mashriq · Mesopotamia · Persian Plateau
Location of the Americas Americas North (Northern • Middle • Central • Caribbean) · South (Southern Cone) · Anglo · Latin Location of Oceania Oceania Australasia · Melanesia · Micronesia · Polynesia
Location of Asia Asia East (Far East • Asia-Pacific) · Southeast (Indochina • Malay Archipelago) · South · Southwest · Central · North (Siberia) Location of the Polar regions Polar Arctic · Antarctica
Location of Europe Europe Western · Central · Eastern · Northern · Southern Oceans of the world Oceans World · Arctic · Atlantic · Indian · Pacific · Southern
See also Continents of the world
Retrieved from "http://en.wikipedia.org/wiki/Arctic"
Categories: Arctic | Poles | Greek loanwords
Hidden categories: All articles with unsourced statements | Articles with unsourced statements since May 2007
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ANTARCTIC
Antarctica
From Wikipedia, the free encyclopedia
(Redirected from Antarctic)
Featured article
For other uses, see Antarctica (disambiguation).
Antarctica http://en.wikipedia.org/wiki/Antarctic
Area (Overall)
(ice-free)
(ice-covered)
14,000,000 km² (5,405,430.2 sq mi)
280,000 km² (108,108.6 sq mi)
13,720,000 km² (5,297,321.6 sq mi)
Population
(permanent)
(non-permanent) 7th
1
≈1,000
Dependencies
4[show]
· Bouvet Island
· French Southern Territories
· Heard Island and McDonald Islands
· South Georgia and the South Sandwich Islands
Official Territorial claims Antarctic Treaty System
8[show]
· Adelie Land
· Antártica
· Antártida Argentina
· Australian Antarctic Territory
· British Antarctic Territory
· Queen Maud Land
· Peter I Island
· Ross Dependency
Unofficial Territorial claims
1[show]
Antártica Brasileira
Reserved the right to make claims
2[show]
· Russian Federation
· United States of America
Time Zones None
UTC-3 (Graham Land only)
Internet TLD .aq
Calling Code Dependent on the parent country of each base
Adelie Penguin chicks in Antarctica, with MS Explorer and an iceberg in the background. The image was taken in January 1999. MS Explorer sank on 23 November 2007, after hitting an iceberg in Antarctica.
Antarctica (en-us-Antarctica.ogg /ænˈtɑɹktɪkə/ (help·info)) is Earth's southernmost continent, overlying the South Pole. It is situated in the southern hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At 14.4 million km² (5.4 million sq mi), it is the fifth-largest continent in area after Asia, Africa, North America, and South America. About 98% of Antarctica is covered by ice, which averages at least 1.6 kilometres (1.0 mi) in thickness.
On average, Antarctica is the coldest, driest and windiest continent, and has the highest average elevation of all the continents.[1] Since there is little precipitation, except at the coasts, the interior of the continent is technically the largest desert in the world. There are no permanent human residents. Only cold-adapted plants and animals survive there, including penguins, seals, mosses, lichen, and many types of algae.
The name Antarctica is the romanized version of the Greek compound word ανταρκτική (antarktikí), feminine of ανταρκτικός (antarktikos)[2], meaning "opposite to the north"[3]. Although myths and speculation about a Terra Australis ("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 Mikhail Lazarev and Fabian Gottlieb von Bellingshausen. However, the continent remained largely neglected for the rest of the 19th century because of its hostile environment, lack of resources, and isolation. The first formal use of the name "Antarctica" as a continental name in the 1890s is attributed to the Scottish cartographer John George Bartholomew. Antarctica is considered a desert, with annual precipitation of only 200 mm (8 inches) along the coast and far less inland.[4]
The Antarctic Treaty was signed in 1959 by twelve countries; to date, forty-six countries have signed the treaty. The treaty prohibits military activities and mineral mining, supports scientific research, and protects the continent's ecozone. Ongoing experiments are conducted by more than 4,000 scientists of many nationalities and with different research interests.[5]
Contents
[hide]
* 1 History
* 2 Geography
* 3 Geology
o 3.1 Geological history and paleontology
+ 3.1.1 Paleozoic era (540–250 mya)
+ 3.1.2 Mesozoic era (250–65 mya)
+ 3.1.3 Gondwanaland breakup (160–23 mya)
o 3.2 Geology of present-day Antarctica
* 4 Climate
* 5 Population
* 6 Flora and fauna
o 6.1 Flora
o 6.2 Fauna
* 7 Politics
o 7.1 Antarctic territories
o 7.2 Countries interested in participating in a possible territorial division of Antarctica
* 8 Economy
* 9 Transport
* 10 Research
o 10.1 Princess Elisabeth Polar Science Station
o 10.2 Meteorites
o 10.3 Volcanic eruption
* 11 Effects of global warming
* 12 Antarctic ozone depletion
* 13 See also
* 14 References
* 15 External links
[edit] History
Main article: History of Antarctica
See also: List of Antarctic expeditions
The snow surface at Dome C Station is representative of the majority of the continent's surface.
An iceberg dwarfs a ship in this 1920s English magazine illustration of a whaler in the Antarctic.
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—had existed since the times of Ptolemy (1st century AD), who suggested the idea to preserve the symmetry of all known landmasses in the world. Depictions of a large southern landmass were common in maps such as the early 16th century Turkish Piri Reis map. Even in the late 17th century, after explorers had found that South America and Australia were not part of 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's ships, HMS Resolution and Adventure, crossed the Antarctic Circle on 17 January 1773, in December 1773 and again in January 1774.[6] Cook in fact came within about 75 miles (121 km) of the Antarctic coast before retreating in the face of field ice in January 1773.[7] 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,[8] NASA,[9] the University of California, San Diego,[10] and other sources[11][12]), ships captained by three men sighted Antarctica in 1820: Fabian Gottlieb von Bellingshausen (a captain in the Russian Imperial Navy), Edward Bransfield (a captain in the Royal Navy), and Nathaniel Palmer (an American sealer out of Stonington, Connecticut). 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 Petrovich Lazarev reached a point within 32 kilometers (20 mi) of the Antarctic mainland and saw ice fields there. The first documented landing on mainland Antarctica was by the American sealer John Davis in Western Antarctica on 7 February 1821, although some historians dispute this claim.
In December 1839, as part of the United States Exploring Expedition of 1838–42 conducted by the United States Navy (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". That part of Antarctica was later named "Wilkes Land", a name it maintains to this day.
In 1841, explorer James Clark Ross passed through what is now known as the Ross Sea and discovered Ross Island (both of which were named for him). He sailed along a huge wall of ice that was later named the Ross Ice Shelf (also named for him). Mount Erebus and Mount Terror are named after two ships from his expedition: HMS Erebus and Terror.[13] Mercator Cooper landed in Eastern Antarctica on 26 January 1853.[14]
The Endurance at night during Ernest Shackleton's Imperial Trans-Antarctic Expedition in 1914.
During an expedition led by Ernest Shackleton in 1907, parties led by T. W. Edgeworth David became the first to climb Mount Erebus and to reach the South Magnetic Pole. Douglas Mawson, who assumed the leadership of the Magnetic Pole party on their perilous return, went on to lead several expeditions until retiring in 1931.[15] 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, the first to traverse the Transantarctic Mountain Range (via the Beardmore Glacier), and the first to set foot on the South Polar Plateau. On 14 December 1911, an expedition led by Norwegian polar explorer Roald Amundsen from the ship Fram became the first to reach the geographic South Pole, using a route from the Bay of Whales and up the Axel Heiberg Glacier.[16] One month later, the ill-fated Scott Expedition reached the pole.
Richard Evelyn 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 and conducting extensive geological and biological research.[17] 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 successfully landed an aircraft there.[18]
The first person to sail single-handed to Antarctica was the New Zealander David Henry Lewis, in a 10-meter steel sloop Ice Bird.
[edit] Geography
Main article: Geography of Antarctica
A satellite composite image of Antarctica.
Maritime Antarctica.
Size comparison Europe-Antarctica.
Centered asymmetrically around the South Pole and largely south of the Antarctic Circle, Antarctica is the southernmost continent and is surrounded by the Southern Ocean; alternatively, it may be considered to be surrounded by the southern Pacific, Atlantic, and Indian Oceans, or by the southern waters of the World Ocean. It covers more than 14 million km² (5.4 million sq mi), making it the fifth-largest continent, about 1.3 times larger than Europe. The coastline measures 17,968 kilometres (11,160 mi) and is mostly characterized by ice formations, as the following table shows:
Coastal types around Antarctica (Drewry, 1983) Type Frequency
Ice shelf (floating ice front) 44%
Ice walls (resting on ground) 38%
Ice stream/outlet glacier (ice front or ice wall) 13%
Rock 5%
Total 100%
Antarctica is divided in two by the Transantarctic Mountains close to the neck between the Ross Sea and the Weddell Sea. The portion west of the Weddell Sea and east of the Ross Sea is called Western Antarctica and the remainder Eastern Antarctica, because they roughly correspond to the Western and Eastern Hemispheres relative to the Greenwich meridian.
About 98% of Antarctica is covered by the Antarctic ice sheet, a sheet of ice averaging at least 1.6 kilometres (1.0 mi) thick. The continent has about 90% of the world's ice (and thereby about 70% of the world's fresh water). If all of this ice were melted, sea levels would rise about 60 metres (200 ft).[19] In most of the interior of the continent, precipitation is very low, down to 20 millimetres (0.8 in) per year; in a few "blue ice" areas precipitation is lower than mass loss by sublimation and so the local mass balance is negative. In the dry valleys the same effect occurs over a rock base, leading to a desiccated landscape.
West Antarctica is covered by the West Antarctic Ice Sheet. 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 streams, which account for about 10% of the ice sheet, flow to one of the many Antarctic ice shelves.
East Antarctica lies on the Indian Ocean side of the Transantarctic Mountains and comprising Coats Land, Queen Maud Land, Enderby Land, Mac Robertson Land, Wilkes Land and Victoria Land. All but a small portion of this region lies within the Eastern Hemisphere. East Antarctica is largely covered by the East Antarctic Ice Sheet.
Mount Erebus, an active volcano on Ross Island.
Vinson Massif, the highest peak in Antarctica at 4,892 metres (16,050 ft), is located in the Ellsworth Mountains. Antarctica contains many other mountains, both on the main continent and the surrounding islands. Although Antarctica is home to many volcanoes, only Mount Erebus is known to be active. Located on Ross Island, Erebus is the southernmost active volcano. There is another famous volcano called Deception Island, which is famous for its giant eruption in 1970. Minor eruptions are frequent and lava flow has been observed in recent years. Other dormant volcanoes may potentially be active.[20] In 2004, an underwater volcano was found in the Antarctic Peninsula by American and Canadian researchers. Recent evidence shows this unnamed volcano may be active.[21]
Antarctica is home to more than 70 lakes that lie at the base of the continental ice sheet. Lake Vostok, discovered beneath Russia's Vostok Station in 1996, is the largest of these subglacial lakes. 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.[22] There is some evidence, in the form of ice cores drilled to about 400 metres (1,300 ft) above the water line, that Vostok's waters may contain microbial life. The frozen surface of the lake shares similarities with Jupiter's moon Europa. If life is discovered in Lake Vostok, this would strengthen the argument for the possibility of life on Europa.[23][24] On 7 February 2008, a NASA team embarked on a mission to Lake Untersee, searching for extremophiles in its highly-alkaline waters. If found, these resilient creatures could further bolster the argument for extraterrestrial life in extremely cold, methane-rich environments.[25]
See also: Extreme points of Antarctica, Antarctic territories, and List of Antarctic and sub-Antarctic islands
[edit] Geology
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| Image courtesy of Jim Elliott/British Antarctic Survey |
| Part of the Wilkins Ice Shelf on tge Southwest Antarctic Peninsula as it began to break apart on March 6, 2008 (from BAS Twin Otter). |
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