ANTARCTICA

Antarctica is Earth’s southernmost continent, underlying the South Pole. It is situated in the Antarctic region of the southern hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At 14.0 million km2 (5.4 million sq mi), it is the fifth-largest continent in area after Asia, Africa, North America, and South America. About 98% of Antarctica is covered by ice, which averages at least 1.6 kilometres (1.0 mi) in thickness.

Antarctica, on average, is the coldest, driest, and windiest continent, and has the highest average elevation of all the continents. Antarctica is considered a desert, with annual precipitation of only 200 mm (8 inches) along the coast and far less inland. 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 plants and animals survive there, including penguins, seals, nematodes, Tardigrades, mites, many types of algae and other microorganisms, and tundra vegetation.

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. The continent, however, 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. 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 various research interests.

Geography

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 14,000,000 km2 (5,400,000 sq mi), making it the fifth-largest continent, about 1.3 times as large as Europe. The coastline measures 17,968 km (11,165 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%

Climate

Antarctica is the coldest place on Earth. The coldest natural temperature ever recorded on Earth was −89.2 °C (−128.6 °F) at the Russian Vostok Station in Antarctica on 21 July 1983. For comparison, this is 11 °C (20 °F) colder than subliming dry ice. Antarctica is a frozen desert with little precipitation; the South Pole itself receives less than 10 cm (4 in) per year, on average. Temperatures reach a minimum of between −80 °C (−112 °F) and −90 °C (−130 °F) in the interior in winter and reach a maximum of between 5 °C (41 °F) and 15 °C (59 °F) near the coast in summer. Sunburn is often a health issue as the snow surface reflects almost all of the ultraviolet light falling on it.

East Antarctica is colder than its western counterpart because of its higher elevation. Weather fronts rarely penetrate far into the continent, leaving the center cold and dry. Despite the lack of precipitation over the central portion of the continent, ice there lasts for extended time periods. Heavy snowfalls are not uncommon on the coastal portion of the continent, where snowfalls of up to 1.22 metres (48 in) in 48 hours have been recorded.

Antarctica is colder than the Arctic 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 winds that pass by the Earth. Another unique spectacle is diamond dust, a ground-level cloud composed of tiny ice crystals. It generally forms under otherwise clear or nearly clear skies, so people sometimes also refer to it as clear-sky precipitation. A sun dog, a frequent atmospheric optical phenomenon, is a bright “spot” beside the true sun.
 

Flora and fauna

The climate of Antarctica does not allow extensive vegetation. A combination of freezing temperatures, poor soil quality, lack of moisture, and lack of sunlight inhibit plant growth. As a result, plant life is limited to mostly mosses and liverworts. The autotrophic community is made up of mostly protists. The flora of the continent largely consists of lichens, bryophytes, algae, and fungi. Growth generally occurs in the summer, and only for a few weeks at most.

 There are more than 200 species of lichens and about 50 species of bryophytes, such as mosses. Seven hundred species of algae exist, most of which are phytoplankton. Multicolored snow algae and diatoms are especially abundant in the coastal regions during the summer. There are two species of flowering plants found in the Antarctic Peninsula: the Antarctic hair grass and the Antarctic pearlwort.
 
Few terrestrial vertebrates live in Antarctica.  Invertebrate life includes microscopic mites. Recently ancient ecosystems consisting of several types of bacteria have been found living trapped deep beneath glaciers. The flightless midge Belgica antarctica, just 12 millimeters (0.5 in) in size, is the largest purely terrestrial animal in Antarctica. The Snow Petrel 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 penguins, blue whales, orcas, colossal squids and fur seals. The Emperor penguin is the only penguin that breeds during the winter in Antarctica, while the Adélie Penguin breeds farther south than any other penguin. The Rockhopper penguin has distinctive feathers around the eyes, giving the appearance of elaborate eyelashes. King penguins, Chinstrap penguins, and Gentoo Penguins also breed in the Antarctic.

Antarctic territories

Antarctica, Argentina territorial claim.svg Antarctica, Australia territorial claim.svg Antarctica, Chile territorial claim.svg Antarctica, France territorial claim.svg Antarctica, New Zealand territorial claim.svg Antarctica, Norway territorial claim.svg Antarctica, United Kingdom territorial claim.svg
Argentina Australia Chile France New Zealand Norway United Kingdom
Main article: Antarctic territorial claims
Date Country Territory Claim limits
1908  United Kingdom  British Antarctic Territory 20°W to 80°W
1923  New Zealand Ross Dependency 150°W to 160°E
1924  France French Southern and Antarctic Lands Adélie Land 142°2’E to 136°11’E
1929  Norway  Peter I Island 68°50′S 90°35′W / 68.833°S 90.583°W / -68.833; -90.583 (Peter I Island)
1933  Australia Australia Australian Antarctic Territory 160°E to 142°2’E and
136°11’E to 44°38’E
1939  Norway  Queen Maud Land 44°38’E to 20°W
1940  Chile Antártica Chilena Province Antártica 53°W to 90°W
1943  Argentina  Argentine Antarctica 25°W to 74°W
None Unclaimed territory
(Marie Byrd Land)
90°W to 150°W
(except the Peter I Island)

The Argentine, British, and Chilean claims all overlap, and have caused friction. The areas shown as Australia’s and New Zealand’s claims were British territory until they were handed over following the countries’ independence. Australia currently claims the largest area. Australia and New Zealand both recognise the British claim, and vice-versa.

Countries interested in participating in a possible territorial division of Antarctica

This group of countries participating as members of Antarctica Treaty have a territorial interest in the Antarctic continent:

  •  Brazil has a designated ‘zone of interest’ that is not an actual claim.
  •  Peru has formally reserved its right to make a claim.
  •  Russia has reserved its right to claim “territories discovered by Russians”, which potentially may refer to the entire continent.
  •  South Africa has formally reserved its right to make a claim.
  •  Spain has formally reserved its right to make a claim.
  •  United States has formally reserved its right to make a claim.

-Let’s discover more interesting things about Antarctica!

http://www.youtube.com/watch?v=AlweOV6U4Vs&feature=related

http://www.youtube.com/watch?v=gpFUJlm7_fo&feature=related

http://www.youtube.com/watch?v=wFd-SfZN1X0&feature=related

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