Antarctica Desert by GhAyAl 2013/08/26 12:44
Antarctica
Earth's southernmost continent, containing the geographic 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 km 2 (5.4 million sq mi), it is the fifth-largest continent in area after Asia, Africa, North America, and South America. For comparison, Antarctica is nearly twice the size of Australia. About 98% of Antarctica is covered by ice that averages at least 1 mile (1.6 km) in thickness.
Area 14,000,000 km 2 (5,400,000 sq mi)
Antarctica
Earth's southernmost continent, containing the geographic 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 km 2 (5.4 million sq mi), it is the fifth-largest continent in area after Asia, Africa, North America, and South America. For comparison, Antarctica is nearly twice the size of Australia. About 98% of Antarctica is covered by ice that averages at least 1 mile (1.6 km) in thickness.
Area 14,000,000 km 2 (5,400,000 sq mi)
GhAyAl 2013/08/26 12:46
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.
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, animals (for example mites, nematodes, penguins, seals and tardigrades), bacteria, fungi, plants, and protista. Vegetation where it occurs is tundra.
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.
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, animals (for example mites, nematodes, penguins, seals and tardigrades), bacteria, fungi, plants, and protista. Vegetation where it occurs is tundra.
GhAyAl 2013/08/26 12:49
Antarctica is the coldest of Earth's continents. 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.
Antarctica is the coldest of Earth's continents. 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.
GhAyAl 2013/08/26 12:50
Each year a large area of low ozone concentration or "ozone hole" grows over Antarctica. This hole covers almost the whole continent and was at its largest in September 2008, when the longest lasting hole on record 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 chlorofluorocarbons or CFCs into the atmosphere, which decompose the ozone into other gases.
Each year a large area of low ozone concentration or "ozone hole" grows over Antarctica. This hole covers almost the whole continent and was at its largest in September 2008, when the longest lasting hole on record 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 chlorofluorocarbons or CFCs into the atmosphere, which decompose the ozone into other gases.
GhAyAl 2013/08/26 14:34
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 as a result of human carbon dioxide emissions.
However, the small amount of surface warming in West Antarctica is not believed to be directly affecting the West Antarctic Ice Sheet'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.
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.
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 as a result of human carbon dioxide emissions.
However, the small amount of surface warming in West Antarctica is not believed to be directly affecting the West Antarctic Ice Sheet'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.
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.
GhAyAl 2013/08/26 14:36
A study published in the sixth edition of the Nature Geoscience journal in 2013 (published online in December 2012) identified central West Antarctica as one of the fastest-warming regions on Earth. The researchers present a complete temperature record from Antarctica's Byrd Station and assert that it "reveals a linear increase in annual temperature between 1958 and 2010 by 2.41.2 C". At the time that the research was published, the American researchers were affiliated with The Ohio State University, the National Center for Atmospheric Research and the University of Wisconsin-Madison.
A study published in the sixth edition of the Nature Geoscience journal in 2013 (published online in December 2012) identified central West Antarctica as one of the fastest-warming regions on Earth. The researchers present a complete temperature record from Antarctica's Byrd Station and assert that it "reveals a linear increase in annual temperature between 1958 and 2010 by 2.41.2 C". At the time that the research was published, the American researchers were affiliated with The Ohio State University, the National Center for Atmospheric Research and the University of Wisconsin-Madison.
GhAyAl 2013/08/26 14:37
According to NASA, 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
According to NASA, 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
GhAyAl 2013/08/26 14:40
Vinson Massif, the highest peak in Antarctica at 4,892 m (16,050 ft), is located in the Ellsworth Mountains. Antarctica contains many other mountains, both on the main continent and the surrounding islands. Located on Ross Island, 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 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, 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.
Vinson Massif, the highest peak in Antarctica at 4,892 m (16,050 ft), is located in the Ellsworth Mountains. Antarctica contains many other mountains, both on the main continent and the surrounding islands. Located on Ross Island, 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 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, 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.
HandsomeDon 2013/08/26 16:52
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