Geography

Antarctica

The continent of Antarctica is located almost entirely south of the Antarctic Circle, (66.5 degrees south Latitude). Only the tip of the Antarctic Peninsula and the fringes of Wilkes Land protrude north of that line.

Roughly centered on the geographic South Pole (coordinates: 90° 00' S, 0° 00' E.), it's total area of Antarctica is 14 million sq km (it's ice-free land area is 280,000 sq km while about 13.72 million sq km is ice-covered).

It is the fifth largest continent, following Asia, Africa, North America, and South America, containing 8.9% of the Earth's land area; and it is larger than Australia and the subcontinent of Europe. It is slightly less than 1.5 times the size of the United States.

 

The antarctic coastline measures about 17,968 km. All of Antarctica utilizes New Zealand Time.

Speculation over the existence of an "unknown southern land" (that is, Terra Australis Incognita) was not confirmed until the early 1820s when British and American commercial operators (i.e. whalers) and British and Russian national expeditions began exploring the Antarctic Peninsula region and other areas south of the Antarctic Circle.

Not until 1840 was it established that Antarctica was indeed a continent and not just a group of islands. In 1895, the Sixth International Geophysical Conference in London, encouraged more active exploration of the region. Several exploration "firsts" were achieved in the early 20th century.

The first Byrd Expedition to the South Pole was during the years 1928-1930. Following World War II, there was an upsurge in scientific research on the continent. A number of countries have set up year-round research stations on Antarctica. Seven have made territorial claims, but not all countries recognize these claims. In order to form a legal framework for the activities of nations on the continent, an Antarctic Treaty was negotiated that neither denies nor gives recognition to existing territorial claims; signed in 1959, it entered into force in 1961.

See Exploration of the Antarctic for a deeper history of human discovery of Antarctica.

Population/Governance/Maritime Claims

Australia, Chile, and Argentina claim exclusive economic zone (EEZ) rights or similar jurisdiction over 200 km extensions seaward from their continental claims, but like the claims themselves, these zones are not accepted by other countries. The other countries with claims are France, New Zealand, Norway and the United Kingdom. Twenty-one of Twenty-eight Antarctic consultative nations have made no claims to Antarctic territory (although Russia and the United States have reserved the right to do so) and do not recognize the claims of the other nations. The only truly international zone on earth, there are many treaties governing the cooperative uses. At the present time, there are fourteen research stations in Antarctica.

The first Antarctic Treaty was signed in 1959 following the extraordinary research conducted during the 1957-58 International Geophysical Year. With the possibility that Antarctic holds vast mineral resources, the political future of this continent may change. The year 2007 has been designated an International Polar Year so global interest in this region will again be heightened.

At the present time, there are about 13,000 tourists who visit the continent each year. Australia has purchased an Airbus to reduce the average time it takes a research party to reach Antarctica from ten days to a few hours. Plans are underway to build a highway (1,632 km long) from the coast, opposite of New Zealand to the South Pole. This is causing some to question how long the continent can be kept in a pristine environmental condition.

Physical Geography

Physical geography involves the multidisciplinary development of information about the processes and patterns that exist and operate within the context of the natural environment. Fundamental information on antarctic physical geography has been collected by the CIA, among other sources.

You may supplement your understanding of physical geography by reading the following Encyclopedia of Earth articles:

Antarctica is the coldest, windiest, harshest continent, and with little precipitation (roughly two inches per year) is the driest place on earth. It is roughly 14 million sq km (5.4 million sq mi), has an average elevation of more than 2000 m (6500 ft), and 98% of the landmass is covered by an ice sheet estimated to be 29 million cu km (7 million cu mi).

The average annual temperature at South Pole Station is -56°F. During the austral summer, temperatures at McMurdo Station may reach as high as 50°F, while at South Pole Station the summer temperature may reach 0°F. Palmer Station has a milder climate, with summer temperatures reaching as high as 55°F.

Beneath its thick ice sheets, Antarctica is a dynamic and diverse continent with mountains, volcanoes, deserts, meteorites, dinosaur fossils, and some of the Earth’s most ancient crust.

Climate

Being the coldest and windiest continent, Antarctica exhibits severe low temperatures that vary with latitude, elevation, and distance from the ocean. The average temperature is -49 °C. East Antarctica is colder than West Antarctica because of its higher elevation. The Antarctic Peninsula has the most moderate climate. Higher antarctic temperatures occur in January along the coast and average slightly below freezing, but the strong temperature gradient between the ice-covered land and the sea, create constant strong winds that can blow up to 200 mph. The water temperature averages 33 °[[fahrenheit|F]. The continent is technically a desert, receiving less than 10" of precipitation annually.

Much research is being conducted on the climatology and meteorology of Antarctica because the conditions here are thought to have an enormous impact on climate patterns on the rest of the planet. There is also much interest in examining how both natural and anthropogenic changes in earth's climate are affecting the ice and biological processes. Because Antarctica contains 90% of earth's ice and 70% of its freshwater, any changes in temperature could cause the ice to melt and raise sea levels world-wide. At the present time, temperatures have risen about 5 degrees from their levels in 1974.

However, the continent was not always that cold. It separated from Gondwanaland about 30 million years ago and froze over about 14 million years ago.

The circumpolar ocean current, travels from west to east off the coast, effectively isolating the continent from the warmer ocean currents to the north. Upwelling of water provides not only nutrients that support a rich variety of ocean life, but provides a contact point for the ocean and the atmosphere to meet so that carbon dioxide can be absorbed.

Antarctica provides a wonderful laboratory to examine the historical patterns of earth's climate. Ice cores taken have enables scientists to peer back 740,000 years in time to analyze the chemistry of earth's atmosphere and to estimate the average temperatures.

The Ozone layer in earth's stratosphere seasonally thins (often referred to as the "ozone hole" as the spring sun warms the atmosphere over the south pole. Cause by the actions of Chlorine and Bromine, this destruction of ozone has profound implications for human health and the biological productivity of earth's ocean.

Geology/Topography

The Continent's terrain is approximately 98% thick, continental ice sheet and about 2% barren rock with average elevations between 2000 and 4000 meters, making it the highest continent on Earth.  Mountain ranges of up to nearly 5000 meters exist. The largest such topographic feature is the Transarctic Mountains which lie in a serpentine pattern across the land from 160° East Longitude, passing West of the South Pole and continuing to the Weddall Sea. There are ice-free coastal areas that include parts of southern Victoria Land, Wilkes Land, the Antarctic Peninsula area, and parts of Ross Island on McMurdo Sound (the site of the National Science Foundation's McMurdo Station). Glaciers form ice shelves along about half of the continent's coastline, and floating ice shelves constitute 11% of the area of the continent. Groups of islands, sometimes called the peri-Antarctic Islands are claimed by various nations and have provided stations for the early whaling ships and modern explorers. Historical and present-day volcanic activity, coupled with an ancient climate that was more tropical, suggests that Antarctica may hold substantial mineral resources.

Further Reading

Disclaimer: This articler contains information that was originally published by, the U.S. Central Intelligence Agency. Topic editors and authors for the Encyclopedia of Earth have edited its content and added new information. The use of information from the U.S. Central Intelligence Agency should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.

 

 

 

 

Glossary

Citation

Draggan, S., & Clough, L. (2013). Antarctica. Retrieved from http://www.eoearth.org/view/article/150117

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