Antarctica Facts
Antarctica is a geographical unit distinguished by the most extraordinary features existing on earth, the best definition of which is extreme. In effect its extreme circumpolar position governs its environmental dynamics, which are different even from those of its opposite, the Arctic, an ocean covered by floating marine ice.
Antarctica is a continent almost completely submerged beneath ice, which not only conceals its topography, but has also influenced its evolution. It is difficult to apply the term "continent" to what at first glance appears to be a huge mass of ice, with no forests, no rivers, no lakes and only limited forms of life; nonetheless Antarctica is one of the most ancient continents and has undergone complex geological processes which determined its geographical location in the southern extreme of the globe.
Extreme features of Antarctica have determined its isolation in human and historical terms, and prevented the settlement of any native population. Antarctica is the only continent which remained unknown to man for such a long period of time; less than 200 years ago, the spirit of adventure and scientific curiosity attracted explorers in search of the legendary land, believed only to exist in ancient myths. Even after its existence was confirmed, this unique environment restricted access for most human purposes. This situation has remained unchanged in spite of recent technological progress which has eased man's occupation of the continent and his related political, economic and scientific activities.
The Antarctic continental mass covers the furthest edge of the southern hemisphere and, seen from space, it looks like a circular shield of ice centered on the South Pole, outlined by the edge of the ice which covers it. The ice mass does not always coincide with the subglacial topography, but often expands beyond it into the sea. The limit of the continent is defined by its southernmost surfaces, whether land or even floating ice shelves, as the ice shelves are also geographically speaking considered land.
The Antarctic coast has an average distance from the South Pole of 2500km (1553nm), and the bulk of the continent lies within the Antarctic Polar Circle (latitude 66° 33'S). The sea surrounding the continent, the Antarctic Ocean, separates Antarctica by vast distances from any other continent land; the closest continent is South America, about 1000km (621nm) distant, New Zealand (2200km/1366nm), Australia (2250km/1397nm) and South Africa (3600km/2236nm).
The isolation of Antarctica is further emphasized by the climatic features of the Antarctic Ocean. Antarctica is one of the coldest, driest and stormiest which, during the winter, is surrounded by a wide layer of marine ice, making access to the continent almost impossible. Antarctic covers an area of 14,000,000 sq km (8,694,000nm). This is one tenth of all the land surface on Earth, or about one and a half times the size of the U.S. Ten percent of the area consists of floating ice shelves, generally seaward extensions of land glaciers. Antarctica is buried beneath a vast ice sheet; bare rock represents only about 1% of the whole area.
Another outstanding feature of Antarctica is its average elevation, the sum of all its heights divided by its surface. Antarctica is the highest of all seven continents, with a mean of 2,050 meters above sea level, against a world average of about 600 meters. The reason for the elevation is the deep layer of ice covering the continent, estimated to average around 2,000 meters in thickness though in some areas it exceeds 4,000 meters. The high and extended mountain chains, which cross the continent, quite frequently exceed heights of 4,000 meters above sea level.
THE FOUR POLES: When talking of the South Pole as the center of Antarctica, the reference is to the Geographical South Pole; however, four different points definable as Poles may be identified in Antarctica:
• The Geographical South Pole corresponds to the point at which the earth's rotation axis passes through the southern hemisphere. It represents the southernmost latitude (90°S), at which all meridians meet.
• The Magnetic South Pole is the point at which all the lines of force of the Earth's magnetic field converge. As the magnetic field is not constant, the position of this pole varies accordingly; it is at present located in the Adelie Land region and its annual displacement is approximately 10-20km (6.2-12.4nm).
• The Geomagnetic South Pole indicates the position of the Magnetic Pole taking the earth to be a homogeneous magnet; it is thus a theoretical definition used to analyze the variations in the Earth's magnetic field. It is located at latitude 78°, 05’S and longitude 111°E.
• The Pole of Relative Inaccessibility is the innermost point of the continent and thus the most distant from any coast. It is located at latitude 82°, 06’S and longitude 54°, 58’E.
ORIGIN OF THE ANTARCTIC: Scientists believe that the Antarctic continent is one of the oldest units of a much larger landmass whose position on Earth has varied through past geological periods. This theory is based on the discovery in Antarctica of plant fossils (ferns and beech trees) and vertebrates (reptiles and amphibians) common to Africa, India and South America. There is also evidence of similarities between geological structures in Antarctica and Australia, Africa and South America, and glacier traces in all continents that can only be explained by the existence of a common continental mass.
The cause(s) of the huge accumulation of ice over Antarctica is still not completely understood, though it is considered to be related to the drift of the continent to its present position, and to past global climatic changes. What is almost certain is that the ice sheet began to form on the eastern side of the continent about 20-25 million years ago, after Antarctica moved away from temperate regions. After several phases of glacier advance and retreat, the ice sheet reached its maximum extent about 18,000 year ago, when much of Canada and Europe were also ice-covered. The present-day ice sheet covers 90% of its former maximum extent.
ANTARCTICA - THE COLD HARD FACTS
• Antarctica is the Earth's 5th largest continent, measuring 14 million square kilometers (5.4 million square miles).
• The ice sheet that covers almost all of Antarctica is the largest body of fresh water on Earth, containing about 90% of the world's ice and 68% of the fresh water.
• If Antarctica's ice sheet were to melt, it would raise the level of the world's oceans about 60 meters (200 feet).
• The thickest part of the ice sheet extends about 4800km (2980m) (15,700 feet) into submerged basins in the rock.
• Antarctica has the greatest average elevation of any continent at 1860 meters (6,100 feet). The average elevation of North America is 720 meters (2,300 feet).
• The highest mountain on the continent is Vinson Massif, 4898 meters (16,077 feet), situated in the Ellsworth Mountains.
• The snowfall in Antarctica is so minimal that the continent has been called "the world's coldest desert." The interior receives less than 3 cm (1 inch) of precipitation a year, making it the driest continent on Earth.
• The Antarctic dry valleys in Victoria Land are among the driest places on Earth. Some scientists believe that no rain has fallen there for two million years. Astronauts have visited the dry valleys because of their similarity to lunar landscapes.
• During winter months, low temperatures cause much of the seas around Antarctica to freeze. At maximum, sea ice covers an area larger than the continent itself.
• The South Pole experiences a six month period of darkness in winter and a six month period of sunlight in summer.
• Antarctica is the only continent in the world with no permanent or indigenous human inhabitants. Larger than the United States, the frozen land is populated by approximately 2,500 people during the summer and fewer than 1,000 in the winter.
LIFE AT PATRIOT HILLS
THE FLIGHT TO PATRIOT HILLS: It takes about 6 hours to fly from Punta Arenas to Patriot Hills, depending on winds encountered along the way. As we take off from the Presidente Carlos Ibanez del Campo Airport and turn south, we see to the left of us Estrecho de Magallanes, better known as the Straits of Magellan. Although Patagonia has been occupied by native tribes for thousands of years, the first recorded passage of the seaway between the Atlantic and Pacific Oceans was by three ships under the command of the Portuguese navigator Ferdinand Magellan in 1520.
In the first hour of the flight we are over a maze of islands representing the western extension of Tierra del Fuego. Then we head out over the Drake Passage, named after the English navigator Francis Drake, who rounded Cape Horn in 1578. These waters are much feared by sailing ships for their rough weather. Now is the time for a snooze because it may be another three hours before we make landfall off Alexander Island. When we do, you may see, far away to your left, the Antarctic Peninsula plateau.
The Antarctic Peninsula consists of an 1800 kilometer long chain of ice-covered mountains, part of the mainland of Antarctica. Its northernmost extremity was first seen by Russian, American and British navigators as recently as 1820, and it was subsequently explored by British, French, Belgian and American expeditions. Alexander Island was first seen in 1821 by a Russian expedition led by Captain Thaddeus Bellingshausen of the Imperial Russian Navy, who named it for Tzar Alexander I, but it was not until 1936 that anyone set foot on the island. Many of the peaks you see along the backbone of Alexander Island in the distance are even now unclimbed and unnamed.
After a narrow stretch of sea mostly hidden by drifting pack ice we come to Ellsworth Land. Ellsworth Land and the Ellsworth Mountains were discovered by Lincoln Ellsworth, an American entrepreneur who made the first flight across Antarctica in 1935; it remained untouched until the mid-1960s. Half an hour before reaching Patriot Hills we fly along the east face of the Sentinel Range, the destination of our climbing passengers. In fine weather this is one of the most spectacular views in all of Antarctica. The highest peaks in the range are Vinson Massif (4898m) and Mount Tyree (4852m) but there are several others over 4000m.
The Nimitz Glacier, a long south-east flowing ice stream, separates the Sentinel Range from the Heritage Range. Crossing it, we begin our descent towards Patriot Hills. Although 99% of the Antarctic ice sheet’s total surface area of 30 million square kilometers consists of snow and requires ski landing gear on aircraft, the Patriot Hills icefield is made of bare blue ice as hard as any skating rink. Here we can land on wheels; which is just as well because the Hercules has no skis.
The icefield was discovered in 1975 by the crew of a Twin Otter aircraft of the British Antarctic Survey. However, it was not until 1986 that the late Captain Giles Kershaw, one of the founding fathers of Adventure Network International, landed a Twin Otter here on wheels. Charles Swithinbank, a renowned glaciologist, and Mike Maxwell, his assistant, spent five days surveying the area to consider the feasibility of using it for transport aircraft. On the basis of their work, the following season ANI arranged for a DC-4 aircraft to prove the concept. Taking off from Punta Arenas on 21 November 1987 under the command of Captain Jim Smith, the DC-4 (N-42185) landed at Patriot Hills 11 hours and 43 minutes later. Kershaw, Swithinbank and Maxwell were on board to savor the moment.
The icefield was not an empty spot in the wilderness. Two ANI Twin Otters had flown ahead to establish a camp and were neatly lined up to welcome the DC-4. With them were two Twin Otters belonging to Fuerza Aerea de Chile; they had flown 2500 km from Teniente Rodolfo Marsh station on King George Island just to witness the landing. It was agreed by all that the concept was proven.
Our camp at Patriot Hills near the southern end of the range is like no other place on Earth; a remote place to be sure, some 670 miles from the nearest habitation - the distance from New York to Chicago - and our closest neighbors are at the South Pole! For almost 2880km (1,800 miles) in any direction there is not a city or town. The six hour flight from the southern tip of Chile will bring you to our camp in the heartland of Antarctica. This area is only accessible by air. When the aircraft leaves to return to Chile you will be struck by the awesome expanse of the area, its beauty, and your isolation from home. You have now landed on the most southerly runway in the world. It was first used by Adventure Network International in 1987 and remains unchanged and continues to be a natural phenomenon.
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The Mountain Madness expedition to Mount Vinson is arguably one of our most intriguing journeys! Located at a latitude of 78 degrees 35 minutes south and 85 degrees 25 minutes west longitude, Vinson is found in the Ellsworth Mountains. 
Day 1-2: Fly to Punta Arenas, Chile. Hotel night on day two.
