Tema: Antarctica - Profesora: Stella Maris Goldenzweig

Students: Romina Sanchez
Sofìa Giuso

History
The history of Antarctica emerges from early Western theories of a vast continent, known as Terra Australis, believed to exist in the far south of the globe. The rounding of the Cape of Good Hope and Cape Horn in the 15th and 16th centuries proved that Terra Australis Incognita ("Unknown Southern Land"), if it existed, was a continent in its own right. In 1773 James Cook crossed the Antarctic Circle for the first time but although he discovered nearby islands, he did not catch sight of Antarctica itself.
In 1820, several expeditions claimed to have been the first to have sighted Antarctica. The first landing was probably just over a year later when American Captain John Davis, a sealer, set foot on the ice. Once the North Pole had been reached in 1909, several expeditions attempted to reach the South Pole. Many resulted in injury and death. The Norwegian Roald Amundsen finally claimed the prize following a dramatic race with the Briton Robert Falcon Scott in December 1911.
The search for Terra Australis Incognita
In the Western world, belief in a Terra Australis—a vast continent located in the far south of the globe to "balance" out the northern lands of Europe, Asia and North Africa—had existed for centuries. Aristotle had postulated a symmetry of the earth, which meant that there would be equally habitable lands south of the known world. The Greeks suggested that these two hemispheres, north and south, were divided by a 'belt of fire’
It was not until Prince Henry the Navigator began in 1418 to encourage the penetration of the torrid zone in the effort to reach India by circumnavigating Africa that the exploration of the southern hemisphere began. In 1473 Portuguese navigator Lopes Gonçalves proved that the equator could be crossed, and cartographers and sailors began to assume the existence of another, temperate continent to the south of the known world.
The doubling of the Cape of Good Hope in 1487 by Bartholomew Diaz first brought explorers within touch of the Antarctic cold, and proved that there was an ocean separating Africa from any Antarctic land that might exist. Ferdinand Magellan, who passed through the Straits of Magellan in 1520, assumed that the islands of Tierra del Fuego to the south were an extension of this unknown southern land, and it appeared as such on a map by Ortelius: Terra australis recenter inventa sed nondum plene cognita ("Southern land recently discovered but not yet known"). In 1513, the Ottoman Turkish admiral Piri Reis also drew a map that has been said to show part of the Antarctic continent.
The doubling of Cape Horn by Drake in 1578 proved that the Tierra del Fuego archipelago was of small extent and that any continent which lay to the south must be within the region of perpetual winter. European geographers connected the coast of Tierra del Fuego with the coast of New Guinea on their globes and allowing their imaginations to run riot in the vast unknown spaces of the south Atlantic, south Indian and Pacific oceans. They sketched the outlines of the Terra Australis Incognita ("Unknown Southern Land"), a vast continent stretching in parts into the tropics. The search for this great south land or Third World was a leading motive of explorers in the 16th and the early part of the 17th centuries.
Schouten and Le Maire rediscovered the southern extremity of Tierra del Fuego and named it Cape Horn in 1615. Quirós in 1606 took possession for the king of Spain all of the lands he had discovered in Australia del Espiritu Santo (the New Hebrides) and those he would discover "even to the Pole". Tasman in 1642 showed that New Holland (Australia) was separated by sea from any continuous southern continent.
Voyagers round the Horn frequently met with contrary winds and were driven southward into snowy skies and ice-encumbered seas; but so far as can be ascertained none of them before 1770 reached the Antarctic Circle, or knew it, if they did. The story of the discovery of land in 64° S. by Dirk Gerritz on board the Blijde Boodschap in 1599 was shown to be the result of a mistake of a commentator, Kasper Barlaeus, in 1622. A similar story of sighting "snow-covered mountains" beyond the 64° S in 1603 is told of the Spanish Gabriel de Castilla.
Better documented is the visit to South Georgia by Anthony de la Roché in 1675, the first ever discovery of land south of the Antarctic Convergence. Soon after the voyage cartographers started to depict on their maps ‘Roché Island’, honoring the discoverer. James Cook was aware of la Roché's discovery when surveying and mapping the island in 1775.
It may safely be said that all the navigators who fell in with the southern ice up to 1750 did so by being driven off their course by chance. An exception may perhaps be made in favor of Halley's voyage in HMS Paramour for magnetic investigations in the South Atlantic when he met the ice in 52° S. in January 1700; but that latitude was his farthest south. A determined effort on the part of the French naval officer Pierre Bouvet to discover the South Land described by a half legendary sieur de Gonneyville resulted only in the discovery of Bouvet Island in 54°10′ S., and in the navigation of 48° of longitude of ice-cumbered sea nearly in 55° S. in 1730.
In 1771, Yves Joseph Kerguelen sailed from France with instructions to proceed south from Mauritius in search of "a very large continent." He lighted upon a land in 50° S. which he called South France, and believed to be the central mass of the southern continent. He was sent out again to complete the exploration of the new land, and found it to be only an inhospitable island which he renamed in disgust the Isle of Desolation, but in which posterity has recognized his courageous efforts by naming it Kerguelen Land.
South of the Antarctic Circle
The obsession of the undiscovered continent culminated in the brain of Alexander Dalrymple, the brilliant and erratic hydrographer who was nominated by the Royal Society to command the Transit of Venus expedition to Tahiti in 1769. The command of the expedition was given by the admiralty to Captain James Cook. Sailing in 1772 with the Resolution, a vessel of 462 tons under his own command and the Adventure of 336 tons under Captain Tobias Furneaux, Cook first searched in vain for Bouvet Island, then sailed for 20 degrees of longitude to the westward in latitude 58° S, and then 30° eastward for the most part south of 60° S, a higher southern latitude than had ever been voluntarily entered before by any vessel. On January 17, 1773 the Antarctic Circle was crossed for the first time in history and the two ships reached 67° 15' S by 39° 35' E, where their course was stopped by ice.
Cook then turned northward to look for French Southern and Antarctic Lands, of the discovery of which he had received news at Cape Town, Cook reached the assigned latitude 10° too far east and did not see it. He turned south again and was stopped by ice in 61° 52′ S by 95° E and continued eastward nearly on the parallel of 60° S to 147° E. On March 16, the approaching winter drove him northward to rest in New Zealand and the tropical islands of the Pacific. In November 1773, Cook left New Zealand, having parted company with the Adventure, and reached 60° S by 177° W, whence he sailed eastward keeping as far south as the floating ice allowed. The Antarctic Circle was crossed on December 20 and Cook remained south of it for three days, being compelled after reaching 67° 31′ S to stand north again in 135° W.
A long detour to 47° 50′ S served to show that there was no land connection between New Zealand and Tierra del Fuego. Turning south again, Cook crossed the Antarctic Circle for the third time at 109° 30′ W before his progress was once again blocked by ice four days later at 71° 10′ S by 106° 54′ W. This point, reached on January 30, 1774, was the farthest south attained in the 18th century. With a great detour to the east, almost to the coast of South America, the expedition regained Tahiti for refreshment. In November 1774, Cook started from New Zealand and crossed the South Pacific without sighting land between 53° and 57° S to Tierra del Fuego; then, passing Cape Horn on December 29, he discovered the Isle of Georgia and Sandwich Land, the only ice-clad land he had seen, before crossing the South Atlantic to the Cape of Good Hope between 55° and 60°. He thereby laid open the way for future Antarctic exploration by exploding the myth of a habitable southern continent. Cook's most southerly discovery of land lay on the temperate side of the 60th parallel, and he convinced himself that if land lay farther south it was practically inaccessible and of no economic value.
First sighting of land
The first land south of the parallel 60° south latitude was discovered by the Englishman William Smith, who sighted Livingston Island on February 19, 1819. Few months later Smith returned to explore the other islands of the South Shetlands archipelago, landed on King George Island, and claimed the new territories for Britain.
In the meantime, the Spanish Navy ship San Telmo sank in September 1819 when trying to cross Cape Horn. Parts of her wreckage were found months later by sealers on the north coast of Livingston Island (South Shetlands). It is unknown if some survivor managed to be the first setting foot on these Antarctic islands.
The first confirmed sighting of Antarctica cannot be accurately attributed to one single person. It can, however, be narrowed down to three individuals. According to various sources, three men all sighted Antarctica within days or months of each other: Fabian von Bellingshausen, a captain in the Russian Imperial Navy; Edward Bransfield, a captain in the British navy; and Nathaniel Palmer, an American sealer out of Stonington, Connecticut. It is certain that on January 28, 1820 (New Style), the expedition led by Fabian von Bellingshausen and Mikhail Petrovich Lazarev on two ships reached a point within 20 miles (40 km) of the Antarctic mainland and saw ice-fields there. On January 30, 1820, Bransfield sighted Trinity Peninsula, the northernmost point of the Antarctic mainland, while Palmer sighted the mainland in the area south of Trinity Peninsula in November 1820. Bellingshausen's expedition also discovered Peter I Island and Alexander I Island, the first islands to be discovered south of the circle.
Exploration
Only slightly more than a year later, the first landing on the Antarctic mainland was arguably by the American Captain John Davis, a sealer, who claimed to have set foot there on February 7, 1821, though this is not accepted by all historians.
On December 1821, Nathaniel Palmer, an American sealer looking for seal breeding grounds, sighted what is now known as the Antarctic Peninsula, located in the continent's northwestern quadrant. In 1823, James Weddell, a British sealer, sailed into what is now known as the Weddell Sea.
The first person to realize that he had actually discovered a whole continent was Charles Wilkes, the commander of a United States Navy expedition. His 1840 voyage discovered what is now known as Wilkes Land, on the southeast quadrant of the continent.
After the North Magnetic Pole was located in 1831, explorers and scientists began looking for the South Magnetic Pole. One of the explorers, James Clark Ross, a British naval officer, identified its approximate location, but was unable to reach it on his trip in 1841. Commanding the British ships Erebus and Terror, he braved the pack ice and approached what is now known as the Ross Ice Shelf, a massive floating ice shelf over 100 feet (30 m) high. His expedition sailed eastward along the southern Antarctic coast discovering mountains which were since named after his ships: Mount Erebus, the most active volcano on Antarctica, and Mount Terror.
The first documented landing on the mainland of East Antarctica was at Victoria Land by the American sealer Mercator Cooper on January 26, 1853.
In 1897, an expedition led by Belgian Adrian de Gerlache left Antwerp, Belgium for Antarctica. The multi-national crew included a Romanian zoologist (Emil Racoviţă), a Polish geologist (Henryk Arctowski), a Belgian navigator/astronomer (George Lecointe), several Norwegians, including Roald Amundsen, and an American surgeon, Dr. Frederick Cook. In 1898, they became the first men to spend winter on Antarctica, when their ship Belgica became trapped in the ice. They became stuck on February 28, 1898, and only managed to get out of the ice on March 14, 1899. During their forced stay, several men lost their sanity, not only because of the Antarctic winter night and the endured hardship, but also because of the language problems between the different nationalities. A year later a British expedition commanded by Norwegian Carstens Borchgrevink became the first to intentionally spend winter on the continent itself.
British National Antarctic Expedition (Discovery)
The British National Antarctic Expedition (1901–1904), led by Robert Falcon Scott, came to within 857 km (463 nautical miles) of the South Pole from its base at McMurdo Sound.
Scottish National Antarctic Expedition
In 1903, the Scottish National Antarctic Expedition established Osmond House, a meteorological observatory on Laurie Island in the South Orkneys. A year later, ownership of the base was passed to Argentina and it was renamed Orcadas Base. It is the continent's oldest permanent base, and, until World War II, the only one present.
British Imperial Antarctic Expedition (Nimrod)
Ernest Shackleton, who had been a member of Scott's expedition, organized and led the British Imperial Antarctic Expedition (1907-09), again with the primary objective of reaching the South Pole. It came within 180 km (97 nautical miles) before having to turn back. during the expedition, Shackleton discovered the Beardmore Glacier and was the first to reach the polar plateau. Parties led by T. W. Edgeworth David also became the first to climb Mount Erebus and to reach the South Magnetic Pole.
Race to the Pole (Fram and Terra Nova)
On December 14, 1911, a party led by Norwegian polar explorer Roald Amundsen from the ship Fram became the first to reach the South Pole, using a route from the Bay of Whales (his camp Polheim and up the Axel Heiberg Glacier. Amundsen was followed by Robert Falcon Scott from the Terra Nova over a month later, using the route pioneered by Shackleton. Scott's party later died on the return journey after being delayed by a series of accidents, bad weather, and the declining physical condition of the men. The Amundsen-Scott South Pole Station was later named after these two men.
Imperial Trans-Antarctic Expedition (Endurance)
The Imperial Trans-Antarctic Expedition of 1914, led by Ernest Shackleton, set out to cross the continent via the pole, but their ship, the Endurance, was trapped and crushed by pack ice before they even landed. The expedition members survived after an epic journey on sledges over pack ice to Elephant Island. Then Shackleton and five others crossed the Southern Ocean, in an open boat called James Caird, and then trekked over South Georgia to raise the alarm at the whaling station Grytviken.
Exploration by air: 1930s to 1950s
US Navy Rear Admiral Richard Evelyn Byrd led five expeditions to Antarctica during the 1930s, 1940s, and 1950s. He overflew the South Pole with pilot Bernt Balchen on November 28 and 29, 1929, to match his overflight of the North Pole in 1926. Byrd's explorations had science as a major objective and pioneered the use of aircraft on the continent. Byrd is credited with doing more for Antarctic exploration than any other explorer. His expeditions set the scene for modern Antarctic exploration and research.
In 1946, Admiral Byrd and more than 4,700 military personnel returned to Antarctica in an expedition called Operation High Jump. Reported to the public as a scientific mission, the details were kept secret and it may have actually been training or testing mission for the military. The expedition was, in both military and scientific planning terms, put together very quickly. The group contained an unusually high amount of military equipment, including an aircraft carrier, submarines, military support ships, assault troops and military vehicles. The expedition was planned to last for eight months but was unexpectedly terminated after only two months. With the exception of some eccentric entries in Admiral Byrd's diaries, no real explanation for the early termination has ever been officially given.
It was not until October 31, 1956 that anyone reached the South Pole again; on that day US Navy Rear Admiral George J. Duffel and others successfully landed a R4D Skytrain (Douglas DC-3) aircraft.
During the International Geophysical Year of 1957, a large number of expeditions to the Antarctic were mounted.
Commonwealth Trans-Antarctic Expedition
In 1956, a United States Navy expedition set up the first permanent based at the South Pole, Amundsen-Scott South Pole Station, by airlift, to support the International Geophysical Year. In 1958, Edmund Hillary's party in the New Zealand party of the Commonwealth Trans-Antarctic Expedition became the third group in history to reach the South Pole by land, and the first group of motor vehicles to reach the pole. The British team led by Vivian Fuchs, met them at the pole shortly afterwards. The expedition completed the first overland crossing of the continent by land via the South Pole. New Zealand mountaineer Sir Edmund Hillary reached the Pole in early January 1958 using farm tractors equipped for polar travel, the first party since Scott's to reach the South Pole overland. Hillary was laying supply depots as part of the Commonwealth Trans-Antarctic Expedition and in typical Hillary style "detoured" to the pole because the trip had gone well. British explorer Sir Vivian Fuchs then arrived at the Pole from the opposite direction later in January, meeting Hillary. Fuchs continued on, making use of the provisions that Hillary had stored, and on March 2 succeeded in reaching Scott Base, completing the overland transpolar crossing that Shackleton had envisaged.

Climate
The blue ice covering Lake Fryxell, in the Transantarctic Mountains, comes from glacial melt water from the Canada Glacier and other smaller glaciers.
Antarctica is the coldest place on Earth. At the 3-kilometer (2 mi)-high Vostok Station in Antarctica, scientists recorded Earth's lowest temperature: −89 °C (−129 °F). As a comparison, this is 11 degrees colder than subliming dry ice. Antarctica is a frozen desert with little precipitation; the South Pole itself receives less than 10 centimeters (4 in) per year, on average. Temperatures reach a minimum of between −80 °C and −90 °C (−112 °F and −130 °F) in the interior in winter and reach a maximum of between 5 °C and 15 °C (41 °F and 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. Eastern 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 meters (48 in) in 48 hours have been recorded.
At the edge of the continent, strong katabatic winds off the polar plateau often blow at storm force. In the interior, however, wind speeds are typically moderate. During summer, more solar radiation reaches the surface during clear days at the South Pole than at the equator because of the 24 hours of sunlight each day at the Pole.
Antarctica is colder than the Arctic for two reasons. First, much of the continent is more than 3 kilometers (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.
Source www.wikipedia.org