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Saturday, November 14, 2020

History of Antarctica

From Wikipedia, the free encyclopedia

Painting of James Weddell's second expedition, depicting the brig Jane and the cutter Beaufoy.

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 term Antarctic, referring to the opposite of the Arctic Circle, was coined by Marinus of Tyre in the 2nd century AD.

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 and his crew crossed the Antarctic Circle for the first time but although they discovered nearby islands, they did not catch sight of Antarctica itself. It is believed he was as close as 240 km (150 mi) from the mainland.

On 27 January 1820, a Russian expedition led by Fabian Gottlieb von Bellingshausen and Mikhail Lazarev discovered an ice shelf at Princess Martha Coast that later became known as the Fimbul Ice Shelf. Bellingshausen and Lazarev became the first explorers to see and officially discover the land of the continent of Antarctica. Three days later, on 30 January 1820, a British expedition captained by Irishman Edward Bransfield sighted Trinity Peninsula, and ten months later an American sealer Nathaniel Palmer sighted Antarctica on 17 November 1820. The first landing was probably just over a year later when American Captain John Davis, a sealer, set foot on the ice.

Several expeditions attempted to reach the South Pole in the early 20th century, during the "Heroic Age of Antarctic Exploration". Many resulted in injury and death. Norwegian Roald Amundsen finally reached the Pole on 13 December 1911, following a dramatic race with the Briton Robert Falcon Scott.

Early exploration

The search for Terra Australis Incognita

In 1570 a rudimentary map by Ortelius showed the imagined link between the proposed continent of Antarctica and South America. Note also the proposed landmasses surrounding the North Pole.

Aristotle speculated, "Now since there must be a region bearing the same relation to the southern pole as the place we live in bears to our pole...".

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 European 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 Bartolomeu Dias 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 fully known").

Map from 1771, showing "Terres Australes" label without any charted landmass.

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. In 1599, according to the account of Jacob le Maire, the Dutch Dirck Gerritsz Pomp observed mountainous land at latitude (64°). If so, these were the South Shetland Islands, and possibly the first European sighting of Antarctica (or offshore-lying islands belonging to it). Other accounts, however, do not note this observation, casting doubt on their accuracy. It has been argued that the Spaniard Gabriel de Castilla claimed to have sighted "snow-covered mountains" beyond the 64° S in 1603, but this claim is not generally recognized.

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".

Francis Drake like Spanish explorers before him had speculated that there might be an open channel south of Tierra del Fuego. Indeed, when Schouten and Le Maire discovered the southern extremity of Tierra del Fuego and named it Cape Horn in 1615, they proved that the Tierra del Fuego archipelago was of small extent and not connected to the southern land.

Finally, in 1642 Tasman showed that even 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 Dutch expedition to Valdivia of 1643 intended to round Cape Horn sailing through Le Maire Strait but strong winds made it instead drift south and east. Northerly winds pushed the expedition as far south as 61°59 S where icebergs were abundant before a southerly wind that begun on April 7 allowed the fleet to advance west. The small fleet led by Hendrik Brouwer managed to enter the Pacific Ocean sailing south of Isla de los Estados disproving earlier beliefs that it was part of Terra Australis.

South of the Antarctic Convergence

The visit to South Georgia by the English merchant Anthony de la Roché in 1675 was the first ever discovery of land south of the Antarctic Convergence. Soon after the voyage cartographers started to depict ‘Roché Island’, honouring the discoverer.

James Cook was aware of la Roché's discovery when surveying and mapping the island in 1775.

Edmond Halley's voyage in HMS Paramour for magnetic investigations in the South Atlantic met the pack ice in 52° S in January 1700, but that latitude (he reached 140 mi off the north coast of South Georgia) was his farthest south. A determined effort on the part of the French naval officer Jean-Baptiste Charles Bouvet de Lozier to discover the "South Land" – described by a half legendary "sieur de Gonneyville" – resulted 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 1739.

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 the Isle of Desolation, but which was ultimately named after him.

The Antarctic Circle

James Cook's 1777 south-up map of South Georgia.

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 17 January 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, but from the rough determination of his longitude by Kerguelen, 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 16 March, the approaching winter drove him northward for rest to 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 20 December 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 30 January 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 29 December, he rediscovered Roché Island renaming it Isle of Georgia, and discovered the South Sandwich Islands (named Sandwich Land by him), 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

Admiral Fabian Gottlieb von Bellingshausen was one of the first to spot the continent of Antarctica.

The first land south of the parallel 60° south latitude was discovered by the Englishman William Smith, who sighted Livingston Island on 19 February 1819. He found some remnants and signs of the wreckage of the Spanish ship San Telmo, but to the date it is unknown if any surviving crew members of the San Telmo was landed there. A 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.

The first confirmed sighting of mainland Antarctica, on 27 January 1820, is attributed to the Russian expedition led by Fabian Gottlieb von Bellingshausen and Mikhail Lazarev, discovering an ice shelf at Princess Martha Coast that later became known as the Fimbul Ice Shelf. Bellingshausen and Lazarev became the first explorers to see and officially discover the land of the continent of Antarctica.

It is certain that the expedition, led by von Bellingshausen and Lazarev on the ships Vostok and Mirny, reached on 28 January 1820 a point within 32 km (20 mi) from Princess Martha Coast and recorded the sight of an ice shelf at 69°21′28″S 2°14′50″W that became known as the Fimbul ice shelf. On 30 January 1820, Edward Bransfield sighted Trinity Peninsula, the northernmost point of the Antarctic mainland. Von Bellingshausen's expedition also discovered Peter I Island and Alexander I Island, the first islands to be discovered south of the circle.

Early exploration

The first landing on the Antarctic mainland is thought to have been made by the American Captain John Davis, a sealer, who claimed to have set foot there on 7 February 1821, though this is not accepted by all historians.

In November 1820, Nathaniel Palmer, an American sealer looking for seal breeding grounds, using maps made by the Loper whaling family, sighted what is now known as the Antarctic Peninsula, located between 55 and 80 degrees west. In 1823, James Weddell, a British sealer, sailed into what is now known as the Weddell Sea. Until the twentieth century, most expeditions were for commercial purpose, to look for the prospects of seal and whale hunting. A piece of wood, from the South Shetland Islands, was the first fossil ever recorded from Antarctica, obtained during a private United States expedition during 1829–31, commanded by Captain Benjamin Pendleton.

Charles Wilkes, as commander of a United States Navy expedition in 1840, discovered what is now known as Wilkes Land, a section of the continent around 120 degrees East.

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 4 year-expedition from 1839 to 1843. 

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.

Map of exploration routes, 1911.

The first documented landing on the mainland of East Antarctica was at Victoria Land by the American sealer Mercator Cooper on 26 January 1853.

These explorers, despite their impressive contributions to South Polar exploration, were unable to penetrate the interior of the continent and, rather, formed a broken line of discovered lands along the coastline of Antarctica. Following the expedition South by the ships Erebus and Terror under James Clark Ross (January, 1841), he suggested that there were no scientific discoveries, or 'problems', worth exploration in the far South. What followed is what historian H.R. Mill called 'the age of averted interest' and in the following twenty years after Ross' return, there was a general lull internationally in Antarctic exploration.

Heroic Age of Antarctic Exploration

The Heroic Age of Antarctic Exploration began at the end of the 19th century and closed with Ernest Shackleton's Imperial Trans-Antarctic Expedition in 1917.

During this period the Antarctic continent became the focus of an international effort that resulted in intensive scientific and geographical exploration and in which 17 major Antarctic expeditions were launched from ten countries.

Origins

Dr. John Murray was the driving force behind the renewal of interest in Antarctic exploration at the beginning of the 20th century.

The initial impetus for the Heroic Age of Antarctic Exploration was a lecture given by Dr. John Murray entitled "The Renewal of Antarctic Exploration", given to the Royal Geographical Society in London, 27 November 1893. Murray advocated that research into the Antarctic should be organised to "resolve the outstanding geographical questions still posed in the south". Furthermore, the Royal Geographical Society instated an Antarctic Committee shortly prior to this, in 1887, which successfully encouraged many whalers to explore the Southern regions of the world and laid the groundwork for the lecture given by Murray.

The Norwegian ship Antarctic was put ashore at Cape Adare, on 24 January 1895.

In August 1895 the Sixth International Geographical Congress in London passed a general resolution calling on scientific societies throughout the world to promote the cause of Antarctic exploration "in whatever ways seem to them most effective". Such work would "bring additions to almost every branch of science". The Congress had been addressed by the Norwegian Carsten Borchgrevink, who had just returned from a whaling expedition during which he had become one of the first to set foot on the Antarctic mainland. During his address, Borchgrevink outlined plans for a full-scale pioneering Antarctic expedition, to be based at Cape Adare.

Adrien de Gerlache, leader of the Belgian expedition.

The Heroic Age was inaugurated by an expedition launched by the Belgian Geographical Society in 1897; Borchgrevink followed a year later with a privately sponsored British expedition. (Some histories consider the Discovery expedition, which departed in 1901, as the first proper expedition of the Heroic Age.)

The Belgian Antarctic Expedition was led by Belgian Adrian de Gerlache. 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 28 February 1898, and only managed to get out of the ice on 14 March 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. This was the first expedition to overwinter within the Antarctic Circle, and they visited the South Shetland Islands.

Early British expeditions

RRS Discovery carried an expedition led by Robert Falcon Scott in 1901.

The Southern Cross Expedition began in 1898 and lasted for two years. This was the first expedition to overwinter on the Antarctic mainland (Cape Adare) and was the first to make use of dogs and sledges. It made the first ascent of The Great Ice Barrier, (The Great Ice Barrier later became formally known as the Ross Ice Shelf). The expedition set a Farthest South record at 78°30'S. It also calculated the location of the South Magnetic Pole.

The Discovery Expedition was then launched, from 1901–04 and was led by Robert Falcon Scott. It made the first ascent of the Western Mountains in Victoria Land, and discovered the polar plateau. Its southern journey set a new Farthest South record, 82°17'S. Many other geographical features were discovered, mapped and named. This was the first of several expeditions based in McMurdo Sound.

Jameson Adams, Frank Wild and Eric Marshall (left to right) of the Nimrod Expedition plant the Union flag at their southernmost position.

A year later, the Scottish National Antarctic Expedition was launched, headed by William Speirs Bruce. 'Ormond House' was established as a meteorological observatory on Laurie Island in the South Orkneys and was the first permanent base in Antarctica. The Weddell Sea was penetrated to 74°01'S, and the coastline of Coats Land was discovered, defining the sea's eastern limits.

Ernest Shackleton, who had been a member of Scott's expedition, organized and led the Nimrod Expedition from 1907 to 1909. The expedition's primary objective was of reaching the South Pole. Based in McMurdo Sound, the expedition pioneered the Beardmore Glacier route to the South Pole, and the (limited) use of motorised transport. Its southern march reached 88°23'S, a new Farthest South record 97 geographical miles from the Pole before having to turn back. During the expedition, Shackleton 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.

Expeditions from other countries

The First German Antarctic Expedition was sent to investigate eastern Antarctica in 1901. It discovered the coast of Kaiser Wilhelm II Land, and Mount Gauss. The expedition's ship became trapped in ice, however, which prevented more extensive exploration.

The Swedish Antarctic Expedition, operating at the same time worked in the east coastal area of Graham Land, and was marooned on Snow Hill Island and Paulet Island in the Weddell Sea, after the sinking of its expedition ship. It was rescued by the Argentinian naval vessel Uruguay.

The French organized their first expedition in 1903 under the leadership of Jean-Baptiste Charcot. Originally intended as a relief expedition for the stranded Nordenskiöld party, the main work of this expedition was the mapping and charting of islands and the western coasts of Graham Land, on the Antarctic peninsula. A section of the coast was explored, and named Loubet Land after the President of France.

A follow up trip was organized from 1908–1910 which continued the earlier work of the French expedition with a general exploration of the Bellingshausen Sea, and the discovery of islands and other features, including Marguerite Bay, Charcot Island, Renaud Island, Mikkelsen Bay, Rothschild Island.

Race to the Pole

Terra Nova bore Robert Falcon Scott and his team on their ill-fated expedition to the South Pole.

The prize of the Heroic age was to reach the South Pole. Two expeditions set off in 1910 to attain this goal; a party led by Norwegian polar explorer Roald Amundsen from the ship Fram and Robert Falcon Scott's British group from the Terra Nova.

Amundsen succeeded in reaching the Pole on 14 December 1911 using a route from the Bay of Whales to the polar plateau via the Axel Heiberg Glacier.

Scott and his four companions reached the South Pole via the Beardmore route on 17 January 1912, 33 days after Amundsen. All five died on the return journey from the Pole, through a combination of starvation and cold. The Amundsen–Scott South Pole Station was later named after these two men.

Further expeditions

The Main Base Hut of the Australasian Antarctic Expedition

The Australasian Antarctic Expedition took place between 1911–1914 and was led by Sir Douglas Mawson. It concentrated on the stretch of Antarctic coastline between Cape Adare and Mount Gauss, carrying out mapping and survey work on coastal and inland territories.

Discoveries included Commonwealth Bay, Ninnis Glacier, Mertz Glacier, and Queen Mary Land. Major accomplishments were made in geology, glaciology and terrestrial biology.

As time wore on it became more and more evident that the ship was doomed by Frank Hurley. (The Endurance trapped in pack ice.)

The Imperial Trans-Antarctic Expedition of 1914–1917 was led by Ernest Shackleton and set out to cross the continent via the South pole. However, their ship, the Endurance, was trapped and crushed by pack ice in the Weddell Sea before they were able to land. The expedition members survived after a journey on sledges over pack ice, a prolonged drift on an ice-floe, and a voyage in three small boats to Elephant Island. Then Shackleton and five others crossed the Southern Ocean in an open boat called James Caird and made the first crossing of South Georgia to raise the alarm at the whaling station Grytviken.

A related component of the Trans-Antarctic Expedition was the Ross Sea party, led by Aeneas Mackintosh. Its objective was to lay depots across the Great Ice Barrier, in order to supply Shackleton's party crossing from the Weddell Sea. All the required depots were laid, but in the process three men, including the leader Mackintosh, lost their lives.

Shackleton's last expedition and the one that brought the 'Heroic Age' to a close, was the Shackleton–Rowett Expedition from 1921–22 on board the ship Quest. Its vaguely defined objectives included coastal mapping, a possible continental circumnavigation, the investigation of sub-Antarctic islands, and oceanographic work. After Shackleton's death on 5 January 1922, Quest completed a shortened programme before returning home.| 

Further exploration

By air

Sir Hubert Wilkins pioneered the exploration of the Arctic regions by aircraft. Pictured, his plane and encampment as part of the Detroit Arctic Expedition, 1926.

After Shackleton's last expedition, there was a hiatus in Antarctic exploration for about seven years. From 1929, aircraft and mechanized transportation were increasingly used, earning this period the sobriquet of the 'Mechanical Age'. Hubert Wilkins first visited Antarctica in 1921–1922 as an ornithologist attached to the Shackleton-Rowett Expedition. From 1927, Wilkins and pilot Carl Ben Eielson began exploring the Arctic by aircraft.

On 15 April 1928, only a year after Charles Lindbergh's flight across the Atlantic, Wilkins and Eielson made a trans-Arctic crossing from Point Barrow, Alaska, to Spitsbergen, arriving about 20 hours later on 16 April, touching along the way at Grant Land on Ellesmere Island. For this feat and his prior work, Wilkins was knighted.

With financial backing from William Randolph Hearst, Wilkins returned to the South Pole and flew over Antarctica in the San Francisco. He named the island of Hearst Land after his sponsor.

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 28 and 29 November 1929, to match his overflight of the North Pole in 1926. Byrd's explorations had science as a major objective and extensively used the aircraft to explore the continent.

Captain Finn Ronne, Byrd's executive officer, returned to Antarctica with his own expedition in 1947–1948, with Navy support, three planes, and dogs. Ronne disproved the notion that the continent was divided in two and established that East and West Antarctica was one single continent, i.e. that the Weddell Sea and the Ross Sea are not connected. The expedition explored and mapped large parts of Palmer Land and the Weddell Sea coastline, and identified the Ronne Ice Shelf, named by Ronne after his wife Edith Ronne. Ronne covered 3,600 miles by ski and dog sled—more than any other explorer in history.

Overland crossing

Edmund Hillary (left) with Rear-Admiral George J. Dufek at Scott Base just before the Commonwealth Trans-Antarctic Expedition's departure from the base.

The 1955–58 Commonwealth Trans-Antarctic Expedition successfully completed the first overland crossing of Antarctica, via the South Pole. Although supported by the British and other Commonwealth governments, most of the funding came from corporate and individual donations.

It was headed by British explorer Dr Vivian Fuchs, with New Zealander Sir Edmund Hillary leading the New Zealand Ross Sea Support team. After spending the winter of 1957 at Shackleton Base, Fuchs finally set out on the transcontinental journey in November 1957, with a twelve-man team travelling in six vehicles; three Sno-Cats, two Weasels and one specially adapted Muskeg tractor. En route, the team were also tasked with carrying out scientific research including seismic soundings and gravimetric readings.

In parallel Hillary's team had set up Scott Base – which was to be Fuchs' final destination – on the opposite side of the continent at McMurdo Sound on the Ross Sea. Using three converted Massey Ferguson TE20 tractors and one Weasel (abandoned part-way), Hillary and his three men (Ron Balham, Peter Mulgrew and Murray Ellis), were responsible for route-finding and laying a line of supply depots up the Skelton Glacier and across the Polar Plateau on towards the South Pole, for the use of Fuchs on the final leg of his journey. Other members of Hillary's team carried out geological surveys around the Ross Sea and Victoria Land areas.

Hillary's party reached the South Pole on 3 January 1958, and was just the third (preceded by Amundsen in 1911 and Scott in 1912) to reach the Pole overland. Fuchs' team reached the Pole from the opposite direction on 19 January 1958, where they met up with Hillary. Fuchs then continued overland, following the route that Hillary had laid and on 2 March succeeded in reaching Scott Base, completing the first overland crossing of the continent by land via the South Pole.

Political history

British claims

The United Kingdom reasserted sovereignty over the Falkland Islands in the far South Atlantic in 1833 and maintained a continuous presence there. In 1908, the British government extended its territorial claim by declaring sovereignty over "South Georgia, the South Orkneys, the South Shetlands, and the Sandwich Islands, and Graham's Land, situated in the South Atlantic Ocean and on the Antarctic continent to the south of the 50th parallel of south latitude, and lying between the 20th and the 80th degrees of west longitude". All these territories were administered as Falkland Islands Dependencies from Stanley by the Governor of the Falkland Islands. The motivation for this declaration lay in the need for regulating and taxing the whaling industry effectively. Commercial operators would hunt whales in areas outside of the official boundaries of the Falkland Islands and its dependencies and there was a need to close this loophole.

In 1917, the wording of the claim was modified, so as to, among other things, unambiguously include all the territory in the sector stretching to the South Pole (thus encompassing all of the present-day British Antarctic Territory). The new claim covered "all islands and territories whatsoever between the 20th degree of west longitude and the 50th degree of west longitude which are situated south of the 50th parallel of south latitude; and all islands and territories whatsoever between the 50th degree of west longitude and the 80th degree of west longitude which are situated south of the 58th parallel of south latitude".

Under the ambition of Leopold Amery, the Under-Secretary of State for the Colonies, Britain attempted to incorporate the entire continent into the Empire. In a memorandum to the governor-generals for Australia and New Zealand, he wrote that 'with the exception of Chile and Argentina and some barren islands belonging to France... it is desirable that the whole of the Antarctic should ultimately be included in the British Empire.'

The first step was taken on 30 July 1923, when the British government passed an Order in Council under the British Settlements Act 1887, defining the new borders for the Ross Dependency - "that part of His Majesty's Dominions in the Antarctic Seas, which comprises all the islands and territories between the 160th degree of East Longitude and the 150th degree of West Longitude which are situated south of the 60th degree of South Latitude shall be named the Ross Dependency."

The Order in Council then went on to appoint the Governor-General and Commander-in Chief of New Zealand as the Governor of the territory.

In 1930, the United Kingdom claimed Enderby Land. In 1933, a British imperial order transferred territory south of 60° S and between meridians 160° E and 45° E to Australia as the Australian Antarctic Territory.

Following the passing of the Statute of Westminster in 1931, the government of the United Kingdom relinquished all control over the government of New Zealand and Australia. This however had no bearing on the obligations of the Governor-General of both countries in their capacity as Governor of the Antarctic territories.

Other European claims

Discovery by Jules Dumont d'Urville of Adélie Land in 1840. This served as a basis for the French claim to this region in 1924.

Meanwhile, alarmed by these unilateral declarations, the French government laid claim to a strip of the continent in 1924. The basis for their claim to Adélie Land lay on the discovery of the coastline in 1840 by the French explorer Jules Dumont d'Urville, who named it after his wife, Adèle. The British eventually decided to recognize this claim and the border between Adélie Land and Australian Antarctic Territory was fixed definitively in 1938.

These developments also concerned Norwegian whaling interests, who wished to avoid the British taxation of whaling stations in the Antarctic and were concerned that they would be commercially excluded from the continent. The whale-ship owner Lars Christensen financed several expeditions to the Antarctic with the view to claim land for Norway and establish stations on Norwegian territory to gain better privileges. The first expedition, led by Nils Larsen and Ola Olstad, landed on Peter I Island in 1929 and claimed the island for Norway. On 6 March 1931, a Norwegian royal proclamation declared the island under Norwegian sovereignty and on 23 March 1933 the island was declared a dependency.

The 1929 expedition led by Hjalmar Riiser-Larsen and Finn Lützow-Holm named the continental land mass near the island as Queen Maud Land, named after the Norwegian queen Maud of Wales. The territory was explored further during the Norvegia expedition of 1930–31. Negotiations with the British government in 1938 resulted in the western border of Queen Maud Land being set at 20°W.

Norwegian expedition landing on the Peter I Island in 1929.

Norway's claim was disputed by Nazi Germany, which in 1938 dispatched the German Antarctic Expedition, led by Alfred Ritscher, to fly over as much of it as possible. The ship Schwabenland reached the pack ice off Antarctica on 19 January 1939. During the expedition, an area of about 350,000 square kilometres (140,000 sq mi) was photographed from the air by Ritscher, who dropped darts inscribed with swastikas every 26 kilometres (16 mi). Germany eventually attempted to claim the territory surveyed by Ritscher under the name New Swabia, but lost any claim to the land following its defeat in the Second World War.

On 14 January 1939, five days prior to the German arrival, Queen Maud Land was annexed by Norway, after a royal decree announced that the land bordering the Falkland Islands Dependencies in the west and the Australian Antarctic Dependency in the east was to be brought under Norwegian sovereignty. The primary basis for the annexation was to secure the Norwegian whaling industry's access to the region. In 1948, Norway and the United Kingdom agreed to limit Queen Maud Land to from 20°W to 45°E, and that the Bruce Coast and Coats Land were to be incorporated into Norwegian territory.

South American involvement

Omond House was built in 1904 by the Scottish National Antarctic Expedition as the first permanent base in Antarctica. It was later sold to Argentina.

This encroachment of foreign powers was a matter of immense disquiet to the nearby South American countries, Argentina and Chile. Taking advantage of a European continent plunged into turmoil with the onset of the Second World War, Chile's president, Pedro Aguirre Cerda declared the establishment of a Chilean Antarctic Territory in areas already claimed by Britain.

Argentina had an even longer history of involvement in the Continent. Already in 1904 the Argentine government began a permanent occupation in the area with the purchase of a meteorological station on Laurie Island established in 1903 by Dr William S. Bruce's Scottish National Antarctic Expedition. Bruce offered to transfer the station and instruments for the sum of 5.000 pesos, on the condition that the government committed itself to the continuation of the scientific mission. British officer William Haggard also sent a note to the Argentine Foreign Minister, Jose Terry, ratifying the terms of Bruce proposition.

In 1906, Argentina communicated to the international community the establishment of a permanent base on South Orkney Islands. However, Haggard responded by reminding Argentina that the South Orkneys were British. The British position was that Argentine personnel was granted permission only for the period of one year. The Argentine government entered into negotiations with the British in 1913 over the possible transfer of the island. Although these talks were unsuccessful, Argentina attempted to unilaterally establish their sovereignty with the erection of markers, national flags and other symbols.  Finally, with British attention elsewhere, Argentina declared the establishment of Argentine Antarctica in 1943, claiming territory that overlapped with British ( 20°W to 80°W) and the earlier Chilean (53°W to 90°W) claims.

In response to this and earlier German explorations, the British Admiralty and Colonial Office launched Operation Tabarin in 1943 to reassert British territorial claims against Argentine and Chilean incursion and establish a permanent British presence in the Antarctic. The move was also motivated by concerns within the Foreign Office about the direction of United States post-war activity in the region.

A suitable cover story was the need to deny use of the area to the enemy. The Kriegsmarine was known to use remote islands as rendezvous points and as shelters for commerce raiders, U-boats and supply ships. Also, in 1941, there existed a fear that Japan might attempt to seize the Falkland Islands, either as a base or to hand them over to Argentina, thus gaining political advantage for the Axis and denying their use to Britain.

In 1943, British personnel from HMS Carnarvon Castle removed Argentine flags from Deception Island. The expedition was led by Lieutenant James Marr and left the Falkland Islands in two ships, HMS William Scoresby (a minesweeping trawler) and Fitzroy, on Saturday 29 January 1944.

Bases were established during February near the abandoned Norwegian whaling station on Deception Island, where the Union Flag was hoisted in place of Argentine flags, and at Port Lockroy (on February 11) on the coast of Graham Land. A further base was founded at Hope Bay on 13 February 1945, after a failed attempt to unload stores on 7 February 1944. Symbols of British sovereignty, including post offices, signposts and plaques were also constructed and postage stamps were issued.

Operation Tabarin provoked Chile to organize its First Chilean Antarctic Expedition in 1947–48, where the Chilean president Gabriel González Videla personally inaugurated one of its bases.

Following the end of the war in 1945, the British bases were handed over to civilian members of the newly created Falkland Islands Dependencies Survey (subsequently the British Antarctic Survey) the first such national scientific body to be established in Antarctica.

Post war developments

Hut built at Hope Bay in 1903. It was there that the only instance of shots fired in anger on the Continent occurred in 1952.

Friction between Britain and the Latin American states continued into the post war period. Royal Navy warships were despatched in 1948 to prevent naval incursions and in 1952, an Argentine shore party at Hope Bay (the British Base "D", established there in 1945, came up against the Argentine Esperanza Base, est. 1952) fired a machine gun over the heads of a British Antarctic Survey team unloading supplies from the John Biscoe. The Argentines later extended a diplomatic apology, saying that there had been a misunderstanding and that the Argentine military commander on the ground had exceeded his authority.

The United States became politically interested in the Antarctic continent before and during WWII. The United States Antarctic Service Expedition, from 1939–1941, was sponsored by the government with additional support came from donations and gifts by private citizens, corporations and institutions. The objectives of the Expedition, outlined by President Franklin D. Roosevelt, was to establish two bases: East Base, in the vicinity of Charcot Island, and West Base, in the vicinity of King Edward VII Land. After operating successfully for two years, but with international tensions on the rise, it was considered wise to evacuate the two bases.

However, immediately after the war, American interest was rekindled with an explicitly geopolitical motive. Operation Highjump, from 1946–1947 was organized by Rear Admiral Richard E. Byrd Jr. and included 4,700 men, 13 ships, and multiple aircraft. The primary mission of Operation Highjump was to establish the Antarctic research base Little America IV, for the purpose of training personnel and testing equipment in frigid conditions and amplifying existing stores of knowledge of hydrographic, geographic, geological, meteorological and electromagnetic propagation conditions in the area. The mission was also aimed at consolidating and extending United States sovereignty over the largest practicable area of the Antarctic continent, although this was publicly denied as a goal even before the expedition ended.

Towards an international treaty

The International Geophysical Year was pivotal in establishing a cooperative international framework in Antarctica, and led on to the Antarctic Treaty System in 1959.

Meanwhile, in an attempt at ending the impasse, Britain submitted an application to the International Court of Justice in 1955 to adjudicate between the territorial claims of Britain, Argentina and Chile. This proposal failed, as both Latin American countries rejected submitting to an international arbitration procedure.

Negotiations towards the establishment of an international condominium over the continent first began in 1948, involving the 7 claimant powers (Britain, Australia, New Zealand, France, Norway, Chile and Argentina) and the US. This attempt was aimed at excluding the Soviet Union from the affairs of the continent and rapidly fell apart when the USSR declared an interest in the region, refused to recognize any claims of sovereignty and reserved the right to make its own claims in 1950.

An important impetus toward the formation of the Antarctic Treaty System in 1959, was the International Geophysical Year, 1957–1958. This year of international scientific cooperation triggered an 18-month period of intense Antarctic science. More than 70 existing national scientific organizations then formed IGY committees, and participated in the cooperative effort. The British established Halley Research Station in 1956 by an expedition from the Royal Society. Sir Vivian Fuchs headed the Commonwealth Trans-Antarctic Expedition, which completed the first overland crossing of Antarctica in 1958. In Japan, the Japan Maritime Safety Agency offered ice breaker Sōya as the South Pole observation ship and Showa Station was built as the first Japanese observation base on Antarctica.

France contributed with Dumont d'Urville Station and Charcot Station in Adélie Land. The ship Commandant Charcot of the French Navy spent nine months of 1949/50 at the coast of Adelie Land, performing ionospheric soundings. The US erected the Amundsen–Scott South Pole Station as the first permanent structure directly over the South Pole in January 1957.

Finally, to prevent the possibility of military conflict in the region, the United States, United Kingdom, the Soviet Union and 9 other countries with significant interests negotiated and signed the Antarctic Treaty in 1959. The treaty entered into force in 1961 and sets aside Antarctica as a scientific preserve, established freedom of scientific investigation and banned military activity on that continent. The treaty was the first arms control agreement established during the Cold War.

Recent history

MV Explorer in Antarctica in January 1999. She sank on 23 November 2007 after hitting an iceberg.

A baby, named Emilio Marcos de Palma, was born near Hope Bay on 7 January 1978, becoming the first baby born on the continent. He also was born farther south than anyone in history.

On 28 November 1979, an Air New Zealand DC-10 on a sightseeing trip crashed into Mount Erebus on Ross Island, killing all 257 people on board.

In 1991 a convention among member nations of the Antarctic Treaty on how to regulate mining and drilling was proposed. Australian Prime Minister Bob Hawke and French Prime Minister Michel Rocard led a response to this convention that resulted in the adoption of the Protocol on Environmental Protection to the Antarctic Treaty, now known as the Madrid Protocol. All mineral extraction was banned for 50 years and the Antarctic was set aside as a "natural reserve, devoted to peace and science".

Børge Ousland, a Norwegian explorer, finished the first unassisted Antarctic solo crossing on 18 January 1997.

On 23 November 2007, the MV Explorer struck an iceberg and sank, but all on board were rescued by nearby ships, including a passing Norwegian cruise ship, the MS Nordnorge.

Women in Antarctica

First women at the South Pole are Pam Young, Jean Pearson, Lois Jones, Eileen McSaveney, Kay Lindsay and Terry Tickhill.

Women were originally kept from exploring Antarctica until well into the 1950s. A few pioneering women visited the Antarctic land and waters prior to the 1950s and many women requested to go on early expeditions, but were turned away. Early pioneers such as Louise Séguin and Ingrid Christensen were some of the first women to see Antarctic waters. Christensen was the first woman to set foot on the mainland of Antarctica. The first women to have any fanfare about their Antarctic journeys were Caroline Mikkelsen who set foot on an island of Antarctica in 1935, and Jackie Ronne and Jennie Darlington who were the first women to over-winter in Antarctica in 1947. The first woman scientist to work in Antarctica was Maria Klenova in 1956. Silvia Morella de Palma was the first woman to give birth in Antarctica, delivering 3.4 kg (7 lb 8 oz) Emilio Palma at the Argentine Esperanza base 7 January 1978.

Women faced legal barriers and sexism that prevented most from visiting Antarctica and doing research until the late 1960s. The United States Congress banned American women from traveling to Antarctica until 1969. Women were often excluded because it was thought that they could not handle the extreme temperatures or crisis situations. The first woman from the British Antarctic Survey to go to Antarctica was Janet Thomson in 1983 who described the ban on women as a "rather improper segregation."

Once women were allowed in Antarctica, they still had to fight against sexism and sexual harassment. However, a tipping point was reached in the mid 1990s when it became the new normal that women were part of Antarctic life. Women began to see a change as more and more women began working and researching in Antarctica.

Arctic exploration

From Wikipedia, the free encyclopedia

The Arctic region is within the red line

Arctic exploration is the physical exploration of the Arctic region of the Earth. It refers to the historical period during which mankind has explored the region north of the Arctic Circle. Historical records suggest that humankind have explored the northern extremes since 325 BC, when the ancient Greek sailor Pytheas reached a frozen sea while attempting to find a source of the metal tin. Dangerous oceans and poor weather conditions often fetter explorers attempting to reach polar regions and journeying through these perils by sight, boat, and foot has proven difficult.

Ancient Greece

Some scholars believe that the first attempts to penetrate the Arctic Circle can be traced to ancient Greece and the sailor Pytheas, a contemporary of Aristotle and Alexander the Great, who, in 325 BC, attempted to find the source of the tin that would sporadically reach the Greek colony of Massilia (now Marseille) on the Mediterranean coast. Sailing past the Pillars of Hercules, he reached Brittany and then Cornwall, eventually circumnavigating the British Isles. From the local population, he heard news of the mysterious land of Thule, even farther to the north. After six days of sailing, he reached land at the edge of a frozen sea (described by him as "curdled"), and described what is believed to be the aurora and the midnight sun. Some historians claim that this new land of Thule was either the Norwegian coast or the Shetland Islands based on his descriptions and the trade routes of early British sailors. While no one knows exactly how far Pytheas sailed, he may have crossed the Arctic Circle. Nevertheless, his tales were regarded as fantasy by later Greek and Roman authorities, such as the geographer Strabo.

The Middle Ages

Viking sailors reached the White Sea and Greenland and North America

The first Viking to sight Iceland was Gardar Svavarsson, who lost his route due to harsh conditions when sailing from Norway to the Faroe Islands. This quickly led to a wave of colonization. Not all the settlers were successful however in the attempts to reach the island. In the 10th century, Gunnbjörn Ulfsson got lost in a storm and ended up within sight of the Greenland coast. His report spurred Erik the Red, an outlawed chieftain, to establish a settlement there in 985. While they flourished initially, these settlements eventually foundered due to changing climatic conditions (see Little Ice Age).They are believed to have survived until around 1450.

Greenland's early settlers sailed westward, in search of better pasturage and hunting grounds. Modern scholars debate the precise location of the new lands of Vinland, Markland, and Helluland that they discovered.

The Scandinavian peoples also pushed farther north into their own peninsula by land and by sea. As early as 880, the Viking Ohthere of Hålogaland rounded the Scandinavian Peninsula and sailed to the Kola Peninsula and the White Sea. The Pechenga Monastery on the north of Kola Peninsula was founded by Russian monks in 1533; from their base at Kola, the Pomors explored the Barents Region, Spitsbergen, and Novaya Zemlya—all of which are in the Arctic Circle. They also explored north by boat, discovering the Northern Sea Route, as well as penetrating to the trans-Ural areas of northern Siberia. They then founded the settlement of Mangazeya east of the Yamal Peninsula in the early 16th century. In 1648 the Cossack Semyon Dezhnyov opened the now famous Bering Strait between America and Asia.

Russian settlers and traders on the coasts of the White Sea, the Pomors, had been exploring parts of the northeast passage as early as the 11th century. By the 17th century they established a continuous sea route from Arkhangelsk as far east as the mouth of Yenisey. This route, known as Mangazeya seaway, after its eastern terminus, the trade depot of Mangazeya, was an early precursor to the Northern Sea Route.

Age of Discovery

Mercator's map of the North Pole (1606)

Exploration to the north of the Arctic Circle in the Renaissance was both driven by the rediscovery of the Classics and the national quests for commercial expansion, and hampered by limits in maritime technology, lack of stable food supplies, and insufficient insulation for the crew against extreme cold.

Renaissance advancements in cartography

Patent from King Henry VII, authorizing John Cabot and his sons to explore new lands in the west

A seminal event in Arctic exploration occurred in 1409, when Ptolemy's Geographia was translated into Latin, thereby introducing the concepts of latitude and longitude into Western Europe. Navigators were better able to chart their positions, and the European race to China, sparked by interest in the writings of Marco Polo, commenced. The Inventio Fortunata, a lost book, describes in a summary written by Jacobus Cnoyen but only found in a letter from Gerardus Mercator, voyages as far as the North Pole. One widely disputed claim is that two brothers from Venice, Niccolo and Antonio Zeno, allegedly made a map of their journeys to that region, which were published by their descendants in 1558.

Northwest Passage

The Northwest Passage connects the Atlantic and Pacific Oceans via the Arctic Ocean. Since the discovery of the American continent was the product of the search for a route to Asia, exploration around the northern edge of North America continued for the Northwest Passage. John Cabot's initial failure in 1497 to find a Northwest Passage across the Atlantic led the British to seek an alternative route to the east.

Interest re-kindled in 1564 after Jacques Cartier's discovery of the mouth of the Saint Lawrence River. Martin Frobisher had formed a resolution to undertake the challenge of forging a trade route from England westward to India. From 1576 to 1578, he took three trips to what is now the Canadian Arctic in order to find the passage. Frobisher Bay is named after him. In July 1583, Sir Humphrey Gilbert, who had written a treatise on the discovery of the passage and was a backer of Frobisher's, claimed the territory of Newfoundland for the English crown.

In 1585, under the employ of Elizabeth I, the English explorer John Davis entered Cumberland Sound, Baffin Island. Davis rounded Greenland before dividing his four ships into separate expeditions to search for a passage westward. Though he was unable to pass through the icy Arctic waters, he reported to his sponsors that the passage they sought is "a matter nothing doubtfull [sic]," and secured support for two additional expeditions, reaching as far as Hudson Bay.

Though England's efforts were interrupted in 1587 because of the Anglo-Spanish War, Davis's favorable reports on the region and its people would inspire explorers in the coming century. In 1609, while in the service of the Dutch East India Company, the English explorer Henry Hudson sailed up what is now called the Hudson River in search of the Passage; he reached present-day Albany, New York, before giving up. He later explored further north into the Arctic and Hudson Bay for the Passage.

The Northeast Passage

Jan Jansson's map of the "Poli Arctici" from 1644.

The Northeast Passage is a broad term for any route lying above the Eurasian continent and stretching between the waters north of the Norwegian Sea to the Bering Strait. The "Northern Sea Route" is defined as a specific portion of such routes. The Northern Sea Route (capitalized) as currently officially defined by Russian Federation law includes shipping lanes falling within Russia's EEZ and extending from the Kara Sea to the Bering Strait along the Russian northern coast.

The idea to explore this region was initially economic, and was first put forward by Russian diplomat Dmitry Gerasimov in 1525. The entire route lies in Arctic waters and parts are only totally free of ice for about two months per year, making it a very perilous journey.

In the mid-16th century, John Cabot's son Sebastian helped organize just such an expedition, led by Sir Hugh Willoughby and Richard Chancellor. Willoughby's crew was shipwrecked off the Kola Peninsula, where they eventually died of scurvy. Chancellor and his crew made it to the mouth of the Dvina River and the town of Arkhangelsk, where they were met by a delegation from the Tsar, Ivan the Terrible. Brought back to Moscow, he launched the Muscovy Company, promoting trade between England and Russia. This diplomatic course allowed British Ambassadors such as Sir Francis Cherry the opportunity to consolidate geographic information developed by Russian merchants into maps for British exploration of the region. Some years later, Steven Borough, the master of Chancellor's ship, made it as far as the Kara Sea, when he was forced to turn back because of icy conditions.

Spitsbergen and Svalbard during the Golden Age of Dutch exploration and discovery (ca. 1590s–1720s). Portion of 1599 map of Arctic exploration by Willem Barentsz. Spitsbergen, here mapped for the first time, is indicated as "Het Nieuwe Land" (Dutch for "the New Land"), center-left. This is a typical map from the Golden Age of Netherlandish cartography.
 
A Dutch map of Jan Mayen during the Golden Age of Dutch exploration and discovery (ca. 1590s–1720s). The Dutch were the first to undisputedly explore and chart coastlines of Jan Mayen and the Svalbard archipelago in the Arctic Ocean.

Western parts of the passage were simultaneously being explored by Northern European countries like England, the Netherlands, Denmark and Norway, looking for an alternative seaway to China and India. Although these expeditions failed, new coasts and islands were discovered. Most notable is the 1596 expedition led by Dutch navigator Willem Barentsz who discovered Spitsbergen and Bear Island.

Fearing English and Dutch penetration into Siberia, Russia closed the Mangazeya seaway in 1619. Pomor activity in Northern Asia declined and the bulk of exploration in the 17th century was carried out by Siberian Cossacks, sailing from one river mouth to another in their Arctic-worthy kochs. In 1648 the most famous of these expeditions, led by Fedot Alekseev and Semyon Dezhnev, sailed east from the mouth of Kolyma to the Pacific and doubled the Chukchi Peninsula, thus proving that there was no land connection between Asia and North America. Eighty years after Dezhnev, in 1728, another Russian explorer, Danish-born Vitus Bering on Sviatoy Gavriil made a similar voyage in reverse, starting in Kamchatka and going north to the passage that now bears his name (Bering Strait). It was Bering who gave their current names to Diomede Islands, discovered and first described by Dezhnev.

It was not until in 1878 that Finnish-Swedish explorer Adolf Erik Nordenskiöld made the first complete passage of the North East Passage from west to east, in the Vega expedition. The ship's captain on this expedition was Lieutenant Louis Palander of the Swedish Royal Navy.

Northwest Passage

Sailing Ship in Arctic Regions
 
Roald Amundsen led the first expedition to reach the South Pole, was the first person to reach both poles, and was the first person to traverse the Northwest Passage.

In the first half of the 19th century, parts of the Northwest Passage were explored separately by a number of different expeditions, including those by John Ross, William Edward Parry, James Clark Ross; and overland expeditions led by John Franklin, George Back, Peter Warren Dease, Thomas Simpson, and John Rae. Sir Robert McClure was credited with the discovery of the Northwest Passage by sea in 1851 when he looked across M'Clure Strait from Banks Island and viewed Melville Island. However, the strait was blocked by young ice at this point in the season, and not navigable to ships. The only usable route, linking the entrances of Lancaster Sound and Dolphin and Union Strait was first used by John Rae in 1851. Rae used a pragmatic approach of traveling by land on foot and dog sled, and typically employed less than ten people in his exploration parties.

The Northwest Passage was not completely conquered by sea until 1906, when the Norwegian explorer Roald Amundsen, who had sailed just in time to escape creditors seeking to stop the expedition, completed a three-year voyage in the converted 47-ton herring boat Gjøa. At the end of this trip, he walked into the city of Eagle, Alaska, and sent a telegram announcing his success. His route was not commercially practical; in addition to the time taken, some of the waterways were extremely shallow.

Knud Rasmussen (1879 - 1933) led several Arctic expeditions. He grew up in Greenland speaking Greenlandic and Danish, and has been called the "father of Eskimology" and was the first Greenlander of Inuit and European descent to cross the Northwest Passage via dog sled. Rasmussen and his friend Peter Freuchen participated in seven Thule Expeditions, named after ultima Thule, and wrote numerous books on their Arctic experiences.

The North Pole

Robert Peary and sledge party with flags at North Pole. Peary has been claimed to be the first person to reach the North Pole.

On April 6, 1909, Robert Peary claimed to be the first person in recorded history to reach the North Pole (although whether he actually reached the Pole is disputed). He traveled with the aid of dogsleds and three separate support crews who turned back at successive intervals before reaching the Pole. Many modern explorers, including Olympic skiers using modern equipment, contend that Peary could not have reached the pole on foot in the time he claimed.

A number of previous expeditions set out with the intention of reaching the North Pole but did not succeed; that of British naval officer William Edward Parry in 1827, the tragic American Polaris expedition under Charles Francis Hall in 1871, the ill-fated Jeannette Expedition commanded by US Navy Lieutenant Commander George W. De Long in 1879, and the Norwegian Fram expedition of Fridtjof Nansen in 1895. American Frederick Cook claimed to have reached the North Pole in 1908, but this has not been widely accepted.

On May 9, 1926, Americans Richard E. Byrd and Floyd Bennett claimed to have flown over the North Pole in a Fokker F.VIIa/3m Tri-motor monoplane. However, their claim to have reached the Pole is disputed.

The crew of the airship Norge (including Roald Amundsen and the American sponsor Lincoln Ellsworth) flew over the Pole on May 12, 1926. This is the first undisputed sighting of the Pole. Norge was designed and piloted by the Italian Umberto Nobile, who overflew the Pole a second time on May 24, 1928. Nobile’s second trip was in the airship Italia that ran into a storm on the return trip and crashed on the ice. Survivors were eventually recovered. Amundsen disappeared, with the crew of his sea plane, during the rescue operations.

The first people to have without doubt walked on the North Pole were the Soviet party of 1948 under the command of Alexander Kuznetsov, who landed their aircraft nearby and walked to the pole.

On August 3, 1958, the American submarine USS Nautilus (SSN-571) reached the North Pole without surfacing. It then proceeded to travel under the entire Polar ice cap. On March 17, 1959, the USS Skate (SSN-578) surfaced on the North Pole and dispersed the ashes of explorer Sir Hubert Wilkins. These journeys were part of military explorations stimulated by the Cold War context.

On April 19, 1968, Ralph Plaisted reached the North Pole via snowmobile, the first surface traveler known with certainty to have done so. His position was verified independently by a US Air Force meteorological overflight. In 1969 Wally Herbert, on foot and by dog sled, became the first man to reach the North Pole on muscle power alone, on the 60th anniversary of Robert Peary's famous but disputed expedition.

The first persons to reach the North Pole on foot (or skis) and return with no outside help, no dogs, air planes, or re-supplies were Richard Weber (Canada) and Misha Malakhov (Russia) in 1995. No one has completed this journey since.

U.S. Air Force Lieutenant Colonel Joseph O. Fletcher and Lieutenant William Pershing Benedict landed a plane at the Pole on May 3, 1952, accompanied by the scientist Albert P. Crary.

On 2 May 2007, BBC's Top Gear got to the 1996 position of the magnetic north pole (78°35.7′N 104°11.9′W) in modified Toyota Hilux.

On 2 August 2007, during Arktika 2007 Russian manned submersibles were the first to descend to the sea-bed below the pole.

On April 26, 2009, Vassily Elagin, Afanassi Makovnev, Vladimir Obikhod, Sergey Larin, Alexey Ushakov, Alexey Shkrabkin and Nikolay Nikulshin after 38 days and over 2,000 km (1,200 mi) (starting from Sredniy Island, Severnaya Zemlya) drove two Russian built cars "Yemelya-1" and "Yemelya-2" to the North Pole.

Corinth Canal

From Wikipedia, the free encyclopedia

Coordinates: 37°56′05″N 22°59′02″E

Corinth Canal
Canal of Corinth.jpg
Specifications
Length6.4 km (4.0 miles)
Maximum boat beam17.6 m (58 ft)
Maximum boat draft7.3 m (24 ft)
Locks0
StatusOpen
History
Principal engineerIstván Türr and Béla Gerster
Construction began1881
Date of first use25 July 1893

The Corinth Canal (Greek: Διώρυγα της Κορίνθου, romanizedDhioryga tis Korinthou) connects the Gulf of Corinth in the Ionian Sea with the Saronic Gulf in the Aegean Sea. It cuts through the narrow Isthmus of Corinth and separates the Peloponnese from the Greek mainland, arguably making the peninsula an island. The canal was dug through the isthmus at sea level and has no locks. It is 6.4 kilometres (4 mi) in length and only 21.4 metres (70 ft) wide at its base, making it impassable for many modern ships. It has little economic importance and is mainly a tourist attraction.

The canal was initially proposed in classical times and a failed effort was made to build it in the 1st century AD. Construction recommenced in 1881 but was hampered by geological and financial problems that bankrupted the original builders. It was completed in 1893, but, due to the canal's narrowness, navigational problems, and periodic closures to repair landslides from its steep walls, it failed to attract the level of traffic expected by its operators.

History

The location of the Isthmus of Corinth; the modern canal is shown in light blue.

Ancient attempts

Several rulers of antiquity dreamed of digging a cutting through the isthmus. The first to propose such an undertaking was the tyrant Periander in the 7th century BC. The project was abandoned and Periander instead constructed a simpler and less costly overland portage road, named the Diolkos or stone carriageway, along which ships could be towed from one side of the isthmus to the other. Periander's change of heart is attributed variously to the great expense of the project, a lack of labour or a fear that a canal would have robbed Corinth of its dominant role as an entrepôt for goods. Remnants of the Diolkos still exist next to the modern canal.

The Diadoch Demetrius Poliorcetes (336–283 BC) planned to construct a canal as a means to improve his communication lines, but dropped the plan after his surveyors, miscalculating the levels of the adjacent seas, feared heavy floods.

The philosopher Apollonius of Tyana prophesied that anyone who proposed to dig a Corinthian canal would be met with illness. Three Roman rulers considered the idea but all suffered violent deaths; the historians Plutarch and Suetonius both wrote that the Roman dictator Julius Caesar considered digging a canal through the isthmus but was assassinated before he could begin the project. Caligula, the third Roman Emperor, commissioned a study in 40 AD from Egyptian experts who claimed incorrectly that the Corinthian Gulf was higher than the Saronic Gulf. As a result, they concluded, if a canal were dug the island of Aegina would be inundated. Caligula's interest in the idea got no further as he too was assassinated before making any progress.

Remains of Nero's canal project in 1881

The emperor Nero was the first to attempt to construct the canal, personally breaking the ground with a pickaxe and removing the first basket-load of soil in 67 AD, but the project was abandoned when he died shortly afterwards. The Roman workforce, consisting of 6,000 Jewish prisoners of war, started digging 40–50-metre-wide (130–160 ft) trenches from both sides, while a third group at the ridge drilled deep shafts for probing the quality of the rock (which were reused in 1881 for the same purpose).

According to Suetonius, the canal was dug to a distance of four stades – approximately 700 metres (2,300 ft) – or about a tenth of the total distance across the isthmus. A memorial of the attempt in the form of a relief of Hercules was left by Nero's workers and can still be seen in the canal cutting today. Other than this, as the modern canal follows the same course as Nero's, no remains have survived.

The Greek philosopher and Roman senator Herodes Atticus is known to have considered digging a canal in the 2nd century AD, but did not get a project under way. The Venetians also considered it in 1687 after their conquest of the Peloponnese but likewise did not initiate a project.

Corinth stone.jpg

Construction of the modern canal

The idea of a canal was revived after Greece gained formal independence from the Ottoman Empire in 1830. The Greek statesman Ioannis Kapodistrias asked a French engineer to assess the feasibility of the project but had to abandon it when its cost was assessed at 40 million gold francs—far too expensive for the newly independent country. Fresh impetus was given by the opening of the Suez Canal in 1869 and the following year, the government of Prime Minister Thrasyvoulos Zaimis passed a law authorizing the construction of a Corinth Canal. French entrepreneurs were put in charge but, following the bankruptcy of the French company that had attempted to dig the Panama Canal, French banks refused to lend money and the company went bankrupt as well. A fresh concession was granted to the Société Internationale du Canal Maritime de Corinthe in 1881, which was commissioned to construct the canal and operate it for the next 99 years. Construction was formally inaugurated on 23 April 1882 in the presence of King George I of Greece.

Share of the company Canal Maritime de Corinthe, issued 1882

The company's initial capital was 30,000,000 francs (US$6.0 million in the money of the day), but after eight years of work it ran out of money and a bid to issue 60,000 bonds of 500 francs each flopped when less than half of the bonds were sold. The company's head, István Türr, went bankrupt, as did the company itself and a bank that had agreed to raise additional funds for the project. Construction resumed in 1890 when the project was transferred to a Greek company, and was completed on 25 July 1893 after eleven years' work.

After completion

The Inauguration of the Corinth Canal (1893) by Konstantinos Volanakis.

The canal experienced financial and operational difficulties after completion. The narrowness of the canal makes navigation difficult. Its high walls channel wind along its length, and the different times of the tides in the two gulfs cause strong tidal currents in the channel. For these reasons, many ship operators were unwilling to use the canal, and traffic was far below predictions. Annual traffic of just under 4 million net tons had been anticipated, but by 1906 traffic had reached only half a million net tons annually. By 1913 the total had risen to 1.5 million net tons, but the disruption caused by World War I resulted in a major decline in traffic.

The Corinth Canal seen from the air, showing the steep limestone walls which proved vulnerable to landslides

Another persistent problem was the heavily faulted nature of the sedimentary rock, in an active seismic zone, through which the canal is cut. The canal's high limestone walls have been persistently unstable from the start. Although it was formally opened in July 1893 it was not opened to navigation until the following November, due to landslides. It was soon found that the wake from ships passing through the canal undermined the walls, causing further landslides. This required further expense in building retaining walls along the water's edge for more than half of the length of the canal, using 165,000 cubic metres of masonry. Between 1893 and 1940, it was closed for a total of four years for maintenance to stabilise the walls. In 1923 alone, 41,000 cubic metres of material fell into the canal, which took two years to clear out.

Serious damage was caused to the canal during World War II. On 26 April 1941, during the Battle of Greece between defending British troops and the invading forces of Nazi Germany, German parachutists and glider troops attempted to capture the main bridge over the canal. The bridge was defended by the British and had been wired for demolition. The Germans surprised the defenders with a glider-borne assault in the early morning of 26 April and captured the bridge, but the British set off the charges and destroyed the structure. Other authors maintain that German pioneers cut the detonation wires, and a lucky hit by British artillery triggered the explosion. The bridge was replaced by a combined rail/road bridge built in 25 days by the IV Railway Engineer Battalion, of the Royal Italian Army's Railway Engineer Regiment.

Three years later, as German forces retreated from Greece, the canal was put out of action by German "scorched earth" operations. German forces used explosives to trigger landslides to block the canal, destroyed the bridges and dumped locomotives, bridge wreckage and other infrastructure into the canal to hinder repairs. The United States Army Corps of Engineers began to clear the canal in November 1947 and reopened it for shallow-draft traffic by 7 July 1948, and for all traffic by that September.

Modern use

Because the canal is difficult to navigate for large vessels, it is mostly used by smaller recreational boats. A notable exception occurred on 9 October 2019, when MS Braemar became the widest and longest ship to cruise through the canal.

Layout

Aerial photograph of the Corinth Canal area (2011)

The canal consists of a single channel 8 metres (26 ft) deep, excavated at sea level (thus requiring no locks), measuring 6,343 metres (20,810 ft) long by 24.6 metres (81 ft) wide at sea level and 21.3 metres (70 ft) wide at the bottom. The rock walls, which rise 90 metres (300 ft) above sea level, are at a near-vertical 80° angle. The canal is crossed by a railway line, a road and a motorway at a height of about 45 metres (148 ft). In 1988 submersible bridges were installed at sea level at each end of the canal, by the eastern harbour of Isthmia and the western harbour of Poseidonia.

Although the canal saves the 700-kilometre (430 mi) journey around the Peloponnese, it is too narrow for modern ocean freighters, as it can accommodate ships only of a width up to 17.6 metres (58 ft) and draft up to 7.3 metres (24 ft). In October 2019, with over 900 passengers on board, a 22.5 metres (74 ft) wide and 195 metres (640 ft) long, Fred. Olsen Cruise Lines cruise ship successfully traversed the canal to set a new record for longest ship to pass through the canal. Ships can pass through the canal only one convoy at a time on a one-way system. Larger ships have to be towed by tugs. The canal is currently used mainly by tourist ships; around 11,000 ships per year travel through the waterway.

Adrenal insufficiency

From Wikipedia, the free encyclopedia

Adrenal insufficiency
Illu adrenal gland.jpg
Adrenal gland
SpecialtyEndocrinology

Adrenal insufficiency is a condition in which the adrenal glands do not produce adequate amounts of steroid hormones, primarily cortisol; but may also include impaired production of aldosterone (a mineralocorticoid), which regulates sodium conservation, potassium secretion, and water retention. Craving for salt or salty foods due to the urinary losses of sodium is common.

Addison's disease and congenital adrenal hyperplasia can manifest as adrenal insufficiency. If not treated, adrenal insufficiency may result in abdominal pains, vomiting, muscle weakness and fatigue, depression, low blood pressure, weight loss, kidney failure, changes in mood and personality, and shock (adrenal crisis). An adrenal crisis may occur if the body is subjected to stress, such as an accident, injury, surgery, or severe infection; death may quickly follow.

Adrenal insufficiency can also occur when the hypothalamus or the pituitary gland does not make adequate amounts of the hormones that assist in regulating adrenal function. This is called secondary or tertiary adrenal insufficiency and is caused by lack of production of ACTH in the pituitary or lack of CRH in the hypothalamus, respectively.

Types

There are three major types of adrenal insufficiency.

Signs and symptoms

Signs and symptoms include: hypoglycemia, dehydration, weight loss, and disorientation. Additional signs and symptoms include weakness, tiredness, dizziness, low blood pressure that falls further when standing (orthostatic hypotension), cardiovascular collapse, muscle aches, nausea, vomiting, and diarrhea. These problems may develop gradually and insidiously. Addison's disease can present with tanning of the skin that may be patchy or even all over the body. Characteristic sites of tanning are skin creases (e.g. of the hands) and the inside of the cheek (buccal mucosa). Goitre and vitiligo may also be present. Eosinophilia may also occur.

Causes

Causes of acute adrenal insufficiency are mainly sudden withdrawal of long-term corticosteroid therapy, Waterhouse–Friderichsen syndrome, and stress in people with underlying chronic adrenal insufficiency. The latter is termed critical illness–related corticosteroid insufficiency.

For chronic adrenal insufficiency, the major contributors are autoimmune adrenalitis (Addison's Disease), tuberculosis, AIDS, and metastatic disease. Minor causes of chronic adrenal insufficiency are systemic amyloidosis, fungal infections, hemochromatosis, and sarcoidosis.

Autoimmune adrenalitis may be part of Type 2 autoimmune polyglandular syndrome, which can include type 1 diabetes, hyperthyroidism, and autoimmune thyroid disease (also known as autoimmune thyroiditis, Hashimoto's thyroiditis, and Hashimoto's disease). Hypogonadism may also present with this syndrome. Other diseases that are more common in people with autoimmune adrenalitis include premature ovarian failure, celiac disease, and autoimmune gastritis with pernicious anemia.

Adrenoleukodystrophy can also cause adrenal insufficiency.

Adrenal insufficiency can also result when a patient has a craniopharyngioma, which is a histologically benign tumor that can damage the pituitary gland and so cause the adrenal glands not to function. This would be an example of secondary adrenal insufficiency syndrome.

Causes of adrenal insufficiency can be categorized by the mechanism through which they cause the adrenal glands to produce insufficient cortisol. These are adrenal dysgenesis (the gland has not formed adequately during development), impaired steroidogenesis (the gland is present but is biochemically unable to produce cortisol) or adrenal destruction (disease processes leading to glandular damage).

Corticosteroid withdrawal

Use of high-dose steroids for more than a week begins to produce suppression of the person's adrenal glands because the exogenous glucocorticoids suppress release of hypothalamic corticotropin-releasing hormone (CRH) and pituitary adrenocorticotropic hormone (ACTH). With prolonged suppression, the adrenal glands atrophy (physically shrink), and can take months to recover full function after discontinuation of the exogenous glucocorticoid. During this recovery time, the person is vulnerable to adrenal insufficiency during times of stress, such as illness, due to both adrenal atrophy and suppression of CRH and ACTH release. Use of steroids joint injections may also result in adrenal suppression after discontinuation.

Adrenal dysgenesis

All causes in this category are genetic, and generally very rare. These include mutations to the SF1 transcription factor, congenital adrenal hypoplasia due to DAX-1 gene mutations and mutations to the ACTH receptor gene (or related genes, such as in the Triple A or Allgrove syndrome). DAX-1 mutations may cluster in a syndrome with glycerol kinase deficiency with a number of other symptoms when DAX-1 is deleted together with a number of other genes.

Impaired steroidogenesis

To form cortisol, the adrenal gland requires cholesterol, which is then converted biochemically into steroid hormones. Interruptions in the delivery of cholesterol include Smith–Lemli–Opitz syndrome and abetalipoproteinemia.

Of the synthesis problems, congenital adrenal hyperplasia is the most common (in various forms: 21-hydroxylase, 17α-hydroxylase, 11β-hydroxylase and 3β-hydroxysteroid dehydrogenase), lipoid CAH due to deficiency of StAR and mitochondrial DNA mutations. Some medications interfere with steroid synthesis enzymes (e.g. ketoconazole), while others accelerate the normal breakdown of hormones by the liver (e.g. rifampicin, phenytoin).

Adrenal destruction

Autoimmune adrenalitis is the most common cause of Addison's disease in the industrialised world. Autoimmune destruction of the adrenal cortex is caused by an immune reaction against the enzyme 21-hydroxylase (a phenomenon first described in 1992). This may be isolated or in the context of autoimmune polyendocrine syndrome (APS type 1 or 2), in which other hormone-producing organs, such as the thyroid and pancreas, may also be affected.

Adrenal destruction is also a feature of adrenoleukodystrophy (ALD), and when the adrenal glands are involved in metastasis (seeding of cancer cells from elsewhere in the body, especially lung), hemorrhage (e.g. in Waterhouse–Friderichsen syndrome or antiphospholipid syndrome), particular infections (tuberculosis, histoplasmosis, coccidioidomycosis), or the deposition of abnormal protein in amyloidosis.

Pathophysiology

Hyponatremia can be caused by glucocorticoid deficiency. Low levels of glucocorticoids leads to systemic hypotension (one of the effects of cortisol is to increase peripheral resistance), which results in a decrease in stretch of the arterial baroreceptors of the carotid sinus and the aortic arch. This removes the tonic vagal and glossopharyngeal inhibition on the central release of ADH: high levels of ADH will ensue, which will subsequently lead to increase in water retention and hyponatremia.

Differently from mineralocorticoid deficiency, glucocorticoid deficiency does not cause a negative sodium balance (in fact a positive sodium balance may occur).

Diagnosis

The best diagnostic tool to confirm adrenal insufficiency is the ACTH stimulation test; however, if a patient is suspected to be suffering from an acute adrenal crisis, immediate treatment with IV corticosteroids is imperative and should not be delayed for any testing, as the patient's health can deteriorate rapidly and result in death without replacing the corticosteroids.

Dexamethasone should be used as the corticosteroid if the plan is to do the ACTH stimulation test at a later time as it is the only corticosteroid that will not affect the test results.

If not performed during crisis, then labs to be run should include: random cortisol, serum ACTH, aldosterone, renin, potassium and sodium. A CT of the adrenal glands can be used to check for structural abnormalities of the adrenal glands. An MRI of the pituitary can be used to check for structural abnormalities of the pituitary. However, in order to check the functionality of the Hypothalamic Pituitary Adrenal (HPA) Axis the entire axis must be tested by way of ACTH stimulation test, CRH stimulation test and perhaps an Insulin Tolerance Test (ITT). In order to check for Addison's Disease, the auto-immune type of primary adrenal insufficiency, labs should be drawn to check 21-hydroxylase autoantibodies.

 

Lie point symmetry

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