ANTARCTIC REGIONS, the name given to part of the earth's surface surrounding the South Pole. Its limits are variously defined by geographers; some consider it to be coexten sive with the Antarctic Ocean, which in a strict sense is bounded by the Antarctic Circle, while others include also that portion of the great Southern Ocean affected by Antarctic influ ences. According to the latter interpretation the region, is approximately defined by the northern limit of the drifting pack-ice or about lat. 50° S. although icebergs are sometimes encountered as far north as lat. 45° S. The Antarctic region is surrounded by a great ex panse of shoreless water which further north is divided by the continental lands into the At lantic, Pacific and Indian Oceans. The area comprised within the Antarctic Circle is about 8,200,000 square miles.
The early explorations into the region south of the equator and the discov ery of numerous lands gave rise to the belief that a vast continent existed near the South Pole. The first voyage of Captain Cook in 1769 showed, however, that New Zealand, contrary to the general opinion, was an island, and in his second voyage, in 1772, it was proved that the continent, if it existed, did not extend be yond the Antarctic Circle.. In 1773 Cook sailed south again and the following year reached lat. 71° 10' S. in long. 106° 54' W., where he was prevented from advancing further by enor mous ice-floes. No land was seen on this voy age, although its presence was indicated by flights of birds. In 1819 Captain Smith rounded Cape Horn and sighted the South Shetland Islands, while in the following year Alexander Land still farther south was discovered by Bellingshausen. Morrell, an English explorer, sailing in 1822, visited the Falkland Islands, Bouvet Islands and South Georgia, and re ported that he found the temperature of both air and water to be milder the farther he ad vanced southward. Biscoe circumnavigated the southern ice region in 1831-32, penetrating be yond lat. 67° S.; he discovered Enderby.Land and its southwestern extension, which he named Graham Land. Kemp sighted and marked Kemp Land in 1833. The Balleny Islands were discovered by Balleny in 1839, and D'Urville, in 1839-40, made a long voyage during which he visited many of the previously discovered lands, changing their names to make room for se lections of his own. The latter also found Adelie Land, an immense tract situated far south of New Zealand and stretching for an unknown distance toward the Pole. The voy ages of Wilkes (1838-42) and of Ross (1841r 42) were of great importance, especially in their scientific aspects. Ross encountered land in 70°
41' S. lat., 172° 30' E. long., which had a steep, rocky coast-line; farther south in 77° 32' S. lat., he found a lofty, active volcano which he named Mount Erebus and an inactive cone called Mount Terror. He sailed for a distance of 450 miles along an unknown ice barrier rising 150 feet above the water. During the next 30 years little was added to our knowledge of the Ant arctic region. Dallman in 1873-74, however, vis ited many of the localities marked by previous explorers and was able to confirm their reports. The Challenger expedition, which started out in 1874, returned with proof of a floating ice bar rier and also accomplished a vast amount of oceanographic investigation. More recently the expedition of Gerlache, who penetrated to lat. 71 36' S., was fruitful in scientific results and added over 100 islands to the list of those pre viously known. Borchgrevinck, a Norwegian, in charge of an English expedition, passed the win ter of 1898-99 in the Antarctic and in the fol lowing summer reached lat. 78° 50' S., the farthest then attained. In 1900 he set out again and succeeded in locating the south magnetic pole in lat. 73° 20' S., long. 140° E.
From 1901 to 1912 Antarctic exploration was very active. Several expeditions were fitted out in 1901 and one of these under Capt. Robert F. Scott reached lat. 82° 17', long. 163°, the farthest south. A Swedish expedition wider Dr. Otto Nordenskjold,1902-04,made many dis coveries but lost its ship, the Antarctic. Other expeditions were under Dr. Erik von Drygalski (1902), W. S. Bruce (1904), Dr. Jean Charcot (1904), and Lieut. Ernest H. Shackleton (1907-09). In 1909-10 Dr. Jean Charcot on his vessel Pourquoi Pas, had a year of successful exploration, in which he found new lands, made new soundings and achieved other valuable scientific results. His work was mainly be tween the 69th and 71st parallels. In 1910 five expeditions were in the field: English, Capt. Robert F. Scott; Norwegian, Capt. Roald Amundsen; Australia, Dr. Douglas Mawson; Japanese, Lieutenant Shirhase; German, Lieut. William Filchner. Captain Scott sailed from New Zealand on his vessel Terra Nova 29 Nov. 1910, with the intention, of establishing win ter headquarters at the foot of Mount Erebus and on King Edward VII Land. Captain Amundsen left Norway in the ship From in the summer of 1910 with the intention of rounding Cape Horn and entering upon the ice-drift across the Polar Sea which he had long con templated. He changed his plans after sailing and when Captain Scott arrived at his proposed winter headquarters he found Amundsen al ready there.