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The Ross Ice Shelf is the largest ice shelf of Antarctica (an area of roughly and about across: about the size of France). It is several hundred metres thick. The nearly vertical ice front to the open sea is more than long, and between high above the water surface. Ninety percent of the floating ice, however, is below the water surface. Most of Ross Ice Shelf is in the Ross Dependency claimed by New Zealand. The ice shelf was named after Captain Sir James Clark Ross, who discovered it on 28 January 1841. It was originally named the Victoria Barrier by Ross after Queen Victoria and later the Great Ice Barrier, as it prevented sailing further south. Ross mapped the ice front eastward to 160°W. ==Exploration== On January 5, 1841, a British Admiralty team in the ''Erebus'' and the ''Terror'', three-masted ships with specially strengthened wooden hulls, was going through the pack ice of the Pacific near Antarctica in an attempt to determine the position of the South Magnetic Pole. Four days later, they found their way into open water and were hoping that they would have a clear passage to their destination. But on 11 January, the men were faced with an enormous mass of ice. Sir James Clark Ross, who was the expedition's commander, remarked: "Well, there's no more chance of sailing through that than through the cliffs of Dover". Ross, who in 1831 had located the North Magnetic Pole, spent the next two years vainly searching for a sea passage to the South Pole; later, his name was given to the ice shelf and the sea surrounding it. Two volcanoes in the region were named by Ross for his vessels.〔(Antarctica.ac.uk )〕 For early Antarctic explorers seeking to reach the South Pole, the Ross Ice Shelf became a starting area. In a first exploration of the area, Robert Falcon Scott made a significant study of the shelf and its surroundings from his expedition's base on Ross Island. These findings were presented at a lecture entitled "Universitas Antarctica!" given 7 June 1911 and were published in the account of Scott's expedition.〔Scott, Robert and Leonard Huxley. ''Scott's Last Expedition in Two Volumes: Vol. II.'' New York: Dodd, Mead and Company, 1913.〕 Both Roald Amundsen and Scott crossed the shelf to reach the Pole in 1911. Amundsen wrote: "Along its outer edge the Barrier shows an even, flat surface; but here, inside the bay, the conditions were entirely different. Even from the deck of the ''Fram'' we were able to observe great disturbances of the surface in every direction; huge ridges with hollows between them extended on all sides. The greatest elevation lay to the south in the form of a lofty, arched ridge, which we took to be about high on the horizon. But it might be assumed that this ridge continued to rise beyond the range of vision". The next day, the party made its first steps on the Barrier. "After half an hour’s march we were already at the first important point—the connection between the sea-ice and the Barrier. This connection had always haunted our brains. What would it be like? A high, perpendicular face of ice, up which we should have to haul our things laboriously with the help of tackles? Or a great and dangerous fissure, which we should not be able to cross without going a long way round? We naturally expected something of the sort. This mighty and terrible monster would, of course, offer resistance in some form or other," he wrote. "The mystic Barrier! All accounts without exception, from the days of Ross to the present time, had spoken of this remarkable natural formation with apprehensive awe. It was as though one could always read between the lines the same sentence: 'Hush, be quiet! the mystic Barrier!' "One, two, three, and a little jump, and the Barrier was surmounted!"〔 (Translated from the Norwegian by A. G. Chater)〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ross Ice Shelf」の詳細全文を読む スポンサード リンク
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