Antarctic science. More than 70 existing national scientific organisations 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 Adélie 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. Antarctic territorial claims Seven sovereign states had made eight territorial claims to land in Antarctica south of the 60° S parallel before 1961. None of these claims have an indigenous population. All claim areas are sectors with the exception of Peter I Island. The South Orkney Islands fall within the territory claimed by Argentina and the United Kingdom, and the South Shetland Islands fall within the areas claimed by Argentina, Chile, and the United Kingdom. These claims have been recognized only between (some of) the seven claiming states. The United Kingdom, France, Australia, New Zealand and Norway all recognize each other's claims (none of their claims overlap with each other). South Africa does not claim sovereignty over Antarctic territory and does not recognise the right or claim to territorial sovereignty by any state. Prior to 1962, the British Antarctic Territory was a dependency of the Falkland Islands and also included South Georgia and the South Sandwich Islands. The Antarctic areas became a separate overseas territory following the ratification of the Antarctic Treaty. South Georgia and the South Sandwich Islands remained a dependency of the Falkland Islands until 1985 when