Sobral Scientific Base (, or simply Base Científica Sobral or Base Sobral) was a permanent, all year-round and now only partially active Argentine Antarctic base and scientific research station named after Argentine polar explorer and scientist José María Sobral. It is located on the Filchner Ice Shelf. History Sobral was founded with the goal of asserting Argentine sovereignty over the area while providing a launch platform for that year's planned land expedition to the South Pole. The establishment of the base required over three months of continuous work done in a then barely-known region under extreme environmental circumstances. More than of equipment were transported by tractors over heavily cracked terrain that slowed and often halted the tracked vehicles and sleds. The settling team went across a total of . A Cessna plane from Belgrano I provided route reconnaissance. Sobral was founded on 2 April; just a day after, operation leader Captain Gustavo Adolfo Giró Tapper sent a radio message to Buenos Aires urging his superior command to speed up launching of the expedition to the South Pole so it could be carried out in the first days of October; he argued that the recently surveyed route between Belgrano I and the foothills of the polar plateau sector had very rough ice and, given the known instability of the Filchner Ice Shelf, the expeditionaires would find their path full of unknown obstacles. Thus, on 26 October 1965 a group of ten men left Belgrano I and a few days later arrived in Sobral, the last foothold before getting to the Pole, which they finally did on 10 December 1965. It was the first time in history that Earth's southernmost point was reached by land through the Weddell Sea. By 1968 the slow drifting of the Filchner barrier was causing deep, often hidden crevices and structural stresses on the buildings. The base was thus closed on 28 October 1968 after three years of continuous service; it was quickly buried by falling snow. 15 years later, in November 1983, it was located and reopened by a six-men reconnaissance patrol after a 9-day trip traveling from Belgrano II on Ski-Doo bikes, with the mission of establishing a new connection route between both bases. The team performed maintenance, made meteorological measurements, and over 23 days surveyed the Diamond Mountains, a place never visited by humans before. After leaving written records in plastic tubes and having