marked the base's placement with flags, they successfully returned to Belgrano II. In 1997 another team reached the place but this time they could not find the buildings, covered under thicker ice. They left fuel tanks for future operations in the region. On 10 October 2000 a six-men research expedition established a scientific camp at Sobral's emplacement and measured local ozone levels with a spectrophotometer. The temporary occupation was conducted by personnel belonging to Belgrano II and a technician from the National Antarctic Directorate; since then, a new expedition is sent every year between September and December, where the lowest annual average concentration of ozone in Antarctica is recorded. In order to reach the remote base this team must travel for distances up to over very rugged ice terrain filled with numerous cracks, which pose an often unpredictable threat. Snowcat heavy vehicles are used to cover half of the route; light vehicles like the Yamaha VK-540 II Ski-Doo are preferred for the rest. The party carries all the necessary equipment for a three-months stay, such as tents, fuel, supplies, survival kits, communication hardware and scientific instruments. Description Sobral is the southernmost Argentine base ever established: it is south of Belgrano I, less than distant from the South Pole, from the Southern Ocean coastline, and from Ushuaia, the nearest port city. Common tasks at the base include maintenance, logistic support for scientific projects, and search and rescue. Scientific activities Scientific research carried out at Sobral include meteorology, ionospheric observations and measurements of Earth's magnetic field. Stratospheric ozone data obtained at the base complements the spectrometer network located in Ushuaia, Marambio and Belgrano II. Climate Because of its high latitude and elevation of above sea level, climatic conditions in the area are extreme: air is very dry, winds often exceed , atmospheric pressure is high and temperatures often fall below The maximum registered temperature at Sobral was , and the minimum, on 14 April 1967. See also Argentine Antarctica Crime in Antarctica List of Antarctic research stations List of Antarctic field camps References External links Fundaciòn Marambio – Base Sobral Dirección Nacional del Antártico Sobral Populated places established in 1965 Filchner-Ronne Ice Shelf 1965 establishments in Antarctica