Southern Patagonian Ice Field
THE LARGEST GLACIERS IN MIDDLE LATITUDES OF THE SOUTHERN HEMISPHERE
The Patagonian Icefields are the largest glaciers in middle latitudes of the Southern Hemisphere and one of the largest icefields in the world outside the polar regions. The Northern Patagonian Ice Field covers an area of 4,200 km2 and includes the famous San Rafael Glacier and Mount San Valentín. The Southern Patagonian Ice Field (SPIF) has an area of 13,000 km2, extending from the Jorge Montt glacier on the north and the Torres del Paine in the south, with more than 80% owned by Chile and the rest to Argentina.
Between 48 ° 20 ‘and 51 ° 30′ south latitude, the Cordillera de los Andes is almost completely covered by a blanket of snow-capped called Southern Patagonian Ice Field (SPIF), the largest of the South after the Antarctic , with an area of 13,000 km ². It has a length of 350 km between the fjords Calen (Canal Baker), and Last Hope (Union Canal) and a width that varies between 40 and 60 km. A mass of ice plateau character of an average height of 1,350 meters, which is interrupted by numerous peaks and mountain range with elevations up to 3600 m, which generated 48 main glacier basins, from which emerge the major languages of ice. Most of them on the western side manage to reach sea level, and reach the eastern slope large Patagonian lakes.
They excel Cord mountain massif Torre and Fitz Roy. To the north is Mount Steffen, Cerro O’Higgins and Lautaro Volcano. Highlight the hills south Murallón, Risopatrón, Cube and Daudet.
Of the 48 major watersheds in the Pacific glaciers include Pio XI glacier, Amalia, Europe, Bernard and Jorge Montt. In this O’Higgins glaciers are recognized, Chico, Viedma, Upsala and Moreno, among the most important. To the south are important Grey glacier, Tyndall and Balmaceda.
Of the 48 CHPS main glacier basins, most have made a deep recession in recent years, with rates of decline that even exceed 100 m a-1 between 1945-1986 for glaciers O’Higgins, Amalia, Upsala and Lucia (Aniya et al. 1997). SPIF few glaciers have presented stability in their foreheads and even three have advanced the glacier Perito Moreno (Rott et al. 1998), Trinidad (in one of our expeditions in 1999, we find that was destroying forests in the bottom of the fjord Exmouth), and especially the Pio XI glacier, which had a rate of advance of 206 m a-1 between 1945 -1995 (Rivera et al. 1997). A strong tendency of front setback, adds a significant loss of ice surface for all the CHPS, estimated at nearly 500 km2 between 1945 and 1986 (Aniya, 1999). Together with the above, it is estimated a significant volume loss due to changes in thickness, thinning with variable rates, with up to 14 m a-1 between 1991 and 1993 for Upsala (Naruse et al. 1997). The recent variations of glaciers in the CHPS, is a clear response to the climatic changes observed in the southern part of the continent, characterized by an increase in temperature (Rosemblüth et al. 1997) and the decrease in rainfall observed at several stations ( Rosemblüth et al. 1995). Nevertheless, specific responses of glaciers to climate change are not linear, but depend on the topography of the glacial basins (hypsometry, slopes, valleys geometry, thickness of ice, moraine material on the surface of ice, etc.). glaciodinámicas and characteristics (speed, flow, calving, surges, etc.).
Due to the great biodiversity of flora and fauna, as well as the limited existing human intervention on the banks of CHPS, this area has been classified as a protected area by the governments of Chile and Argentina. In 1959, the Chilean government declared a southern portion of the CHPS englaciado and their surroundings, such as the Torres del Paine National Park, which has an approximate area of 181,000 ha. and has been declared a UNESCO Biosphere Reserve. In Chilean territory, the rest of CHPS was declared a national park in 1969, becoming Bernardo O’Higgins Park, the largest nature reserve in Chile with 3,525,901 ha. In the same vein, the whole portion of SPIF located in the Republic of Argentina, is inserted into the Los Glaciares National Park with 450,000 hectares., Which is considered among the 25 mountain regions of exceptional importance for science and conservation, for what is defined as a World Heritage Site (World Heritage Site) according to IUCN. Despite its binational character and status of protection, the CHPS is one of the least studied areas of the planet englaciadas.