IANIGLA   20881
Unidad Ejecutora - UE
capítulos de libros
Glacier Fluctuations in the Central Andes of Mendoza, Argentina from 1894/ 1896 to 2005.
World Water Atlas IGU Commission for Water Sustainability
Aberystwyth University
Lugar: Aberystwyth, UK; Año: 2010;
Glaciers act as sensitive indicators of climate change. As glaciers store or release water, this “natural regulation” of runoff from glacierized areas is critical to water supply and use in semi-arid regions. This work presents the response of four glaciers to climate change in the Andean Central Cordillera of Mendoza, Argentina (33º and 35º S latitude) since the late 19th. The fluctuations of the Las Vacas (Fig. 1), Güssfeldt, El Azufre and El Peñón glaciers have been studied since the end of the 19th century to 2007, through the use of historical records data, topographic maps, aerial photographs taken in 1963 and 1974, satellite images (TM) of different years, and GPS measurements in the field. Satellite remote sensing is a useful tool for studying glacier fluctuations because areas are often inaccessible.   The Las Vacas and Güssfeldt glaciers are 5.68 km and 6.52 km long, respectively, on the image of 2007. According to the ETH (2001) they are large glaciers (5 to<10 km) and El Azufre and El Peñón (3.50 and 3.20 km, respectively) are medium-sized glaciers (1 to 5 <km). They are flowing toward the south-east. Figures 2 and 3 shows that there is a clear trend to the retreat from 1894/1896 to 2007 only interrupted by minor advances or standstills. The remarkable signal characteristics of glacier length changes immediately appear by looking at cumulative values and different size categories (Fig. 4). There is a marked retreat of the Las Vacas glacier from 1896 to 1963, and slightly between 1963 and 1974. The glacier advanced between 1974 and 2003, and retreated between 2003 and 2007. The front retreated 2.92 km between 1896 and 2007. The Güssfeldt glacier retreated between 1896 and 1987, continued retreating slightly between 1987 and 1999, and remained relatively stationary between 1999 and 2007. Its front retreated 4.99 km from 1896 to 2007. Large glaciers give strong smoothed signals of trends with a delay of several decades (ETH, 2001). The El Azufre and El Peñón glaciers have undergone a general retreat over the considered period (Fig. 3) and within this retreat the glaciers show small advances or standstills. A marked retreat can be observed between 1894/1897 and 1963. The glaciers advanced between 1963 and 1986, remained nearly stationary between 1986 and 1990, retreated from 1990 to 2004 and advanced slightly during 2004-2007. The glacier fronts retreated 0.94 and 1.12 km, respectively between 1894/1897 and 2007. It is interesting to note that these two glaciers show similar behavior. The typical response time of these medium-sized glaciers is in the order of decades (ETH, 2001). The advance of Las Vacas, El Azufre and El Peñón glaciers during the 80s and 90s, could be related with the strong ENSO events of 1982-1983, 1986-1987 and 1997-1998.