Equilibrium Line Altitude Fluctuation on the South West Slope of Nevado Coropuna Since The Last Glacial Maximum (Cordillera Ampato, Perú)

The main aim of this research was to reconstruct the LLGM (local last glacial maximum), 1955 and 2007 glacial phases on the South West slope of Nevado Coropuna to obtain valuable information on the changes that have occurred and analyze the glacier evolution. For this purpose the ELA (Equilibrium Line Altitude) indicator has been used as a reference, with the AABR (Area x Altitude Balance Ratio) method, based on the principle of weighting the mass balance according to the distance above or below the ELA of that area. An ELA of 4762 m was obtained for the LLGM, 5779 m for 1955 and 5850 m for 2007, implying a vertical shift of 1088 m from the LLGM to 2007 and of 71 m from 1955 to 2007. The total glaciated surface was reduced by 21.5% between 1955 and 2007 and the temperature shift from LLGM to 2007 was 9.13 oC (0.0091oC/m). The ice of glaciers makes them valuable for climate research, this method offers quantitative information and the analysis of this data may contribute to research into climate change and climatic trends for future predictions.