%0 Thesis
%A Giraldez Míner, Claudia
%T Glacier evolution in the South West slope of Nevado Hualcán (Cordillera Blanca, Perú)
%D 2011
%U https://hdl.handle.net/20.500.14352/46425
%X Glaciers and ice caps constitute Essential Climate Variables (ECV) within the Global Climate Observing System (GCOS) and its terrestrial component, the Global TerrestrialObserving System (GTOS), as related to the United Nations Framework Convention on Climate Change (UNFCCC)” (WGMS, 2008).Glaciers are not only key indicators of global climate change, but also a water supply upon which depend an increasing amount of people, and a source of natural hazards. By the study and monitoring of glaciers, the rate of change can be quantified, climatic interpretations may be inferred, and future climate change scenarios predicted. In this way, the processes of climate change adaptation and disaster risk reduction can be assessed and advised.This project was triggered by the GLOF form Lake 513 which took place the 11th of April 2010 in the SW slope of Nevado Hualcán. The aim of this work was to reconstruct earlierglacial phases in the SW slope of Nevado Hualcán in order to generate quantitative information on surface areas and ELAs as a first step for further analysis on glacierevolution, glacier-climate relations, glacier hazards and climate change.The specific conclusions of the present report are:1) Moraines on the SW slope of Nevado Hualcán were identified and mapped and served as the reference to reconstruct the geometry of paleo-glaciers in the LIA andYD glacial phases. Current glaciers were also delimited for 1962 and 2003 using aerial photographs and Google Earth.2) From the delimitation of glaciers, their correspondent surface areas were calculated and compared. The results show that the surface of glaciers has retreated 41,6 km²from YD to 2003 and 3,1 km² from 1962 to 2003, which corresponds to a deglaciation 58 rate of 0,076 km²/year (76.000 m²/year). The results match with the generaldecreasing trend previously observed by other authors.3) From the delimitation of glaciers, their ELAs AABR were calculated. The results show an altitudinal shift of the ELAs AABR from YD to 2003: the vertical shift respect to2003 was 472 m from YD, 130 m from LIA and 106 m from 1962, this last corresponds to a vertical shift of 2,59 m/year. When the ELA altitude shifts above the upper limit ofa glacier, its accumulation zone disappears, and also its positive mass balance, thus the glacier will be condemned to disappear. The results show that ELAs in the SWslope of Nevado Hualcán are in some cases just 162 m below the upper limits of glaciers, revealing prompt terminal stages of some glaciers.4) Changes in ELAs are caused by changes in climatic conditions. As a first approximation, it was assumed that the changes in ELA corresponded solely to changes in temperature. The temperature shift from LIA to 2003 was estimated to be 0,78ºC.
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