20th-century glacier recession and regional hydroclimatic changes in northwestern Patagonia

MASIOKAS, M.H.; VILLALBA, R.; LUCKMAN, B.H.; LASCANO, M.E.; DELGADO, S.; STEPANEK, P.

London, Ontario, Canada

Simposio; Environmental Research Western Earth Day Colloquium, University of Western Ontario, Canadá.; 2007

Department of Geography, UWO

Here we document the occurrence of significant glacier and hydroclimatic changes in northwestern Patagonia during the past century. Widespread glacier recession is observed by comparison of repeat photographs of some of the earliest documents for glaciers in southern South America. Linear trends in regionally-averaged annual and seasonal climate records indicate significant warming and decreasing precipitation over the 1912-2002 interval. A climatic index based on winter precipitation and summer temperature records that mimics glacier mass balance relationships shows a strong negative trend which agrees with the drastic glacier recession shown by the photographic comparisons. Regionally-averaged mean annual streamflow records provide an independent verification check of this climatic series with a strong negative trend and highly significant positive (negative) correlations with the regional precipitation (temperature) series. This highlights the existence of a regionally coherent hydroclimatic signal and the utility of these records as environmental indicators for northwestern Patagonia between 38° and 45°S. Given the socio-economic importance of rivers and glaciers in this area, further research is needed to evaluate the full range of natural hydroclimate variability and improve understanding of the potential impacts of the future warmer and drier climates projected for this region.