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Hydrological and geomorphological significance of rock glaciers in the dry Andes, Chile (27°–33°S)
Author(s) -
Azócar G. F.,
Brenning A.
Publication year - 2009
Publication title -
permafrost and periglacial processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.867
H-Index - 76
eISSN - 1099-1530
pISSN - 1045-6740
DOI - 10.1002/ppp.669
Subject(s) - glacier , rock glacier , geology , physical geography , permafrost , hydrology (agriculture) , sediment , digital elevation model , elevation (ballistics) , geomorphology , glacier mass balance , climate change , oceanography , geography , remote sensing , geotechnical engineering , geometry , mathematics
The latitudinal‐altitudinal distribution of rock glaciers in the dry Chilean Andes between 27° and 33°S was analysed and their hydrological and geomorphological significance evaluated. Statistical estimation techniques were used based on digital elevation models and air photo interpretation, and sediment budget models were applied to assess surface‐lowering rates. The estimated specific density of rock glaciers in the study area is 1.4 per cent, which corresponds to 147.5 km 2 and a water equivalent of 2.37 km 3 . A comparison with glacier water equivalents derived from revised glacier inventory data shows that rock glaciers are more significant stores of frozen water than glaciers between 29° and 32°S. The latitudinal‐altitudinal distribution of rock glacier limits roughly follows the mean annual air 0°C isotherm, but in the southern part of the study area it extends into elevations where modern regional mean annual air temperatures exceed 0°C. High Andean surface‐lowering rates inferred from rock glacier sediment budget models are in the order of 0.6–0.7 mm yr −1 , which is comparable to previous results from the dry Chilean Andes, but lower than in the more humid Andes further south. Copyright © 2009 John Wiley & Sons, Ltd.