There is growing evidence to suggest that the number of debris-covered glaciers around the World is increasing. These glaciers, that often have extensive supraglacial debris cover, respond to changing global temperatures in different ways to so called ‘clean’ debris free glaciers, but the number of studies on such glaciers is low. The Glacier d’Estellete is a small glacier located on the southern side of the Mont Blanc massif, in Val Veny, Italy. It has extensive supraglacial debris cover. In recent years, the retreat of the glacier snout has accelerated, with considerable reduction also observed in ice thickness measured through annual GPS surveys. This paper presents some results of these observations, enhanced by lidar data acquired by NERC ARSF in 2010, to determine rates of ice reduction. Initially, the lidar data were compared with satellite derived DEMs (Terra ASTER), but these were found to be of insufficient quality, and so year-on-year variation in ice altitude was derived from dGPS and lidar observations only. Overall, glacier ice was observed to be thinning at rates of 5-6 m per year. Rates in the retreat of the glacier snout were often much less dramatic. Historical observations show a ‘stepped’ retreat due to underlying topography, with ice-cored moraines often becoming detached from the main glacier. Ice extent beneath the debris-cover was mapped by using the lidar data in conjunction with multispectral Terra ASTER data, again validated with GPS observations. These results not only contribute to understanding the mass balance of debris covered glaciers and their response to environmental change, but also have important geomorphological implications for methods of reconstructing and interpreting past ice extent.
|Publication status||Unpublished - 2013|
|Event||NERC ARSF Biennial Workshop on Airborne Remote Sensing - University of Glasgow, School of Geographical and Earth Sciences, Glasgow, United Kingdom|
Duration: 3 Sep 2013 → 3 Sep 2013
|Workshop||NERC ARSF Biennial Workshop on Airborne Remote Sensing|
|Period||3/09/13 → 3/09/13|