Suivi de l’évolution de la couverture détritique d’un glacier noir par photo-comparaison: Le glacier d’Estelette, Massif du Mont Blanc

As part of a research programme into the controls on the evolution of the supraglacial debris cover of Glacier d’Estelette, a study of debris cover extent has been conducted over two timescales, decennal and annual. By comparison of aerial photographs, a reduction (1952 - 1993) then extension (1993 - 2006) of the debris cover could be correlated with contemporary phases of glacier advance then retreat. Its proportion of the 2/3 glacier surface area has oscillated between 31.1% and 52.2%. A comparison of oblique terrestrial photographs has confirmed the increase of debris covered glacier which characterised the last half-century, with an increase of debris cover between 2006 and 2007. These results confirm that the climatic signal recorded by the glacier’s dynamic response is the principal control on the extent of the debris cover, via the intensity of ablation and the glacier velocity.