Miage Glacier

Miage Glacier at sunset, as seen from eastern Val Veny in August 2010

Miage Glacier is a debris-covered glacier in northwestern Italy. It is situated on the southwest flank of the Mont Blanc Massif, flowing from Col de Bionnassay (3892m above sea level) into Val Veny in the extreme northwest of Italy. It is Italy's longest glacier at a length of roughly 10km and the largest debris-covered glacier in Europe. Approximately 5km² of its total area of ~11km² is covered in debris originating primarily in rockfall from surrounding walls and avalanching in accumulation areas of its four tributaries. Debris carried along within the glacier, however, is also being exposed at accelerating rates due to accelerating thinning of the glacier tongue.

The number of sources of supraglacial debris as well as the unusual, mica schist-dominated lithology of the rock walls surrounding the glacier, makes for a varied debris lithology; debris cover becomes continuous at ~2400m asl and remains unbroken to the terminus. Patchy areas can occur, however, where crevasses or moulins occur. Debris thickness generally increases from a few cm at 2400m asl to over 1m at the terminus at ~1775m asl, although the spatial distribution of thicknesses is inhomogenous especially on parts of the northern terminal lobe.