Annals of Glaciology 40 2005 207 Calving processes and lake evolution at Miage glacier, Mont Blanc, Italian Alps G. DIOLAIUTI,1 M.P. KIRKBRIDE,2 C. SMIRAGLIA,1 D.I. BENN,3 C. D’AGATA,1 L. NICHOLSON3 1Department of Earth Sciences ‘Ardito Desio’, University of Milan, Via Mangiagalli 34, I-20133 Milan, Italy E-mail:
[email protected] 2Department of Geography, University of Dundee, Dundee DD1 4HN, UK 3School of Geography and Geosciences, University of St Andrews, St Andrews, Fife KY16 9AL, UK ABSTRACT. A marginal ice-contact lake at Miage glacier, Mont Blanc, Italian Alps, has been studied to reconstruct changes in lake area. Historical sources, comprising sketches, maps, photographs and scientific surveys, have been supplemented by recent field surveys. These include surveys of glacier surface velocity (which varied along the glacier tongue from 70 m a–1 in the upper part to about 6 m a–1 close to the snout, consistent with data in the literature, showing that velocity rates have remained constant during the last 40 years), volumetric ice-cliff loss (––92 000 Æ 180 m3 in 2002–03), lake temperature and bathymetry, and qualitative observation of calving events, crevassing, and meltwater production. Results indicate that the lake has been stable for the last half-century following a period of enlargement due to ice-marginal retreat. The lake hydrology is complex, with possible reversals of englacial water flow causing infrequent emptying episodes. The debris cover on the glacier and ice-cliff surfaces seems to have played an important role in the ice-cliff evolution and the calving phenomena; calving is driven by undercutting at the water-line aided by the opening of water- and debris-filled crevasses in the glacier surface.