Portal de Periódicos da CAPES

Observations on the rock glaciers of Monte Emilius (valle d'Aosta, Italy)

1992; Wiley; Volume: 3; Issue: 2 Linguagem: Inglês

10.1002/ppp.3430030215

1099-1530

Claudio Smiraglia,

Geology and Paleoclimatology Research

Abstract Monte Emilius (3559 m a.s.l.) is a small mountain massif situated on the southern slope of Valle d'Aosta (Italy). Twenty‐six rock glaciers have been identified by use of aerial photographs. They are classified on the basis of their activity and subdivided into valley‐wall forms, cirque‐floor forms and valley‐floor forms. The mean altitude of the fronts of the active rock glaciers is 2849 m a.s.l., whereas that of the inactive rock glaciers is 2453 m a.s.l. Utilizing data from six meterological stations in Valle d'Aosta, the large‐scale climatological boundary conditions at the lower limits of the active rock glaciers were defined by calculating the thermal gradient (0.58 °C/100 m) and total annual precipitation. The MAAT at the mean altitude of the active rock glaciers fronts proved to be −2.1 °C. This altitude should represent therefore the lower boundary of discontinuous permafrost.