Variazioni di spessore e di volume della lingua del Ghiacciaio dei Forni (Alpi Centrali, Gruppo Ortles-Cevedale) nel XX secolo. Risultati e confronti di metodologie

Forni Glacier (Central Alps, Ortles-Cevedale Group): area and volume tongue variations during the 20th century. Methods and results

Abstract

Area and volume variations of the Forni Glacier tongue during the 20th century were computed by comparing three different maps, surveyed in 1929, 1953 and 1998 respectively. Digital Elevation Models (DEM) relevant to the above-mentioned epochs were carried out and compared in ARC/INFO environment. As no maps were available for the 1998 glacial tongue surface, a proper topographic survey was carried out using carrier-phase GPS technique. Area and volume variations occurred from 1929 to 1953 are -0.70 km² and about -70 million m³ (-44 m w.e.) respectively, while the values for the following period are -0.45 km² and about -15.5 million m³ (-22 m w.e.) respectively. The results obtained applying the above-mentioned method for the 1929-1953 period were compared with those analytically obtained by Abbadessa in 1955, giving a good fit.