Die Gletscher um "1850" und "HEUTE" im Bünderland und in den angrenzenden Gebieten : Untersuchungen zur Höhenlage, Veränderungen und räumlichen Struktur von Schneegrenzen

Abstract. An inventory of data for the extent of ice in 1850 is presented and compared to the extent of alpine glaciers in 1973 as recorded by the Swiss glacier inventory. Special attention is given to the position and spatial Variation of snowline altitudes based on data for the general ice retreat between 1850 and 1973.
The ränge of snowline altitudes (as given by the 2 :1 -equilibrium line calculation) reflects the topography and the related change from wet perialpine to dry continental inneralpine areas. In addition, the effects of local condition are superimposed on this trend. The overall climatically induced rise in snowline altitudes between 1850 and 1973 is 77 +/-51 m. The considerable ränge of 340 m as compared to the actual Situation in 1973 demonstrates the influence of local topography, geometry and dip of the glacier surface on the snowline altitude.
The mean altitude of the firnline in 1973 quantifies the melting during the last year of Observation 1972/73. The glaciers in the regions of Bernina, Bergell and Kesch are more strongly affected than in other areas during this budget period. On the average, the firnline altitude rose 120 m above de 2 :1 - equilibrium line corresponding to the surface geometry of that year.
The data presented and the climatological information will be analysed and deciphered in more details.