Glacial Landscapes and their Spatial Variability in the Temperate and Subpolar Latitudes^∗

Abstract

The mountain glacionival belt can be considered as a type of desert, occurring under conditions of deficit incoming heat with incoming moisture being in a solid state. Two main types of landscape, glacial and periglacial, can be distinguished in this belt. The specific climate, influenced by large quantities of solid precipitation and year-round presence of the underlying snow and ice surface, is unique to the glacionival belt. Differences within this general type of climate are primarily a reflection of the degree of continentality of the locality and of its specific position within its particular highland area; the latitudinal position of a locality is only of secondary importance. These relationships are considered the principal ones for analysis of the geographical aspects of glacier landscapes.

Within the highlands of the temperate zone, four types of glacier landscapes can be distinguished: oceanic, maritime, temperate-continental, and extreme-continental. They succeed each other regularly (as a rule, eastward) within each highland area. Variability of the main criteria for glacier classification in the different types of resulting landscapes are illustrated. These include the altitude of the equilibrium line, the values for snow accumulation at this altitude, the glacier activity index (altitudinal gradient of accumulation and ablation), and relations between the processes of ice formation. Consideration is also given to the variability of related landscape characteristics that provide indications of the regime of the natural processes both within the glacier body and outside its boundaries. These include the mean duration of ice exchange, glacier velocity, temperature at the lower limit of the active ice layer and at the ice/bedrock interface, and the proportion of meltwater runoff to total runoff. The paper points to the importance of comparing secular changes in the height of the equilibrium line to that of the upper timberline for an understanding of the evolution of natural conditions of the alpine and glacionival belts. Combined studies of glacier and periglacial landscapes are important for mountain geoecology, glaciology, and other physical and geographical sciences.