(Ground) Ice in the Proglacial Zone

Abstract

In mid-latitude mountains, most of the valley glaciers currently experience distinct and enhanced volume and area loss. In parallel with the glacier retreat, the related proglacial areas enlarge, leaving unconsolidated sediments and ground ice of different origins and thus forming a transitional landscape, as developing from a glacial to a non-glacial environment. The erosion, transport and accumulation of sediment in these proglacial areas are characterized by high spatio-temporal dynamics, which are typically highest in the direct glacier forefield and become more inactive with increasing distance to the glacier front. Glacial, periglacial, fluvial and gravitational processes occur and highly interact in space and time. The glacial history of recently deglaciated zones influences the complex thermal regime of the subsurface and determines the current ground ice occurrence. Besides the glacio-fluvial processes, low-temperature conditions, as well as the occurrence of ground ice, are the most effective drivers for geomorphic dynamics and related landform evolution in these proglacial areas. A deeper knowledge of ongoing processes as well as of the amounts of sediment and ground ice is decisive to assess the availability of unconsolidated sediment for potential hazardous processes (e.g. debris flows) and the availability of water from ground ice bodies. There is an increasing need for high-resolution data (e.g. repeated topographic data) of proglacial areas as well as the systematic monitoring of these environments.