Swiss Alpine Snowfield — Crevasse Pattern Overhead
849.00 د.إ
The Aletsch Glacier’s accumulation zone photographed from 400 metres — the snowfield’s compressive crevasse patterns showing the glacier’s flow stress field, the crevasse geometry mapping the internal ice dynamics.
Description
The Aletsch Glacier — Europe’s largest glacier — expresses its internal flow dynamics in the pattern of crevasses visible from altitude. Crevasses form where tensile stress in the ice exceeds the ice’s tensile strength, and their orientation is perpendicular to the maximum tensile stress direction — meaning the crevasse pattern directly maps the glacier’s stress field and, by extension, its flow velocity field. This photograph, made at 400 metres above the accumulation zone during a summer glaciological survey flight, shows the crevasse pattern of a zone where the glacier’s flow velocity is increasing — the transverse (across-flow) crevasses perpendicular to the flow direction indicate longitudinal extension. The snowfield surface between crevasses shows wind-etched sastrugi oriented by the prevailing wind direction. The blue ice walls of the crevasses provide a colour contrast with the white snow surface.
