Morphometry of glacial cirques in the Cantabrian Range (Northwest Spain)

Abstract

Two study areas were selected in the Cantabrian Range, in northern Spain, in order to analyse the morphometric characteristics of Pleistocene glacial cirques in a relatively mar- ginal glacial environment. The Western Massif of Picos de Europa (WMPE) (highest altitude at 2,596 m) is characterised by Alpine-like relief and a geological landscape mainly dominated by calcareous outcrops. The sierras of Southwest Asturias (SSWA) (highest altitude at 2,002 m) is a typical Palaeozoic landscape of Appalachian-like relief and is dominated by old erosion surfaces. A statistical analysis found few relationships between environmental factors (altitude, aspect and lithology) and cirque morphometry in the WMPE. Glacial cirque development in this area is therefore likely to be more influenced by structural processes (such as differential erosion and fractures) and karstic erosion. In contrast, a clear increase in cirque size is observed with increasing altitude in the SSWA. In both study areas, cirques are predominantly distrib- uted in areas with N and NE aspects, but particularly so in the SSWA which is of lower alti- tude than the WMPE. In the SSWA but not the WMPE, the horizontal dimensions of the cirques tend to increase more rapidly than the vertical dimensions, supporting the allometric model of glacial cirque development in this area.