Hypsometric analysis to identify spatially variable glacial erosion

Relatively little research has been undertaken on the use of digital elevation models to recognize the spatially variable glacial imprint of a landscape. Using theoretical topographies and a landscape evolution model, we investigate to what extent the hypsometric analysis of digital elevation models may be used to recognize the glacial signature of mountain ranges. A new morphometric parameter, which we term the hypsokyrtome (from the Greek: ipsos = elevation, kyrtoma = curvature), is derived from the gradient of the hypsometric curve. The efficacy of the hypsometric integral and hypsokyrtome is tested through the study of the Ben Ohau Range, New Zealand, whose glacial imprint has been described previously. With a numerical model we further test the geomorphic parameters in describing the morphologies of regions subject to diverse climatic and tectonic conditions. The hypsokyrtome is highly sensitive to glacial erosion, and the maps produced provide insights into the spatial distribution of glacial erosion. We use SRTM data and focus on two alternative geomorphic settings: the European Alps and the Apennines. The former has been affected by both fluvial and glacial erosion while the latter mainly exhibits a fluvially dominated morphology. The correlation between elevations with increased glacial erosion and Last Glacial Maximum (LGM) equilibrium line altitudes (ELAs) suggests the prevalence of a "glacial buzz saw" in the Alps, indicating that climate may put a limit on alpine topography. Copyright 2011 by the American Geophysical Union.