The potential contribution of high-resolution glacier flow modelling to structural glaciology

Abstract

Abstract The three-dimensional stress and strain fields derived through high-resolution flow modelling of Haut Glacier d’Arolla, Switzerland are used to predict the generation, passage and surface expression of a variety of structural forms at the glacier. Flow vectors and strain ellipses are computed and illustrated in plan-form and long section. The model is used to predict the formation and orientation of surface crevasses, and, once healed, the downglacier evolution of their traces. Similarly, the evolution of primary stratification where it crops out at the glacier surface is predicted. The resulting stratification pattern compares well with that revealed in aerial photographs of the glacier. Finally, the three-dimensional strain field is used to track the (accumulation area) burial, (englacial) transport and (ablation area) exposure of ice deposited within a pre-defined elevation range. This deposition-transport-exposure tracking allows the location of ice that was initially deposited at any defined location on the glacier to be identified. Such information is of significance in interpreting, for example, the distribution of ash and isotopic horizons within a glacier. We conclude that high-resolution three-dimensional flow modelling has the potential to provide a powerful tool for investigating the genesis and evolution of valley glacier structures.