The Contribution of Discontinuous Rock-Mass Failure to Glacier Erosion

Abstract

Geomechanical rock-mass properties control the response of bedrock to applied stresses and can be summarized in a linear Mohr-Coulomb equation, which defines the principal parameters determining failure. Nevertheless, in studying the erosion of bedrock by glacier ice, little attention has been paid to failure criteria though a coincidence of erosion all and forms with fracture systems at regional and local scales has been demonstrated. Few studies have analysed the precise nature of the fracture geometry, or proposed its mechanical impact in association with glacier ice.This investigation proposes that, since almost all bedrock possesses identifiable fracture systems, the properties of discontinuous rock mass (DRM) be regarded as defining primary conditions of stress and stability which are subsequently modified directly and indirectly by glacier ice. Consequent rock-mass failure modes are prescribed by discontinuity geometry and applied stresses, and evidence from North Wales confirms the validity of the theoretical treatment of rock-mass properties, and explains the accordance of landforms with structure.