Consolidation of sediments by glaciers: relations between sediment geotechnics, soft-bed glacier dynamics and subglacial ground-water flow

Abstract

AbstractA theory of subglacial consolidation is developed which shows how the meltwater flux beneath a glacier leaves a consolidation signature from which many important glacier-dynamic properties can be inferred. Conditions under which water is discharged through channels or in a thin film at the ice—bed interface or by ground-water flow are discussed, and it is concluded that glaciers flowing over aquifers of high transmissibility can induce deep circulation patterns quite different from non-glacial circulation. Examples of glacial pre-consolidation profiles in sediments from The Netherlands and England are used to illustrate how basal melting rates, subglacial ground-water flow patterns, ice overburden, basal shear stress, ice-surface profile and the amount of sediment removed by erosion can be inferred.