Contributor to erosion in glacial system Regelation (dissolution of carbonates) Plucking/quarrying on lee side of bumps Freezing of water within cracks Cracks (joints) present in rocks Rock composition & strength Sediments vs bedrock at bed Bed permeability Roughness of bed Slope of bed Presence of water at base, allowing sliding Topography of bed focuses stresses Length of time ice is there Discharge rates Subglacial water speed Amount of sediment within basal ice With Warmbased? x x x x x x x x x x x x x x x With Coldbased? Hydrology Bed effects effects x x x x x x x x x x x x x x x x x x x x x x x x x x