Bedforms of Thwaites Glacier, West Antarctica: Character and Origin

Bedforms of Thwaites Glacier, West Antarctica both record and affect ice flow, as shown by geophysical data simple models. Glacier flows across the tectonic fabric Antarctic rift system with its bedrock highs sedimentary basins. Swath radar seismic surveys glacier bed have revealed soft-sediment flutes 100 m or more high extending 15 km basins downglacier from highs. Flutes end at prominent hard-bedded moats on stoss sides next topographic We use models to show that flow against topography increases pressure between till upglacier along over a distance scales topography. In this basal zone pressure, ice-contact water would be excluded, thus increasing drag ice-till coupling flux, removing allow erosion creates moats. Till carried highlands then deposited in lee-side positions forming bedforms prograde time, remain soft top through feedbacks match till-deformational fluxes well The part surveyed here are because has persisted long time geological setting, not is anomalous. Bedform development likely caused evolution lubricating were redistributed, eroded grew.