Funds are provided to support a study of the spatial and temporal variability in basal stress regime of Breiðamerkurjökull, a glacier with deformable sediments at its base (a soft-bedded glacier). Soft-bedded ice masses are thought to be particularly sensitive to climate change. Yet, the mechanics of soft-bedded glacier flow remain poorly understood. Current ice sheet and glacier models used to predict future sea level rise rely on largely unconstrained parameterizations of basal shear stress and till rheology, leading to high uncertainties in output. This study will collect and analyze data targeted at elucidating weaknesses in current understanding of soft-bedded glacier motion, thus providing improved quantitative descriptions of the governing physical processes. Taking advantage of Breiðamerkurjökull?s accessibility and long history of observations the principal investigators will assemble an unprecedented array of remote-sensing and field data. These data will resolve variations in the glacier stress regime and basal conditions over a range of spatial and temporal scales. This study will develop new and innovative techniques for inferring basal conditions from observations of surface motion and ice-penetrating radar.
