Grant Award View - GA68322-V1

Laboratory experiments, using ice from Law Dome ice cores, will replicate the microstructural changes previously identified in fast flowing ice streams. We will systematically measure the effects of deformation on natural polycrystalline ice and compare this to patterns observed in ice cores. Using a fabric analyser microscope we are able to continuously record stress, strain distributions, crystallographic preferred orientation(CPO)and grain size evolution at incremental strain steps up to 50% shortening. Such data sets have the advantage that they allow for the continuous assessment of the relationships between the changing microstructure, CPO and rheology in a material that traditionally has only been experimentally deformed to <20% shortening. Comparisons will also be made to neutron diffraction observations obtained from synthetic ice experimentally deformed at ANSTO. Results will significantly advance our understanding of constraints on strain localization in dynamic ice systems.