Deformation of ice on the grain scale by means of high-resolution crystal-orientation measurements using X-ray Laue and Electron backscatter diffraction

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Recent observations on deformation microstructures on the grain scale of Antarctic ice samples reveal findings, which promise constriction of a gap in our knowledge concerning the processes controlling the flow of ice sheets. Continuation to pursue these findings can give important insight into rate-limiting processes in general and especially into the question, whether non-basal dislocations play a significant role. High-resolution full crystal-orientation measurements conducted with X-ray Laue diffraction and Electron backscattered diffraction (EBSD) in combination with microstructure mapping (µSM) provide information to identify the different subgrain boundary- and dislocation types. µSM and Laue diffraction are successfully applied on ice, whereas EBSD, although a well-established method in other materials sciences, is still rarely used for ice. However, EBSD will offer important new findings for deformation processes in polycrystalline ice. This knowledge can contribute to an improved definition of parameters and exponent for the flow law of ice.