This MRI award supports the acquisition of a cold-room equipped micro CT unit for the study of structures in ice, frozen soil and snow/firn. The intellectual merit of the work is that it will provide important insights on a number of environmental questions, such as the effects of climate change on the Polar Regions. The unit will enable non-destructive reconstruction of three dimensional micro-structure based on x-ray absorption. Examples of studies for which the cold-adapted micro-CT instrument will be used include understanding snow metamorphism in order to model the effects of snow-pack, characterizing the microstructure, particularly the porosity, permeability and micro-chemistry of firn, which can yield critical information on climate change, and examining the 3-D character of brittle compressive failure in ice to provide new knowledge about not only the fracture of the ice cover on the Arctic Ocean but also new insights into rupture of the Earth?s crust. The broader impacts of the proposed activity relate to both understanding issues to do with climate change and the training of students. It is expected that many graduate students will use the instrument in their research and undergraduate students will be encouraged to engage in research and learn about instrumentation of this kind. The instrument will be incorporated into the laboratory component of a course taught by the PI every year entitled Methods of Materials Characterization. It is expected that the lifetime of this instrument will be on the order of 10 years and the instrument will be made available to both Dartmouth and outside users for their research. Results of the research will be widely disseminated.
