This project is a study of how the antarctic sea ice cover responds to stresses applied by wind and ocean waves, and how the temperature distribution within the sea ice affects these responses. Experiments will be conducted on the deformation and fracture of sea ice occurring in McMurdo Sound by applying a series of controlled stresses and observing their effects. It is known that large ice floes do not fracture in the same way as small ones do, therefore it is necessary to carry out experiments on the scale of tens of meters in order to validly extrapolate the fracture process to the larger scales that have applications to engineering problems of breaking ice. The crucial elements for this study are the obtaining of detailed information on the microstructure of the ice, such as crystal structure, brine channels, and other flaws in the ice fabric, and having a sound theoretical framework to guide the experimental work and subsequent model development. A key effect is the initiation and growth of microcracks within the ice. One component of the work will be carried out jointly with the New Zealand Antarctic program. This concerns the fracture mechanics of fatigue crack propagation, the utilization of microstructural observations to verify magnetic resonance measurements of the structure of inclusions in the ice, and the acoustic emissions of fracture zones.
