Splits and shear faults that form within the sea ice cover of the Arctic Ocean during winter result in reductions in the sea ice's integrity, albedo and effectiveness as a thermal barrier to the transfer of heat from the ocean to the atmosphere. Funds are provided to perform new experiments and modeling aimed at elucidating the fundamental physical processes that underlie these types of fractures within the winter sea ice cover. The focus of this proposal is the set of conditions under which each type of fracture forms, the underlying physical mechanisms, and how confinement governs the transition from splitting to faulting. To examine these issues, the principal investigators propose a series of systematic experiments on salt-water ice (and on fresh-water ice for comparison) with a long-term goal of better understanding the physics of sea ice failure. In addition, they propose to develop quantitative models of these physics, using as inputs direct observations of the physical processes.
