In sea ice geophysics, the formulation and implementation of a continuum anisotropic ice dynamics model is required in order to increase the spatial resolution of the Polar Ice Prediction System (PIPS) used by the National/ Naval Ice Center to provide sea-ice analyses, forecasts, outlooks and ship-routing recommendations within the marginal ice zone of Arctic and Antarctic seas. Currently, too little is known about the formation of leads in the Arctic, a situation that should rapidly improve via automated ice-tracking SAR algorithms. Many questions remain concerning the inΒ―uences of inhomogeneities (thermal cracks, ridges, thickness variability, and rubble) on wave propagation, constitutive behavior and overall ice strength at various scales. Floe scale ice models appear to oer the means to bridge the scales between geophysical and structural applications by being able to accurately model the mechanics of ridging, rafting and leading. At the scale of ice forces on structures and ships, a diverse range of creepbrittle failure modes awaits incorporation into ice force models. Knowledge concerning the multiaxial compressive failure of freshwater and saline ice is now available. The constitutive modeling of sea ice lags well behind that for freshwater ice. The important issues of scale eects and inhomogeneities on tensile strength at lab-to structuralscale are discussed, as are the links between various scales.