Investigating the impacts of polycrystalline anisotropy on the flow and fracture of glaciers

This project will address fundamental aspects of glacial dynamics arising from the anisotropies of its crystalline structure, ultimately informing efforts to predict the evolution of the Earth’s ice sheets, a problem of considerable societal importance. Our ability to predict future sea-level rise is currently limited by our ability to model the evolution of the Earth’s ice sheets, whose collapse has the potential to outstrip other contributions to sea-level rise over the next centuries.

Ice flows viscously as a complex non-Newtonian fluid. However, ice-sheet simulations typically assume an isotropic flow rheology that neglects known viscoplastic anisotropies. The project will explore exciting new research themes addressing the generation of anisotropies and their effects on large-scale ice flow and break-up.

A central focus is the development and mathematical analysis of models describing the generation and influence of anisotropy, and explore its implications using analytical and numerical methods. Depending on preference, the project can focus on idealised configurations (e.g. ice divides and obstacles), and/or move towards the interpretation of velocimetric data via inversion methods. The outcomes would thereby provide key contributions to the growing research effort of predicting the future of Earth’s ice sheets.Pine Island Glacier, the most rapidly thinning glacier in Antarctica, showing its calving front and a large transverse crack. Smaller fractures at the edges (top and bottom) suggest differential flow, which may be directly related to the anisotropy of the ice.

The crystalline structure of ice, illustrating the three distinct modes of slip that create anisotropic dynamics.