Bradley Lipovsky

Fracturing processes limit the ability of floating ice shelves to stabilize marine ice sheets. Here, I argue that ice shelves are most susceptible to fracture when their thickness is less than the brittle–ductile transition thickness H*?, defined as the depth at which the overburden pressure equals the local yield strength in tension. A fracture mechanical analysis, compared with time-lapse imagery and thickness maps demonstrate the ice dynamical role of the brittle–ductile transition. These findings suggest the existence of a calving–thinning instability whereby thinning-induced brittleness increases calving rates and reduces buttressing.