Permalink : http://hdl.handle.net/2115/45435

KEYWORDS : Dynamic recrystallization;Ice sheets;Microstructures;Fabrics

Recrystallization mechanisms are known to accommodate the deformation as observed along ice cores. The three main processes are classically described as being, successively from the top of the cores, normal grain growth, rotation dynamic recrystallization and migration dynamic recrystallization. Recent observations on local mechanisms at the grain scale tend to question this description. This paper aims at presenting the basic knowledge about dynamic recrystallization processes in materials, with focus on the corresponding mechanisms occuring during deformation of granular ice, more particularly along ice cores. We stress the significance of the scale to consider when analysing the mechanisms, depending on the applications. In particular, we will demonstrate that dislocation substructures can develop locally, due to strong strain heterogeneities, without challenging the classical description that explains the evolution of average grain size and fabrics along ice cores.