We review the efforts taken by scientists to describe how the stress tensor in polycrystalline ice depends upon the deformation history which an ice sample encounters during its motion through an ice sheet. Until very recently, the ice was conjectured to respond to deformations as an isotropic body, and variations in its fluidity were accounted for by enhancement factors. Anisotropy came into focus with the analysis of ice samples from deep ice cores. We give an account on the attempts how induced anisotropy is conceptually described and how it is related to the rotation of the crystallites, dislocation glide, grain growth and recrystallization. In particular we try to give reasons why such a complex description is required if the flow within ice sheets has a chance to be realistically modeled.
Advances in Constitutive Modeling of Anisotropic Ice in Polar Ice Sheets
PLACIDI L;
2003-01-01
Abstract
We review the efforts taken by scientists to describe how the stress tensor in polycrystalline ice depends upon the deformation history which an ice sample encounters during its motion through an ice sheet. Until very recently, the ice was conjectured to respond to deformations as an isotropic body, and variations in its fluidity were accounted for by enhancement factors. Anisotropy came into focus with the analysis of ice samples from deep ice cores. We give an account on the attempts how induced anisotropy is conceptually described and how it is related to the rotation of the crystallites, dislocation glide, grain growth and recrystallization. In particular we try to give reasons why such a complex description is required if the flow within ice sheets has a chance to be realistically modeled.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
