Objectif To construct a new Reduced Model - a system of partial differential equations - which describes the dominant thermomechanical balances governing the flow of a large ice sheet, which incorporates the anisotropy induced by the evolution of fabric (realignments of crystal axes) as ice descends to depth. Samples from deep ice cores will be examined to establish the distinct shear responses on planes at different inclinations, and deduce the dominant shear planes and their normal axes. Numerical simulation of the deformation of a polycrystal aggregate with initially random distribution of axes will be performed to observe the evolution of axes realignments, and infer dependence on stress and deformation. Frame indifferent constitutive laws, which incorporate structure evolution to model observed behaviour, will be constructed. Within the project the new laws will be incorporated into the mass, momentum and energy balance of a gravity driven ice sheet flow, and investigation of simplifications achieved by co-ordinate stretching to reflect the large aspect ratios will be done. The reduced models will be applied to idealised flows to illustrate the effects of fabric, and to specific examples of current ice sheet configurations. Champ scientifique natural sciencesmathematicspure mathematicsmathematical analysisdifferential equationspartial differential equationssocial scienceslaw Programme(s) FP4-ENV 2C - Specific programme of research and technological development in the field of environment and climate, 1994-1998 Thème(s) 010102 - The climate system in the past Appel à propositions Data not available Régime de financement CSC - Cost-sharing contracts Coordinateur UNIVERSITY OF EAST ANGLIA Contribution de l’UE Aucune donnée Adresse University Plain NORWICH Royaume-Uni Voir sur la carte Liens Site web Opens in new window Coût total Aucune donnée Participants (4) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE France Contribution de l’UE Aucune donnée Adresse Rue Molière 54, Université de Grenoble 1 38402 SAINT-MARTIN-D'HERES Voir sur la carte Coût total Aucune donnée Centre National de la Recherche Scientifique France Contribution de l’UE Aucune donnée Adresse 14 avenue Edouard Belin 31400 Toulouse Voir sur la carte Coût total Aucune donnée NERC British Antarctic Survey Royaume-Uni Contribution de l’UE Aucune donnée Adresse High Cross Madingley Road CB3 0ET Cambridge Voir sur la carte Coût total Aucune donnée Technische Hochschule Darmstadt Allemagne Contribution de l’UE Aucune donnée Adresse 1,Hochschulstrasse 64289 Darmstadt Voir sur la carte Coût total Aucune donnée