Change in ice rheology during climate variations – implications for ice flow modelling and dating of the EPICA Dome C core

Geoffroy Durand (1) , F. Gillet-Chaulet (2) , A. Svensson (1) , O. Gagliardini (2) , S. Kipfstuhl (3) , J. Meyssonnier (2) , F. Parrenin (2) , P. Duval (2) , D. Dahl-Jensen (1)

1 NBI - Niels Bohr Institute [Copenhagen]
2 LGGE - Laboratoire de glaciologie et géophysique de l'environnement
3 AWI - Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine

The study of the distribution of crystallographic orientations (i.e., the fabric) along ice cores provides information on past and current ice flow in ice-sheets. Besides the usually observed formation of a vertical single maximum fabric, the EPICA Dome C ice core (EDC) shows an abrupt and unexpected strengthening of its fabric during termination II around 1750 m depth. Such strengthening has already been observed for sites located on an ice-sheet flank. This suggests that horizontal shear could occur along the EDC core. Moreover, the change in the fabric leads to a modification of the effective viscosity between neighbouring ice layers. Through the use of an anisotropic ice flow model, we quantify the change in effective viscosity and investigate its implication for ice flow and dating.

Domaines: Interfaces continentales, environnement; Sciences de la Terre

Geoffroy Durand, F. Gillet-Chaulet, A. Svensson, O. Gagliardini, S. Kipfstuhl, et al.. Change in ice rheology during climate variations – implications for ice flow modelling and dating of the EPICA Dome C core. Climate of the Past, 2007, 3 (1), pp.155-167. ⟨hal-00330748⟩