Ice flow modelling at EPICA Dome C and Dome Fuji, East Antarctica

F. Parrenin (1) , G. Dreyfus (2) , Geoffroy Durand (1, 3) , S. Fujita (4) , O. Gagliardini (1) , F. Gillet (1) , Jean Jouzel (2) , K. Kawamura (5) , N. Lhomme (1) , Valérie Masson-Delmotte (2) , C. Ritz (1) , J. Schwander (6) , H. Shoji (7) , R. Uemura (4) , O. Watanabe (4) , N. Yoshida (8)

1 LGGE - Laboratoire de glaciologie et géophysique de l'environnement
2 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
3 NBI - Niels Bohr Institute [Copenhagen]
4 NiPR - National Institute of Polar Research [Tokyo]
5 Center for Atmospheric and Oceanic Studies [Sendai]
6 Physics Institute
7 New Energy Resources Research Center
8 FCRC - Frontier Collaborative Research Center

1-D ice flow models are used to construct the age scales at the Dome C and Dome Fuji drilling sites (East Antarctica). The poorly constrained glaciological parameters at each site are recovered by fitting independent age markers identified on each core. We reconstruct past accumulation rates, that are larger than those modelled using the classical vapour saturation pressure relationship during glacial periods by up to a factor 1.5. During the Early Holocene, changes in reconstructed accumulation are not linearly related to changes in ice isotopic composition. A simple model of past elevation changes is developed and shows an amplitude variation of 110–120 m at both sites. We suggest that there is basal melting at Dome C (0.56±0.19 mm/yr). The reconstructed velocity profile is highly non linear at both sites, which suggests complex ice flow effects. This induces a non linear thinning function in both drilling sites, which is also characterized by bumps corresponding to variations in surface elevation with time.

Domaines: Interfaces continentales, environnement; Sciences de la Terre

F. Parrenin, G. Dreyfus, Geoffroy Durand, S. Fujita, O. Gagliardini, et al.. Ice flow modelling at EPICA Dome C and Dome Fuji, East Antarctica. 2008. ⟨hal-00330720⟩