A full Stokes ice flow model for the vicinity of Dome Fuji, Antarctica, with induced anisotropy and fabric evolutionH. SEDDIK, R. GREVE, T. ZWINGER and L. PLACIDI AbstractA three-dimensional, thermo-mechanically coupled ice flow model with induced anisotropy has been applied to a ~ 200 x 200 km domain around the Dome Fuji drill site, Antarctica. The model ("Elmer/Ice") is based on the open-source multi-physics package Elmer (http://www.csc.fi/elmer/) and solves the full Stokes equations. Flow-induced anisotropy in ice is accounted for by an implementation of the Continuum-mechanical, Anisotropic Flow model, based on an anisotropic Flow Enhancement factor ("CAFFE model"). Steady-state simulations for present-day climate conditions are conducted. The main findings are: (i) the flow regime at Dome Fuji is a complex superposition of vertical compression, horizontal extension and bed-parallel shear; (ii) for an assumed geothermal heat flux of 60 mW/m2 the basal temperature at Dome Fuji reaches the pressure melting point and the basal melting rate is ~ 0.35 mm/a; (iii) in agreement with observational data, the fabric shows a strong single maximum at Dome Fuji, and the age of the ice is decreased compared to an isotropic scenario; (iv) as a consequence of spatially variable basal melting conditions, the basal age tends to be smaller where the ice is thicker and larger where the ice is thinner. The latter result is of great relevance for the consideration of a future drill site in the area. The Cryosphere 5 (2), 495-508 (2011). |
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