Attempts to extract mantle viscosity and lithospheric thickness in Antarctica from glacial isostatic adjustment (GIA) data are frustrated by the relative scarcity of relative sea–level (RSL) data. Geodetic trend signals now have sufficient signal-to-noise ratios that forward models can be used to ‘best-fit' the parameters of GIA-Earth structure models. Trends reported from the Gravity Recovery and Climate Experiment (GRACE) analysis centers and continuously operating Global Positioning System (cGPS) data reported to the International GPS Service (IGS) analysis centers provide important constraints. New geologic, ice and sediment core, and exposure age data, also constrain ice history at the margins of the east Antarctic ice sheet along the coast of the Indian Ocean. A family of GIA models can adequately fit the spatial-dependence of geodetic (GRACE + cGPS) trend data that span 2003 - mid 2007 in this region, but each has deficiency in matching the amplitudes of the trend signals.