Geodetic signatures of glacial changes in Antarctica
rates of geoid height change and radial displacement due to present and past ice mass variations
Zum Verlinken/Bookmarken: http://dx.doi.org/10.23689/fidgeo-578
This study is concerned with the forward modelling of the present-day glacial-isostatic adjustment (GIA) of the earth to present and past changes of the Antarctic ice sheet (AIS). We predict temporal variations in the geoid height and topographic height within the context of the Gravity Recovery and Climate Experiment (GRACE) satellite mission and terrestrial Global Positioning System (GPS) stations in Antarctica. We first adopt an elastic-compressible earth model and calculate the earth's response to seasonal (< 1 a) and secular (~ 100 a) ice-mass changes. Then, we consider a viscoelastic-incompressible earth model and determine the earth's response to the melting of the AIS since the last glacial maximum (LGM), i.e. the post-glacial rebound (PGR). Both models are radially symmetric and self gravitating. A range of viscosity values account for the uncertainty in the viscosity stratification and the lateral heterogeneity of the mantle beneath Antarctica. We employ six load models simulating the most important temporal aspects of the AIS's evolution. Finally, we predict the geoid-height change and the land uplift and compare them with recent GRACE observations and determinations of the uplift rate for the permanent GPS stations along the Antarctic coast.