GPS measurements to constrain geodynamic processes in Fennoscandia

Investigators are acquiring and interpreting data from continuous Global Positioning System (GPS) sites (Figures 1, 2) in Fennoscandia as part of project BIFROST (Baseline Inferences for Fennoscandian Rebound Observations, Sea level, and Tectonics). The ultimate goals of BIFROST are to use the GPS determinations of three‐dimensional crustal velocities associated with glacial isostatic adjustment [e.g., James and Lambert, 1993; Mitrovica et al., 1993, 1994b] to estimate the viscosity of the Earth's mantle below Fennoscandia, to constrain the space‐time history of the Late Pleistocene ice load in the region, and to correct the extensive Fennoscandian tide gauge record for the influence of vertical motions. Already, with less than 3 years of continuous GPS data, the determinations of vertical motion are precise enough to observe the broad pattern of postglacial uplift in this region.