Horizontal GIA Velocities and Reference-Frame Determination Jim Davis, Mark Tamisiea, and Tom Herring
Reference Frame
Following Slides GIA deformations calculated in CE frame (standard) GIA deformations after rotation that establishes reference frame
Conclusions GIA may introduce a systematic error in rotation of ~1 mm/yr We need a greater density of GPS sites in GIA-deforming regions (but: sensitive to ice-model errors) Radial motions perhaps more important, but we still require a greater site density in these areas (also see Mark Tamisiea’s presentation) We need to extend suite of Earth models for which we have the viscoelastic Green’s functions. We probably need to make the western “site cutoff” for SNARF farther east than for this solution.
Recommendations SNARF group needs to have working standard solution: Sites well distributed Well on stable NA Velocities and covariances