Global Plate Motion Parameters Derived from Actual Space Geodetic Observations

Recent results of time-dependent geodetic SLR and VLBI observations provide us with precise data of global baseline changes and station coordinate shifts. These data are interpreted as plate tectonic motions, and they are used to derive uniform plate rotation vectors. We use four different data sets: VLBI station coordinate shifts, VLBI baseline changes, and SLR baseline changes (all evaluated by NASA GSFC) , as well as SLR coordinate shifts from DGFI/I. The resulting plate rotation vectors of five plates are opposed to current geophysical parameters. The discrepancies are discussed.