Observing tectonic plate motions and deformations from satellite laser ranging

For the first time satellite laser ranging (SLR) measurements from LAGEOS are revealing changes in geodetic station positions suggestive of predicted global tectonic plate motions. A detailed discussion of the latest SLR results is given herein. Since the accuracy of tectonic plate velocities increases with the repetition rate and accuracy in the measurement of interplate distances, activities are also described for increasing the temporal resolution and precision of baseline determinations. The LAGEOS laser data for the period January 1979 to the end of 1982 have been reanalyzed. The results of this analysis are now approaching the useful accuracies required by geophysics. For the better annually determined stations they include consistencies of 2–3 cm in station heights and 2 cm in annual baselines. The SLR results show overall agreement with the geologic tectonic rate model of Minster and Jordan with a linear cross correlation of 0.61 for 34 observed interstation rates. Improved temporal resolution was obtained in the measurement of specific baselines of moderate length through the large number of simultaneously observed passes.