Plate Motions and Deformation from Lageos

Abstract

LAGEOS laser ranging observations collected by the global tracking network between May 1976 and December 1988 have been analysed to yield a comprehensive geodetic parameter solution. Some of the stations in the participating network have a continuous tracking record over the full LAGEOS mission lifetime and can be used to monitor positions in a limited network for over 12 years. However, the introduction of several new stations of improved precision has allowed determination of relative positions to centimeter accuracy for each quarter of as year solution since the beginning of 1980. A nine year history of these three-dimensional positions yields horizontal inter-station baseline rates to an accuracy of a few mm/yr as well as vertical displacement rates to similar accuracy. Comparisons of the measurements of plate motion between sites centrally located within the plates with those predicted by current geological models agree to better than 9 mm/yr RMS. The phenomena of post-glacial rebound is considered as an explanation for the vertical motion.