The relative motion between Africa and Eurasia as derived from ITRF2000 and GPS data

Abstract

Studies of intra- and inter-plate deformation typically need a model describing the motions of the stable part of the tectonic plates for reference purposes. We have developed DEOS2k, a model for the current motion of seven major tectonic plates derived from space-geodetic observations. This paper focuses on relative motion between Africa and Eurasia. In the past, this motion has been poorly established because of poor data coverage for Africa. DEOS2k is based on ITRF2000 [Altamimi et al., 2002] and new African GPS observations. It is an improvement over the NUVEL-1A model for predicting the present-day relative motions of these two plates. DEOS2k predicts in northeastern Africa that Africa-Eurasia relative motion is about 40% smaller in magnitude than NUVEL-1A and trends more to the northwest. This is consistent with independent local geodetic observations. A similar shift in orientation, clockwise, is observed at the western tip of the plate boundary.