Current Plate Motions

Horizontal versus vertical plate motions

We review both present and past motions at major plate boundaries, which have the horizontal component in average 10 to 100 times faster (10–100 mm/yr) than the vertical component (0.01–1 mm/yr) in all geodynamic settings. The steady faster horizontal velocity of the lithosphere with respect to the upward or downward velocities at plate 5 boundaries supports dominating tangential forces acting ...

Gps Constraints on Africa (nubia) and Arabia Plate Motions

A continuous kinematic model of plate-tectonic motions

S U M M A R Y One of the many problems in the study of plate-mantle coupling is the disparity between the theory of mantle dynamics-which involves continuum physics-and the theory of plate tectonics-which employs discontinuous plates. This discordance causes a variety of difficulties in geodynamic models, e.g. infinite tractions between the plates and mantle. As motions of the Earth’s surface d...

Decelerating Nazca-South America and Nazca-Pacific Plate Motions

Space geodetic estimates of the rate of Nazca-South America convergence and Nazca-Pacific spreading averaging over several years show that present day rates are significantly slower than the 3 million year average NUVEL-1A model. The implied rates of deceleration are consistent with longer term trends extending back to at least 20 Ma, about the time of initiation of Andes growth, and may reflec...

An integrated global model of present-day plate motions and plate boundary deformation

S U M M A R Y In this paper we present a global model (GSRM-1) of both horizontal velocities on the Earth’s surface and horizontal strain rates for almost all deforming plate boundary zones. A model strain rate field is obtained jointly with a global velocity field in the process of solving for a global velocity gradient tensor field. In our model we perform a least-squares fit between model ve...