THE ROLE OF SHEAR ZONES IN CARIBBEAN PLATE MOTION

Two major shear zones that record the relative motion between the North and South American plates are located along the northern and southern Caribbean plate boundaries. In order to understand how these shear zones contribute to the geodynamics at the Cocos and Antilles subduction zones and the motion of the Caribbean plate, the 3D structure of the shear zones will be built into 3D geodynamic models. The 3D structure of Caribbean plate and bounding shear zones has been made using plate boundary data with an approximated depth of 80km. To study this area using numerical modelings, the viscosity at each shear zone needs to be verified. 3D numerical models testing variations in the viscosity of each zone zone are are presented. A Comparison between predict and observed plate velocities will provide information on which viscosities produce a realistic result.