Velocity field across the southern Caribbean plate boundary and estimates of Caribbean/South-American plate motion using GPS geodesy 1994-2000

Global Positioning System (GPS) observations between 1994 and 2000 at twent y-two sites in the Lesser Antilles and northern South-America indicate that the Caribbean plate, along its southern boundary, slips at a rate of 20.5 +/- 2 mm/a with an azimuth of N 84 degrees +/- 2 degrees E at 65 degrees W, relative to the South-American plate. East of 68 degrees W, 80% of the dex tral slip is contained within a 80-km wide shear zone centered on the El Pi lar-San Sebastian fault system. West of 68 degrees W the plate boundary bro adens to more than 300 km with dextral shear shared between the northeast t rending Bocono fault (9-11 mm/a) in western Venezuelan, and an offshore sys tem near the northern coast.