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 twenty-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° ± 2° E at 65° W, relative to the South-American plate. East of 68° W, 80% of the dextral slip is contained within a 80-km wide shear zone centered on the El Pilar-San Sebastián fault system. West of 68° W the plate boundary broadens to more than 300 km with dextral shear shared between the northeast trending Boconó fault (9-11 mm/a) in western Venezuelan, and an offshore system near the northern coast.