Velocity field across the Southern Caribbean Plate Boundary and estimates of Caribbean/South‐American Plate Motion using GPS Geodesy 1994–2000

Abstract

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.