An Updated GPS Velocity Field For Puerto Rico And Virgin Islands: Constraints On Tectonic Setting And Internal Deformation

Abstract

Puerto Rico and the northern Virgin Islands define the eastern end of the Greater Antilles, while the Puerto Rico trench and the Muertos Trough define the northern and the southern limits of the North American - Caribbean plate boundary zone. Three microplates have been defined: (1) Gonave, to the west; (2) Hispaniola, at the center; and (3) Puerto Rico and the northern Virgin Islands (PRVI) at the eastern end. Global Positioning System (GPS) geodesy was previously conducted in this region from 1994 to 2003. It was concluded that the locus of the highest permissible on-surface deformation in Puerto Rico and the northern Virgin Island is within the Lajas Valley, in southeastern Puerto Rico. This thesis presents 32 updated and reprocessed (IGS05) GPS velocities from 32 different sites and locations in the PRVI block. Data were collected and analyzed from 11 newly installed continuous GPS stations. 11 campaign stations were re-occupied while another 10 campaign stations, which could not be re-occupied in 2011 were simply reprocessed in IGS05 with the other 22 stations. The goal was to rigorously test for the magnitude and location of internal deformation within the PRVI microplate.