Velocities from six continuous and 14 campaign sites within the boundaries of the Caribbean plate, including eight new sites from previously unsampled areas of Honduras and Nicaragua at the western edge of the Caribbean plate, are described and tested for their consistency with Caribbean–North America plate motion and a rigid Caribbean plate model. Sites in central Honduras and Guatemala move 3–8 mm yr −1 westward with respect to the Caribbean plate interior, consistent with distributed east-to-west extension in Guatemala and the western two-thirds of Honduras. A site in southern Jamaica moves 8 ± 1 mm yr −1 westward relative to the Caribbean plate interior, indicating that most or all of Jamaica is unsuitable for estimating Caribbean plate motion. Two sites in southern Hispaniola also exhibit anomalous motions relative to the plate interior, consistent with a tectonic bias at those sites. An inversion of the velocities for 15 sites nominally located in the plate interior yields a well-constrained Caribbean plate angular velocity vector that predicts motion similar to previously published models. Data bootstrapping indicates that the solution is robust to better than 1 mm yr −1 with respect to both the site velocities that are used to estimate the plate angular velocity and the site velocity uncertainties. That velocities at seven of eight GPS sites in eastern Honduras and Nicaragua are consistent with the motions of sites elsewhere in the plate interior indicates that much or all of eastern Honduras and Nicaragua move with the plate interior within the 1–2 mm yr −1 resolution of our data. It further suggests that the morphologically prominent, but aseismic Guayape fault of eastern Honduras is inactive. Tests for possible east-to-west deformation across the Beata Ridge and Lower Nicaraguan Rise in the plate interior establish a 95% upper bound of ∼2 mm yr −1 for any deformation across the two features, significantly slower than a published estimate of 9.0 ± 1.5 mm yr −1 during the past 23 Ma for deformation across the Beata Ridge.

During the last ~100 years, tectonic geodesy has evolved from sparse field-based measurements of crustal deformation to the use of space geodetic techniques involving observations of satellites and from satellites orbiting Earth, which reveal a variety of tectonic processes acting over a wide range of spatial and temporal scales. Early terrestrial measurements using triangulation and leveling techniques characterized large displacements associated with great earthquakes and led to the recognition of the fundamental mechanics of seismic faulting and the earthquake cycle. More precise measurements using ground-based laser ranging allowed for the characterization and modeling of interseismic strain buildup and determination of slip rates on major faults. Continuous and highly accurate point measurements of strain, tilt, and fault creep have captured intriguing deformation transients associated with slow slip events on active faults. The greatly improved precision, spatial and temporal resolution, global coverage, and relatively low cost of space geodetic measurements led to a revolution in crustal deformation measurements of a range of tectonic processes. Very Long Baseline Interferometry, the Global Positioning System, Interferometric Synthetic Aperture Radar, and space-based image geodesy complement each other to comprehensively capture tectonics in action at scales ranging from meters to global and seconds to decades. Space geodetic measurements allow for the precise measurement of global plate motions, the determination of strain rate fields and fault slip rates in distributed plate-boundary deformation zones, and characterization of subtle intra-plate deformation. These measurements provide increasingly important constraints for earthquake hazard studies. Space geodesy also allows for the recognition and detailed model exploration of a number of transient deformation processes during the post-earthquake deformation phase of the earthquake cycle. Measurements of postseismic deformation transients provide important insights into the mechanisms, rheological properties, and dynamics of crustal deformation. Increasingly, seafloor geodetic measurements provide information about deformation on the 70% of the Earth's surface that were previously inaccessible. Future improvements of modern geodetic techniques promise to further illuminate details of crustal deformation at all spatial and temporal scales, leading to an improved understanding of the dynamics of active tectonics.