Ps Receiver Function Imaging of the Northeast Caribbean Plate Boundary

Abstract

The Caribbean plate originated in the Pacific during the Cretaceous and migrated eastward with respect, to North and South America, to its present location. Due to the plate's tectonic history, the Caribbean region consists of complex fault systems, which are likely to have disrupted the Moho. To study the region's subsurface structure a 3D image of the Northeast Caribbean is produced via Ps receiver functions. Ps receiver functions are time series computed from three-component seismograms that identify waves converted from P- to S- type at discontinuities, such as the Moho and subducting lithosphere. Data were requested from the IRIS data management center for events that occurred in the 2005–2015 time period with magnitudes of 5.5–8.0 and epicentral distances of 30–95° from stations in the study region. Data preparation steps include tapering, removing the trend and mean, and rotating from Z–N–E to L–Q–T (ray-based) coordinate systems. Ps receiver functions were then computed via iterative deconvolution in the time domain and the best receiver functions were stacked to generate a 3D image of the subsurface. The image places constraints on the structure of the subsurface and may elucidate the causes and styles of deformation occurring in the region. Depths to discontinuities will be calculated using Ps–P time delays and velocity models produced independently. Results of this research will also contribute to characterizing seismic wave propagation in the Northeast Caribbean and, ultimately, the region's seismic hazard.

AAPG Datapages/Search and Discovery Article #90219 © 2015 GCAGS, Houston, Texas, September 20-22, 2015