Principal Investigator: Paul Mann

Graduate Students: Jean-Paul van Gestel (Ph.D. student), Stefan Muszala

Funded by: National Science Foundation

Check out the data from the EW9605 cruise!

This is a cooperative project involving the University of Puerto Rico, The University of Texas at Austin and the University of Southern California. The Puerto Rico Trench and northern margin of the island of Puerto Rico occupy a zone of tectonic transition between subduction tectonics of the Lesser Antilles island arc and strike slip fault system to the west. The Main Ridge area of the Puerto Rico Trench is selected as the focus of this study as it appears to be the zone of active collision between elevated fracture zones on the downgoing North America plate and the Puerto Rico island slope of the overriding Caribbean plate. The fracture zones appear to extend beneath the Caribbean plate and act as asperities marked by the higher-than-average of incidence of earthquakes. An added complexity is the presence of east-west striking left-lateral strike-slip faults on the island slope of Puerto Rico that appear continuous with earthquake faults mapped onland in the Dominican Republic. The plan for this project is to map this area with sidescan/bathymetric(MR1) and geophysical (magnetic, gravity and 4-channel seismic.) The data will be acquired on a single 20-day cruise. The MR1 data will be processed on board and at the University of Puerto Rico and the seismic data will be processed at UTIG. Funds are also provided to reprocess and migrate some of the existing UTIG data in the work area.

Publications related to this study:
Grindlay, N., Mann, P., Dolan, J. and van Gestel, J. P., 2005, Neotectonics and subsidence of the northern Puerto Rico-Virgin Islands margin in response to the oblique subduction of high-standing ridges, in Mann, P., editor, Active Tectonics and Seismic Hazards of Puerto Rico, the Virgin Islands, and Offshore Areas, Geological Society of America Special Paper 385, p. 31-60.

van Gestel, J. P., Mann, P., Grindlay, N., and Dolan, J. F., 1999, Three-phase tectonic evolution of the northern margin of Puerto Rico as inferred from an integration of seismic reflection, well, and outcrop data: Marine Geology, v. 161, p. 257-286.

Muszala, S., Grindlay, N., and Bird, R., 1999, Three-dimensional Euler deconvolution and tectonic interpretation of marine magnetic anomaly data in the northern Puerto Rico trench: Journal of Geophysical Research, v. 104, p. 29,175-29,187.

van Gestel, J. P., Mann, P., Grindlay, N., and Dolan, J. F., 1998, Structure and tectonics of the late Cenozoic Puerto Rico-Virgin Islands carbonate platform as determined from seismic reflection studies: Journal of Geophysical Research, v. 103, p. 30,505-30,530.