HR: 1340h
AN: T33B-1363    [Abstracts]
TI: Proyecto Caribe: Preliminary Results From an Ongoing Broadband, Passive Seismic Array Experiment in Venezuela
AU: * Baldwin, T K
EM: tkb@indiana.edu
AF: Department of Geological Sciences, Indiana University 1001 East Tenth Street, Bloomington, IN 47405 United States
AU: Pavlis, G
AF: Department of Geological Sciences, Indiana University 1001 East Tenth Street, Bloomington, IN 47405 United States
AU: Vernon, F
AF: Scripps Institution of Oceanography, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093 United States
AU: Eakins, J
AF: Scripps Institution of Oceanography, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093 United States
AU: Rendon, H
AF: Fundacion Venezolana de Investigaciones Sismologicas, Prolongacion Calle Mara El LLanito, Caracas, 76880 Venezuela
AU: Alvarado, L
AF: Fundacion Venezolana de Investigaciones Sismologicas, Prolongacion Calle Mara El LLanito, Caracas, 76880 Venezuela
AU: Vasquez, R
AF: Fundacion Venezolana de Investigaciones Sismologicas, Prolongacion Calle Mara El LLanito, Caracas, 76880 Venezuela
AB: Proyecto Caribe is an ongoing experiment to investigate the large scale structure and tectonic framework of the northern boundary of South America. A 77 station, broadband array is currently operational in Venezuela with instruments running from the craton south of the Orinoco River to OBS instruments located on oceanic crust of the Caribbean plate. Initial work on seismicity suggests this experiment will improve detection and location of events in the Orinoco basin and southern Venezuela where national network coverage is sparse. The data from the experiment suggests there are large variations in the propagation characteristics of regional phases across Venezuela. In particular, we note that high amplitude, impulsive Sn phases are observed in the Maturin Basin, but Lg is not observed there. In contrast, stations on the craton south of the Orinoco River commonly record both Sn and Lg. This indicates a major difference in lower crust and upper mantle structure for the two regions. Initial measurements of P wave residuals from teleseismic earthquakes indicate a large signal is present. We currently are working with the first 7 months of data collected from the array to develop a preliminary P wave tomographic model to gain insights on the three-dimensional geometry of the Caribbean-South American plate boundary.
DE: 8180 Tomography
DE: 9360 South America
DE: 7218 Lithosphere and upper mantle
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting