HR: 0800h
AN: T21B-0525    [Abstracts]
TI: Preliminary Earthquake Locations From the Costa Rica Component of the TUCAN Network
AU: * Gonzalez, V
EM: vgonzale@una.ac.cr
AF: Observatorio Vulcanologico y Sismologico de Costa Rica (OVSICORI-UNA), Universidad Nacional Apartado 2346-3000, Heredia, 2346-3000 Costa Rica
AU: Protti, M
EM: jprotti@una.ac.cr
AF: Observatorio Vulcanologico y Sismologico de Costa Rica (OVSICORI-UNA), Universidad Nacional Apartado 2346-3000, Heredia, 2346-3000 Costa Rica
AU: Fischer, K
EM: Karen_Fischer@Brown.EDU
AF: Department of Geological Sciences, Brown University Box 1846, Providence, RI 02912-1846 United States
AU: Rychert, C A
AF: Department of Geological Sciences, Brown University Box 1846, Providence, RI 02912-1846 United States
AU: Walker, A
AF: Department of Geological Sciences, Brown University Box 1846, Providence, RI 02912-1846 United States
AU: Abers, G A
EM: abers@bu.edu
AF: Department of Earth Sciences, Boston University 685 Commonwealth Ave., Boston, MA 685 Common United States
AU: Auger, L
AF: Department of Earth Sciences, Boston University 685 Commonwealth Ave., Boston, MA 685 Common United States
AU: Syracuse, E
AF: Department of Earth Sciences, Boston University 685 Commonwealth Ave., Boston, MA 685 Common United States
AU: Plank, T A
AF: Department of Earth Sciences, Boston University 685 Commonwealth Ave., Boston, MA 685 Common United States
AB: The TUCAN (Tomography Under Costa Rica And Nicaragua) network is a multi-institutional and international project funded by the US National Science Foundation as part of the Subduction Factory Initiative of the MARGINS program. The project's objective is to tribute to the understanding of the local tectonic processes that cause extreme changes in the fluxes of geochemical tracers associated with subducting sediments from Nicaragua to Costa Rica. The observed variations hint that the subduction factory must be behaving differently at depth over short distances. The TUCAN network is a 48 station broadband seismic array composed of two dense (~10 km spacing) lines across the volcanic arcs in Nicaragua and Costa Rica and two other lines (~30 km spacing) parallel to the trench, one in the forearc, at the foothills of the volcanic arc, and the other along the back arc ~70 km from the arc. This network was designed and deployed this summer to collect, for 18 months, seismic data that will be analyzed in many different ways including precise earthquake locations, local velocity and attenuation tomography, receiver functions, anisotropy studies and local, regional and teleseismic wave phases analysis. We will present preliminary earthquake locations recorded at the Costa Rica component of the TUCAN network. The cross line in Costa Rica extends from where the seismogenic zone of large underthrust earthquakes occur along the Nicoya segment at depth of 30 km, to 40 km into the backarc from where the deepest portion (~150 km) of the seismic slab projects to the surface. This geometry combined with OVSICORI's permanent seismic network promises precise local earthquake locations.
DE: 7230 Seismicity and seismotectonics
DE: 8120 Dynamics of lithosphere and mantle--general
DE: 7215 Earthquake parameters
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting