HR: 0800h
AN: T11C-0732    [Abstracts]
TI: Seismic Strong Motion Array Project (SSMAP) to Record Future Large Earthquakes in the Nicoya Peninsula area, Costa Rica
AU: * Simila, G
EM: gsimila@csun.edu
AF: California State University Northridge, 18111 Nordhoff St., Northridge, CA 91330,
AU: LaFromboise, E
EM: elafromboise@yahoo.com
AF: California State University Northridge, 18111 Nordhoff St., Northridge, CA 91330,
AU: McNally, K
EM: karen.mcnally@webtv.com
AF: U. C. Santa Cruz, 1156 High Street, Santa Cruz, Ca 95064,
AU: Quintereo, R
EM: rquinter@una.ac.cr
AF: Universidad Nacional, PO Box 2346-3000, Heredia, CR 2345-3000, Costa Rica
AU: Segura, J
EM: rsegura@una.ac.cr
AF: Universidad Nacional, PO Box 2346-3000, Heredia, CR 2345-3000, Costa Rica
AB: The seismic strong motion array project (SSMAP) for the Nicoya Peninsula in northwestern Costa Rica is composed of 10 – 13 sites including Geotech A900/A800 accelerographs (three-component), Ref-Teks (three- component velocity), and Kinemetric Episensors. The main objectives of the array are to: 1) record and locate strong subduction zone mainshocks [and foreshocks, "early aftershocks", and preshocks] in Nicoya Peninsula, at the entrance of the Nicoya Gulf, and in the Papagayo Gulf regions of Costa Rica, and 2) record and locate any moderate to strong upper plate earthquakes triggered by a large subduction zone earthquake in the above regions. Our digital accelerograph array has been deployed as part of our ongoing research on large earthquakes in conjunction with the Earthquake and Volcano Observatory (OVSICORI) at the Universidad Nacional in Costa Rica. The country wide seismographic network has been operating continuously since the 1980's, with the first earthquake bulletin published more than 20 years ago, in 1984. The recording of seismicity and strong motion data for large earthquakes along the Middle America Trench (MAT) has been a major research project priority over these years, and this network spans nearly half the time of a "repeat cycle" (~ 50 years) for large (Ms ~ 7.5- 7.7) earthquakes beneath the Nicoya Peninsula, with the last event in 1950. Our long time co- collaborators include the seismology group OVSICORI, with coordination for this project by Dr. Ronnie Quintero and Mr. Juan Segura. The major goal of our project is to contribute unique scientific information pertaining to a large subduction zone earthquake and its related seismic activity when the next large earthquake occurs in Nicoya. We are now collecting a database of strong motion records for moderate sized events to document this last stage prior to the next large earthquake. A recent event (08/18/06; M=4.3) located 20 km northwest of Samara was recorded by two stations (Playa Carrillo and Nicoya) at distances of 25-30 km with maximum acceleration of 0.2g.
DE: 1207 Transient deformation (6924, 7230, 7240)
DE: 1219 Gravity anomalies and Earth structure (0920, 7205, 7240)
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting