HR: 16:20h
AN: S24A-01    [Abstracts]
TI: Historic Seismicity, Computed Peak Ground Accelerations, and Seismic Site Conditions for Northeast Mexico
AU: * Montalvo-Arriet, J C
EM: montalvo@fct.uanl.mx
AF: Facultad de Ciencias de la Tierra, UANL, Carr. Linares-Cerro Prieto, km8, Linares, NL 67700, Mexico
AU: Galván-Ramírez, I N
EM: garinoe@hotmail.com
AF: Facultad de Ciencias de la Tierra, UANL, Carr. Linares-Cerro Prieto, km8, Linares, NL 67700, Mexico
AU: Ramos-Zuñiga, L G
EM: lgrz_alrd@hotmail.com
AF: Facultad de Ciencias de la Tierra, UANL, Carr. Linares-Cerro Prieto, km8, Linares, NL 67700, Mexico
AU: Navarro de León, I
EM: inavarro@yahoo.com
AF: Facultad de Ciencias de la Tierra, UANL, Carr. Linares-Cerro Prieto, km8, Linares, NL 67700, Mexico
AU: Ramírez-Fernández, J A
EM: juanaram@mail.uanl.mx
AF: Facultad de Ciencias de la Tierra, UANL, Carr. Linares-Cerro Prieto, km8, Linares, NL 67700, Mexico
AU: Quintanilla-López, Y
EM: yennyql@hotmail.com
AF: Facultad de Ciencias de la Tierra, UANL, Carr. Linares-Cerro Prieto, km8, Linares, NL 67700, Mexico
AU: Cavazos-Tovar, N P
EM: npcavazost@pep.pemex.com
AF: Facultad de Ciencias de la Tierra, UANL, Carr. Linares-Cerro Prieto, km8, Linares, NL 67700, Mexico
AB: In this study we present the historic seismicity, computed peak ground accelerations, and mapping of seismic site conditions for northeast Mexico. We start with a compilation of the regional seismicity in northeast Mexico (24- 31°N, 87-106°W) for the 1787-2006 period. Our study area lies within three morphotectonic provinces: Basin and Range and Rio Grande rift, Sierra Madre Oriental and Gulf Coastal Plain. Peak ground acceleration (PGA) maps were computed for three different scenarios: 1928 Parral, Chihuahua (MW = 6.5); 1931 Valentine, Texas (MW = 6.4); and a hypothetical earthquake located in central Coahuila (MW = 6.5). Ground acceleration values were computed using attenuation relations developed for central and eastern North America and the Basin and Range province. The hypothetical earthquake in central Coahuila is considered a critical scenario for the main cities of northeast Mexico. The damage associated with this hypothetical earthquake could be severe because the majority of the buildings were constructed without allowance for seismic accelerations. The expected PGA values in Monterrey, Saltillo and Monclova range from 30 to 70 cm/s2 (0.03 to 0.07g). This earthquake might also produce or trigger significant landslides and rock falls in the Sierra Madre Oriental, where several cities are located (e.g. suburbs of Monterrey). Additionally, the Vs30 distribution for the state of Nuevo Leon and the cities of Linares and Monterrey are presented. The Vs30 data was obtained using seismic refraction profiling correlated with borehole information. According to NEHRP soil classification, sites classes A, B and C are dominant. Sites with class D occupy minor areas in both cities. Due to the semi-arid conditions in northeast Mexico, we obtained the highest values of Vs30 in Quaternary deposits (alluvium) cemented by caliche. Similar values of Vs30 were obtained in Reno and Las Vegas, Nevada. This work constitutes the first attempt at understanding and characterizing soil velocity profiles, the areal distribution of different site classes, ground shaking amplification, and the nature of seismic hazards in northeast Mexico.
DE: 7200 SEISMOLOGY
DE: 7212 Earthquake ground motions and engineering seismology
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
SC: Seismology [S]
MN: 2007 Joint Assembly