Crustal Structure below the Valley of Mexico Estimated from Receiver Functions
Por:
Cruz-Atienza V.M., Iglesias A., Pacheco J.F., Shapiro N.M., Singh S.K.
Publicada:
1 dic 2010
Resumen:
Receiver functions (RFs) from two permanent stations (CUIG and ZAIG) of the Mexican broadband network were calculated to infer the crustal structure at both sites. The data were stacked to allow uncertainty estimations and inverted using two global optimization algorithms: simulated annealing and genetic algorithms. Strong and systematic azimuthal dependence was observed in the stacked functions at CUIG site, which is located in the Mexican volcanic belt (MVB). Assuming a one-dimensional five-layer model per azimuthal stack, these variations were explained with the same upper crustal structure including a superficial similar to 2 km-thick low-velocity layer associated with the MVB and a well-defined Conrad interface around 15 km depth, different depths for the Moho discontinuity, and variations in both the S-wave velocity and Poisson's ratio for the upper mantle. Our inversion of observed RFs at CUIG and theoretical considerations suggest an eastward crustal thickening of at least 5 km
Filiaciones:
Cruz-Atienza V.M.:
Univ Nacl Autonoma Mexico, Inst Geofis, Dept Sismol, Mexico City 04510, DF, Mexico
Iglesias A.:
Univ Nacl Autonoma Mexico, Inst Geofis, Dept Sismol, Mexico City 04510, DF, Mexico
Pacheco J.F.:
Observatorio Vulcanológico y Sismológico de Costa Rica, Universidad Nacional de Costa Rica, Apartado 2346-3000, Heredia, Costa Rica, Brazil
Shapiro N.M.:
Département de Sismologie, Institut de Physique du Globe de Paris, Boite 89-4 place Jussieu, 75252 Paris cedex 05, France
Singh S.K.:
Univ Nacl Autonoma Mexico, Inst Geofis, Dept Sismol, Mexico City 04510, DF, Mexico
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