Iglesias, A. and Clayton, R. W. and Pérez‐Campos, X. and Singh, S. K. and Pacheco, J. F. and García, D. and Valdés‐González, C.
S wave velocity structure below central Mexico using high-resolution surface wave tomography.
Journal of Geophysical Research B, 115
Art. No. B06307.
- Published Version
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Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20100709-135147262
Shear wave velocity of the crust below central Mexico is estimated using surface wave dispersion measurements from regional earthquakes recorded on a dense, 500 km long linear seismic network. Vertical components of regional records from 90 well-located earthquakes were used to compute Rayleigh-wave group-velocity dispersion curves. A tomographic inversion, with high resolution in a zone close to the array, obtained for periods between 5 and 50 s reveals significant differences relative to a reference model, especially at larger periods (>30 s). A 2-D S wave velocity model is obtained from the inversion of local dispersion curves that were reconstructed from the tomographic solutions. The results show large differences, especially in the lower crust, among back-arc, volcanic arc, and fore-arc regions; they also show a well-resolved low-velocity zone just below the active part of the Trans Mexican Volcanic Belt (TMVB) suggesting the presence of a mantle wedge. Low densities in the back arc, inferred from the low shear wave velocities, can provide isostatic support for the TMVB.
|Additional Information:||© 2010 American Geophysical Union.
Received 26 January 2009; accepted 11 January 2010; published 15 June 2010.
This study was supported by the Tectonics
Observatory of Caltech and by the PAPIIT‐UNAM project IN104308.
MASE was funded by the Gordon and Betty Moore Foundation. We thank
E. Debayle and M. Sambridge for providing their tomographic and resolution
codes. O. A. Castro kindly assisted us in relocating some of the events
used in this study. We thank S. I. Franco‐Sánchez for the help in preparing
the last versions of Figures 6 and 7. SSN and C.I.S., I.I., UNAM staff
generously provided us seismic data from their networks. We thank all
MASE volunteers, most of them undergraduate students. Finally, we thank
the JGR Editor and two anonymous reviewers for their comments and
suggestions that led to a much improved manuscript. Contribution 91 of the
|Group:||Caltech Tectonics Observatory, Seismological Laboratory|
|Funding Agency||Grant Number|
|Caltech Tectonics Observatory||UNSPECIFIED|
|Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica - Universidad Nacional Autónoma de México (PAPIIT-UNAM) ||IN104308 |
|Gordon and Betty Moore Foundation ||UNSPECIFIED|
|Subject Keywords:||surface wave tomography; structure below central Mexico; MASE
|Other Numbering System:|
|Other Numbering System Name||Other Numbering System ID|
|Caltech Tectonics Observatory||91|
|Official Citation:||Iglesias, A., R. W. Clayton, X. Pérez‐Campos, S. K. Singh, J. F. Pacheco, D. García, and C. Valdés‐González (2010),
S wave velocity structure below central Mexico using high‐resolution surface wave tomography, J. Geophys. Res., 115, B06307,
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited On:||09 Jul 2010 21:13|
|Last Modified:||31 Jan 2017 20:56|
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