Shallow travel-time tomography below southern Mexico
- Creators
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Huesca-Pérez, Eduardo
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Husker, Allen
Abstract
P and S wave travel-time tomographies as well as a Vp/Vs ratio image of the crust below southern Mexico were developed using data from the Meso-American Subduction Experiment (MASE) broad-band temporary network. The profile used in the tomography starts at the Pacific coast and runs 205 km inland perpendicular to the trench with a depth of 55 km. Results show fast P and S-wave velocities from the coast to 40 km inland in the descending section of the Cocos slab, a low P-wave anomaly between 50 km and 90 km above the corner where the slab becomes subhorizontal and low P and S-wave velocities above the slab between 90 and 205 km. The Vp/Vs image shows two areas with high values: (1) the zone where the slab descends from the coast to 60 km inland; and (2) between 90 km - 160 km from the coast where Non-Volcanic Tremors (NVT) are also found to occur. Low Vp/Vs values are found where the slab bends (60 km - 90 km) probably due to it being a highly stressed, dry region of the crust. Normal Vp/Vs values are found within the crust farther than 160 km from the coast despite strong evidence of high pore fluid pressure in that region. This is probably due to the proportional reduction of the P-wave velocity with the S-wave velocity due to high temperature and low effective pressure.
Additional Information
© 2012 Union Fisica Mexicana. Received: July 25, 2011; accepted: May 03, 2012; published on line: June 29, 2012. We would like to thank Dr. Arturo Iglesias Mendoza for providing his seismic catalogue for Mexican earthquakes during the period 2005-2007 and for all his valuable advices during the development of this study. We also thank Dr Luis Quintanar Robles and the Servicio Sismológico Nacional (SSN) for providing the catalogue of the Valley of Mexico whose data has been employed in this study. Finally we thank the MASE team whose seismograms have been employed. This research was supported by CONACYT CVU 177244.Attached Files
Published - v51n3a6.pdf
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Additional details
- Eprint ID
- 109432
- Resolver ID
- CaltechAUTHORS:20210608-075404360
- Consejo Nacional de Ciencia y Tecnología (CONACYT)
- CVU 177244
- Created
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2021-06-09Created from EPrint's datestamp field
- Updated
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2021-06-09Created from EPrint's last_modified field