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Tomography and thermal state of the Cocos plate subduction beneath Mexico City

Husker, Allen and Davis, Paul M. (2009) Tomography and thermal state of the Cocos plate subduction beneath Mexico City. Journal of Geophysical Research D, 114 (B4). Art. No. B04306. ISSN 0148-0227. doi:10.1029/2008jb006039. https://resolver.caltech.edu/CaltechAUTHORS:20210518-133030879

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Abstract

The geometry and thermal state of the subducting Cocos plate beneath Mexico City has been enigmatic because of the absence of a deep Wadati‐Benioff zone. We present a tomographic image of the slab based on inversion of 8869 teleseismic P wave travel times measured on a portable broadband seismic network. The images combined with receiver function analysis show that the slab runs flat from the coast to near Mexico City, where it dives into the mantle just before the Trans‐Mexican Volcanic Belt with a dip of ∼75°. It continues down to a depth of ∼500 km at a distance of 400 km from the trench, where the tomography reveals that the dipping portion ends. As well as standard block tomography, we invert the travel time residuals for the parameters of a thermal slab model and find a slab thickness of 40 km that is consistent with the (15 Ma) age of the Cocos plate. The combination of a young hot plate and truncation at depth can explain the lack of deep seismicity due to high temperatures and lower negative buoyancy compared with an older, thicker, nontruncated plate.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1029/2008jb006039DOIArticle
ORCID:
AuthorORCID
Husker, Allen0000-0003-1139-0502
Additional Information:© 2009 American Geophysical Union. Issue Online: 28 April 2009; Version of Record online: 28 April 2009; Manuscript accepted: 18 February 2009; Manuscript revised: 24 December 2008; Manuscript received: 27 August 2008. This work was supported by the Tectonics Observatory at Caltech, the Center for Embedded Network Sensors (CENS) at UCLA, NSF award EAR0609707, PAPIITUNAM projects IX120004 and IN119505‐3, and UC MEXUS project 04105384. The MASE experiment was funded by the Gordon and Betty Moore Foundation. Contribution 90 from the Tectonics Observatory. We thank the numerous volunteers for their many hours of field work. We also thank Luca Ferrari and another anonymous reviewer for their comments improving the article.
Group:Caltech Tectonics Observatory
Funders:
Funding AgencyGrant Number
Caltech Tectonics ObservatoryUNSPECIFIED
UCLAUNSPECIFIED
NSFEAR-0609707
Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica (PAPIIT)IX120004
Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica (PAPIIT)IN119505‐3
Universidad Nacional Autónoma de México (UNAM)UNSPECIFIED
University of California Institute for Mexico and the United States (UC MEXUS)04105384
Gordon and Betty Moore FoundationUNSPECIFIED
Subject Keywords:subduction; tomography; Mexico
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Tectonics Observatory90
Issue or Number:B4
DOI:10.1029/2008jb006039
Record Number:CaltechAUTHORS:20210518-133030879
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20210518-133030879
Official Citation:Husker, A., and Davis, P. M. (2009), Tomography and thermal state of the Cocos plate subduction beneath Mexico City, J. Geophys. Res., 114, B04306, doi:10.1029/2008JB006039
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:109180
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:19 May 2021 18:15
Last Modified:19 May 2021 18:15

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