Horizontal subduction and truncation of the Cocos Plate beneath central Mexico
Abstract
Based on analysis of data from a trans-Mexico temporary broadband seismic network centered on Mexico City, we report that the subducting Cocos Plate beneath central Mexico is horizontal, and tectonically underplates the base of the crust for a distance of 250 km from the trench. It is decoupled from the crust by a very thin low viscosity zone. The plate plunges into the mantle near Mexico City but is truncated at a depth of 500 km, probably due to an E-W propagating tear in the Cocos slab. Unlike the shallow slab subduction in Peru and Chile, there is active volcanism along the Trans Mexican Volcanic Belt (TMVB) that lies much further inland than regions to either side where subduction dip is not horizontal. Geodynamical modeling indicates that a thin weak layer such as imaged by the seismic experiment can explain the flat subduction geometry.
Additional Information
© 2008 American Geophysical Union. Received 25 June 2008; revised 13 August 2008; accepted 19 August 2008; published 27 September 2008. This work was supported by the Tectonics Observatory at Caltech, the Center for Embedded Network Sensors (CENS) at UCLA, NSF award EAR0609707, PAPIIT-UNAM 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. Approximately half of the stations were radio linked to the Internet allowing near-real time access to the data using software protocols designed by CENS computer scientists Igor Stubailo, Sam Irvine, Martin Lukac, Richard Guy and Vinayak Naik. We thank the many volunteers who contributed their time to the field work. We thank Luca Ferrari and an unknown reviewer for comments that improved the paper.Attached Files
Published - PERgrl08.pdf
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Additional details
- Eprint ID
- 12265
- Resolver ID
- CaltechAUTHORS:PERgrl08
- Caltech Tectonics Observatory
- Center for Embedded Network Sensors (CENS), UCLA
- EAR-0609707
- NSF
- IX120004
- PAPIIT-UNAM
- IN119505-3
- PAPIIT-UNAM
- 04105384
- UC MEXUS
- Gordon and Betty Moore Foundation
- Created
-
2008-10-31Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field
- Caltech groups
- Caltech Tectonics Observatory, Caltech Tectonics Observatory. MesoAmerican Subduction Experiment (MASE), Seismological Laboratory, Division of Geological and Planetary Sciences
- Other Numbering System Name
- Caltech Tectonics Observatory
- Other Numbering System Identifier
- 90