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Viscous flow model of a subduction zone with a faulted lithosphere: Long and short wavelength topography, gravity and geoid

Zhong, Shijie and Gurnis, Michael (1992) Viscous flow model of a subduction zone with a faulted lithosphere: Long and short wavelength topography, gravity and geoid. Geophysical Research Letters, 19 (18). pp. 1891-1894. ISSN 0094-8276. http://resolver.caltech.edu/CaltechAUTHORS:20130215-104458691

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Abstract

The essential features of observed topography, free air gravity, and the geoid over subduction zones have been reproduced with a dynamically self consistent viscous flow model of a subduction zone with a faulted lithosphere. A fault between the overriding and subducting plates is crucial to understanding lithospheric deformation and gravity in a subduction zone. The topography for models with a fault is characterized by a deep and narrow trench and a broad and shallow back-arc depression, quite different from viscous models without faults which only have a broad and large depression over subducting slabs. For a model in which a slab is 600 km long and 80 Myr old, the resulting trench is approximately 3 km deep and 100 km wide and the back-arc basin is about 1.5 km deep and 600 km wide; the model is characterized by a long wavelength geoid high of about 30 m over the slab, a local geoid low of 10 m over the trench and a 150 mgal gravity low over the trench. The fact that trench depth and width are reproduced in models with a small resisting shear stress, 50 bars, suggests that convergent plate boundaries are probably weak.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1029/92GL02142 DOIUNSPECIFIED
http://onlinelibrary.wiley.com/doi/10.1029/92GL02142/abstractPublisherUNSPECIFIED
Additional Information:© 1992 by the American Geophysical Union. Received: June 22, 1992; accepted August 17, 1992. We thank Xiaohong Wang for help in designing elements for cases with small dip angles. H. Pollack made helpful comments on the manuscript. Funded by the David and Lucile Packard Foundation and NSF grants EAR-8957164 and EAR-8904660.
Group:Seismological Laboratory
Funders:
Funding AgencyGrant Number
David and Lucile Packard Foundation UNSPECIFIED
NSFEAR-8957164
NSFEAR-8904660
Record Number:CaltechAUTHORS:20130215-104458691
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20130215-104458691
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:36952
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:15 Feb 2013 23:58
Last Modified:11 Jun 2015 12:59

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