Hall, Chad E. and Gurnis, Michael (2005) Strength of fracture zones from their bathymetric and gravitational evolution. Journal of Geophysical Research B, 110 (B1). Art. No. B01402. ISSN 0148-0227. http://resolver.caltech.edu/CaltechAUTHORS:20121119-135044771
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Fracture zone evolution is investigated using dynamic models that allow the fault zones to freely slip. This is an improvement over past formulations where bathymetric offsets were imposed kinematically. The models use a viscoelastoplastic rheology that incorporates the influence of fault friction on fracture zone slip history. Using viscoelastic plates, we assess the role of small-scale convection on removal of the lowermost thermal lithosphere beneath fracture zones. Through a comparison of synthetic gravity to free-air gravity across fracture zones we find that the amplitude of the gravity jump across fracture zones is best fit by models with weak faults that have depth-averaged yield strengths <10 MPa. Fracture zones with such low strengths can convert to subduction zones with ∼100 km of convergence. Many fracture zones do not fit plate subsidence models with locked or slipping faults but are better fit by systems that are tectonically deformed by modest amounts of extension.
|Additional Information:||© 2005 American Geophysical Union. Received 9 July 2004; accepted 20 October 2004; published 18 January 2005. We thank Y. Podladchikov and A. Poliakov for sharing their PARAVOZ program. We used GMT software developed by P. Wessel and W. Smith. This research has been supported by NSF grants EAR-0003558 and EAR-0337253. We thank D. Sandwell, P. Wessel, and an anonymous reviewer for constructive comments. Computations were performed at the Center for Advanced Computing Resources of the California Institute of Technology. This represents contribution 9088 of the Division of Geological and Planetary Sciences, California Institute of Technology.|
|Subject Keywords:||fracture zones; oceanic lithosphere; Pacific plate; Geodesy and Gravity: Rheology of the lithosphere and mantle (7218, 8160); Marine Geology and Geophysics: Gravity and isostasy (1218, 1222); Tectonophysics: Dynamics of lithosphere and mantle: general (1213); Tectonophysics: Rheology: crust and lithosphere (8031); Tectonophysics: Stresses: crust and lithosphere|
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|Official Citation:||Hall, C. E. and M. Gurnis (2005), Strength of fracture zones from their bathymetric and gravitational evolution, J. Geophys. Res., 110, B01402, doi:10.1029/2004JB003312.|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Jason Perez|
|Deposited On:||19 Nov 2012 22:23|
|Last Modified:||27 Dec 2012 03:02|
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