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dc.contributor.authorGordon, Richard G.
Houseman, Gregory A.
dc.date.accessioned 2015-07-09T15:30:04Z
dc.date.available 2015-07-09T15:30:04Z
dc.date.issued 2015
dc.identifier.citation Gordon, Richard G. and Houseman, Gregory A.. "Deformation of Indian Ocean lithosphere: Evidence for a highly nonlinear rheological law." Journal of Geophysical Research: Solid Earth, (2015) http://dx.doi.org/10.1002/2015JB011993.
dc.identifier.urihttp://hdl.handle.net/1911/80856
dc.description.abstract The width of diffuse oceanic plate boundaries is determined by the rheology of oceanic lithosphere. Here we apply thin viscous sheet models, which have been successfully applied to deformation in several continental deforming zones, to investigate the deformation of oceanic lithosphere in the diffuse oceanic plate boundaries between the India, Capricorn, and Australia Plates. We apply kinematic boundary conditions based on the current motion between these plates. We neglect buoyancy forces due to plate thinning or thickening and assume that the thin viscous sheet has the same depth-integrated nonlinear viscosity coefficient everywhere. Our initial models have only one adjustable parameter, n, the power-law exponent, with n = 1, 3, 10, 30, and 100. The predicted width of the deforming zone decreases with increasing n, with n ≥ 30 explaining the observations. This n value is higher than has been estimated for continental lithosphere and suggests that more of the strength of oceanic lithosphere lies in layers deforming by faulting or by dislocation glide than for continental lithosphere. To obtain a stress field that better fits the distribution and type of earthquake focal mechanisms in the diffuse oceanic plate boundary, we add a second adjustable parameter, representing the effect of slab pull stretching the oceanic plate near the Sumatra Trench. We show that an average velocity increment on this boundary segment of 5 mm a−1 (relative to the average velocity of the India and Australia Plates) fits the observed distribution of fault types better than velocities of 3.3 mm a−1 or 10 mm a−1.
dc.language.iso eng
dc.rights Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
dc.title Deformation of Indian Ocean lithosphere: Evidence for a highly nonlinear rheological law
dc.type Journal article
dc.contributor.funder National Science Foundation
dc.contributor.funder National Centre for Earth Observation
dc.citation.journalTitle Journal of Geophysical Research: Solid Earth
dc.subject.keywordrheology
Indian Ocean
oceanic lithosphere
diffuse plate boundaries
strain fields
Indo-Australian Plate
dc.contributor.publisher Wiley
dc.type.dcmi Text
dc.identifier.doihttp://dx.doi.org/10.1002/2015JB011993
dc.identifier.grantID OCE-1131638 (National Science Foundation)
dc.type.publication publisher version


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