Goulding, NJ, Ribe, NM, Castelnau, O et al. (2 more authors) (2015) Analytical Parametrization of Self-Consistent Polycrystal Mechanics: Fast Calculation of Upper Mantle Anisotropy. Geophysical Journal International, 203 (1). 334 - 350 (17). ISSN 0956-540X
Abstract
Progressive deformation of upper mantle rocks via dislocation creep causes their constituent crystals to take on a non-random orientation distribution (crystallographic preferred orientation or CPO) whose observable signatures include shear-wave splitting and azimuthal dependence of surface wave speeds. Comparison of these signatures with mantle flow models thus allows mantle dynamics to be unraveled on global and regional scales. However, existing self-consistent models of CPO evolution are computationally expensive when used in 3-D and/or time-dependent convection models. Here we propose a new method, called ANPAR, which is based on an analytical parameterisation of the crystallographic spin predicted by the second-order (SO) self-consistent theory. Our parameterisation runs approximately 2-6x10^4 times faster than the SO model and fits its predictions for CPO and crystallographic spin with a variance reduction > 99%. We illustrate the ANPAR model predictions for the deformation of olivine with three dominant slip systems, (010)[100], (001)[100] and (010)[001], for three uniform deformations (uniaxial compression, pure shear, simple shear) and for a corner-flow model of a spreading mid-ocean ridge.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This article has been accepted for publication in Geophysical Journal International, © 2015 the Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | Mantle processes; Creep and deformation; Seismic anisotropy |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Funding Information: | Funder Grant number NERC NE/K008803/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 22 Jul 2015 15:45 |
Last Modified: | 21 Oct 2018 05:31 |
Published Version: | http://dx.doi.org/10.1093/gji/ggv304 |
Status: | Published |
Publisher: | Oxford University Press |
Identification Number: | 10.1093/gji/ggv304 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:88280 |