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On the role of anisotropic viscosity for plate‐scale flow
Author(s) -
Becker T. W.,
Kawakatsu H.
Publication year - 2011
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl048584
Subject(s) - anisotropy , scale (ratio) , geology , viscosity , flow (mathematics) , geophysics , mechanics , physics , optics , thermodynamics , quantum mechanics
We study the role of partial melt‐ or lattice fabric‐induced, viscous anisotropy for lithosphere‐asthenosphere interactions using mantle flow models. Mechanical anisotropy has only a moderate influence on plate‐scale flow and global geoid predictions for the cases considered, and anisotropic weakening effects are similar to those due to effective, isotropic viscosity reduction. While anisotropy modifies details of mantle flow and may be relevant for time‐dependent scenarios, it may be safely ignored for a range of other studies. These findings increase our confidence in previous isotropic modeling. They also imply that melt‐rich layers may be a dynamically valid explanation for the lithosphere‐asthenosphere boundary, as far as our anisotropic models are applicable.