1. Limited impact of anisotropic thermal conductivity in the mantle wedge on the slab temperature in the Tohoku subduction zone, Northeast Japan.
- Author
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Morishige, M. and Tasaka, M.
- Subjects
- *
SUBDUCTION zones , *THERMAL conductivity , *SLABS (Structural geology) , *WEDGES , *IRON & steel plates , *TEMPERATURE , *OLIVINE - Abstract
• Effects of anisotropic thermal conductivity on the thermal structure are investigated. • Two regions with a high degree of anisotropy are observed in the mantle wedge. • Slab temperature changes only slightly due to the anisotropic thermal conductivity. The effects of anisotropic thermal conductivity due to the crystallographic-preferred orientation (CPO) of olivine in the mantle wedge on the steady-state thermal structure of the Tohoku subduction zone, Northeast Japan, are investigated using geodynamic modeling. Four different olivine crystal fabrics are modeled based on theoretical CPO development in the mantle wedge: random (i.e., isotropic thermal conductivity), A-type, C-type, and E-type fabrics. The thermal conductivity in the mantle wedge is highly anisotropic in the regions just above the descending slab and near the base of the overriding plate. The obtained temperature differences between the anisotropic and isotropic cases are only up to 30 °C within the slab. Therefore, the impact of anisotropic thermal conductivity on the slab temperature may be limited when anisotropy is only considered in the mantle wedge. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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