Limited impact of anisotropic thermal conductivity in the mantle wedge on the slab temperature in the Tohoku subduction zone, Northeast Japan
Limited impact of anisotropic thermal conductivity in the mantle wedge on the slab temperature in the Tohoku subduction zone, Northeast Japan
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DOI：
10.1016/j.tecto.2021.229110
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发表时间：
2021-10
期刊：
影响因子：
2.9
通讯作者：
M. Morishige;M. Tasaka
中科院分区：
文献类型：
--
作者：
M. Morishige;M. Tasaka
利用地球动力学模拟研究了地幔楔中橄榄石晶体择优取向（CPO）引起的各向异性热导率对日本东北俯冲带稳态热结构的影响。四种不同的橄榄石晶体组构是基于地幔楔中的理论CPO发展建模的：随机（即，各向同性热导率）、A型、C型和E型织物。地幔楔中的热导率在下降板块上方和覆盖板块底部附近的区域是高度各向异性的。在各向异性和各向同性情况下获得的温差在板内仅高达30 °C。因此，当只考虑地幔楔的各向异性时，各向异性热导率对板块温度的影响可能是有限的。
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.