Seismic response and anisotropy of a model hcp iron inner core
Seismic response and anisotropy of a model hcp iron inner core
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模型 hcp 铁内核的地震响应和各向异性
DOI：
10.1016/j.crte.2014.04.001
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发表时间：
2014
影响因子：
1.4
通讯作者：
P. Cardin
中科院分区：
文献类型：
--
作者：
A. Lincot;R. Deguen;S. Merkel;P. Cardin
我们提出了一个框架，模拟测量地震各向异性的模型内核通过计算旅行时残差的合成地震射线传播通过模型。该方法首先测试简单的内核结构模型组成的层具有不同的各向异性，经常在文献中提出。这些模型与地球动力学不一致。因此，我们将该方法扩展到一个数值生长的内核组成的Fe-Fe流产生的过剩的结晶在赤道带，诱导多晶纹理。整体内核各向异性比单晶小七倍。成分分层放大了15%的全球各向异性，而凝固纹理的增加减少了2倍。因此，在测试的地球动力学模型中，没有任何已发表的内核条件下的铁-镁弹性模型允许重现地震学出版物中报道的3%圆柱各向异性。此外，我们的模型表明，额外的信息，如深度依赖性和所观察到的各向异性的传播是揭示内核的动力学和历史的关键。
We present a framework for simulating the measurement of seismic anisotropy in a model inner core by computing travel time residuals of synthetic seismic rays propagated through the model. The method is first tested on simple inner core structural models consisting of layers with distinct anisotropy, as often proposed in the literature. Those models are not consistent with geodynamics. Hence, we extend the method to a numerically grown inner core composed of ɛ-Fe with flow generated from an excess of crystallization in the equatorial belt, inducing polycrystalline textures. The global inner core anisotropy is seven times smaller than that of the single-crystal. Compositional stratification amplifies the global anisotropy by 15% while the addition of solidification textures reduces it by a factor of two. As such, and within the tested geodynamical models, no published elastic model of ɛ-Fe at inner core conditions allows one to reproduce the 3% cylindrical anisotropy reported in seismology publications. In addition, our models demonstrate that additional information, such as the depth dependence and the spread of the observed anisotropy is a key for revealing the dynamics and history of the inner core.
影响因子：
56.9
作者：
Dubrovinsky, L.;Dubrovinskaia, N.;Abrikosov, I. A.
通讯作者：
Abrikosov, I. A.