New Finite-Element Modelling of Subduction Processes in the Andes Using Realistic Geometries
New Finite-Element Modelling of Subduction Processes in the Andes Using Realistic Geometries
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DOI：
10.1007/978-3-642-37222-3_13
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
S. Zeumann;Rekha Sharma;Rene Gassmöller;T. Jahr;G. Jentzsch
中科院分区：
文献类型：
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作者：
S. Zeumann;Rekha Sharma;Rene Gassmöller;T. Jahr;G. Jentzsch
这项工作的目的是通过有限元模拟更好地了解俯冲带中的地球物理过程。在这里我们研究了各种参数对变形和应力场的影响。测试的参数是摩擦系数、收敛倾角、俯冲带的弯曲、真实几何形状和粘弹性。将摩擦系数从0.0增加到0.4会使压缩增加28%。对于这两个摩擦系数，与直线收敛相比，倾斜导致更大的压缩。模型结果与实际地形数据的比较表明，即使地壳结构是概括的，也有相当大的相似之处。为了得到更逼真的岩石圈结构，我们采用了严格约束密度模型的几何结构。对于这些模型，我们选择了智利北部伊基克周围南美俯冲区的区域。在模型中考虑粘性对应力和应变有很大的影响。在纯弹性模型中，应力和应变的发展几乎是线性的。相反，粘弹性模型的曲线显示了应变的最大应力和最大曲率区域。应力分布与地震分布吻合较好。
The aim of this work is the better understanding of geophysical processes in subduction zones by Finite element modelling. Here we study the effects of various parameters on the deformation and stress field. The tested parameters are the friction coefficient, convergence obliquity, bending of the subduction zone, realistic geometry and visco-elasticity. Increasing the friction coefficient from 0.0 to 0.4 increases the compression by 28 %. For both friction coefficients obliquity leads to higher compression compared to straight convergence. Comparison of the model results with real topographic data reveals considerable analogies even if crustal structure is generalised. To obtain a more realistic structure for the lithosphere we adopted the geometry from well constrained density models. For these models we chose the region in the South American subduction zone around Iquique in North Chile. Including viscosity in the models has a large effect on stress and strain. In a pure elastic model stress and strain develops nearly linear. In contrast curves for the visco-elastic models show a stress maximum and a zone of maximum curvature for the strain. The stress pattern agrees well with the earthquake distribution.