Impact of topography and three-dimensional heterogeneity on coseismic deformation
Impact of topography and three-dimensional heterogeneity on coseismic deformation
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DOI：
10.1093/gji/ggz060
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发表时间：
2019-05-01
影响因子：
2.8
通讯作者：
Tromp, Jeroen
中科院分区：
文献类型：
--
作者：
Langer, Leah;Gharti, Hom Nath;Tromp, Jeroen
随着空间大地测量观测技术的发展，对板块边界变形的认识有了很大的提高。然而，大多数同震变形的理论和数值模型仍然非常简单，不包括现实的地球结构。3-D材料异质性和地形往往被忽视，因为简单的模型被认为是足够的，现有的工具不能很容易地适应复杂的异质性。在这项研究中，我们证明了3-D异质性的重要性，采用光谱元素的方法，将地形和3-D材料的属性。使用抛物线山模型和2010年马乌莱地震的地形模型，我们表明，地形特征可以改变所观察到的地表变形模式的形状。我们还估计了同震地表变形，由于使用现实地形和三维弹性结构的2015年廓尔喀地震的滑动分布模型，并发现地形的存在导致观测到的地表位移模式的形状发生变化，而材料的不均匀性主要影响观测到的位移的大小。我们的研究结果表明，包括地形，特别是可以影响同震变形建模的预测。
Knowledge of deformation at plate boundaries has been improved greatly by the development of observational techniques in space geodesy. However, most theoretical and numerical models of coseismic deformation have remained very simple and do not include realistic Earth structure. 3-D material heterogeneity and topography are often neglected because simple models are assumed to be sufficient and available tools cannot easily accommodate complex heterogeneity. In this study, we demonstrate the importance of 3-D heterogeneity using a spectral element method that incorporates topography and 3-D material properties. Using a parabolic hill model and a topographic model of the 2010 Maule earthquake, we show that topographic features can alter the shape of observed surface deformation patterns. We also estimate the coseismic surface deformation due to a model of the slip distribution of the 2015 Gorkha earthquake using realistic topography and 3-D elastic structure, and find that the presence of topography causes changes in the shape of observed surface displacement patterns, while material heterogeneities primarily affect the magnitude of observed displacements. Our results show that the inclusion of topography in particular can affect predictions of coseismic deformation modelling.