摘要Based on the finite element numerical algorithm, the coseismic displacements of the Wenchuan MS8.0 earthquake are calculated with the rupture slip vectors derived by Ji and Hayes as well as Nishimura and Yaji. Except in a narrow strip around the rupture zone, the coseismic displacements are consistent with those from GPS observation and InSAR interpretation. Numerical results show that rupture slip vectors and elastic properties have profound influences on the surface coseismic deformation. Results from models with different elastic parameters indicate that: ① in homogeneous elastic medium, the surface displacements are weakly dependent on Poisson’s ratio and independent of the elastic modulus; ② in horizontally homogeneous medium with a weak zone at its middle, the thickness of the weak zone plays a significant role on calculating the surface displacements; ③ in horizontally and vertically heterogeneous medium, the surface displacements depend on both Poisson’s ratio and elastic modulus. Calculations of coseismic deformation should take account of the spatial variation of the elastic properties. The misfit of the numerical results with that from the GPS observations in the narrow strip around the rupture zone suggests that a much more complicated rupture model of the Wenchuan earthquake needs to be established in future study.
Abstract：Based on the finite element numerical algorithm, the coseismic displacements of the Wenchuan MS8.0 earthquake are calculated with the rupture slip vectors derived by Ji and Hayes as well as Nishimura and Yaji. Except in a narrow strip around the rupture zone, the coseismic displacements are consistent with those from GPS observation and InSAR interpretation. Numerical results show that rupture slip vectors and elastic properties have profound influences on the surface coseismic deformation. Results from models with different elastic parameters indicate that: ① in homogeneous elastic medium, the surface displacements are weakly dependent on Poisson’s ratio and independent of the elastic modulus; ② in horizontally homogeneous medium with a weak zone at its middle, the thickness of the weak zone plays a significant role on calculating the surface displacements; ③ in horizontally and vertically heterogeneous medium, the surface displacements depend on both Poisson’s ratio and elastic modulus. Calculations of coseismic deformation should take account of the spatial variation of the elastic properties. The misfit of the numerical results with that from the GPS observations in the narrow strip around the rupture zone suggests that a much more complicated rupture model of the Wenchuan earthquake needs to be established in future study.
基金资助:the National Natural Science Foundation of China under grant No. 40774045 and partially supported by the program from Chinese Academy of Sciences under grant No. KZCX2-YW-QN507
通讯作者:
Jinshui Huang
E-mail: jshhuang@ustc.edu.cn
引用本文:
Feng Li, Jinshui Huang. Three-dimensional numerical simulation on the coseismic deformation of the 2008 MS8.0 Wenchuan earthquake in China[J]. 《地震学报》英文版, 2010, 23(2): 191-200.
Feng Li, Jinshui Huang. Three-dimensional numerical simulation on the coseismic deformation of the 2008 MS8.0 Wenchuan earthquake in China. Earthquake Science, 2010, 23(2): 191-200.
