基于地壳分层的震后变形分析

基于球体粘弹性地球模型,研究走滑断层、逆断层、张裂断层。顾及不同地壳分层结构的震后变形影响,定量分析了实际地壳分层模型与模拟均匀模型之间的地表变形差异。计算结果显示,地壳结构的不同对震后地表变形的差异影响很大,超过现有高精度测量技术的精度。

Effect of Crustal Layering on Post-Seismic Deformation

Post-seismic deformations are investigated about strike-slip,thrust and tensile faulting considering different crustal layering structures in a spherical elastic-viscoelastic Earth model.Differences of surface deformation calculated between a homogeneous Earth model and stratified Earth models are quantitatively compared and discussed in detail.The results show that strike-slip dislocation faulting due to the crust medium impact is mainly concentrated on the surface horizontal deformation,when calculating the deformation difference accumulated after 10 and 15 years,it is up to 10.7 mm and 12.4 mm in x direction and up to 5.8 mm and 6.8 mm in y direction respectively.The dip-slip dislocation faulting due to the crust medium impact is mainly concentrated on vertical deformation and the vertical deformation difference is up to 6.7 mm and 9.4 mm,respectively between homogeneous and layering models after 10 and 15 years' accumulation.The tensile dislocation faulting due to the crust medium impact is mainly concentrated on both horizontal and vertical deformation that the horizontal deformation difference in y direction is up to 16.3 mm and 20.3 mm separately while vertical deformation difference is up to 6.7 mm and 8.9 mm respectively between homogeneous and layering models after 10 and 15 years' accumulation.These results demonstrate that the distortion in surface deformation caused by ignoring layering properties of crustal structures greatly exceeds the current accuracy of GPS survey(2 mm) and therefore can not be ignored.