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.