地震位错理论是地震断层面滑动与地表物理场变化之间的理论关系，是研究震源机制、反演断层滑动模型、解释地震产生物理场变化及大地测量数据必不可少的理论基础。该项目将申请者现有弹性球形地球模型的位错理论发展到粘弹球形地球模型的位错理论。解决粘弹变形理论中拉普拉斯逆变化积分的积分路径的选择和数值计算的困难，完成粘弹性球形地球模型震后变形的计算方法，使其可以计算各种震后物理量变化。研究粘弹位错理论在可压缩性与不可压缩性两种情况下的差异，以及粘滞参数构造对震后变形的响应特征。应用粘弹球形地球模型的位错理论对于2004 年苏门答腊海沟型大地震(M9.3)以及2011 年日本东北大地震 (M9.0)进行研究，讨论两个地区的粘滞性构造。通过比较半无限空间的层状粘弹介质模型与本研究的球形层状粘弹介质模型的差异，研究地球曲率在粘弹位错理论中的影响。编写和优化粘弹地球模型的震后变形的计算程序，并向研究者开放。

Dislocation theory is a basic theory to link the seismic source and the surface geophysical and geodetic observations, and can be used to study the source mechanism, invert fault slip distribution, and interpret the geophysical and geodetic data. This study will expand current dislocation theory for an elastic earth model to that for a visco-elastic earth model, by overcoming the theoretical and numerical difficulties in the inverse Laplace transform. The output of this study will be able to compute post-seismic deformation such as displacement, geoid and gravity changes. The project will investigate the difference between the deformation for pressible and incompressible earth models. As an application, the new theory will be applied to the 2004 Sumatra earthquake (M9.3) and the 2011 Tohoku-Oki earthquake (M9.0), and the visco-elastic structure of the two areas will be investigated and discussed. Finally, the effect of the earth curvature will be discussed by comparing the theoretical deformations calculated for the spherical earth model and half-space earth model. The project will complete computing program and open to other scientists.