近20多年来大地测量技术的发展，特别GPS观测的广泛应用，对地壳形变的观测和研究达到了前所未有的精度和广度。通过对大地震震后形变的研究，我们可以较好的了解岩石圈以及上地幔的结构和性质，从而提高我们对岩石圈动力学过程的认识。然而我国东北、华北地区自从上个世纪70年代以来没有再发生7级以上大地震，对本地区流变学结构和性质的认识可以通过研究区域外的大地震来实现。我们最近建立的三维粘弹性有限元模型能够很好的模拟2011年9级日本大地震震后观测到的近场震后形变。本课题将基于已有数值模型，利用我国，俄罗斯以及韩国境内的GPS观测数据，对我国东北部地区的岩石圈和上地幔结构和性质做深入研究，探讨2011年日本地震对我国东北及华北地区活动断层的应力影响和演化，从而对地震灾害评估提供参考。

Great earthquakes produce large coseismic deformation up to thousands of kilometers from the rupture area. The subsequent viscoelastic relaxation of the earthquake-induced stresses in the upper mantle causes large significant postseismic crustal deformation that can be recorded by GPS stations. Integrating geodetic observations with numerical methods, we may have a better understanding of the lithospheric structure and rheology of the upper mantle. Benefited from modern geodetic technique in last two decades, we have been able to delineate the crustal deformation at an unprecedented resolution on space and time. However, there have not been any Mw7 and over earthquakes in the northeastern (NE) China since the last 70’s. Therefore, study of the rheology structure in NE China may be obtained through investigating far-field great earthquakes. We have developed three dimensional viscoelastic finite element models to study the postseismic deformation of the 2011 Mw9.0 Tohoku-Oki earthquake. Our model has produced well fit to the overall pattern of the GPS observations in Japan. In this project we would like to integrate our finite element model of the Japan earthquake with recent GPS observations in NE China, Russia and Korea. We hope to improve our understanding of the rheology structure in NE China and to understand the stress distribution and evolution over active faults in NE China due to the 2011 Japan earthquake. This project thus help the assessment of the earthquake hazards in this region.