日本Mw9.0地震引起的中国东北地区库仑应力时空演化研究

2011年日本Mw9.0地震距今已达10年，中国东北地区监测到的震后变形累积量早已超过同震响应，基于完善的黏弹性球体位错理论和最新GNSS观测数据，研究该地震震后变形在中国东北地区主要断裂带上引起的库仑应力变化，对防震减灾工作具有重要参考意义。本项目拟以自重、可压缩和连续分层结构的弹性球体位错理论为基础，考虑地球的黏滞性结构，完善地震引起的地球内部震后变形计算方法。综合日本列岛、韩国、中国东北及俄罗斯远东地区最新GNSS观测数据，提取日本Mw9.0地震引起的大范围、长时间尺度震后变形，优化东北地区地幔黏滞性结构。基于上述研究结果模拟日本Mw9.0地震在中国东北地区引起的震后应力变化，结合该区域主要断裂带参数的空间分布提升库仑应力时空演化的可靠性。该研究不仅有助于理解中国东北地区地壳变形特征，还能为该区域的地震危险性分析提供支撑。

The accumulated post-seismic deformation in Northeast China has already exceeded the co-seismic responses since the 2011 Tohoku-Oki Mw9.0 earthquake occurred ten years ago. Based on the sophisticated viscoelastic spherical dislocation theory and the latest GNSS observation data, the study of the Coulomb stress changes caused by the post-seismic deformation on the main fault of Northeast China has important referenced significance for earthquake prevention and disaster mitigation. This project will consider Earth’s viscous structure based on the self-gravitation, compressibility and continuously layered spherical dislocation theory, and improve the calculation method of post-seismic internal deformation. Simultaneously, this project will synthesize the latest GNSS observation data from the Japanese archipelago, South Korea, Northeastern China and the Russian Far East to extract large-scale and long-term post-seismic deformation caused by the Tohoku-Oki Mw9.0 earthquake, and optimize the viscous structure of the mantle. Finally, this project will simulate the post-seismic stress changes on the main fault of Northeast China based on the above research results, and combine the spatial distribution of fault parameters to improve the reliability of the temporal and spatial evolution of Coulomb stress. This research not only helps to understand the characteristics of crustal deformation in Northeast China, but also provides support for seismic risk analysis in this region.