本项目针对中国地震科学实验场强震孕震机理研究亟需的构造应力场模型，用大地测量及地震学方法，对川滇地区近年来所积累的海量观测数据进行系统的搜集与分析。用GNSS与InSAR等观测研究该地区地壳应变场时空演化；开展基于地形与同震应力变化来计算绝对构造应力场的研究；综合地震位置、震源机制解、破裂方向性信息，确定中强地震的发震断层与强震活动特性；确定大批中小地震震源机制，并反演区域构造应力场的时空变化；应用全波形反演对地壳与上地幔各向异性结构进行三维成像。最终整合所有手段所得到的结果，构建川滇地区应力场模型，分析川滇地区主要断裂带应力应变积累的区域构造应力加载特征，认识中强以上地震发震断层的构造应力背景以及地震发生前后构造应力场随时间演变特征，进一步探讨川滇地区强震的孕震机理。

In this project, we aim to establish the tectonic stress field model for the purpose of understanding the seismogenic behavior of strong earthquakes in the Chinese Earthquake Science Laboratory. We employ geodesy and seismology techniques to conduct a systematic collection and analysis of the huge amount of data accumulated in the Sichuan-Yunnan area over the recent decades. We will study the regional spatial-temporal variations of crustal deformation using GNSS and InSAR observations; estimate the absolute stress field based on topography and co-seismic stress changes; determine the rupture planes of moderate-to-large earthquakes using a joint analysis of earthquake locations, focal mechanisms and source directivities, and investigate their spatial pattern; determine the focal mechanisms of moderate and small earthquakes and use them to invert for the relative stress field; conduct full-wave seismic tomography to study the 3D variation of anisotropy. Finally, we will integrate the results from all techniques to establish the regional tectonic stress field model of the Sichuan-Yunnan area, which will be used to understand the loading process and strain-stress accumulation along the major fault zones, the background tectonic stress responsible for the ruptures of stronger earthquakes, the possible changes in stress field before and after major earthquakes, and the seismogenic behavior of strong earthquakes in the Sichuan-Yunnan region.