The Deformation Characteristics of Sichuan-Yunnan Region in Recent Period

Based on the GPS observation data since 1999, recent deformation characteristics of Sichuan-yunnan region is analyzed, slip rates of main faults are calculated, meanwhile, GPS profiles are combined to analyze the periods of the earthquake generating. The results show that, East edge of Sichuan-Yunnan block:Xianshuihe fault, Anninghe fault, Zemuhe fault, Xiaojiang fault have intense activity, and the movement of the faults are given priority to left-lateral strike-slip. Honghe fault is still in the weak deformation area and the middle section of the Honghe fault zone is the maximum shear strain rate region, while the shear deformation in the northwest and southeast segment of the Honghe fault is higher, which deserves further attention. After Wenchuan earthquake, due to the adjustment of regional stress field and strain redistribution, the activity of the Anning river fault zone is relatively small, easing gradually, and the sliding component has the obvious tendency of slowing down, and the blocking depth of the Anning river fault zone has increased to a certain extent. With the south of the material, the speed of the south segment of the Xiaojiang fault is slowed down and the locking depth increases. GPS velocity profile in parallel to the fault direction of the Xiaojiang fault line shows that the deformation of the fault zone is smooth and the deformation scale is large, showing that there are strong blocking phenomenon. After the Ludian earthquake, the strain release of Zhaotong and Lianfeng fault zone was not significant, compression strain and shear deformation accumulation of Zhaotong-lianfeng is weakening, may indicate that the compressive strain accumulating background is higher.