基于2014年康定6.3级地震震后形变分析区域介质特征

以2014年康定6.3级地震震后InSAR形变资料为约束，采用三层粘弹性地震周期模型及遗传算法反演鲜水河断裂南东段的康定地震震区深部介质粘弹性层厚度及粘滞系数。最优拟合结果表明：1）该区域下地壳粘弹性层厚度为5 km，粘滞系数为9.9×10¹⁷ Pa·s，且断层两侧下地壳流变存在显著的横向不均一性。2）将断层两侧分别反演，显示断层南西盘下地壳粘滞系数（8.7×10¹⁷ Pa·s）略小于断层北东盘下地壳粘滞系数（1.2×10¹⁸ Pa·s）。

Regional Medium Characteristics Based on Post-Earthquake Deformation Analysis of Kangding Ms6 .3 Earthquake in 2014

We use InSAR deformation data after the 2014 Kangding M_S6.3 earthquake as constraints, and use the three-layer viscoelastic seismic period model and genetic algorithm to invert the viscoelastic layer thickness and viscosity coefficient of deep medium in the focal region of Kangding earthquake in the southeast section of Xianshuihe fault. The results show that: 1) The thickness of the viscoelastic layer in the lower crust of Kangding area is 5 km, and the viscosity coefficient is 9.9 × 10¹⁷ Pa·s. The rheological properties of lower crust and lower mantle media on both sides of the fault have significant lateral heterogeneity. 2) By inversion on both sides of the fault, the viscous coefficient of the lower crust of the southwest fault (8.7 × 10¹⁷ Pa·s) is slightly smaller than that of the northeast fault (1.2 × 10¹⁸ Pa·s).