【摘要】 在离散波数法(DWN)基础上,计算了武定M6.5地震断层破裂在周围介质中产生的位移时程(位移理论地震图)和动态位移场;进行弹性动力学转换后,求得应变时程和动态应变场;最后得到了武定M6.5地震所产生的动态库仑破裂应力变化量和动态库仑破裂应力变化场,进而研究其与后续余震的关系.结果表明,动态应力最大峰值和静态应力的正区均呈非对称性分布,两者的分布特征与余震的分布特征基本一致.在动态应力峰值为正的确定区应力值超过了0.1MPa触发阈值,在静态应力值为正的确定区应力值超过了0.01MPa触发阈值.这说明动态应力和静态应力均有助于余震的发生.更多还原

【Abstract】 Based on the discrete wavenumber method, this paper calculates time-history of displacement (the theoretical seismogram of displacement) and dynamic displacement field caused by the Wuding M6.5 earthquake. Then the time-history of strain and the dynamic strain field are obtained by elastodynamic transformation. Finally we calculate the dynamic Coulomb rupture stress changes and the dynamic Coulomb rupture stress changes field caused by the Wuding M6.5 earthquake, and then discuss its relationship with the subsequent aftershocks. The results show that the spatial distribution patterns of the positive region of dynamic stress peak value and static stress are both asymmetric, which are basically identical with distribution features of the aftershocks. The dynamic stress peak value and the static stress in the positive region are more than 0.1 MPa and 0.01 MPa of the triggering threshold, respectively, which indicates that the dynamic and static stresses are helpful for the occurrence of aftershocks.更多还原