芦山7.0级地震产生的应力变化场及其对滇东地区的影响研究

Research on Influence of Coulomb Stress Changes Induced by Lushan M_S7. 0 Earthquake on Eastern Yunnan Areas

根据芦山7.0级地震震源破裂过程的最新研究结果,采用3个震源模型计算了地震产生的库仑破裂应力变化,研究了库仑破裂应力变化的空间分布与余震活动分布的关系,探讨芦山地震的发生对滇东地区影响。结果表明,90%以上芦山地震的后续地震活动分布于正的库仑破裂应力区域,余震活动受到了主震的应力触发作用。滇东地区一直处于应力闭锁状态,芦山7.0级地震的发生,可能对滇东的小江断裂带及其以西地区有一定的应力触发作用。

The Lushan Ms7.0 earthquake occurred on Apr.20,2013 in Lushan Country,Ya＇an City,Sichuan Province.According to the newest research results of source rupture process for Lushan Ms7.0 earthquake,we used three source models to calculate the coulomb failure stress changes induced by the Lushan Ms7.0 earthquake,and analyze the relationship between the spatial distribution of coulomb failure stress changes and the aftershock activity distribution.Moreover,we discussed the influence of Lushan Ms7.0 earthquake on the Eastern Yunnan.The results show that the more than 90% of aftershock activities distributed in the areas with the positive coulomb failure stress,which were triggered by the stress effect of main shocks,Lushan Ms7.0 earthquake might have stress triggering on Xiaojiang Fault and its adjacent western region,for the reason that Eastern Yunnan was on the stress blocking state.