【摘要】 根据地震破裂过程中的多普勒效应,利用多台波谱参数推算九江—瑞昌MS5.7地震的震源破裂参数,得到主震的破裂方位角φ0≈319.6,°破裂速度约为2.3 km/s,用最小二乘法拟合的相关系数极值约为0.80。在此基础上,分别计算了主震在4.8级强余震的两个节面上的静态库仑应力变化量,结果显示:主震在4.8级余震节面Ⅰ、Ⅱ上的静态库仑应力变化均为正值,分别为0.48 MPa和0.02 MPa。主震在节面Ⅰ、Ⅱ上产生的静态库仑应力的变化十分接近。应力增加的区域主要位于主震断层的右侧,应力减小的区域主要分布在震中南部。统计显示:绝大部分余震均发生在静态库仑应力增加的区域内,尤其是在节面Ⅰ上,表明主震破裂产生的库仑破裂应力变化对4.8级余震的发生有重要的触发作用,同时也有利于大多数余震的发生。更多还原

【Abstract】 According to the Doppler Effect in the earthquake rupture process,we use the multi-station spectrum to calculate rupture parameters of the Jiujiang-Ruichang MS5.7 earthquake in Jiangxi.We get the results that the rupture azimuth is about 319.6°,the rupture velocity is about 2.3 km/s,and the fitted minimum correlation-coefficient is about 0.80 by minimum squares.And on this basis,We calculate the variation of static Coulomb stress separately in the two rupture planes of the MS4.8 aftershock.The results show that the variation of the static Coulomb stress separately on two nodal planes are positive,the values are about 0.48 MPa and 0.02 MPa respectively.The variations of static Coulomb stress on nodalⅠ and Ⅱ are very close.Stress-increasing area is mainly located on the right of the main earthquake fault.Stress-reducing area is mainly located to the south of the epicenter.Most of the aftershocks occur in the static Coulomb stress-increasing region,especially on the nodal.This shows the Coulomb failure stress variation caused by the main shock has an important role in triggering of the MS4.8 aftershock,and also conductive to majori aftershocks’ occurrence.更多还原