中文摘要：

根据2014年鲁甸MS6.5地震的区域构造和余震共轭分布特征,本文首先计算了1733年小江断裂带北段M7.75地震,1850年则木河断裂带M7.5地震和1974年马边MS7.1地震对鲁甸MS6.5地震震源机制解两个节面的黏弹性库仑应力作用,结果显示NNW向发生主破裂的包谷垴—小河断裂受到这3次地震,尤其是1850年M7.5地震明显的库仑应力作用,我们认为则木河断裂的高速左旋走滑运动以及7级以上强震的重复发生对于包谷垴—小河断裂的强震孕育和断裂演化方面具有促进作用;然后分析了鲁甸6.5级地震的共轭破裂与余震分布特征,并分别计算了两个共轭破裂面单独破裂对另一破裂面的库仑应力作用,结果显示NEE向破裂促进NNW向破裂的发生,而NNW向破裂后则阻碍了NEE向破裂的进一步发展,最终发展成以NNW向破裂为主的共轭破裂事件;最后计算了共轭破裂产生的库仑应力变化对余震的影响,认为位于NEE向破裂面西侧的余震集中分布主要是由于应力触发作用而形成.

英文摘要：

The MS6.5 Ludian earthquake in 2014 occurred in a complex tectonic region with aftershocks distributed on two conjugated fault planes.To study this detailed rupture characteristic and the tectonic regime of the earthquake,we first calculated the viscoelastic coulomb stress changes of the three nearby historical earthquakes on the two nodal planes of the MS6.5Ludian earthquake,including the 1733 M7.75 earthquake on the Xiaojiang fault,the 1850 M7.5earthquake on the Zemuhe fault,and the 1974 MS7.1Mabian earthquake.The results show that the NNW rupture plane,the Baogunao-xiaohe fault,received the obvious positive coulomb stress changes caused bythe 1850 M7.5earthquake on the Zemuhe fault.While the NNE rupture plane obtained negative coulomb stress changes by the three earthquakes. We considered the high left-lateral slip behavior and repeated strong earthquake activities of the Zemuhe faults promoted the formation and strong earthquake activities of the Baogunao-Xiaohe fault.Then we analyzed the characteristics of the aftershock distribution on the conjugated rupture planes. After dividing the Ludian earthquake into 2separate events on each of the rupture plane,we calculated the coulomb stress changes of the 2events on the other conjugated fault plane,respectively.The results show the rupture of the NEE plane activated the dislocation of the NNW plane,while the dislocation of the NNW plane obstructed the further movement of the NEE plane.And the Ludian earthquake in2014 behaved as a mainly NNW-ruptured event with conjugated aftershock distribution.Finally,we calculated the coulomb stress changes on the aftershocks by the mainshock.And the results show the aftershocks clustered in the area west to the NEE rupture plane were triggered by the MS6.5Ludian earthquake.