2014年8月3日云南鲁甸M_w6.1(M_s6.5)地震破裂过程  

Rupture process of the 3 August 2014 Ludian,Yunnan,M_w6.1(M_s6.5)earthquake

作　　者：张勇[1] 许力生[2] 陈运泰[1,2] 刘瑞丰[3] 

机构地区：[1]北京大学地球与空间科学学院,北京100871 [2]中国地震局地球物理研究所,北京100081 [3]中国地震台网中心,北京100045

出　　处：《地球物理学报》2014年第9期3052-3059,共8页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41090291);中国地震局地球物理研究所基本业务费(DQJB12C01);地震行业基金(201108002)联合资助

摘　　要：2014年8月3日云南鲁甸Mw6.1（Ms6.5）地震是一次规模不大、但灾害严重的走滑型地震事件.受走滑型地震辐射图型的影响,远震地震资料在特定方位上信噪比不高,给此次地震发震断层面的确定造成了一些干扰.本文概述了鲁甸地震发生后2.4小时发布的作为地震应急响应的破裂过程快速反演工作,以及随后对反演结果的修订工作.修订结果中,两个双力偶节面的反演都显示破裂方向朝地表和走向方向扩展.结合现有的烈度分布和余震精确定位结果,根据破裂方向和烈度与余震分布的优势方向的一致性,确定鲁甸地震是发生在走向162°,倾角86°的近乎垂直于地面的以左旋走滑为主的断层面上的一次破裂事件.根据破裂过程反演得到的震源时间函数,大部分地震矩在破裂开始后2-5 s内集中释放.比较集中的地震矩释放过程可能是此次地震面波震级明显高于矩震级,且造成严重地震灾害的原因之一.The 3 August 2014 Ludian earthquake（Mw6.1,Ms6.5）is a disastrous strike-slip but not a large-scale event.Influenced by the radiation pattern,the signal-to-noise ratios of teleseismic data are low at certain azimuths,causing some difficulties in distinguishing the causative fault.This paper reviews the fast rupture process inversion of the Ludian earthquake for rapid earthquake emergency response,which was completed 2.4 hours after the earthquake occurrence,and introduces the following revision works.From the revised rupture models,results of two nodal planes of double couple both indicate rupture propagations toward the ground surface and strike directions.Based on the consistencies between rupture area and intensities and aftershock distributions,it can be concluded that the Ludian earthquake was a left lateral strikeslip event ruptured on a nearly vertical fault with strike 162°and dip 86°.From the source time function determined in rupture process inversion,a large part of the seismic moment was released between 2 s and 5 s after the rupture initiation.The intensive moment release history may be associated with the relatively high surface wave magnitude and the serious disaster of this earthquake.

关 键 词：鲁甸地震 波形反演 破裂过程 

分 类 号：P315[天文地球—地震学]