基于恢复地震数据获取震级、震源机制及破裂过程的评价——以2013年四川芦山M_W6.6地震为例  

Evaluation of investigating magnitude,source mechanism and rupture process based on restored seismic data--Taking the 2013 Lushan M_W6.6 earthquake in Sichuan as an example

作　　者：张小艳 郝金来[2,3] 高星 王伟[1] ZHANG XiaoYan;HAO JinLai;GAO Xing;WANG Wei(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;Key Laboratory of Earth and Planetary Physics,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Innovation Academy for Earth Science,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]资源与环境信息系统国家重点实验室,中国科学院地理科学与资源研究所,北京100101 [2]地球与行星重点实验室,中国科学院地质与地球物理研究所,北京100029 [3]中国科学院地球科学研究院,北京100029

出　　处：《地球物理学报》2020年第6期2262-2273,共12页Chinese Journal of Geophysics

基　　金：国家自然科学基金面上项目(41574058);国家重点研发计划政府间国际创新合作专项(2018YFE0100100)资助.

摘　　要：区域地震波形对于震源研究非常重要,但限幅问题限制了区域地震台网数据的运用,并影响到震源参数测定的准确度.本文利用恢复后的芦山地震区域地震波形,研究了芦山地震的震级、点源机制解以及破裂过程.基于震中距99~300km恢复前与恢复后地震数据获取的面波震级分别为7.01与7.06级.分别利用7个震中距150~250km宽频带台站的恢复前和恢复后的数据反演点源机制解,与参考机制解相比,滑动角偏差自13°减小到了4°.基于7个震中距81~134km的区域地震波形联合远场数据获得的震源破裂过程结果,其主要参数(如滑动分布、破裂速度等)与强地面运动波形联合远场数据得到的结果具有很好的一致性.研究结果表明,本文所采用的数据恢复方法具有较高的可靠性,有效提高了震源参数测定的准确度.Regional seismic waveforms are very useful for investigating earthquake source.However,partial near-field seismic data of Regional Seismic Network are clipped.Therefore,it could not be applied to determine the accurate source parameters directly.In this paper,the magnitude,source mechanism and rupture process of M_W6.6 Lushan earthquake were studied based on the restored regional seismic waveforms.The magnitude changed from 7.01 to 7.06 based on clipped and restored surface waves of stations with epicentral distances from 99 km to 300 km.Clipped and restored regional waveforms of 7 stations with epicentral distance 150 km to 250 km are utilized to get the source mechanism respectively.Compared to the reference mechanism solution,the misfit of rake angle is reduced from 13° to 4°.Based on 7 regional seismic waveforms with epicentral distance from 81 km to 134 km combined with teleseismic data,the main parameters(such as slip distribution,rupture velocity,etc.)of the rupture process are similar to that of the result constrained by local strong motion data and teleseismic waveforms.These studies verify that this method is reliable and can play an important role in the earthquake source research.

关 键 词：限幅地震数据 地震数据恢复 芦山地震 震源机制 

分 类 号：P315[天文地球—地震学]