基于遗传算法的地震烈度衰减参数反演方法及应用  

Inversion method and application of seismic intensity attenuation parameters based on genetic algorithm

作　　者：何奕成 彭小波 夏文君 霍祝青[1] 陈楠 徐年[1] He Yicheng;Peng Xiaobo;Xia Wenjun;Huo zhuqing;Chen Nan;Xu Nian(Jiangsu Earthquake Agency,Nanjing 210014,China;School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China;Institute of Disaster Prevention,Hebei Sanhe 065201,China)

机构地区：[1]江苏省地震局,中国南京210014 [2]中国科学技术大学地球空间科学学院,中国南京210014 [3]防灾科技学院,中国河北三河065201

出　　处：《地震学报》2020年第4期435-446,I0001,共13页Acta Seismologica Sinica

基　　金：国家自然科学基金(41874051);江苏省地震局青年科学基金(201807)联合资助。

摘　　要：收集郯庐断裂带中南段59次地震的等震线数据,运用遗传算法,将郯庐断裂带中南段按照断裂带东侧和西侧分区,分别反演其地震烈度衰减参数,反演时使目标函数的一范数最小,同时对烈度衰减曲线的远场施加约束,通过自助抽样(Bootstrap)技术多次重复反演以对反演结果的稳定性进行评价,并将断裂带东侧和西侧的烈度衰减曲线分别与第五代地震动参数区划图进行对比。结果表明:使用本文提出的方法进行反演可使烈度衰减曲线即使不进行近、远场补点,也能收敛;断裂带东侧和西侧的结果均与第五代地震动参数区划图的结果存在差异,且断裂带东侧与西侧的结果也不同。这种差异可能与断裂带两侧的介质速度结构及衰减效应等因素的差异有关。Isoseismal lines of 59 earthquakes occurred in middle south segment of Tanlu fault zone are collected.Seismic intensity attenuation parameters in eastern and western part of Tanlu fault are inversed respectively by genetic algorithm.The one norm of misfit function is used and constraint on far field of seismic intensity attenuation curve is added during the inversion.A bootstrap technique is adopted to repeat the inversion process for several times to evaluate the stability of inversion.Results are compared with the fifth generation seismic ground motion parameter zonation map,it shows that seismic intensity attenuation curve can converge even no data are added in near and far filed by proposed inversion method in this paper.Seismic intensity attenuation of eastern and western part of Tanlu fault are different from those of fifth generation seismic ground motion parameter zonation map.Besides,the seismic intensity attenuation of eastern part and western part are different from each other.This difference may be related to the medium velocity structure and attenuation characteristic.

关 键 词：郯庐断裂带 烈度衰减 遗传算法 模型约束 

分 类 号：P315.9[天文地球—地震学]