中强地震能量震级测定  

Energy magnitude determination of moderate-strong earthquakes

作　　者：李赞 刘瑞丰[1] 孔韩东 王子博 袁乃荣[2] Li Zan;Liu Ruifeng;Kong Handong;Wang Zibo;Yuan Nairong(Institute of Geophysics, China Earthquake Administration. Beijing 100081, China;Institute of Physical Science and Information Engineering, Hebei Normal University,Shijiazhuang 050024, China)

机构地区：[1]中国地震局地球物理研究所,中国北京100081 [2]河北师范大学物理科学与信息工程学院,中国石家庄050024

出　　处：《地震学报》2019年第3期289-301,I0001,共14页Acta Seismologica Sinica

基　　金：中国地震局地球物理研究所基本科研业务费专项(DQJB18B04)资助

摘　　要：本文根据地震波衰减特性,开展了利用宽频带地震波形数据测定地震波能量E_S和能量震级M_e的方法研究。利用震中距处于20°-98°范围内的宽频带远震P波波形数据,测定了4次国外和4次国内中强震的能量震级M_e,并对其面波震级M_S、矩震级M_W及能量震级M_e进行了分析对比。结果表明:面波震级M_S表示的是地震在某一固定频率所辐射的地震波能量大小;矩震级M_W与地震所产生的断层长度、断层宽度、震源破裂的平均位错量等静态构造效应密切相关;而能量震级M_e反映的是震源动态特征,与地震震源的动力学特性密切相关。由于地震是以地震波形式辐射,能量主要集中在震源谱的拐角频率附近,因此能量震级M_e更适合描述地震的破坏性。由此可见,联合测定面波震级M_S,矩震级M_W和能量震级M_e对于地震定量研究以及地震灾害与风险评估具有重要作用。This paper,based on the seismic wave attenuation characteristics,explores a method for utilizing broadband seismic waveform data to measure seismic energy ES and energy magnitude Me. The energy magnitudes M_e of four overseas and four domestic moderate-strong earthquakes are measured by using broadband teleseismic P waveform data with epicentral distance in the range of 20°-98°. The comparison of surface wave magnitude MS,moment magnitude MW and energy magnitude M_e of several earthquakes shows that:surface wave magnitude MS represents the magnitude of the energy of seismic wave radiating at a fixed frequency;the moment magnitude MW is closely related to the static structural effects such as the length of fault,the width of fault and the average dislocation amount of the source rupture produced by the earthquake;the energy magnitude Me reflects source dynamic characteristics and is closely related to the dynamic characteristics of the seismic source. The energy radiated by the earthquake in the form of seismic waves is mainly concentrated near the corner frequency of the source spectrum,so the energy magnitude Me is more suitable to describe the destructiveness of the earthquake. Therefore,joint determination of surface wave magnitude MS,moment magnitude MW and energy magnitude Me are of great significance for quantifying and evaluating the disasters caused by earthquakes or tsunamis.

关 键 词：地震波能量 能量震级 宽频带远震P波波形数据 震源动态特征 震源谱 

分 类 号：P315.3[天文地球—地震学]