摘要
根据地震波衰减特性,采用一维速度模型开展了快速测定辐射能量E_S和能量震级M_(e)的方法研究。利用全球地震台网和国家数字测震台网提供的宽频带资料,测定了2014-2019年间M_(W)≥6.0的115次浅源地震的辐射能量和能量震级,将计算结果与其它机构的结果进行对比。结果表明:利用本文方法可在得到地震数据半小时内计算出稳定的M_(e),且本文的测定结果与美国地震学研究联合会的结果基本一致。地震造成的灾害与能量震级的大小密切相关,当Me>M_(W)时,地震灾害较为严重;在所有的地震类型中,发震断层类型为走滑型时,其地震辐射能量的效率高,M_(e)明显大于M_(W)。通过分析2018年2月4日和2019年4月18日台湾花莲两次M_(W)6.1地震能量释放的差异得出,发生在相似位置且具有相同的震源机制的两次地震,尽管它们的M_(W)相同,但M_(e)相差很大,接近0.5。M_(e)与M_(W)的差异表明,M_(W)只能获得有关震源的静态特征,它与地震引起的断裂面积、断裂平均位错等静态构造效应密切相关,而M_(e)可以提供震源的动态信息,从而客观评价地震的破坏强度。因此,本文使用的方法既能准确测定能量震级M_(e)又能极大提高其测定速度,非常适用于快速反应系统。本研究可以为未来地震台网将能量震级M_(e)作为日常产出震级提供参考,为快速评估大地震造成的灾害提供更多信息。
Based on seismic waves’attenuation characteristics and the one-dimensional velocity model,we conducted a study for the rapid determination of radiated seismic energy ES and energy magnitude M_(e).The seismic recordings obtained from the Global Seismographic Network and China Seismological Digital Network were used to calculate the ES and M_(e)of 115 shallow earthquakes with M_(W)≥6.0 from 2014 to 2019,and the results were compared with M_(W)and M_(e)produced by other institutions.The results show the stable M_(e)can be obtained within half an hour after obtaining the seismic data,and the M_(e)values of IRIS were consistent with the earthquakes analyzed in this study.The earthquake damage is closely related to the size of energy magnitude M_(e),and the devastation that an earthquake can cause is more serious when the energy magnitude M_(e)is far greater than the moment magnitude M_(W).In all types of earthquakes,the efficiency of radiated energy for earthquakes with strike-slip faults is high,with M_(e)being significantly greater than M_(W).Next,by analyzing two M_(W)6.1 earthquakes occurred in Hualien,Taiwan region on February 4,2018 and April 18,2019,it is concluded that two earthquakes with the same source mechanism in similar locations,although they have the same moment magnitude M_(W),the energy magnitude M_(e)vary greatly,close to 0.5.M_(W)can only obtain the source’s static characteristic,which is closely related to the static tectonic effects such as fault area and average dislocation of rupture caused by earthquakes.In contrast,M_(e)can provide the source’s dynamic information and objectively evaluate the damage intensity of an earthquake.Therefore,the approach applied in this study can ensure the accuracy of the results and greatly improve the measurement speed of energy magnitude M_(e),which is very suitable for a rapid response system.Our research results can provide a reference for the future seismic network to take energy magnitude M_(e)as daily output magnitude and provide more information for rapid assessment of disasters caused by large earthquakes.
作者
王子博
刘瑞丰
李赞
孔韩东
袁乃荣
Wang Zibo;Liu Ruifeng;Li Zan;Kong Handong;Yuan Nairong(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;College of Physics,Hebei Normal University,Shijiazhuang 050024,China)
出处
《地震学报》
CSCD
北大核心
2021年第2期194-203,I0001,共11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,DQJB20K30)
政府间国际科技创新合作重点专项(2018YFE0100100)资助。
关键词
地震辐射能量
能量震级
宽频带记录
矩震级
radiated seismic energy
energy magnitude
broadband recording
moment magnitude
