摘要
地震辐射能量是表示震源动态特征的物理量,测定地震辐射能量在地震灾害评估、地震定量化研究和工程地震学研究中具有重要作用。文中利用全球地震台网提供的波形数据,针对2021年5月21日发生的云南漾濞地震开展了地震辐射能量测定研究工作,得到的主要结果为:本次地震的辐射能量为1.6×1013 J,能矩比为9.9×10^(-6),低于全球走滑型地震的平均能矩比;将本次地震与2014年10月7日景谷M W6.1地震进行对比发现,虽然2次地震的矩震级相同、震源机制相似、震中仅相距290km,但景谷地震的能矩比(1.58×10^(-5))是本次漾濞地震(9.9×10^(-6))的1.6倍;根据时频分析结果发现,景谷地震地震波中的高频能量高于漾濞地震。以上结果表明,漾濞地震属于能量释放效率较低的走滑型地震。相对高频的地震波能量与地震近断层灾害密切相关,因此我们认为除去震源深度、地质条件和建筑结构的差异外,较低的能量释放效率是导致这次地震的与同震级的地震相比,相同烈度的区域面积较小的原因之一。
Radiated seismic energy is a fundamental physical quantity that can be used to represent the dynamic characteristic of the earthquake source,and it is a reliable indicator of the high-frequency component radiated by the seismic source which goes into the seismic waves.Estimating radiated seismic energy has an important role in seismic hazard assessment,quantification of earthquake research,and engineering seismology.Therefore,it is of great significance for the rapid determination of the seismic radiated energy after an earthquake as a reference.After the Yangbi earthquake on May 21,2021 in Yunnan Province,we measured the radiated seismic energy for the Yangbi earthquake based on the broadband recordings provided by the Global Seismograph Network.The results show that the radiated seismic energy is estimated to be 1.6×1013 J;the corresponding M e value is 5.9,which is smaller than M W;The difference between the single station value and the average value is less than 0.2 units in the determination of energy magnitude for more than 70%of the stations;Based on the results of the seismic moment obtained by Global Centroid Moment Tensor(GCMT),it can be concluded that the energy-moment ratio is 9.9×10^(-6),which is considerably weaker than the global average value of(4×10^(-5))for the strike-slip earthquakes.Several previous studies showed that due to the difference in the source rupture process,even earthquakes with small differences in seismic moment and focal mechanism that occurred in the same seismotectonic area may have obviously different amounts of radiated seismic energy.Therefore,we compared this event with Jinggu earthquake that occurred on October 7,2014.Although the moment magnitudes and focal mechanisms of the two earthquakes are similar,and the epicenter distance is only 290km apart,the area of the same isoseismal for the Jinggu earthquake is significantly larger than the Yangbi earthquake.Earthquake intensity indicates the level of ground shaking,which is associated with the high-frequency components
作者
王子博
刘瑞丰
孙丽
李赞
孔韩东
WANG Zi-bo;LIU Rui-feng;SUN Li;LI Zan;KONG Han-dong(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;China Earthquake Networks Center,Beijing 100045,China)
出处
《地震地质》
EI
CSCD
北大核心
2021年第4期908-919,共12页
Seismology and Geology
基金
中国地震局地球物理研究所基本科研业务专项(DQJB21X28,DQJB20K30)
政府间国际科技创新合作重点专项(2018YFE0100100)共同资助。
关键词
漾濞M_(S)6.4
地震
辐射能量
能矩比
等震线
the Yangbi earthquake in Yunnan
radiated seismic energy
energy-moment-ratio
isoseismal
