2022年9月5日泸定地震震级的计算与对比分析

Calculation and comparison of the magnitude of Luding earthquake on Septemper 5,2022

针对不同机构发布的2022年9月5日泸定地震体波震级m_(b)存在偏差的问题开展研究。通过梳理国内外主要震级发布机构的体波震级m_(b)定义,分析了不同机构震级存在差异的原因。同时,基于禁核试北京国家数据中心现有的地震观测台网和集成的震级计算程序,计算了不同机构体波震级m_(b)。结果表明,不同机构之间的震级偏差是由各自震级定义的不同所致,其中包括幅值测量方式和量规函数的不同;此外,还受观测台网的影响,即使采用同一震级定义,观测台网不同时得到的震级也会存在偏差。

This paper studies the deviation of the body-wave magnitude m_(b)of the Luding earthquake on Septem_(b)er 5,2022 released by different institutions.By sorting out the body-wave magnitude definitions given by major domestic and international earthquake magnitude reporting agencies,we summarized the reasons for the deviation of the body-wave magnitude m_(b)among different institutions.Based on the present seismic observation network of Beijing National Data Centre and the integrated magnitude calculation programs,the body-wave magnitude is calculated according definitions of each institution.The results show that the magnitude deviation between institutions is mainly caused by different definitions of m_(b)from these institutions,including the influence of amplitude measurement methods,the calibration functions,and affection of the observation network.Even if using the same magnitude definition,the magnitude obtained from different observation networks will also have deviations.