四川测震台网M_(L)震级特征研究  

Study on Characteristics of Local Magnitude M_(L) from Sichuan Seismic Network

作　　者：黄春梅[1] 罗勇 魏娅玲[1] 王宇航[1] HUANG Chunmei;LUO Yong;WEI Yaling;WANG Yuhang(Sichuan Earthquake Agency,Sichuan Chengdu 610041,China)

机构地区：[1]四川省地震局,四川成都610041

出　　处：《四川地震》2023年第4期8-12,18,共6页Earthquake Research in Sichuan

基　　金：四川省地震局地震科技专项(LY2203);中国地震局工程力学研究所基本科研业务费专项资助项目(2020EEEVL0101)联合资助.

摘　　要：基于2013—2022年四川测震台网记录到的四川及邻区2.0≤M_(L)≤5.5的36693次地震事件观测资料,利用震级残差统计方法得到59个区域台站的单台ML震级与台网平均ML震级的偏差、各单台记录地震的平均偏差和标准偏差。结果显示:震级偏差统计直方图基本呈正态分布,相对集中于-0.5~0.5;单台M_(L)震级偏差沿龙门山断裂带两侧分区特征明显,呈现“东高西低”,即川西高原地区台站M_(L)震级偏小及四川盆地台站M_(L)震级偏大特征;从ML震级随震中距的变化曲线来看,当震中距<150 km时,单台测定的M_(L)震级较台网平均震级偏小,当震中距≥200 km时,单台测定的ML震级较台网平均震级偏大。In this paper,the observation data of 36693 earthquakes with magnitudes at 2.0≤M_(L)≤5.5 in Sichuan and adjacent areas were recorded by Sichuan Seismic Network from 2013 to 2022.We used a statistical method of magnitude residual to calculate the deviation between the single M_(L) magnitude of 59 stations and the mean magnitude of networks,mean deviation,and standard deviations.The statistical histograms of magnitude deviation are basically distributed and relatively concentrated at-0.5~0.5.The M_(L) magnitude showed obvious zoning characteristics at different sides of the Longmen Shan Fault,which presents a pattern with’high in the east and low in the west’.In other words,the M_(L) magnitude of the stations at Plateau in the western Sichuan is smaller,whereas the M_(L) magnitude of the stations in the Sichuan Basin is larger.The curve of M_(L) variation along with the epicentral distance showed that the M_(L) magnitude at stations of the epicentral distance(<150 km)is smaller than the average network magnitude.However,the M_(L) magnitude measured at stations of epicentral distance(≥200 km)is larger than the average network magnitude.

关 键 词：四川台网 M_(L)震级 单台震级偏差 震级残差统计法 

分 类 号：P315.3[天文地球—地震学]