蒙宁交界区b值时空变化特征  

Analysis of the spatio-temporal variation characteristics of b-value in the Inner Mongolia-Ningxia junction

作　　者：王耀临 刘伟 柴宁娇 张帆[2] 张建中[2] 段昊 WANG Yaolin;LIU Wei;CHAI Ningjiao;ZHANG Fan;ZHANG Jianzhong;DUAN Hao(Wujiahe SeismicStation,Inner Mongolia Autonomous Region 015323,China;Earthquake Agency of Inner Mongolia Autonomous Region,Hohhot 010010,China)

机构地区：[1]乌加河地震台,中国内蒙古自治区015323 [2]内蒙古自治区地震局,中国呼和浩特010010

出　　处：《地震地磁观测与研究》2021年第3期55-63,共9页Seismological and Geomagnetic Observation and Research

基　　金：内蒙古自治区地震局局长基金(项目编号:2020JC15)。

摘　　要：选取1970—2019年蒙宁交界区中国台网中心地震目录,结合研究区地质构造,分析震级与地震频次以及时间与地震频次的关系。利用极大似然法,设定不同的窗长和步长,对研究区进行b值时空扫描,对比b值时间曲线,发现某些中强震发生在b值下降到异常水平然后上升的过程。采用矩形窗和圆形窗分别进行空间扫描,对比发现,研究区低b值分布在(104°—105°E,36°—38°N)区域;对研究区16次中强震进行震例回溯,结果发现,5次地震发生在低b值区域,表明低b值区有发生中强震的可能。This paper uses the earthquake catalog of the Inner Mongolia-Ningxia junction area from 1970 to 2019 provided by the China Earthquake Networks Center,combined with the geological structure of the study area,to analyze the relationships between magnitude and earthquake frequency and between time and earthquake frequency.This paper uses the maximum likelihood method to scan the b-value in the study area in time and space domains and compares b-value curves for different window lengths and step lengths.It was found that some moderate earthquakes occurred during the process when the b value dropped to an abnormal level and then rose again.Spatial scanning was carried out using rectangle and circular windows for comparison.It is found that the low b-value in the study area is in the area of 104°—105°E and 36°—38°N.We carried out retrospective research for 16 moderate earthquakes in the study area,the results show that 5 earthquakes occurred in low b-value areas,indicating that moderate earthquakes may occur in low b-value areas.

关 键 词：蒙宁交界区域 B值 时空扫描 

分 类 号：P315.7[天文地球—地震学]