甘东南重力、b值异常与岷县—漳县M6.6地震关系探讨  

Relationship Between the Gravity and b-value Anomalies in Southeast Gansu and the Minxian—Zhangxian M6.6 Earthquake

作　　者：冯建林[1] 李德庆[1] 檀玉娟[1] 秦建增[1] 谢汝一[1] 刘冬阳 FENG Jianlin;LI Deqing;TAN Yujuan;QIN Jianzeng;XIE Ruyi;LIU Dongyang(Geophysical Exploration Center,China Earthquake Administration,Zhengzhou 450002,Henan,China)

机构地区：[1]中国地震局地球物理勘探中心,河南郑州450002

出　　处：《地震工程学报》2018年第4期802-807,共6页China Earthquake Engineering Journal

基　　金：中国地震局震情跟踪合同制项目(2016010216;2017010201);中国地震局地震行业专项(201508009-08)

摘　　要：利用甘东南测网2010—2014年的流动重力观测数据,分析2013年7月22日甘肃岷县—漳县M6.6地震前后1a尺度的重力场变化,并结合地震b值图像和GNSS结果进一步分析甘东南重力、b值异常与岷县—漳县M6.6地震的关系,结果表明:(1)测区重力异常经历了由"区域重力负值变化→持续负值变化→转折上升正变化—发震→震后恢复变化"的时空演化过程;(2)岷县—漳县M6.6地震前后b值曲线出现"低值—高值—回落发震"的变化特征;(3)岷县—漳县M6.6地震发生在重力变化高梯度带上、"0"等值线附近和低b值区域。In this paper,the gravity changes of one year scale before and after the Minxian-Zhangxian M 6.6 earthquake on July 22,2013 are analyzed using the mobile gravity observation data from 2010 to 2014 in southeast Gansu network,and then the relationship between the gravity and b-value anomalies in southeast Gansu and the Minxian-Zhangxian M 6.6 earthquake is discussed considering the b-value image and global navigation satellite systems result.The results indicate the following:(1)The gravity anomaly in the study area underwent a spatiotemporal evolution from regional negative gravity change to constant negative change,positive change of turn and increase,earthquake occurrence,and then recovery after the earthquake;(2)before and after the Minxian-Zhangxian M 6.6 earthquake,the b-value curve shows characteristics of low value-high value-reduction and shock;(3)the Minxian-Zhangxian M 6.6 earthquake occurred in a high gradient zone of gravity change near the"0"contour line and the low b-value region.

关 键 词：重力异常 b值异常 岷县-漳县M6.6地震 甘东南 

分 类 号：P315[天文地球—地震学]