2016年1月21日门源M_(S)6.4地震前重力非潮汐变化特征分析  

Gravity non-tidal variation characteristics before the Menyuan MS 6.4 earthquake on Jan.21,2016

作　　者：翟丽娜[1,2] 刘华建[3] 杨牧萍 李彤霞 李宇彤[1] ZHAI Lina;LIU Huajian;YANG Muping;LI Tongxia;LI Yutong(Liaoning Earthquake Agency,Shenyang 110034,China;Jilin University,Changchun 110000,China;General Hospital of Mineral Exploration of Liaoning Province,Shenyang 110034,China)

机构地区：[1]辽宁省地震局,中国沈阳110034 [2]吉林大学,中国长春110000 [3]辽宁省矿产勘查总院,中国沈阳110034

出　　处：《地震地磁观测与研究》2023年第5期125-131,共7页Seismological and Geomagnetic Observation and Research

基　　金：地震科技星火计划(项目编号:H21007Y);中国地震局震情跟踪(项目编号:2023010202)。

摘　　要：选取2015—2018年兰州和高台连续重力观测站整点值数据,分析2016年1月21日门源M_(S)6.4地震前2个台站连续重力数据非潮汐变化特征,发现2个台站在此次地震发生前1年,分别观测到重力数据出现持续约6个月的重力非潮汐上升变化,月均变化速度分别为9.36μGal、6.17μGal,累计变化振幅分别达到56.15μGal、37.05μGal。通过对观测站点周边观测环境的详细核实和理论计算,排除台站周边环境干扰因素,认为震前6个月的重力非潮汐持续性下降变化应与此次M_(S)6.4地震孕震过程有关。本研究结果可为揭示此次门源地震的孕震机理提供一定参考,为后续地震预测中重力观测指标的建立提供一定参考。Continuous gravitational observation data at the Gaotai and Lanzhou seismic stations before the Menyuan M_(S)6.4 earthquake were analyzed and studied.The results show that both stations observed non-tidal gravity decline changes that lasted 6 months one year before the earthquake,with variation rates of about 9.36μGal per month at Gaotai Seismic Station and about 6.17μGal per month at Lanzhou Seismic Station,respectively.The cumulative variation amplitudes are about 56.15μGal and 37.05μGal respectively.Through verification,theoretical calculation,and analysis,the disturbance of the surrounding environment is excluded.It is believed that the continuous decline in non-tidal gravity over 6 months before the earthquake may be related to the seismogenic process.The results of this study may provide an important reference for the construction of the earthquake prediction index system based on continuous gravitational observations.

关 键 词：门源M_(S)6.4地震 连续重力 地震监测 非潮汐变化 

分 类 号：P315.726[天文地球—地震学]