摘要
电离层异常是地震短临预报过程的重要参考,目前已经积累了丰富的研究成果。与地震电离层异常形成机制相关的LAI耦合模型也得到了发展,其中声重波途径受到了广泛关注。本研究基于中国大陆构造环境监测网络(CMONOC)GNSS观测站提取到的北斗导航卫星系统(BDS)电离层总电子含量(TEC)数据,通过小波变换等分析方法,对2023年12月18日甘肃积石山M_(W)6.0地震前14 h至震后2 h内TEC扰动的频谱特征和时空变化进行了探究,并与背景扰动信号和外源信号进行了对比。结果表明,临震前声重波扰动信号主要表现为向外辐散的弧状结构,反向定位结果表明该扰动弧源点接近震源位置。该扰动信号同时还受到了MSTIDs背景信号的载波作用和两个外源信号的干扰。最后,讨论了地表声重波信号的激发起源机制,指出地震孕育过程与声重波的联系仍需进一步验证和探究。
Ionospheric precursors are crucial indicators for short-term earthquake preparation,and abundant observations of them have been accumulated.Meanwhile,developments concerning the formation mechanisms of seismology ionospheric anomalies have led to increasing interest in the LAI coupling process,in which the AGW-agent hypothesis has been intensively discussed.Based on the BDS TEC data collected by CMONOC GNSS stations,this paper explores the spectral characteristics and spatial-temporal variations of the TEC perturbations from 14 hours before to 2 hours after the Jishishan M_(W)6.0 earthquake on December 18,2023,in Gansu Province,China.According to the results,the pre-earthquake AGW-induced perturbation originated from points close to the epicenter and then dispersed outward as an arc-like structure.In addition,the background signal MSTIDs played the role of a carrier in the propagation of the perturbation,while the other two external signals exerted an interference effect on it.Finally,two promising candidates for the excitation and origination of the surface AGW signal are reviewed.Nevertheless,the connection between earthquake preparation and AGW signals needs further validation and investigation.
作者
刘红
张学民
杨娜
LIU Hong;ZHANG Xue-min;YANG Na(Institute of Earthquake Forecasting,China Earthquake Administration,Beijing 100036,China)
出处
《地震》
CSCD
北大核心
2024年第4期62-81,共20页
Earthquake
基金
中国地震局地震预测研究所基本科研业务经费专项(CEAIEF20230401)
国家自然科学基金国际(地区)合作与交流项目(42361144794)
“十四五”国家装备预研项目(50925020104)。
