摘要
地震震前多参数异常及其时空关联性的回顾性分析是深入认识地震孕震过程,探究多参数异常变化可能物理机制的关键.因此,本文以空基数据包括地表温度、空气温度、潜热通量、晴空长波辐射和地基数据包括钻孔温度、水溶氡气、水溶氦气、钻孔形变作为研究参数,提取2017年新疆精河M_(W)6.3地震震前各参数时空异常变化,分析多参数异常变化之间的时空关联并探究其可能的物理机制.结果表明,精河地震前多个参数显示出异常变化.空基参数异常主要分布在震中西/西南部及北/东北部,最大异常分布出现在地震前一个月,且对应的异常变化高值区位于震中附近.钻孔温度未出现异常变化,水溶氦气显著异常变化出现在地震前四个月,水溶氡气显著异常变化则出现在地震前一个月,钻孔形变NE-SW分量压缩速率加快,NW-SE则由压缩状态转为拉张状态.空基和地基观测参数的异常变化在时间序列上呈现明显的链式过程,钻孔形变为第一个异常变化参数,水溶氡气为最后一个,异常集中变化时段在7月10日至7月15日.此外,钻孔形变NW-SE方向由压缩转为拉张的时段与空基参数异常变化时段相一致.在空间分布上,地表温度、空气温度和长波辐射异常分布范围与研究区应力积累区域吻合,而潜热通量异常空间分布则主要受区域地形因素影响.综合上述研究成果,本研究认为精河地震震前多种参数异常变化可能的物理模型为正极空穴模型.
Retrospective analysis of multi-parameter anomalies and exploring pre-earthquake chain process are critical for understanding the earthquake preparation process and its physical machine.Consequently,space-based observations including surface temperature(ST),air temperature(AT),surface latent heat flux(SLHF)and outgoing longwave radiation under clear sky(OLR)were combined with ground-based observations such as borehole temperature(BT)and water-solute gas.In this study,we identify spatial-temporal anomalies of various parameters before 2017 Jinghe earthquake,investigate pre-earthquake chain processes,and discuss the physical mechanism of multi-parameter anomaly behaviors.Anomalies in space-based parameters are distributed mainly in the west-southwest and north-northeast directions of the epicenter.The most extensive anomaly distribution occurred one month before the earthquake,with the high-value area of anomaly changes surrounding the epicenter.Significant water-soluble helium and radon anomaly variations respectively occurred four and one months before the earthquake.The NW-SE component of borehole deformation shifted from compressed state to stretched state.There had been a chain of various parameter anomalies before earthquake.The borehole deformation was the first anomaly variation parameter,and water-soluble radon gas was the last.The anomaly spatial distribution of ST,AT and OLR all coincide with the compression stress area.We suggest that p-hole activation mechanism best explains the pre-earthquake chain process in this study.
作者
吴玮莹
单新建
屈春燕
李新艳
朱治国
姜卫平
WU WeiYing;SHAN XinJian;QU ChunYan;LI XinYan;ZHU ZhiGuo;JIANG WeiPing(State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China;Earthquake Agency of Ningxia Hui Autonomous Region,Yinchuan 750001,China;Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830011,China;Wuhan University,Wuhan 430072,China)
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第9期3335-3350,共16页
Chinese Journal of Geophysics
基金
国家重点研发计划“综合利用空间观测技术的大地震孕育发生变形时空特征研究”项目(2018YFC1503602)资助。
关键词
精河地震
震前多参数异常变化
时空关联性
正极空穴模型
Jinghe earthquake
Various parameters anomalies in the pre-earthquake period
Spatial-temporal correlations
p-hole activation mechanism
