四川江油台地电场优势方位角异常核实与分析

Verification and Analysis of the Dominant Azimuth Anomaly of the Geoelectric Fields at the Jiangyou Station,Sichuan Province

针对四川江油台短极距NS与NE方向间的优势方位角在2022年8月15日开始出现的离散异常和2022年11月29日开始出现的跃变异常进行现场核实。通过观测系统检查、环境干扰调查、人为干扰排查、典型干扰分析、异常定量计算和震例回溯,综合分析结果显示:2022年11月29日开始出现的优势方位角数据跃变为人为干扰(电极更换),2022年8月15日至2023年7月出现的优势方位角离散变化可能为地震前兆异常。

This paper verified on-site two anomalies at the Jiangyou Station,Sichuan Province such as 1)the discrete anomaly on dominant azimuth between the short polar range NS and NE directions that occurred on August 15,2022,and 2)the jump anomaly that occurred on November 29,2022.We conducted observation system inspection,environmental interference investigation,human interference investigation,typical interference analysis,anomaly quantification calculation,and earthquake case tracing.We suggest that the dominant azimuth data jump that occurred on November 29,2022 is related to human interference(electrode replacement),whereas the discrete changes in dominant azimuth that occurred from August 15,2022 to the present may be precursor anomalies.