四川地区2019年11月5日地磁加卸载响应比异常分析

Reliability Analysis of Abnormal Geomagnetic Loading and Unloading Response Ratio in Sichuan on November 5,2019

针对2019年11月5日四川地区出现的地磁加卸载响应比异常现象,通过初步异常判断、仪器运行状态检查、观测资料可靠性检查、环境干扰调查、高压直流输电情况调查、磁扰活动影响分析和台站基础数据对比,综合认为该日出现的地磁加卸载响应比的异常受外界干扰可能性很小,该日异常是地震前兆异常的可能性较大;结合地磁加卸载响应比法的震例总结和预测指标,认为此次异常出现后的约6个月,阈值线附近区域存在发生M_(S)≥5.0中强地震的可能。

We studied the abnormal phenomenon of geomagnetic loading and unloading response ratio in Sichuan on November 5,2019.Based on the preliminary abnormal judgment,instrument operation status inspection,observation data reliability inspection,environmental interference investigation,high-voltage DC transmission investigation,magnetic disturbance activity impact analysis,and station basic data comparison,we suggest that the abnormal phenomenon of geomagnetic loading and unloading response ratio was unlikely to be interfered by external factors.Furthermore,we suggest that the daily anomaly is more likely to be an earthquake precursor anomaly.Combined with the summary of earthquake cases and prediction indicators of the geomagnetic load,unload response ratio methods,we suggest that moderate strong earthquakes with M_(S)≥5.0 near the threshold line could be happened within about 6 months after the occurrence of the anomaly.