【摘要】 2022年9月5日和9月18日，四川泸定和中国台湾花莲在13天内相继发生强震。为探究地震前的地磁前兆异常，本研究对全国地磁台站数据日变形态进行了系统分析，结果显示：在泸定地震前55天（2022年7月12日）和花莲地震前42天（2022年8月7日），地磁日变形态均出现畸变，由正常的“V”型变为“W”型双低点形态。此外异常区域可划分出清晰的分界线，分界线两侧的日变相位存在约2小时的时差。通过分析日变畸变的成因，研究发现该现象与地球内外电流体系的异常变化密切相关，尤其是地球内部感应涡旋电流体系的改变。该畸变可能反映了地震孕育过程中深部构造活动的加速演化，此类异常与强震具有显著关联性，可作为短临地震预报的重要参考指标。更多还原

【Abstract】 On September 5,2022 and September 18,2022, strong earthquakes occurred in Luding,Sichuan Province and Hualien, Taiwan, China within 13 days. In order to explore the geomagnetic precursory anomalies before the earthquake, this study systematically analyzed the daily variation patterns of the national geomagnetic station data. The results showed that 55 days before the Luding earthquake(July 12,2022) and 42 days before the Hualian earthquake(August 7,2022), the geomagnetic daily variation patterns were distorted, from the normal ‘V’ type to the ‘W’ type double low point shape. In addition, the anomaly area can be divided into clear dividing lines, and the diurnal phase on both sides of the dividing line has a time difference of about 2 hours. By analyzing the causes of diurnal variation distortion, it is found that this phenomenon is closely related to the abnormal changes of the current system inside and outside the earth, especially the change of the induced eddy current system inside the earth. This distortion may reflect the accelerated evolution of deep tectonic activities during earthquake preparation. The analysis shows that such anomalies have a significant correlation with strong earthquakes and can be used as an important reference index for short-term and imminent earthquake prediction.更多还原