2015年3月14日安徽阜阳发生4.3级地震,对蒙城台、周口台、嘉山台3个台站2013—2016年地电场优势方位角进行计算和分析,结果显示: 该地震前5个月,距离震中较近的蒙城台、周口台地电场优势方位角出现了准同步的明显偏转,异常持续近8个月,地震后4个月内蒙城台、周口台地电场优势方位角恢复到背景水平; 通过对比发现,蒙城台地电场谐波中NS向周期小于4.8h的振幅在震前出现明显增大变化,可能与该地震的孕育和发生相关; 嘉山台震中距较远,地电场优势方位角未发现明显的异常。

On March 14,2015,a magnitude 4.3 earthquake occurred in Fuyang,Anhui. This article examines the dominant azimuth angles of the geoelectric fields recorded at the Mengcheng,Zhoukou,and Jiashan stations from 2013 to 2016. The analysis reveals that five months before the earthquake,the dominant azimuth angles of the geoelectric fields at Mengcheng and Zhoukou stations-both located closer to the epicenter-exhibited a significant quasi-synchronous deviation. This anomaly persisted for nearly eight months. A few months after the earthquake,the dominant azimuth angle of geoelectric field at the Zhoukou station returned to its background level. Further analysis showed a markable increase and change in the amplitude of the NS direction in the short harmonic component of the geoelectric field at Mengcheng station before the earthquake,which may be linked to the generation and occurrence of the earthquake. In contrast,Jiashan station,located farther from the epicenter,did not exhibit any noticeable anomalies in the dominant azimuth of the geoelectric field.

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中国地震局地震科技星火计划(XH200501)、中国地震局2022年度震情跟踪定向工作任务(2022010311)共同资助