Geomagnetic Anomalies Evolution Associated with the Honghe M5.0 Earthquake on November 19,2022—Based on Data of High-density Geomagnetic Observation Array
Based on data of 1 10 high-density geomagnetic observation arrays in the middle and southern sections of the Xiaojiang Fault,we investigated potential precursors to the M5.0 Honghe earthquake in Yunnan Province,which occurred on November 19,2022.Abnormal geomagnetic signals,specifically diurnal variations,were detected using two methods:the geomagnetic load-unload response ratio and the ratio of daily amplitude.Our results indicate that,approximately one month before the earthquake,the geomagnetic load-unload response ratios at points 043,052 and 068 exceeded the threshold of 3.0.Additionally,the ratios of daily amplitude at points 008,037,052,060,062 and 076 surpassed the 3.0 threshold about two and a half months prior to the event.During this period,the influence of magnetic storms and other external disturbances was excluded from the observed data.Most of the anomaly points were located far from the earthquake epicenter,and the magnitude of the anomalies decreased with increasing distance from the epicenter.
Honghe earthquakeGeomagnetic observation arraySeismic magnetic anomalyAnomalies analysis
NETL
NSTL
万方数据
