摘要
基于小江断裂中南段布设的110个高密度地磁台阵观测数据,利用地磁加卸载响应比和日变幅逐日比两种方法分析了 2022年11月19日云南红河5.0级地震前地磁日变化异常特征.研究结果显示,震前1个月左右,编号043、052、068三个测点出现了同步加卸载响应比超过3.0的高值异常,震前两个半月左右,编号008、037、052、060、062、076六个测点出现了同步日变幅逐日比超过3.0的高值异常,排除磁暴影响和人为干扰后,认为上述多测点同步高值异常与红河5.0级地震有关.异常测点大多分布在震中距较远的区域,而异常幅度均呈现出震中距越大,幅度越小的特征.
Abstract
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.
NETL
NSTL
万方数据