极化方法在成都地磁台的应用研究

发布时间：2018-03-27 19:39

  本文选题：地磁场　切入点：极化方法　出处：《地震学报》2017年04期

【摘要】：以成都台FHDZ-M15地磁组合观测系统产出的秒采样观测数据为研究对象,应用极化方法提取该台站附近几次中强震前的超低频(ULF)磁异常信号.成都台极化值长期曲线具有一定的年变化特征,利用傅里叶拟合消除周期变化后,对残差进行分析.结果显示,极化值增高现象与其后2个月内台站周边区域的ML≥5.0地震有很好的对应关系,高值异常持续3—5日,与外空场活动无关,且逆冲型地震前的极化值异常幅值高于走滑型地震.
[Abstract]:The second sampling observation data produced by the FHDZ-M15 geomagnetic combined observation system of Chengdu station are taken as the research object. The ultralow frequency (ULF) magnetic anomalies before several moderate and strong earthquakes near the station were extracted by polarization method. The long term polarization curve of Chengdu station has a certain annual variation characteristic, and the periodic variation is eliminated by Fourier fitting. The residual error is analyzed. The results show that the phenomenon of increasing polarization value has a good correspondence with the ML 鈮，

本文编号：1672949