欢迎访问《地震》,

地震 ›› 2020, Vol. 40 ›› Issue (3): 131-141.doi: 10.12196/j.issn.1000-3274.2020.03.010

• • 上一篇    下一篇

基于幅相法的地磁低点位移异常可靠性分析方法

黄颂1,2, 姚丽3, 姜楚峰1,2   

  1. 1.湖北省地震局, 湖北 武汉 430071;
    2.中国地震局地震研究所, 湖北 武汉 430071;
    3.中国地震台网中心, 北京 100045
  • 收稿日期:2019-07-02 出版日期:2020-07-31 发布日期:2020-07-28
  • 通讯作者: 姚丽,高级工程师。E-mail:yl@seis.ac.cn
  • 作者简介:黄颂(1988-),男,湖北武汉人,工程师,主要从事地磁场数据分析与地震预测工作。
  • 基金资助:
    中国地震局地震研究所和地壳应力研究所基本科研业务费专项资助项目(IS201966314-11)

Validity Analysis of Geomagnetic Low-point Displacement Based on Amplitude-phase Method

HUANG Song1,2, YAO Li3, JIANG Chu-feng1,2   

  1. 1. Hubei Earthquake Agency, Wuhan 430071, China;
    2. Institude of Seismology, CEA, Wuhan 430071, China;
    3. China Earthquake Networks Center, Beijing 100045, China
  • Received:2019-07-02 Online:2020-07-31 Published:2020-07-28

摘要: 地磁低点位移法和幅相法都是地震短临阶段的预报方法, 两者均是通过提取地磁垂直分量日变化中的畸变信息对地震的发生给出预测意见, 低点位移法可以提取反相位畸变异常的持续时间, 但虚报率高, 无法确定每次异常的可靠性。而幅相法可以为异常提供定量判定依据。为应对低点位移法虚报率较高的不足, 本文应用幅相法计算2008年至2018年间出现的159次低点位移异常, 提取反映地磁反相位畸变程度的瞬时差值面积均值Sx及残差C, 并以此作为判断震前低点位移异常可靠性的标准。结果显示, 使用本文给出的标准可以将低点位移法的异常报对率从39%提高到70%, 证明了基于幅相法的低点位移异常可靠性分析方法的有效性, 提高了低点位移法的实用性。统计结果还显示不同地区震前异常具有不同的特征, 如新疆、 西藏与川滇地区震前异常的Sx、 C的变化范围和均值存在差异。

关键词: 地磁日变化, 地磁低点位移, 地磁幅相法

Abstract: Geomagnetic low-point displacement method and amplitude-phase method are frequently used for short term earthquake forecasting, both of which are based on distortions in diurnal variation of the geomagnetic vertical component. Low-point displacement method is able to extract the duration of anti-phase anomalous distortion, but this method is always with higher false rate and the reliability of each anomaly cannot be determined. In order to deal with this problem, the amplitude-phase method is used to 159 anomalies occurring during 2008 to 2018, and the transient difference area Sx and error C standing for the extent of anti-phase distortions are extracted as a standard to validate the low-point displacement anomalies before earthquakes. The results show that the criteria suggested in this paper makes the accuracy of low-point displacement anomalies related to earthquakes rise from 39% to 70%. It demonstrates the effectiveness of amplitude-phase method and its actual application ability. The statistical results also exhibit the regional differences, in which the ranges and mean values of Sx and C differ before the earthquakes in Xinjiang, Tibet, Yunnan and Sichuan regions.

Key words: Geomagnetic diurnal-variation, Geomagnetic low-point displacement, Geomagnetic amplitude-phase method

中图分类号: