地磁低点位移频谱特征及机理探讨

英文篇名：Spectral features of geomagnetic low point displacement and discussion on its mechanism
中文刊名：地震学报
英文刊名：Acta Seismologica Sinica
作者：张学民 ; 钱家栋 ; 王亚丽 ; 赵旭 ; 欧阳新艳 ; 赵庶凡
英文作者：Zhang Xuemin1) ; Qian Jiadong1) Wang Yali2) Zhao Xu2) Ouyang Xinyan1) Zhao Shufan1) 1) Institute of Earthquake Sciences ; China Earthquake Administration ; Beijing 100036 ; China 2) China Eathquake Networks Center ; Beijing 100036 ; China
中文关键词：地磁Z分量 ; 低点位移 ; 快速傅氏变换 ; DEMETER卫星 ; 电子密度
英文关键词：geomagnetic Z component ; low point displacement ; FFT ; DEMETER satellite ; electron density
出版日期：2008-10-15
机构：中国地震局地震预测研究所;中国地震台网中心;
年：2008
期：05
出版单位：地震学报

摘要

以河北省昌黎地震台为例,使用该台地磁Z分量的分钟值数据,分别对比了正常时段、磁暴发生时段、低点位移时段的主要频率谱值变化特征.通过多频点功率谱对数拟合,发现在数据长度相等的情况下,相对于正常时段而言磁暴时段各频率的能量明显增强,特别是高频端尤其明显;而当大范围低点位移发生时,高频端的能量基本与正常时段持平,但4个小时以上的周期功率谱大部分要低于正常段.通过对多日低点位移时段的FFT累加与正常时段对比后发现,低点位移发生时,8.5小时和13.7小时周期的频谱值增加.通过与DE-METER卫星观测的电子密度数据空间图象进行对比,发现地磁低点位移的发生与空间Ne的增加有很好的对应性.最后对这些变化特征及低点位移可能产生的机制进行了探讨.
As an example, this paper analyzed Z component of the geomagnetic record at Changli station in Hebei province, to investigate the low point displacement characteristics. The minute data of geomagnetic Z component was used to analyze the spectral values of its main frequency components during normal time, geomagnetic storm time and low point displacement time, respectively. After fitting ten high spectral values with a logarithmic function, it is found that, with the same length of data, the spectral values at geomagnetic storm time increase apparently as compared with those at normal time, especially at high frequency part. When low point displacement occurred, the spectral values at high frequency approximate to those at normal time, but spectral values at periods above 4 hours are mostly lower than those at normal time. By accumulating some FFT results at low point displacement and normal time, it is shown that, spectral values at periods of 8.5 and 13.7 hour increase at low point displacement time relative to those at normal time. By comparing our result with the images of Ne observed at DEMETER satellite, we found that the occurrence of geomagnetic low point displacement well corresponds to the increase of Ne in ionosphere. Finally we discussed these spectral features and the mechanism of geomagnetic low point displacement.

引文

丁鉴海,黄雪香.1988.地磁“低点位移”现象及其与地震的关系[J].地震学报,10(4):552--561.
    丁鉴海,刘杰,余素荣,肖武军.2004.地磁日变化异常与强震的关系[J].地震学报,26(增刊):79--87.
    丁鉴海,索玉成,余素荣.2005.地磁场与电离层异常现象及其与地震的关系[J].空间科学学报,25(6):536--542.
    丁鉴海,于素荣,索玉成.2006.地球变化磁场观测资料在强地震短期预报中的应用[G]∥中国地震局监测预报司编.GPS、卫星遥感及地球变化磁场地震短期预测方法研究.北京:地震出版社:1--179.
    郭增建,秦保燕,李海华.1977.磁暴、天气韵律与发震时间[J].地震战线,(3):26--29.
    黄雪香,余素荣.2000.地磁低点位移异常类型特征与地震活动[J].地震,20(4):39--44.
    李琪,杨冬梅,张素琴,赵永芬,张建国.2005.地磁转换函数方法之典型震例及数模对比[J].地震,25(3):85--90.
    李明光,粱秀兰.1989.利用地磁Z分量日变低点预报地震的新探索[J].四川地震,(4):50--59.
    陆远忠,邓志辉,李胜乐.2000.基于GIS的地震分析预报系统[M].成都:成都地图出版社:1--232.
    史勇军,孙燕萍,朱燕,范索琴,热汗古·亦明克里木,巴克·买买提.2002.伽师强震群活动过程中喀什台地磁加卸载响应比变化特征研究[J].内陆地震,16(1):84--88.
    吴小平.2003.利用地磁低点位移预测发震时间[J].四川地震,(1):33--36.
    吴小平,辛华,张永久.2004.地磁“低点位移”与“磁暴”相结合预测发震时间[J].四川地震,(2):22--26.
    解用明,乔子云.2003.地磁交汇法在地震预报中的应用[J].山西地震,(1):27--29.
    赵洁,朱振家,张彩艳,张俏丽.2005.嘉峪关地磁低点位移异常与干扰因素的讨论[J].地震地磁观测与研究,26(6):42--45.
    Lebreton J P,Stverak S,Travnivek P,Maksi movic M,Klinge D,Merkallio S,Lagoutte D,Poirier B,Blelly P L,Koza-cek Z,Salaquarda M.2006.The ISL Langmuir probe experi ment procession onboard DEMETER:Scientific objec-tives,description and first results[J].Planet Space Sci,54(5):472--486.
    Parrot M,Berthelier J J,Lebreton J P,Sauvaud J A,Santolik O,Bleck J.2006.Examples of unusual ionospheric obser-vations made by the DEMETERsatellite over seismic regions[J].Phys Chem Earth,31:486--495.
    Pulinets S A,Boyarchuk K A,Hegai V V,Ki m V P,Lomonosov A M.2000.Quasielectrostatic model of at mosphere-thermosphere-ionosphere coupling[J].Adv Space Res,26(8):1209--1218.