基于快速傅里叶方法的地震前兆振幅谱分析
|
摘要
利用FFT方法,对地电、地磁、形变及重力等前兆时间序列信号进行分析,结果显示,宝昌地震台及乌加河地震台地电两测向日均值时间序列存在3个主要谐波分量,其中周期近一年的分量物理意义明确.FFT方法在精确确定前兆时间序列中的干扰信息周期时具有较好的效果。
In this paper,the time series of geoelectrical resistivity,geomagnetism,earth deformation and gravity are processed with fast Fourier transform method,"FFT" for short.There are three main harmonics in daily mean data of the earth resistivity,recorded at Baochang and Wujiahe seismic stations.The harmonic with a period of approximately one year,has physical meaning.Different items in same geomagnetic station or same items in different geomagnetic stations,usually contain four main harmonics whose periods are 24,12,8 and 6 hours. Besides there exist tidal waves,there are different harmonics in the minute values recorded by horizontal pendulum tiltometer,water tube inclinometer,and gravimeter.It can be effective measuring the periods of noise precisely using FFT.But there are still many jobs to do in future,for example improving methods,the selection of data,explaining physical meaning of harmonic,etc.
In this paper,the time series of geoelectrical resistivity,geomagnetism,earth deformation and gravity are processed with fast Fourier transform method,"FFT" for short.There are three main harmonics in daily mean data of the earth resistivity,recorded at Baochang and Wujiahe seismic stations.The harmonic with a period of approximately one year,has physical meaning.Different items in same geomagnetic station or same items in different geomagnetic stations,usually contain four main harmonics whose periods are 24,12,8 and 6 hours. Besides there exist tidal waves,there are different harmonics in the minute values recorded by horizontal pendulum tiltometer,water tube inclinometer,and gravimeter.It can be effective measuring the periods of noise precisely using FFT.But there are still many jobs to do in future,for example improving methods,the selection of data,explaining physical meaning of harmonic,etc.
引文
陈绍绪,王宝坤,张跃刚.北地区地倾斜中短期地震前兆识别及预报方法研究[J].地壳形变与地震,1999,19(4):8-14.
戴勇,闫海滨,胡博,等.张北6.2级地震宝昌地震台地电异常特征及机制分析[J].地震地磁观测与研究,2009,30(1): 51-55.
傅再扬,吴绍祖,郑永通.福建地区地倾斜中短期前兆异常识别及映震效果初探[J].华南地震,2003,23(4):66-70.
温艳,邵逸.基于FFT的信号谱分析[J].中国新通信,2010,(5):70-71.
杨丽娟,张白桦,叶旭桢.快速傅里叶变换FFT及其应用[J].光电工程,2004,31:1-2.
张继红,乔惠珍.地磁前兆异常的动态从属函数[J].地球物理学进展,2005,20(1):142-146.
Cooley J W and Tukey J W.An Algorithm for the Machine Computation of the Complex Fourier Series[J].Mathematics of Computation,1965,19:297 -301.
戴勇,闫海滨,胡博,等.张北6.2级地震宝昌地震台地电异常特征及机制分析[J].地震地磁观测与研究,2009,30(1): 51-55.
傅再扬,吴绍祖,郑永通.福建地区地倾斜中短期前兆异常识别及映震效果初探[J].华南地震,2003,23(4):66-70.
温艳,邵逸.基于FFT的信号谱分析[J].中国新通信,2010,(5):70-71.
杨丽娟,张白桦,叶旭桢.快速傅里叶变换FFT及其应用[J].光电工程,2004,31:1-2.
张继红,乔惠珍.地磁前兆异常的动态从属函数[J].地球物理学进展,2005,20(1):142-146.
Cooley J W and Tukey J W.An Algorithm for the Machine Computation of the Complex Fourier Series[J].Mathematics of Computation,1965,19:297 -301.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心