与1983年11月7日菏泽5.9级地震可能有关的菏泽台地磁转换函数异常变化

利用菏泽地磁台二年半时间内198个地磁短期变化,首先用快速傅里叶变換法求出其离散傅氏谱,然后用最小二乘法得到其转换函数。分析表明,尽管转换函数在某种程度上受到计算方法引起的一定误差的影响,但1983年11月7日菏泽5.9级地震前后的异常变化是明显的。通过与某些干扰因素的相关性分析和统计检验认为,这一异常变化可能是与这次地震有关的前兆性变化。 

POSSIBLE ANOMALOUS CHANGES OF GEOMAGNETIC TRANSFER FUNCTIONS AT HEZE STATION RELATED TO THE M5.9 HEZE EARTHQUAKE OF NOV. 7, 1983

The dispersed Fourier spectra of 198 geomagnetic short period variations at Heze during two years and a half are obtained by fast Fourier transform. Then, the transfer functions of these geomagnetic events are calculated with the data of dispersed Fourier spectra by the method of least squares. It is found out from these results that the anomalous changes of the transfer functions before and after the M 5.9 Heze earthquake of Nov. 1983 are definite, though the transfer functions suffer somewhat from influences of calculating errors. It is suggested that the anomalous changes of transfer functions may be precursory changes related to the occurrence of the earthquake by statistical tests and correlation analyses between transfer functions and some disturbance factors.