【摘要】 对2006年3月—2009年2月DEMETER卫星VLF电磁场频谱数据的分析发现,全球地震电离层电磁场频谱有以下特征:50～300 Hz为地震电离层效应的优势频段;距离地震空间位置越近,地震异常越显著;不同半球的地震,异常方向和方位不同;对地磁夏季北半球地震的研究表明,海洋地震主要为正异常,陆地地震为负异常;地磁夏季,不同半球地震的磁场频谱异常显著不同,北半球的正异常偏南,而负异常偏北,南半球的负异常偏东北,而正异常偏西南。更多还原

【Abstract】 By analyzing the electromagnetic spectrum data observed by DEMETER satellite during the time interval between March 2006 and February 2009,it is found that the characteristics of electric field power spectrum of global ionosphere in DEMETER altitude are as follows:the 50-300 Hz frequency band about earthquake ionospheric effect are the dominant frequency the closer,the distance to seismic spatial position,the more significant seismic anomaly;indifferent hemispheres of the earthquake,abnormal azimuthal direction is different.The studies on the events in northern hemisphere in geomagnetic summer show that the anomaly corresponding marine quakes occured in geomagnetic summer the frequency spectrum anomaly of geomagnetic field basically were positive and these land negative and corresponding the quakes in different hemisphere were significantly different:these in the northern hemisphere were positive and meridional,and negative anomaly of north but negative anomaly opposite in the southern hemisphere,the negative anomaly were northeast and positive ones southwest.更多还原