中低纬度地区磁暴频谱特性及其与唐山地震的关系

CHARACTERISTICS OF GEOMAGNETIC STORM SPECTRA IN MIDDLE AND LOW LATITUDE REGIONS AND THEIR RELATION WITH THE TANGSHAN EARTHQUAKE

  • 摘要: 本文对北京、青光、昌黎、广州、佘山、武昌、长春等7个地磁台1973——1977五年期间80个磁暴的振幅谱进行了分析和对比,得到中低纬度地区磁暴频谱的一般特性.结果表明:①7个台磁暴频谱的变化趋势同步;②在周期0.5——6.8小时的频率范围内,振幅谱的斜率 b 值相当稳定,反映了在此频段内磁暴能量具有恒定的分配因子;③广州、佘山、武昌、长春四台振幅谱截矩 a 的年均值相当稳定,而距唐山震区较近的北京、青光、昌黎三台 a 的年均值均有不同程度的显著变化.这可能与1976年7月28日强烈的唐山地震有关.

     

    Abstract: In this paper, the characteristics of 80 magnetic storms have been analyzed and compared for the observatories of the seven places: Beijing Qingguang, Changli, Guangzhou, Sheshan, Wuchang and Changchun during 1973-1977.The general natures of the magnetic storm spectral amplitude have been obtained. The results show:1. There are synchronous trends of change in the magnetic storm spectral amplitude for the seven observatories.2. The spectral slopes of all the magnetic storms are almost the same. The yearly average values of the spectral slope b are quite steady within the period range from 0.5 to 6.8 hours. That is, the magnetic storms have the same energy partitioning factor.3. There are significant changes in the yearly average values of spectral intercepts for the three observatories of Beijing, Qingguang and Changli which are near the Tangshan earthquake area, but the yearly average values of the spectral intercepts are quite steady for the four observatories of Guangzhou, Sheshan, Wuchang and Changchun which are far from the Tangshan area. It seems likely that the significant changes are related to the great Tangshan earthquake of July 28, 1976.

     

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