一、前言对唐山地震期间青光台的地磁短周期变化进行了分析,目的是检验在唐山地震前是否由于应力活动使地下物质的电导性质发生变化,为今后用地磁预报地震的工作探索一条途径。地球电离层、磁层外场引起的地磁短周期变化,可以反映地壳及上地幔的电磁性质-电导率的状态,或与之有关的水及热流的活动状态,这些状态可能和震前膨胀有关。本世纪初人们就用地磁短周期变化探查地壳及上地幔电导率的空间变化,研究地下 I. Preface The analysis of short-period changes of geomagnetic in Qingguangtai during the Tangshan earthquake aims at examining whether the conductivity of underground materials changes due to stress activities before the Tangshan earthquake and exploring a way for future use of geomagnetic forecasting earthquakes . Earth’s ionosphere and the magnetic field caused by short-term changes in geomagnetic field can reflect the crust and upper mantle electromagnetic properties - the state of conductivity, or related water and heat flow activity, these states may be related to pre-earthquake expansion. Early this century, people use short-period changes in geomagnetic exploration of the crust and upper mantle conductivity of the spatial variation of underground