河北省近年地磁Z分量长期变特征

本文利用河北省昌黎、红山等８个地磁台Ｚ分量资料，计算了年均值和各台相对红山台的差值。结果表明，近年内各地磁台Ｚ分量变化趋势是一致的，均属非线性变化，年变速率逐渐加大，１９９４—１９９３年的年变率已是１９７８—１９７７年的３倍左右。同时，又反映出各台的差异，有变化速率由东南向西北逐渐变小的特征。指出这一特征可能对相当范围的地磁长期变有一定的代表性

Characteristics of Secular Variation of Geomagnetic Z Component in Hebei Province

The data of the geomagnetic Z component at 8 stations of Changli,Hongshan et al in Hebei province had been used to calculate the annual mean value and the differential value of the annual mean value of each station vesus that of Hongshan station The results suggested that the variation trend of the geomagnetic Z component in the stations of late years is coincident,and the variation is nonlinear,the annual variation rate increases increasingly,the annual variation rate of 1994-1993 is 3 times the rate of 1978-1977,and the difference between the stations is characterized by the rate decrease from ES to WN The paper suggested that the characteristic is typical of the secular geomagnetic variation in some area