摘要
计算分析了银川台1983年1月~1996年10月的地磁周期T=9~200min的复转换函数A的模|A|、总误差σz和帕金森矢量或韦氏矢量,并将其在银川台400km范围内8次中强地震发生时的变化进行了研究。结果表明:周期为12、20、26、35、45、60、75、90min的|A|、σz磁方位角αp及其方差Δαp在震前有明显的异常变化,帕金森矢量或韦氏矢量在震前指向震中。
The modules |A| of complex transfer functions for the geomagnetic field with the periods of T=9~200 minutes from January 1983 to October 1996 at Yingchuan seismic station are calculated and analyzed as well as the overall error σz and Parkinson or Wiess vector.The variation of those for 8 moderate and strong earthquakes 400 km far from Yingchuan station are studied.The study showed that the |A|,σz,magnetic azimuth αp and difference Δαp varied abnormously at the periods 12,20,26,35,45,60,75 and 90 minutes and the Parkinson or Weiss vector pointed toward the epicenters before the earthquakes.