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为了研究1976年唐山地震的磁效应,本文在文献[1]的基础上,利用北京测区六年(1975—1981)的磁测资料,分析了北京地区地磁场长期变化的局部差异,正常(无强震)时期地磁统计量的变化特性,以及长期变化局部差异对地磁统计量的影响.正常时期与地震前后地磁统计量的对比分析表明,唐山地震对北京地区地磁场总强度统计量的影响是显著的.通过不同区域测点、测线的各种组合,计算了地震前后统计量的空间分布,以确定测区信息最强的区域.唐山地震在北京地区所产生的磁效应的统计性质如下:1.异常信息不是短期的波动,而是呈趋势性变化,其持续时间至少一年;2.离震中较近的 S 区异常显著,其主要根据是,地磁统计量 S_(mj),b_(sn)和(?)在 S 区变化显著.特别是统计信息的局部差异与长期变化明显不同,前者呈东西分布,后者主要呈北南走向;3.趋势性异常变化的平均空间差异随时间的变化在测区总体并不显著,但在 S 区这种差异的时间变化,在震前1976年3—6月却是显著的.
In order to study the magnetic effect of the Tangshan earthquake in 1976, based on the literature [1], this paper analyzes the local differences of long-term changes of the geomagnetic field in Beijing based on the magnetic measurement data of Beijing area for six years (1975-1981) No strong earthquakes), and the effect of local long-term variation on geomagnetic statistics.Comparison of geomagnetic statistics before and after the earthquake shows that the influence of Tangshan earthquake on the total strength statistics of geomagnetic field in Beijing Is significant.Through various combinations of measuring points and measuring lines in different regions, the spatial distribution of statistics before and after earthquakes is calculated to determine the most informative region of the survey area.The statistical properties of the magnetic effects generated by the Tangshan earthquake in Beijing As follows: 1. Abnormal information is not a short-term fluctuation, but a trend change, and its duration is at least one year. 2. The S area near the epicenter is abnormally significant, which is mainly based on the geomagnetic statistic S mj, The changes of b_ (sn) and (?) are significant in area S. Especially, the local difference and long-term change of statistical information are obviously different, the former is east-west distribution and the latter is mainly north-south direction.3.The average spatial difference of trend anomaly Change over time is not significant in the overall survey area, but the change in time for this difference S region, before the earthquake of 1976 3 - is remarkable in June.