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本文收集了1973—1977年北京、红山、昌黎、青光地磁台2206个急始型与湾扰型的短周期变化事件,以及80个磁暴的资料。在周期与视周期为1分钟至24小时的频率域内,分析了各台△Z/△H 及其随周期的变化,以及 Wiese 矢量的变化,比较了各台地磁短周期变化的 H、Z、D 分量相对于红山台的变化。分析结果表明:(1)在唐山震区周围的渤海地区确实存在地磁短周期变化异常,其空间分布与频率特性相当稳定,似乎不受唐山地震的影响。(2)从各台结果的分析比较中发现,只有昌黎台地磁短周期变化持续时间为1—5分钟的(?)在唐山地震前后存在明显差异。唐山地震前,昌黎台的 Wiese 矢量及其偏差矢量的变化较大,可能反映了在唐山地震孕育过程中地下电导率的变异,上述昌黎台地震前后1—5分钟(?)的显著差异,也许与地震前后地下电导率变异有关。综合考虑异常的时空特性、频率范围与唐山地震的关系,上述差异性可能是唐山地震短周期地磁效应的反映。
In this paper, the short period variation events of 2206 emergent type and bay disturbance types in Beijing, Hongshan, Changli, and Qingguang stations from 1973 to 1977 were collected, and the data of 80 magnetic storms were collected. In the frequency range from 1 minute to 24 hours, the variations of △ Z / △ H and their variations with periods and Wiese vectors are analyzed. The changes of H, Z, D component relative to the changes of Hongshan Taiwan. The analysis results show that: (1) there is indeed anomalous geomagnetic short-period variation in the Bohai Sea around the Tangshan earthquake area. Its spatial distribution and frequency characteristics are quite stable, and it does not seem to be affected by the Tangshan earthquake. (2) From the analysis and comparison of the results, it is found that there is a significant difference (?) Between the short duration of Changli station and the short duration of 1-5 minutes in the Tangshan earthquake. Before the Tangshan earthquake, the Changle station’s Wiese vector and its deviation vector changed greatly, which may reflect the variation of underground conductivity during the gestation of Tangshan earthquake. The significant difference between 1-5 minutes before and after the Changli station earthquake And before and after the earthquake underground conductivity variation. Taking into account the relationship between the anomalous temporal and spatial characteristics and the frequency range and the Tangshan earthquake, the above-mentioned differences may be the reflection of the geomagnetic effect in the short period of the Tangshan earthquake.