某些大震前往往观测到电磁异常现象,一般认为有两种可能造成这种异常现象的产生:一类是当电磁波穿越孕震区时,由于孕震过程中传播介质物性改变所引起的传播异常;另一类则是发自震源的电磁辐射造成的。为了探讨震前电磁波异常在地震预报中的作用,我们在本省中部和北部进行了一些观测试验。 北部观测网和中部观测网的建立是根据对 Some electromagnetic anomalies are often observed before some large earthquakes. It is generally considered that there are two kinds of anomalies that may cause this kind of anomaly: one is the propagation caused by the physical change of the propagation medium during the seismogenic process when the electromagnetic wave traverses the seismogenic zone Abnormal; the other is caused by electromagnetic radiation from the source. In order to investigate the role of anomalous electromagnetic waves before earthquakes in earthquake prediction, we conducted some observations in the central and northern parts of the province. The establishment of the North Observatory and Central Observatory is based on