华北地区强震前地磁短期异常特征研究

Research on short-term abnormal characteristics of geomagnetism before the strong earthquakes in North China region

从地震前兆信息"场"的概念出发,利用空间线性度方法对华北地区强震前多台地磁Z值观测资料进行组合计算,得到描述孕震过程中前兆场的特征量空间线性度α。该文分别组合计算了华北地区发生的7次5级以上强震前的地磁Z值观测资料。结果表明,强震前半年内震源区附近地磁Z值的空间线性度α有明显的下降异常变化。

Based on the concept of information field of earthquake precursors, using the method of the spatial linearity to calculate the geomagnetism data of Z direction we can find the precursory characteristic value-spatial linearity short-term abnormal characteristic value (α), which describes the earthquake source region in the process of earthquake preparation. By analyzing the geomagnetism data of Z direction before seven strong earthquakes with M>5 previously happened in North China, we can conclude that the spatial linearity (α) of geomagnetism data of Z direction will decline obviously nearby the earthquake source region before half a year of the strong earthquake.