图42  共和7.0级地震前格尔木水氡异常曲线

      （a）月均值曲线；（b）月均值自适应域值

Fig. 42  Curves of radon content in groundwater at Geermu station

         before the M7.0 Gonghe earthquake

      （a）Curve of monthly mean value；

      （b）Curve of monthly mean self-adapting shreshold values