The dynamic characteristics of underground water-level anomalies of beijing well-net before zhangbei Ms6.2 earthquake

Before the Ms6.2 earthquake of Jan. 10, 1998 in Zhangbei, Heibei province, a group of precursory anomalies developing from trend to short and impeding term were observed in some of wells within Beijing water well-net. The distribution of these anomalies and their external characteristics and developing processes in different stages are described in detail in this paper. The results show that the internal relationship between the dynamic water-level features and the acumulative processes of stress and strain during the seismogenic processes in the source region exists, and gives many helpful enlightening guidance for seismologists. Therefore, this study has a certain refenence value for precursory researches on earthquake prediction.