Abstract: Analysing the radon data from several wells in Beijing-Tianjin region, it is believed that the main characteristics of radon anomalous field in this region before the Tangshan earthquake are as follows:1) There was a trend anomaly of the regional average variations in radon for nearly four years, and the anomalous duration was closely related to the Tangshan earthquake (including strong aftershocks). 2) The moderate-term anomaly of radon (1975.8-1976.4) showed a radiative transmission phenomenon from the epicentre to the surface at a speed of 35km/month.3) Just before the Tangshan earthquake (some smaller shocks had occurred in early July, 1976), the sharp radon variations showed itself an opposite pattern, converging from the surroundings towards the epicentre at a speed of about 25-30km/day.The characteristics mentioned above are discussed on the basis of premonitory creep together with the results of simulation tests. It is presumed that if the linear strain reachs 10^-6-10^-5 in the study region, the anomalous variations in radon can be observed distinctly.

摘要： 本文通过对京津地区十个重点井孔水氡资料的处理分析,发现唐山地震前,京津地区水氡异常场有几个显著的特征。京津唐一带区域性水氡的升高变化,是该区构造应力场加强的结果,当观测区域受力达到线应变为10^-6—10^-5数量级的状态时,可以观测到水氡明显的异常变化。水氡中短期异常的扩散现象及临震突跳的收缩现象,是与震源应力场直接有关联的前兆变化。水氡异常的机理是复杂的,是多种作用的综合。