序言 河北地区经历了前10(1966—1976)年的地震活动高潮期和后10(1977—1986)年的平静期之后,近期老震区以及之外地区的地震趋势如何,是大家关注的问题;特别是1986年,在全国范围内M_s≥5.0级地震次数比1985年有所增高,河北这个不稳定的敏感地区动态如何,它牵动着千万人的心。因此,对本区地震活动性的研究以及趋势估计是非常重要的。 Preface In Hebei Province, after experiencing the climax of the seismic activity in the first 10 years (1966-1976) and the tranquility of the latter 10 (1977-1986), the recent earthquakes in and outside the earthquake area have been the focus of attention In particular, in 1986, the number of M_s≥5.0 earthquakes nationwide increased from 1985 to the present. What is the dynamics of this unstable and sensitive area in Hebei? It affects the hearts of tens of millions of people. Therefore, it is very important to study the seismicity and the trend of this area.