§1.緒言北京地区自古以来曾遭受多次剧烈地震的影响,迄今仍未趋于稳定。为了保障人民生命、財产和建設事業的安全,研究北京的地震現象,确定地震危險性的程度,以便采取适当的抗震措施,显然是当前刻不容緩的任务。远在1954年春,在中国科学院地震工作委員会的領导下,即开展了北京地震的研究。在工作过程中,經地球物理研究所和历史研究所第三所的密切配合并得到北京市 §1. INTRODUCTION The Beijing area has suffered from many severe earthquakes since ancient times and has not stabilized so far. In order to ensure the safety of people’s life, property and construction, it is obviously an urgent task to study the earthquake in Beijing and determine the extent of the earthquake risk so that appropriate measures against earthquakes can be taken. As far back as the spring of 1954, under the leadership of the Seismological Commission of the Chinese Academy of Sciences, a study was conducted on the earthquake in Beijing. In the course of his work, the Institute of Geophysics and the Institute of History closely cooperate and get Beijing