一、前言长江三峡蕴藏着极其丰富的水利资源,为我国当前最大的水利电力枢纽工程所在地。这里地震工作开展较早,本世纪二十年代以来,中外地学界曾在此进行了多方面考察。新中国成立后,在着手规划开发长江水利资源的初期,己布设了三峡地震台网,同时开展了地震地质调查和地形变观测工作。笔者在峡区周围曾参加过多次地震考察,发现黄陵背斜东西两侧地震时,在远离震中的钟祥和荆门地区出现等震线单独封闭的独立烈度异常区。在等震线分布 I. Preface The Three Gorges of the Yangtze River is rich in water conservancy resources and is the site of the largest hydropower project in our country. Earthquake work here started earlier, since the twenties of this century, Chinese and foreign scholars have conducted a multi-faceted study here. After the founding of New China, at the initial stage of planning and developing the Yangtze River water conservancy resources, the Three Gorges Seismic Network has been set up. At the same time, seismic geological survey and topographic observation have been carried out. The author has participated in many seismic surveys around the Gap area. When it was discovered that the eastern and western sides of the Huangling anticline were quake-prone, an independent, anomalous area with isoseismic isolation was found in the areas of Zhongxiang and Jingmen far from the epicenter. Isochord distribution