Abstract: A destructive earthquake occurred around Changde,Hunan Province,south-central China in 1631.The previous research of this earthquake yielded 4 different epicenter locations and isoseismal intensity maps.The authors replotted the isoseismals of this event based on checking historical earthquake records,in which the intensity value of the innermost isoseismal is Ⅷ.We concluded that the depth of this earthquake is from 15km to 18km.The basic considerations of our conclusion are as follows:a.This earthquake occurred in an area of lacustrine and fluvial deposits,with the magnitude of M 6¹/2;b.The geometrical center of the innermost isoseismal is the epicenter;c.The depth of epicenter is about 15 to 18km,which is based on the statistical relation between magnitude,depth of the earthquake source and epicenter intensity as well as Xie's statistical result.Finally,the authors discussed the influences of different ground conditions on the textual research and identification of historical data.

Key words: Changde earthquake, historical records, intensity distribution, ground condition, lacustrine and fluvial deposit

摘要： 1631年(明崇祯4年)在常德附近发生了一次破坏性地震,前人对该地震作过探讨研究,曾给出了4个等震线图和震中定位。文中在重新查阅历史记载资料的基础上,重新绘制了该地震的等震线,其极震区的烈度为Ⅸ度,相对应的震级为6³/4级。以该地震内圈等震线的几何中心为震中,根据梅世蓉-萨瓦连斯基有关震中烈度、震级和震源深度之间的统计关系,以及谢毓寿的统计结果,得到的震源深度为15～18km。最后文中还讨论了历史资料考证、判别的问题和不同地基条件的影响。

关键词: 常德地震, 历史记载资料, 烈度分布, 地基条件的影响, 河湖淤泥沉积