公元600年秦陇地震发震构造分析及考证研究

ANALYSIS AND TEXTUAL RESEARCH OF THE SEISMOGENIC STRUCTURE OF THE QIN-LONG EARTHQUAKE IN 600 A. D.

据史料记载,公元600年秦陇地区发生了一次大地震。关于此次地震的震中位置、震级、震中烈度和发震构造长期存在争议。根据在陇县固关一带发现的地震崩塌体,同时结合史料考证、卫星影像判读、野外调查、探槽开挖、年龄测试等手段,研究认为:公元600年秦陇地震的发震构造为六盘山东麓断裂南段固关段;秦陇地震震中在陇县固关镇一带,震级为6级,震中烈度为Ⅸ度。该地震的研究对于六盘山地区地震危险性评估和青藏块体北东向扩展的动力学过程理解有重要意义。

According to Chinese historical records,an earthquake struck the ancient Qin-Long area in 600 A.D.,and caused serious social impact.The epicenter,earthquake magnitude,epicentral intensity,and seismogenic structure of this earthquake have long been disputed.In this study,based on the earthquake collapses found in Guguan town,Longxian county,combined with multiple research methods including historical data verification,satellite images interpretation,field observation,geologic trench excavation,age dating,it shows that the seismogenic structure of the earthquake is the Guguan segment of east Liupanshan fault,and the epicenter should be located near Guguan town,Longxian county.Its magnitude was around 6 3/4 and the epicentral intensity was inferred asⅨ.This study on the historical earthquake in this area has great significance to the earthquake hazard assessment in Liupanshan area and the understanding of the kinetic process of the northeastward expanding of the Tibet Plateau.