1119年前郭地震发震构造讨论

Discussion on the Seismogenic Structure of Qianguo Earthquake of 1119 AD

在充分收集和考证前人研究成果的基础上,深入分析地震史料隐含的约束条件。以石油三维物探、浅层地球物理勘探和联合钻孔探测资料为基础,结合地质和地貌调查,研究1119年前郭地震的震中位置和发震构造。在1119年前郭地震的影响范围内,发现一条区域内规模最大的晚更新世活断层--孤店断裂,总长度约为66km,由两个连续性较好的弧型段组成,钻孔资料显示其上断点埋深约为24 m,存在晚更新世以来的断裂活动。经过断层地震危险性评估,认为孤店断裂可能是1119年前郭地震的发震构造。

Based on the full collection and textual research on the basis of predecessors’research results,as well as analysis in-depth of the implicit constraint conditions of the historical earthquake,we study the epicenter of the earthquake location and seismogenic structure,through three-dimensional petrolic geophysical data,the shallow geophysical prospecting and the joint drilling detection,as well as the seismic geological and geomorphic survey.At the same time in the process of detection,within the scope of influence of Qianguo Earthquake of 1119 AD,we found the greatest Late Pleistocene active fault in the zone,named Gudian Fault.The fault is about 66 km long on the seismic profiles from petroleum exploration and consists of two continuous arcs.The buried depth of the fault breakpoint is shallower than 24 m.Through earthquake risk assessment,we judge that the Gudian Fault is most likely the seismogenic structure of the Qianguo earthquake of 1119 AD.