鄂东襄樊-广济断裂黄州段未来地震危险性分析

Seismic Risk Analysis in Huangzhou Section of Xiangfan-Guangji Fault in the Eastern Hubei

通过对鄂东襄樊-广济断裂黄州段的地质构造、第四纪活动性、地震活动和现今地壳变形的分析,综合判定该段断裂的活动性和构造特征。该断裂是中国东部地区典型的弱-中等活动断裂。采用地震构造类比法和矩震级经验关系,综合评估了断裂的未来可能最大发震震级为6.0级;利用历史和现今地震活动资料,建立了按500a归算的震级-频度关系,采用泊松概率模型,计算得到襄樊-广济断裂黄州段未来50~200a地震平均复发间隔和发震概率等定量参数。该成果可为区域地震危险分析及工程抗震设防提供参考。

Based on the analysis of geological structure,Quaternary activity,seismic activity and recent crustal deformation in Huangzhou section of Xiangfan-Guangji fault in the eastern Hubei,the activity and tectonic characteristics of the fault were determined synthetically.The result shows this fault is a typical weak-medium active fault in the eastern part of China.Then the seismic structure analogy and moment magnitude empirical relationship were adopted to evaluate the possible maximum seismicity of the fault,which is M s6.0.Historical and modern seismic activity data were used to establish a magnitude-frequency relationship model by 500 a.Finally the Poisson probability model was utilized and quantitative parameters such as recurrence period and occurrence probability of Huangzhou section of Xiangfan-Guangji fault in the coming 50 to 200 a were calculated.This result can provide a reference for regional seismic hazard analysis and engineering seismic fortification.