基于三维断层源的概率地震危险性分析——以马边-盐津断裂为例  

Probabilistic Seismic Hazard Analysis Based on Three-dimensional Fault Source--Taking the Mabian-Yanjin Fault as an Example

作　　者：孔军 张萌[2] KONG Jun;ZHANG Meng(Guizhou Earthquake Agency,Guiyang 550001,China;Institute of Geophysics,China Earthquake Administration,Beijing 100081,China)

机构地区：[1]贵州省地震局,贵阳550001 [2]中国地震局地球物理研究所,北京100081

出　　处：《华北地震科学》2023年第4期84-91,共8页North China Earthquake Sciences

基　　金：中国地震局地球物理研究所自主立项项目(JY2022Z53)。

摘　　要：以马边盐津断裂为例,旨在建立一种基于三维断层源的概率地震危险性分析方法。首先,根据马边-盐津断裂带的断层源模型,通过地震矩平衡原理和潜在震源区发生率转换两种途径分别建立了断层源模型的震级-频度关系,其中地震矩平衡原理综合考虑了特征地震模型和G-R模型两种震级频度关系,采用Openquake软件计算了断裂附近基于4种适用于断层源的地震动预测模型的未来50年地震危险性结果。结果表明,纯面源、断层源方案一和断层源方案二地震危险性依次增大,且采用不同的衰减关系所得结果存在一定离散性;两种基于断层源的计算结果均表明目前对地震危险性的估计偏低。该结果可对未来三维断层源的地震危险性分析工作提供一定的参考。Taking the Mabian-Yanjin fault as an example,this paper aims to establish a probabilistic seismic hazard analysis method based on three-dimensional fault sources.First of all,according to the fault source model of the Mabian-Yanjin fault zone,the magnitude-frequency relationship of the fault source model is established by means of the principle of seismic moment balance and the transformation of the occurrence rate of the potential source region.Among them,the seismic moment balance principle comprehensively considers the magnitude-frequency relationship of characteristic earthquake model and G-R model.The Openquake software is used to calculate the seismic hazard results in the next 50 years based on four ground motion prediction models suitable for fault sources.The results show that the seismic risks of pure non-point source,fault source scheme 1 and fault source scheme 2 increase in turn,and the results obtained by using different attenuation relations are discrete to a certain extent.The calculation results based on fault sources show that the current estimation of seismic risk is on the low side.The results of this paper can provide some reference for seismic hazard analysis of three-dimensional fault sources in the future.

关 键 词：概率地震危险性 断层源模型 地震矩平衡 地震动衰减关系 

分 类 号：P315.24[天文地球—地震学]