Abstract: Based on faults surveying and research data in Tianjin area,through studying tectonic structure,Quaternary activity,deep structure,stress and strain fields and seismicity on the Tianjin Fault,the activity and tectonic features of the fault are determined synthetically.Using seismo-geological data,and the historical and moderm seismicity data,the frequency-magnitude relationship model reckoning by 500years is established and the relationship between the upper limit of maximum magnitude M_mu and a_t/b is fit,which is applied to evaluating potential earthquake's maximum magnitude on moderately and weakly active blind faults in the fault sub-areas of the region.Then Poisson probability model is adopted and quantitative parameters such as the maximum magnitude,occurrence probability,recurrence period of the south Tianjin Fault in the coming 50～200 years are calculated.

Key words: seismic risk, quantitative evaluation, fault sub-area, frequency-magnitude relationship, maximum magnitude, occurrence probability, recurrence period

摘要： 以天津市活断裂探测资料为基础,通过对天津断裂的地质构造、第四纪活动性,深部构造、构造应力场与形变场及地震活动性等的研究,综合判定了天津北、天津南断裂的活动性与构造特征;利用地震地质、历史与现今地震活动性资料,建立了按500a归算的震级-频度关系模型,拟合了天津地区的最大震级上限M_mu与a_t/b的关系,用于对区内各断层小区中-弱隐伏活动断层潜在地震最大震级的评估。采用泊松概率模型,估算出天津南断裂未来50～200a发生地震的最大震级、发生概率及复发周期等定量参数。

关键词: 地震危险性, 定量评价, 断层小区, 震级-频度关系, 最大震级, 发震概率, 复发周期