龙门山地区地震活动性广义极值模型构建

以龙门山地区为研究区, 利用1931年至2010年历史地震数据, 时限取80年, 时间间隔取10年, 构建地震活动性广义极值模型, 估计龙门山地区震级上限和强震重现水平。 结果表明龙门山地区地震活动性广义极值模型服从具有有限上界的Weibull分布, 震级上限为8.3, 未来20年、 50年、 100年龙门山地区的强震重现水平分别为7.9、 8.1、 8.1。 起始年由1930年至1933年逐年平移, 时间间隔不变, 震级上限及强震重现水平的计算结果相差不到0.2级, 表明本文构建的龙门山地区广义极值模型具有一定程度的稳定性, 可为地震区划以及地震危险性分析研究提供参考。

Generalized Extreme Value Model of Seismicity for the Longmenshan Region

Choosing the Longmenshan region as the study area, making use of the historical earthquake data from the year 1931 to 2010, taking 10 years as the time interval, this paper establishes a generalized extreme value model of seismicity, and it estimates the magnitude upper bound and the strong earthquake return level associated with the Longmenshan region. The results indicate that the model follows the Weibull distribution with a finite upper bound; the magnitude upper bound is 8.3; and the strong earthquake return level in 20, 50, 100 future years are 7.9, 8.1, 8.1, respectively. Moving the starting year from 1930 to 1933 year by year, remaining the time interval constantly, we find that the difference of the results of the maximal magnitude and of the strong earthquake return level are less than 0.2, which means that the generalized extreme value model for the Longmenshan region has some degree of stability; moreover, the results can be a reference for earthquake zoning and seismic hazard analysis research.