地震危险性分析中几个重要环节的关联性  

INTERRELATION AMONG SEVERAL IMPORTANT LINKS IN SEISMIC RISK ANALYSIS

作　　者：黄玮琼[1] 吴宣[1] 

机构地区：[1]中国地震局地球物理研究所,中国北京100081

出　　处：《地震学报》2006年第3期269-276,共8页Acta Seismologica Sinica

基　　金：地震科学联合基金(103051)资助

摘　　要：为进一步揭示地震统计区划分、潜在震源区划分和地震活动性参数确定三者的关联性,在100°E^120°E和29°N^42°N范围内,寻找出21个位于不同位置、具有一定代表性的场点,研究在非均匀分布与均匀分布两种模型下,地震统计区活动性参数的不确定性对这些场点危险性估计的影响.综合本次与以往的研究结果表明,不同的地震统计区划分方案会改变一个统计区所包含的地震资料,加上地震统计时段选取的不确定性,会导致统计区地震活动性参数估计的不确定性.这种不确定性变化越大,均匀分布模型对场点危险性估计所产生的不确定影响也越大,也即地震统计区划分环节起主要作用.在一个地震统计区内,划分潜在震源区和空间分布函数的不等权分配,提高了有可能发生大地震地方及其附近地区地震动参数的估计值.在这些地方,潜在震源区划分不确定性的影响是很明显的,尤其对场点地震动参数(如烈度)绝对值的影响更为显著,也即潜在震源区划分环节起主要作用.一般来说,潜在震源区划分环节的影响仅对最高和次高震级上限潜在震源区内的场点及最高震级上限潜在震源区附近的场点起主要作用,而对那些处于低震级上限潜在震源中的场点,则还是地震统计区划分不确定性的影响大于潜在震源区划分不确定性的影响.In order to further reveal the interrelation among division of seismic statistical regions, delimitation of potential seismic sources and estimation of seismicity parameters, we select 21 representative sites located in different places within the range of 100°E-120°E, 29°N-42°N to study the influences of seismicity parameter uncertainties of statistical regions on seismic risk estimations of these sites in the inhomogeneous and homogeneous distribution models. Combining the results from this study and previous ones, we can see that different schemes for dividing seismic statistical regions can change the seismic data in a statistical region. The uncertain data and additional uncertainty in selecting time intervals for seismic statistics will result in uncertainty of seismicity parameters estimation in a statistical region. For the homogeneous model, the larger the variation of this uncertainty is, the greater the uncertain influence on the seismic risk estimation of a site will be, which means that the division of seismic statistical regions makes a major contribution. In a seismic statistical region, the delimitation of potential sources and variant weight assignment of spatial distribution functions can raise the estimated values of ground motion parameters in the place where great earthquake might occur and its vicinity. In these places, the influence of uncertainty in potential source delimitation is very obvious, especially on the absolute magnitude of ground motion parameters （e. g. , intensity）, which means that the link of potential source delimitation makes a major effect. Generally speaking, the link of potential source delimitation affects mainly the sites located in the potential sources with the highest and second-high upper-limit earthquake magnitudes or in the vicinity of those with the highest upper-limit magnitude. While for the sites located in the potential source with low upper-limit magnitudes, the uncertainty influence of statistical region division is larger than that of potential

关 键 词：地震统计区 活动性参数 潜在震源区 均匀分布 非均匀分布 不确定性 关联性 

分 类 号：P315.5[天文地球—地震学]