鲁东—黄海活动地块背景地震活动及未来强震危险性  

Background Seismicity and Application in Seismic Hazard Assessment in the Ludong—Huanghai Active Block

作　　者：杨云[1] 霍祝青[1] 王维[1] 李鸿宇[1] 

机构地区：[1]江苏省地震局,江苏南京210014

出　　处：《地震工程学报》2016年第A01期22-29,共8页China Earthquake Engineering Journal

基　　金：江苏省地震局青年科学基金项目(201002);震情跟踪专项工作任务(2014020115)

摘　　要：利用历史中强地震和近40年的区域台网地震资料,采用地震复发间隔变异系数和活动性参数b值空间扫描方法,对鲁东—黄海活动地块的背景地震活动进行研究。结果表明:研究区域内中强地震活动的主体区域是南黄海南部坳陷区和陆地苏南隆起区,目前都处于中强地震活动平静期;b值空间分布显示,苏南隆起区南边缘最低,南黄海南部坳陷区次之。结合区域地质构造背景和活动性参数图像,研究区域内现今地震活动主要受NW向、NNE向和近EW向活动断裂控制,中强地震沿该方向断裂分布或丛集在它们与NE向断裂交汇处。Based on historical mid-strong earthquake and seismic data from the regional networkover the past 40 years,the space and magnitude risks of future earthquake in the research region are discussed in this study.Three aspects are used in analysis： the G-R relation. which is an important seismological statistic; the space distribution of the seismicity parameter based on the by value calculated by contemporary minor earthquake records; and the geologic structure. which gives an historical and contemporary earthquake activity background. The northeast fault in the research region is the dominant fault in the area.It was formed in an earlier atonic framework was thereafter formed; its activities have been weaker since the late Quaternary. The fault is cut by three faults that were formed later： the NW trending fault, NNE trending fault,and the nearly EW trending fault.These three faults were still apparently active in the middle and late Quaternary,and they are currently the main dominant earthquake structures.Historically, the southern depression in the southern Yellow Sea and the uplift in the south of Jiangsuhave been the main active regions associated with moderately strong earthquakes.Statistical calculations of the regional earthquake recurrence interval without consideration of the relationship between time and magnitude , shows that the two regions are responsible for repeatingstrong earthquakes with obvious characteristics of a midstrong earthquakes cluster,are that they are now in a relatively quiet period. In this respect , the parameters of a-value , b-value , and a/b were calculated,and the spatial distribution of these parameters was determined.The parameters were obtained from the spatial distribution of minimum complete magnitudes since 1972.Consid-ering the epicenter distribution of historical and modern earthquakes, we performed a number of statistical analyses and made conclusions.The evident diversity of epicenter distribution and seis-micity paramete

关 键 词：鲁东-黄海活动地块 地震复发行为 6值 地震危险性 

分 类 号：P315[天文地球—地震学]