鄂尔多斯地块周缘应力状态与强震危险性分析  

Stress State and Strong-earthquake Risk around the Ordos Block

作　　者：梁向军[1,2] 王霞[1,2] 宋美琴[1,2] 陈慧[1,2] Liang Xiangjun;Wang Xia;Song Meiqin;Chen Hui(Shanxi Earthquake Agency,Taiyuan 030021,China;National Continental Rift Valley Dynamics Observatory of Taiyuan,Taiyuan Seismic Station,Taiyuan 030025,China)

机构地区：[1]山西省地震局,太原030021 [2]太原大陆裂谷动力学国家野外科学观测研究站,太原030025

出　　处：《中国地震》2019年第4期726-737,共12页Earthquake Research in China

基　　金：中国地震局地震预测研究所科研专项(2017IES010104、2017IES010105);国家重点研发计划项目(2017YFC1500502-01);山西省科技厅项目(201801D221044);2019年度震情跟踪专项工作任务(2019010106)共同资助

摘　　要：针对鄂尔多斯周缘断陷盆地带,基于b值、Δb空间扫描和多参数(b、E、n、a/b)组合计算结果,综合分析各段落的应力状态,进而判定它们的危险性。结果显示:整个周缘断陷带的年发生率、年释放率均整体下降,揭示出该区域2010年6月以来呈现出地震弱活动状态;b值较1970~2010年结果变化并不显著,内蒙古磴口-五原值得注意地区、同心-灵武值得注意地区、晋冀蒙交界危险区和侯马-运城值得注意地区4个区域仍处于匀速的应力积累状态;结合多参数组合揭示的应力状态和断裂习性,认为内蒙磴口-五原地区未来发震危险性最高,但近期发震的紧迫性不强,同心-灵武地区危险性有所增强,侯马-运城地区危险性持续,晋冀蒙交界地区危险性有所降低,其余段落近期复发强震的可能性不大。Based on the calculation results of b-value,Δb spatially scanning and multiple-seismicity-parameter-value combinations(b,E,n,a/b),we comprehensively analyze the stress state of basins around the Ordos block and then determine their risks.The results show that annually seismicity rate and annually strain-release-rate generally decrease in the fault depression belt around the Ordos block,revealing the weak seismicity of this region since June,2010.The difference of b-value between 1970~2018 and 1970~2010 is not obvious.The areas that are worthy of attention,including Dengkou-Wuyuan in Inner Mongolia,Tongxin-Lingwu,the junction zone of Shanxi-Hebei-Inner Mongolia and Houma-Yuncheng,remain constant stress accumulation state.Combined with the stress state reflected by multiple-seismicity-parameter-value combinations and fault habit,the probability of strong-earthquake is the highest in Dengkou-Wuyuan,Inner Mongolia,but the urgency of that in the near future is not strong.The risk of Tongxin-Lingwu area enhances a little.The risk of the Houma-Yuncheng area still continues.The risk of junction zone of Shanxi-Hebei-Inner Mongolia decreases a little.The probability of strong-earthquake on other sections is small in the near future.

关 键 词：鄂尔多斯周缘 b Δb 多参数 强震危险性 

分 类 号：P315[天文地球—地震学]