基于密集台阵H/V谱比法探测三河——平谷沉积层界面结构和隐伏断层  

Detection of Sanhe-Pinggu sedimentary interface structure and buried fault based on dense array H/V spectral ratio method

作　　者：唐志伟 张怀 尹光耀 张冰 李志伟 石耀霖 TANG ZhiWei;ZHANG Huai;YIN GuangYao;ZHANG Bing;LI ZhiWei;SHI YaoLin(National Key Laboratory of Earth System Numerical Modeling and Application,College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 101408,China;Beijing Yanshan Earth Critical Zone National Research Station,University of Chinese Academy of Sciences,Beijing 101408,China;Beijing Institute of Spacecraft Environment Engineering,China Academy of Space Technology,Beijing 100081,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai Gaungdong 519080,China)

机构地区：[1]地球系统数值模拟与应用全国重点实验室,中国科学院大学地球与行星科学学院,北京101408 [2]北京燕山地球关键带国家野外科学观测研究站,中国科学院大学,北京101408 [3]中国空间技术研究院北京卫星环境工程研究所,北京100081 [4]南方海洋科学与工程广东省实验室(珠海),广东珠海519080

出　　处：《地球物理学报》2025年第4期1329-1339,共11页Chinese Journal of Geophysics

基　　金：国家重点研发计划项目(2023YFC3007303)资助。

摘　　要：三河—平谷地区位于太行山—燕山隆起和华北平原沉降带的结合处,该区域晚新生代以来构造活动强烈,强震频发.横贯该地区北东走向的夏垫断裂带被认为是1679年三河—平谷8.0级地震的发震断层,整个断裂带分布在较厚沉积层的华北平原西缘.盆地-丘陵-山地结合部的地质特征与盆地结构效应对大震诱发的地震波强地面运动具有显著放大效应.为获取该区域沉积层的精细结构,本文基于密集台阵(由496个台站组成,间隔0.5~5 km)记录的背景噪声利用H/V谱比法计算了各个台站处的峰值频率,并通过频率-厚度转换方法获得了三河—平谷地区三维第四纪沉积层界面结构.结果表明,受隐伏断裂带的影响,沉积层厚度由北西至南东方向整体呈现“厚-薄-厚-薄”趋势,北东部较薄、西南部较厚特点.大兴隆起和宝坻隆起处沉积层厚度约为100~300 m,北京凹陷和大厂凹陷处沉积层厚度约为300~800 m.反演结果与钻井勘探结果和地震勘探剖面基本一致,且沉积层的起伏与隐伏断裂带的分布具有良好的对应关系.本文获得的三维第四纪沉积层精细结构将为区域地震强震模拟、隐伏断层识别、大震危险性量化评估提供关键的数据约束与盆地结构参考模型.The Sanhe-Pinggu area is located at the junction of the Taihang Mountain-Yanshan Uplift and the settlement zone of the North China Plain.This region has experienced intense tectonic activity with frequent earthquakes.The north-east Xiadian fault zone is thought to be a seismic fault caused by the 1679 Sanhe-Pinggu magnitude 8.0 earthquake.To obtain the detailed structure of the sedimentary layers in this area,based on the ambient noises recorded by the dense seismic array(composed of 496 stations with an interval of 0.5~5 km),the peak frequency at each station was calculated by H/V spectral ratio method,and the 3D Quaternary sedimentary structure in the Sanhe-Pinggu area was obtained by frequency-thickness conversion method.The results show that,under the influence of the hidden fault zone,the thickness of the sedimentary layer shows a trend of"thick-thin-thick-thin"from north-west to south-east,with thinner characteristics in the northeast and thicker in the southwest.The sedimentary layer thickness is approximately 100~300 meters in the Daxing Uplift and Baodi Uplift areas,and 300~800 meters in the Beijing Depression and Dachang Depression areas.The inversion results are consistent with drilling exploration data and seismic profiles,and the undulations of the sedimentary layers correspond well with the distribution of the hidden fault zone.The 3D Quaternary sedimentary structure obtained in this paper provides critical data constraints and basin structure reference models for regional seismic strong earthquake simulation,hidden fault identification,and quantitative assessment of seismic hazard.

关 键 词：密集台阵 背景噪声 H/V谱比法 第四纪沉积层 

分 类 号：P315[天文地球—地震学]