背景噪声频率-贝塞尔变换法研究厦门岛浅层S波速度结构  

Study on shallow S-wave velocity structure of Xiamen Island with the frequency-Bessel transform method from seismic ambient noise

作　　者：李海艳 陈晓非 陈举庆 蔡辉腾 刘琦 冯旭平 张功恒 LI HaiYan;CHEN XiaoFei;CHEN JuQing;CAI HuiTeng;LIU Qi;FENG XuPing;ZHANG GongHeng(School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China;Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology,Southern University of Science and Technology,Shenzhen Guangdong 518055,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,China;Shenzhen Key Laboratory of Deep Offshore Oil and Gas Exploration Technology,Southern University of Science and Technology,Shenzhen Guangdong 518055,China;Xiamen Institute of Marine Seismology,China Earthquake Administration,Xiamen Fujian 361116,China;Department of Earth and Space Sciences,Southern University of Science and Technology,Shenzhen Guangdong 518055,China)

机构地区：[1]中国科学技术大学地球和空间科学学院,合肥230026 [2]广东省地球物理高精度成像技术重点实验室(南方科技大学),广东深圳518055 [3]南方海洋科学与工程广东省实验室(广州),广州511458 [4]深圳市深远海油气勘探技术重点实验室(南方科技大学),广东深圳518055 [5]中国地震局厦门海洋地震研究所,福建厦门361116 [6]南方科技大学地球与空间科学系,广东深圳518055

出　　处：《地球物理学报》2024年第7期2654-2667,共14页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(U1901602);广东省地球物理高精度成像技术重点实验室(2022B1212010002);南方海洋科学与工程广东省实验室(广州)人才团队引进重大专项(GML2019ZD0203);深圳市深远海油气勘探技术重点实验室项目(ZDSYS20190902093007855);福建省地震局科技基金专项(SF202207)共同资助。

摘　　要：为获取厦门岛浅层三维速度结构,本文使用福建省地震局于2019年布设的50个流动地震台站组成的密集台阵所记录到的垂向分量波形数据,计算背景噪声互相关,利用频率-贝塞尔变换(F-J)法提取子台阵的瑞利波相速度频散曲线进行反演,获取子台阵下方一维S波速度结构,并通过插值得到厦门岛4 km以内的三维S波速度模型.结果表明,整体上厦门岛S波速度随深度增加呈现递增趋势,在近地表处的横向不均匀性显著.0~1 km深度的S波速度大体上呈现“北高南低”的特征,与岩性分布有较好的对应关系.随着深度的递增,高低速特征分布逐渐呈现为连续性较好,近北东向展布的条带状.结合前人研究结果,本文推测这一现象与厦门岛岩层在不同时期受到挤压和拉张作用形成的褶皱和断裂相关,反映了厦门岛所经历的多次构造变动和岩浆侵入事件.垂向剖面的速度差明显区与研究区断裂带位置具有一定的对应关系.研究结果可为厦门岛的构造演化研究和地质灾害评估提供新的科学依据.To obtain the shallow 3-D S-wave velocity structure of Xiamen Island,we calculated the noise cross-correlation function of the vertical components of continuous ambient noise waveforms,observed by a temporary 50-station seismic array on Xiamen Island in 2019.Then,we extracted the Rayleigh wave phase velocity dispersion curves by the frequency-Bessel transform(F-J)method,inverted the 1-D S-wave velocity structures under the subarrays,and finally obtained the 3-D S-wave velocity model of 0~4 km depth for this region by interpolation.The results show that the S-wave velocity of Xiamen Island increases with depth,and the lateral inhomogeneity is obvious near the surface.The S-wave velocity at 0~1 km depth is mainly"high in the north and low in the south",which coincides well with lithology distribution.As the depth increases,the horizontal distribution of S-wave velocity gradually becomes a strip with good continuity and near-northeastward spreading.According to previous studies,we inferred that this phenomenon is related to folds and faults formed by compressions and extensions during different periods,and implies multiple tectonic movements and magmatic intrusions in Xiamen Island.The obvious velocity difference in the vertical section corresponds to the location of the fault zone in the study area.The results can provide a scientific basis for the study of tectonic evolution and the assessment of geological hazards in Xiamen Island.

关 键 词：背景噪声成像 频率-贝塞尔变换法 厦门岛 浅层S波速度结构 

分 类 号：P315[天文地球—地震学]