首页|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

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

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

Ambient noise tomographyFrequency-Bessel transform methodXiamen IslandShallow S-wave velocity structure

李海艳、陈晓非、陈举庆、蔡辉腾、刘琦、冯旭平、张功恒

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中国科学技术大学地球和空间科学学院,合肥 230026

中国地震局厦门海洋地震研究所,福建厦门 361116

南方科技大学地球与空间科学系,广东深圳 518055

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

南方海洋科学与工程广东省实验室(广州),广州 511458

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

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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

国家自然科学基金项目广东省地球物理高精度成像技术重点实验室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深圳市深远海油气勘探技术重点实验室项目福建省地震局科技基金专项

U19016022022B1212010002GML2019ZD0203ZDSYS20190902093007855SF202207

2024

地球物理学报
中国地球物理学会 中国科学院地质与地球物理研究所

地球物理学报

CSTPCD北大核心
影响因子:3.703
ISSN:0001-5733
年,卷(期):2024.67(7)
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