Estimating the Shear-Wave Velocities of Shallow Sediments in the Yellow Sea Using Ocean-Bottom-Seismometer Multicomponent Scholte-Wave Data
Estimating the Shear-Wave Velocities of Shallow Sediments in the Yellow Sea Using Ocean-Bottom-Seismometer Multicomponent Scholte-Wave Data
复制标题
利用海底地震仪多分量肖尔特波数据估算黄海浅层沉积物的剪切波速度
DOI：
10.3389/feart.2022.812744
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发表时间：
2022-01
影响因子：
2.9
通讯作者：
Tianyao Hao
中科院分区：
文献类型：
--
作者：
Yuan Wang;Qingyu You;Tianyao Hao
Scholte波频散分析是有效的成像相对较低的剪切波速度的浅海沉积物在边缘海。四分量海底地震仪（OBS）与拖曳气枪震源相结合可以经济有效地采集海洋频散地震数据。高阶色散Scholte波模式的提取是色散分析方法中最关键的问题。极低的剪切波速度和严重的衰减，在顶部数百米的边缘海沉积物提供了一个不均匀的分散的能量分布的四个组成部分的Scholte波数据。基模色散能量在垂直分量中占主导地位，高阶模在水平分量中占主导地位。提出了四分量OBS Scholte速度谱叠加方法，该方法能有效、快速、鲁棒地提取高阶模。利用大体积气枪阵列主动式OBS地震剖面，对北黄海复杂浅海沉积物的剪切波速度结构进行了成像。四分量速度谱叠加法可以在1.0- 7.0Hz的低频范围内成像第四高阶Scholte波模式。从单个垂直分量的色散能量图像中只能识别出二阶模。多模色散曲线的联合反演可以为反演模型提供更高的精度和更深的约束，因此，与单个基模反演相比，五个模式的约束深度增加了1.9倍。反演的剖面表明，剪切波速度较低，为123-670 m/s，350 m范围内横向变化较强。反转的剪切波速度结构反映了区域主要地质构造。
Scholte-wave dispersion analysis is effective at imaging the relatively low shear-wave velocity of shallow marine sediments in marginal seas. The combination of a four-component ocean-bottom-seismometer (OBS) and a towed air-gun source can economically and effectively acquire the marine dispersive seismic data. Extracting higher-order dispersive Scholte wave modes is the most critical problem in the dispersion analysis method. The extremely low shear-wave velocity and severe attenuation in the top hundreds of meters of marginal sea sediment provide an uneven dispersive energy distribution for the four components of the Scholte wave data. The fundamental mode dispersive energy dominates in the vertical component and higher-order modes dominate in the horizontal component. We developed the method of the four-component OBS Scholte velocity-spectra stacking, which can effectively, rapidly, and robustly extract higher-order modes. We imaged the shear-wave velocity structure of complicated shallow marine sediment in the North Yellow Sea using an active OBS seismic profile with a large-volume air-gun array. The fourth higher-order Scholte wave mode can be imaged with the four-component velocity-spectra stacking method with a lower frequency range of 1.0–7.0 Hz. Only the second-order mode can be recognized from the dispersion energy image of the single vertical component. The joint inversion of multimode dispersion curves can provide more accuracy and deeper constraints for the inverted model; thus, the constraint depth with five modes increases by a factor of 1.9 compared with single fundamental mode inversion. The inverted profile suggests a low shear-wave velocity of 123–670 m/s and strong lateral variations within 350 m. The main regional geological structures are shown by the inverted shear-wave velocity structure.
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影响因子：
2.4
作者：
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通讯作者：
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作者：
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影响因子：
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作者：
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通讯作者：
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