Moho estimates for the Yellow Sea and Bohai Basin were developed from the EGM2008 gravity, ETOPO1 topography/bathymetry, and NOAA’s sedimentary thickness databases. Spectral correlation analysis between the free-air gravity anomalies (FAGA) and the terrain’s gravity effects (TGE) at 20 km altitude was made to estimate the terrain-correlated FAGA, which can provide information on the isostatic status of the study area. This study included the additional terrain gravity effects due to density contrasts from sedimentary rock thickness variations over the Yellow Sea. Spectral correlation filtering of the FAGA with the TGE estimated the terrain correlated FAGA, which were subtracted from the TGE to infer isostatically compensated gravity effects for inversion constraints on the Moho modeling. The derived Moho estimates show considerable sensitivity to the sedimentary thickness variations and tectonic features of the Yellow Sea region. In addition, the gradients in the dynamic crustal topography inferred from the terrain-correlated FAGA show apparent associations with the distribution of the Yellow Sea’s earthquakes with predominantly strike-slip focal mechanisms.

中文翻译：

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从光谱相关的自由空气和地形重力数据对黄海（西海）进行Moho建模

黄海和渤海盆地的Moho估算值是根据EGM2008重力，ETOPO1地形/测深法和NOAA的沉积厚度数据库得出的。进行了20 km高空自由重力异常（FAGA）与地形重力效应（TGE）之间的光谱相关分析，以估算与地形相关的FAGA，这可以提供有关研究区域等静压状态的信息。这项研究包括由于黄海上沉积岩厚度变化引起的密度对比而引起的其他地形重力影响。用TGE对FAGA进行光谱相关滤波可以估算与地形相关的FAGA，然后从TGE中减去与地形相关的FAGA，以推断出等静补偿的重力效应，从而对Moho模型进行反演约束。得出的Moho估计值对黄海地区的沉积厚度变化和构造特征显示出相当大的敏感性。此外，由地形相关的FAGA推断出的动态地壳地形的梯度与黄海地震的分布具有明显的联系，主要是走滑震源机制。