Hydrodynamic processes and their impacts on the mud deposit in the Southern Yellow Sea
Hydrodynamic processes and their impacts on the mud deposit in the Southern Yellow Sea
复制标题
DOI：
10.1016/j.margeo.2014.11.012
复制
发表时间：
2015-02
期刊：
影响因子：
2.9
通讯作者：
Chun-yan Zhou;P. Dong;Guangxue Li
中科院分区：
文献类型：
--
作者：
Chun-yan Zhou;P. Dong;Guangxue Li
采用数据分析和水动力模拟相结合的方法，研究了黄海陆架上泥质沉积物的沉积过程，以确定对泥质沉积物形成有重要影响的主导因素。数据分析广泛使用了现有数据，特别是最近收集的深层岩心数据，同时使用包含潮汐、波浪和风影响的3D水动力学模型研究了水动力和沉积物运输过程。根据高分辨率Chirp声纳剖面资料和岩心资料，估计黄海中部泥的平均沉积速率为3.6 × 107t a−1。现有的沉积学、矿物学、地球化学和流体流动资料均表明，黄河、长江排出的细粒沉积物以及老黄河三角洲的重悬浮沉积物是南黄海泥沉积的主要来源。本研究证实了潮流确实是将细粒泥沙输送到中部泥滩的主要因素，但波浪效应也很重要，因为它负责维持悬浮物浓度并引起泥沙再悬浮。在冬季风暴中，波浪对老黄河三角洲周围的影响尤为显著，因为在这些风暴期间，主要由亚洲季风引起的环流可以将大量的细沉积物从老黄河三角洲输送到中部。模拟结果表明，在当前水动力条件下，约16% （1.33 × 108t a−1）的黄河泥沙被运出渤海海峡，其中约44% （5.72 × 107t a−1）最终被运至南黄海。不考虑波动效应的对应值分别为9.8%和2.6%。结果表明，尽管黄海海平面明显上升，潮流场和波浪分布也发生了相应的变化，但在过去12 kyr里，CS泥区沉积速率基本保持不变。其原因被认为是低水期较弱的海流和波浪被较短的悬浮物从古黄河到CS泥区所需要的距离所补偿，从而在CS泥区保持了近乎恒定的沉积速率。
The sedimentation processes of mud deposits on the continental shelves of the Yellow Sea (YS) are investigated using a combined data analysis and hydrodynamic modeling approach in order to identify the dominant factors that contribute significantly to the formation of these deposits. The data analysis makes extensive use of existing data, especially recently collected deep core data while the hydrodynamic and sediment transport processes are studied using a 3D hydrodynamics model that incorporates the effects of tides, waves and wind. The average deposit rate of the Central Yellow Sea Mud (CS) is estimated to be 3.6 × 107t a− 1based on high-resolution Chirp sonar profiles combined with core data. Available sedimentological, mineralogical, geochemical and fluid flow data all indicate that the fine sediments discharged from Huanghe River and Changjiang River as well as the resuspended sediments from the Old Huanghe Delta are the main sources for the mud deposits in the Southern Yellow Sea (SYS). This study confirms that tidal current flow is indeed the main agent for transporting the fine sediment to the mud patch in the central SYS but wave effect is also significant as it is responsible for maintaining suspension concentration and causing sediment resuspension. The wave influence is particularly notable around the Old Huanghe Delta in winter storms as during these storm periods current circulation, mainly caused by the Asian Monsoon, can transport a large quantity of fine sediments from the Old Huanghe Delta to the central SYS. Under the present hydrodynamic conditions, the modeling results showed that approximately 16% (1.33 × 108t a− 1) of the Huanghe River-derived sediment is transported out of Bohai Strait, of which around 44% (5.72 × 107t a− 1) will finally be transported to the South Yellow Sea. The corresponding values without accounting for the wave effects are 9.8% and 2.6%, respectively. It is noted that the deposition rate in the CS mud area over the past 12 kyr is virtually constant despite the significant rise in sea-level and associated changes in the tidal current fields and wave distributions in the Yellow Sea. The reason for this is believed to be that the weaker currents and waves during a lower water period is compensated by the shorter distance the suspended sediments have to travel from the paleo-Huanghe River to the CS mud area, thus maintaining a nearly constant deposition rate in the CS mud area.