Wave climate, sediment supply and the depth of the sand-mud transition: A global survey
Wave climate, sediment supply and the depth of the sand-mud transition: A global survey
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波浪气候、沉积物供应和砂泥转变深度：全球调查
DOI：
10.1016/j.margeo.2008.05.005
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发表时间：
2008
期刊：
影响因子：
2.9
通讯作者：
P. Hill
中科院分区：
文献类型：
--
作者：
D. George;P. Hill
研究了波浪、气候和泥沙补给对砂泥过渡深度的影响。砂泥转换深度(SMT)是基于已公布的14个地点的表层样品的粒度数据，这些样品来自不同的以河流输入的以波浪为主的沿海环境，包括高能量(哥伦比亚河、鳗鱼河、俄罗斯河、圣洛伦索河、铜河和内皮亚河)、中等能量河(埃布罗河、尼罗河、圣克拉拉河、曾文河和高坪河)和低能量河(波河、佩斯卡拉河和特隆托河)。由岸线断面上的样品编制了几何平均直径(GMD)和泥浆百分比，发现这两个纹理描述符之间存在显著的相关性。名义上，SMT定义为从GMD&>63微米到<；63微米的过渡。MUD百分比和GMD之间的相关性允许将SMT定义为从<；25%MUD到<；25%MUD的过渡。这一双重定义适用于14个系统，并列出了每个系统的hSMT。HSMT与波浪引起的底部剪应力等于最大泥沙颗粒的临界冲刷剪应力的深度以及hSMT与有效波高之间存在相关性。HSMT与附近河流输沙量之间缺乏相关性，说明泥沙供给对沙泥过渡深度的影响很小，或者在本研究中没有得到充分的体现。陆架宽度和坡度与hSMT和有效波高之间的形式线性关系的残差不相关。HSMT与波浪气候之间的关系有助于在波浪控制的海岸环境中刻度侵蚀和沉积的数值模型，预测偏远或难以接近地区的海底性质，以及根据古岩中从砂岩到泥岩的相变化重建古深度。
The influences of wave climate and sediment supply on the depths of sand–mud transitions (hSMT) are investigated. Depths of sand–mud transitions (SMT) are based on published granulometric data from surface samples gathered from 14 sites in different wave-dominated coastal environments with fluvial input, including high energy (Columbia, Eel, Russian, San Lorenzo, Copper, and Nepean rivers), moderate energy (Ebro, Nile, Santa Clara, Tseng-wen and Kao-ping rivers), and low energy (Po, Pescara and Tronto rivers) regimes. Geometric mean diameter (GMD) and mud percent are compiled from samples along shore-normal transects, and significant correlation is found between these two textural descriptors. Nominally, the SMT is defined as the transition from GMD >63 µm to <63 µm. The correlation between mud percent and GMD permits an alternative, complementary definition of the SMT as the transition from <25% mud to >25% mud. This dual definition is applied to the 14 systems, and hSMTis tabulated for each system. Correlation is found between hSMTand the depth at which wave-induced bottom shear stress equals the critical erosion shear stress of the largest mud particles and also between hSMTand significant wave height. Lack of correlation between hSMTand sediment load of nearby rivers indicates either that the influence of sediment supply on depth of the sand–mud transition is small or is not adequately represented in this study. Shelf width and slope do not correlate with residuals from a formalized linear relationship between hSMTand significant wave height. The relationship between hSMTand wave climate is useful for calibration of numerical models of erosion and deposition in wave-dominated coastal environments, for prediction of seabed properties in remote or inaccessible areas, and for reconstruction of paleodepth based on facies changes from sand to mud in ancient rocks.