| one publication added to basket [14278] | Wave effects on sediment water exchange in a submerged sand bed
Rutgers van der Loeff, M.M. (1981). Wave effects on sediment water exchange in a submerged sand bed. Neth. J. Sea Res. 15(1): 100-112
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, more
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| Author | | Top |
- Rutgers van der Loeff, M.M.
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| Abstract |
A method has been developed to measure the apparent diffusion in the upper layer of a sandy sediment in situ, with minimum disturbance of wave and current conditions. The upper 1 to 1,5 cm of a sandflat with little bioturbation in the Dutch Wadden Sea showed an increased diffusivity under low to moderate wave action. Below this depth molecular diffusion prevailed. A relation is derived to estimate the turbulent diffusion coefficient that is associated with the turbulent mixing resulting from wave induced percolation of the sediment. It is shown that, in the North Sea as well as in the tidal flat, this bottom percolation rarely contributes significantly to the diffusion in the sediment. It is suggested that the observed increased diffusivities near the sediment surface are related to small scale turbulence in the unconsolidated upper layer, caused by bottom swell and tidal currents. |
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