Resuspension, bottom-current

An analysis of the contributions to the skin friction shows that the surface waves play the dominant role. The shear stress induced by bottom currents exceeds the low fluff threshold only occasionally, especially during inflow events of saline water through the narrow channels. Therefore, an estimation of the resuspension potential of bottom sediments may be based on waves only, as, for instance, done by Jonsson (2006). However, without bottom currents some events will be missing, and, more important, no conclusions about the transport paths are possible. 

One final comment about these mass flux calculations is necessary. Deposition of effluent particles on the sea bottom is by no means permanent. Several processes acting alone or in concert may result in the removal of the effluent particle from its original site of deposition. These processes include (1) physical removal resulting from bottom-current or storm-surge resuspension and (2) chemical removal resulting from ingestion or disturbance (bioturbation). The simultaneous effect of several of these processes has been considered by Hendricks (4). 

Where the waves and currents weaken, resuspended sediment settles back down to the seafloor. Given the small particle sizes of the suspended material (mostly 3 to 10 pm), redeposition can take many years. The resulting redistribution of sediments creates patches of clay, mud, and exposed rock on the continental margins. In other words, resuspension from waves and currents can cause some sediments to become reUct deposits. Hard bottoms can serve as good habitats for some members of the benthos as they promote the formation of coral reefs. For paleoceanographers, relict deposits are problematic because they represent gaps, or imconformities, in the sedimentary record. 

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