Upwelling and sedimentation dynamics

Abstract

It was found that the location and distributional pattern of certain sea bottom mud patches in the Yellow Sea and East China Sea are identical with the geographical location and flow pattern of the upwelling above. Following a general description by Hu (1984) of the role of upwelling in sedimentation, this study presents a two—dimensional numerical model to further examine the sedimentation dynamics in upwelling areas. The model shows that advection by ocean circulation, downward settling due to gravity and turbulent mixing are the main mechanisms controlling the movement of suspended matters, and that the upwelling on the shelf favors deposition near the bottom. It is concluded that on the shelf (1) wherever there is upwelling, mud sediment must exist; and (2) the closer to the center of upwelling, the greater the concentration of suspended matters in the water, the greater the depositing rate near the bottom and the finer the sediment on the sea bed.