GURADUALLY VARIED FLOW ANALYSIS OF SUBMARINE TURBIDITY CURRENTS ON THE CONTINENTAL SLOPE

Abstract

 It has recently been found that submarine turbidity currents travel very long distances due to the extremely small entrainment or diffusion between turbid water and fresh water at the density interface. In this study, we analyzed numerically the motion of submarine turbidity currents neglecting the entrainment of seawater from the top of the layer, and examined the behavior of long-runout submarine turbidity currents in the downstream direction. As a result, It turned out that the profiles of density interfaces of the submarine turbidity currents resemble the S₂ and S₃ curves of open channel flow depending on the conditions, and there are cases where the flow converges to a normal flow condition (in which flow does not slow down). Although there are cases where the flow disappears, there is a precise critical layer thickness (thickness of submarine turbidity currents), like the critical flow depth, between such cases and cases where the flow converges to the normal flow condition. The layer thickness must be somewhat small to converge to a normal flow condition.