Origin of Morphodynamic Stability of Intertidal Sand Bars

Abstract

The persistent nature of intertidal sand bars has been the subject of much speculation concerning the hydrodynamic mechanisms involved, but its origin remains enigma. Here, we aim to resolve this question by introducing salient geophysics to the analysis of intertidal sediments, in contrast to the physics of fluids above the sediments. The geophysical evidence combined with theoretical modeling and analysis demonstrates that the feedback between the effects of suction dynamics and sediment transport and morphology plays a crucial role in the intertidal bar morphodynamics, yielding the persistent nature of the intertidal sand bars. Our finding may fundamentally alter the current perspective, leading to a new level of understanding, of sediment transport and bar behavior at waterfronts that are ubiquitous in rivers, estuaries, and coastal seas.