Fluid Mud Properties in Nautical Depth Estimation

Abstract

Fluid mud is a non-Newtonian slurry of aggregated fine sediment present in numerous bays, estuaries, and lakes. It is a transitory state of mobile mud whose properties are relevant to the definitions and utility of hydrodynamic, acoustic, and, particularly, nautical depth in navigation channels. For estimation of the nautical depth up to which mud must be removed to keep its resistance against vessel propulsion low, processes underpinning fluid mud transport are briefly reviewed. Data from a coastal harbor are revisited to illustrate the role of shear rheometry as an essential component of the method for nautical depth estimation. Broadening the application to channels laden with organic muck often found in many ports, such as those in the southern United States, will require new data and understanding of the biomechanical properties of organic aggregates. Fluid mud dynamics is integral to such efforts.