Spilling into confinement: modelling the morphodynamics of sedimentary deposits in deep-water submarine slope systems

Ocean floor channels on slopes are the main conduits for particulate transfer from continents to oceans. Modern erosionally-confined systems form complicated geomorphologies, but their erosional nature and present-day inactivity means little is known about their evolution. Whilst channels are dominated by bypass [sediment travelling through a channel without leaving much trace] for much of their lifespan, their corresponding overbank deposits may record a more complete record of their evolution. The main constituent of these deposits are low-density gravity currents. However, the sedimentology and vertical successions of these features are poorly constrained because they are rarely identified in the rock record, or intersected by wells in modern systems. The dynamic morphology and complex fluid dynamics of the flows within these channels has not been captured experimentally or numerically. Novel physical experiments will comprise a larger outer surface to represent the slope valley confinement, and smaller inset sinuous channel forms, both leveed and terraced, will mimic the thalweg channel. In parallel, the 3D CFD modelling component (ANSYS CFX) will aim to replicate the erosion and deposition from different levels of density stratified flows from the physical experiments where the input parameters and boundary conditions are well constrained.