Sediment Dispersion from the Coast to the Continental Slope in the Southeastern Beaufort Sea

The Mackenzie Shelf in the southeastern Beaufort Sea annually receives a large amount of fluvial and terrestrial sediments at the order of 1.3 × 10⁸ tonnes/yr. Understanding the processes and mechanisms which deliver sediment from the coast to the continental shelf and beyond to the slope is a classic problem in sedimentology. In this study, a three dimensional particle tracking tool is used to improve our understanding of the processes, pathways and forcing mechanisms responsible for driving sediment transport from near the coast to the shelf and down the continental slope in the southeastern Beaufort Sea. The hourly currents from TOPAZ4, a coupled ocean sea ice data assimilation (DA) system for the North Atlantic Ocean and Arctic are used as the driving data for the particle model. The sediment distribution rate on the Mackenzie Shelf is estimated from the particle accumulation over a 3-year time-series (2011-2013). The model results provide a full picture of sediment transport in the Beaufort Sea coast zone in different seasons. For the resuspension of sediments are usually connected with storm events, special attentions are put on the cases of sediment deliveries associated with northwesterly storm surges and down-welling conditions on the shoreface.