ESTIMATING SEDIMENT TRANSPORT IN THE LOWER SHOREFACE, MANTOLOKING, NEW JERSEY

Current and past studies suggest transport processes in the lower shoreface may be responsible for the exchange of sediment between the shoreface and inner shelf, as implied by the presence of shore attached ridges and associated bedforms. Lower shoreface transport may be a significant component of coastal sediment budgets, potentially supplying sediment to beaches, as well as maintaining shore attached sand ridges, which dampen the effects of storms and act as a sand source for beach nourishment projects. However, along populated and highly engineered coastal environs, such as the Atlantic coast of New Jersey, lower shoreface transport processes remain only loosely understood. As a result, human intervention in the lower shoreface, for example, the mining of sand ridges for beach nourishment, could have significant implications for future coastal protection. A region of New Jersey currently undergoing extensive nourishment is the Barnegat Peninsula, a narrow barrier spit that was severely impacted by Superstorm Sandy. Sonar mapping of the seabed offshore of Mantoloking, New Jersey, in the northern part of the peninsula, has revealed the presence of numerous megaripple-like bedforms spanning shore attached ridges along the lower shoreface, indicative of active or past transport. This study investigates potential transport in the Mantoloking area using seabed sediment samples, bedform mapping and profiling, and historic hydro/meteorological data. This investigation will provide preliminary results for a more detailed study of sediment movement in the lower shoreface, with the potential for forward modeling of future seabed and nearshore morphologies.