Nearshore dynamics of artificial sand and oil agglomerates

TitleNearshore dynamics of artificial sand and oil agglomerates
Publication TypeJournal Article
Year of Publication2015
AuthorsP. Dalyander S, Plant NG, Long JW, McLaughlin M
JournalMarine pollution bulletin
Date Published2015-Jul-15
Accession NumberMEDLINE:25956438
KeywordsDeepwater Horizon Oil Spill
AbstractWeathered oil can mix with sediment to form heavier-than-water sand and oil agglomerates (SOAs) that can cause beach re-oiling for years after a spill. Few studies have focused on the physical dynamics of SOAs. In this study, artificial SOAs (aSOAs) were created and deployed in the nearshore, and shear stress-based mobility formulations were assessed to predict SOA response. Prediction sensitivity to uncertainty in hydrodynamic conditions and shear stress parameterizations were explored. Critical stress estimates accounting for large particle exposure in a mixed bed gave the best predictions of mobility under shoaling and breaking waves. In the surf zone, the 10-cm aSOA was immobile and began to bury in the seafloor while smaller size classes dispersed alongshore. aSOAs up to 5cm in diameter were frequently mobilized in the swash zone. The uncertainty in predicting aSOA dynamics reflects a broader uncertainty in applying mobility and transport formulations to cm-sized particles.