1 research outputs found
Marine Snow Settling Velocities at an Oil Spill Site and a Control Site in the Northern Gulf of Mexico
After budgeting for response efforts and natural processes, over one million barrels of oil from the BP oil spill were unaccounted for. A hypothesis coined The Dirty Blizzard formed subsequent to observations of large and numerous oiled marine snow aggregates amidst the surface slick proposed that a large quantity of oil sank to depth via the aggregates. Having reached the seafloor, aggregates were subject to microbial degradation and to redistribution due to bottom currents. To assist in characterizing redistribution of particles near the seafloor, sediment traps, marine snow cameras, and acoustic Doppler current profilers (ADCPs) were deployed at two sites below the continental shelf break. One site was underneath the oiling footprint near the location of the Deepwater Horizon wellhead and another site was away from the oiling footprint in an area of observed natural seepage. Since oiled particles presumably contained constituents dense enough to sink buoyant oil, which continued to degrade leaving behind relatively heavy components, it was hypothesized that particles at the oiled site would have faster settling velocities than particles at the unoiled site. Using data from time the ADCPs, the sediment traps, and the marine snow profiling cameras, an examination of particle sources is undertaken. Marine snow was not found to be denser underneath the oiling footprint, and marine snow flux periodicities did not match current periodicities