GULF OIL DISASTER
"One major research concern is the huge clouds and plumes of hydrocarbons that formed in the Gulf waters up to 2,500 feet below the surface after the April 3, 2010, Deepwater Horizon drilling rig explosion.
The authors say the plumes appear to have been caused by the use of dispersants applied directly at the wellhead, some 5,000 feet below the surface. The application of dispersants at those depths is unique to this spill and something that needs to be understood, the researchers say. Previously dispersants were sprayed only on surface slicks."