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Trapped Oil

November 22, 2014

Some 200 million gallons of oil flowed into the Gulf of Mexico from the damaged Macondo well during the Deepwater Horizon disaster in 2010, but scientists estimate that half of that never reached the surface. In a new studyto understand what happened to the rest, David Valentine (UC Santa Barbara), Chris Reddy (WHOI), and colleagues analyzed data from 3,000 samples of seafloor sediments collected at 534 locations by expeditions in 2010 and 2011. They concluded that tiny oil droplets, which were trapped in a deep-flowing plume, coagulated and sank to the seafloor—much of it within 45 miles of the well. (Illustration by Jack Cook, Woods Hole Oceanographic Institution)