Researchers say they have found a large fallout plume of oil on the seafloor from the 2010 Deepwater Horizon
disaster in the Gulf of Mexico. According to a report in the Proceedings of the National Academy of Sciences, a portion of the 2 million barrels of oil thought to be trapped in the deep sea after the spill appears to have settled across a 1,250-square-mile patch of the seafloor centered around the Macondo Well, which discharged an estimated 5 million barrels of oil in the nearly three months between its blowout in April and eventual capping in July. The oil is concentrated in the top half-inch of the seafloor, and mostly distributed in patchy deposits to the southwest of the well, the study found. These deposits account for between 4 and 31 percent of the Macondo oil sequestered in the deep ocean, researchers estimate. The rest has likely been deposited outside this area, they say, but has evaded detection so far because of its patchiness.