WASHINGTON (AP) - The BP oil spill left an oily "bathub ring" on the sea floor that's about the size of Rhode Island, new research shows.
The study by David Valentine, the chief scientist on the federal damage assessment research ships, estimates that about 10 million gallons of oil coagulated on the floor of the Gulf of Mexico around the damaged Deepwater Horizons oil rig.
Valentine, a geochemistry professor at the University of California Santa Barbara, said the spill from the Macondo well left other splotches containing even more oil. He said it is obvious where the oil is from, even though there were no chemical signature tests because over time the oil has degraded.
"There's this sort of ring where you see around the Macondo well where the concentrations are elevated," Valentine said. The study, published in the latest Proceedings of the National Academy of Sciences, calls it a "bathtub ring."
Oil levels inside the ring were as much as 10,000 times higher than outside the 1,200-square-mile ring, Valentine said. A chemical component of the oil was found on the sea floor, anywhere from two-thirds of a mile to a mile below the surface.
The rig blew on April 20, 2010, and spewed 172 million gallons of oil into the Gulf through the summer. Scientists are still trying to figure where all the oil went and what effects it had.