Oiled sediment. This photo shows the swash zone at USGS sampling location MS-39 on East Ship Island, MS. Waves have cut a steep section into the sand, revealing alternating layers of clean and sticky organic-rich sand that are visible after low tide. (The swash zone is the zone that is alternately covered and exposed by waves.) Captions and Photo source: Shane Stocks / USGS
Oil patties and tarballs were discovered as deep as 2 feet (0.6 meter) beneath beaches dirtied by the Gulf of Mexico oil spill—the deepest oil yet found by a team of University of South Florida coastal geologists that’s been studying the effects of the oil spill on Gulf beaches since early May. The previous record had been 6 inches (about 15 centimeters) deep, said geologist Ping Wang, the team’s leader.
The discoveries suggest that toxic oil lies hidden under even “clean” patches of beaches along the U.S. Gulf Coast, and that oil-spill cleanup crews are only scratching the surface.
Because the buried oil is both harder to clean and slower to break down, it could be a long-lasting threat to beachgoers, both animal and human, experts say…