Gulf Spill Pictures: Toxic Oil Found Just Under Beaches

Buried Oil

Photograph by Chris Combs, National Geographic

Just inches below the surface of a popular beach near Pensacola, Florida, lies one of many buried ribbons of solid oil from the still-spewing Deepwater Horizon spill off Louisiana. Pictured near more obvious, surface oil mats, the oil ribbon was uncovered by University of South Florida coastal geologists on July 1.

Elsewhere along the Pensacola-area beach, oil was found as far down as 2 feet (0.6 meter)—the deepest oil yet found by the team, which has 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.

(Gulf Oil Spill Pictures: Oil, Tarballs Hit Beaches.)

Published July 5, 2010

Weathered Oil

Photograph by Chris Combs, National Geographic

On July 1 machete-wielding coastal geologist Katie Brutsché cut pits (such as the one pictured at lower right) into layers of Pensacola Beach sand to reveal oil invisible—and largely inaccessible—to cleanup crews, whose focus is on the surface oil, such as those seen at lower left.

This "weathered" oil—mainly tarballs and tar mats—began washing ashore around June 23 in Pensacola. (See pictures of Gulf oil atop Pensacola Beach.)

Waves buried much of the oil under new layers of sand, particularly this week, when Hurricane Alex spawned rough seas around the Gulf. (See "Hurricane Alex Pushes 'Worst Oil' Ashore; Cleanup Slowed.")

(Gulf Oil Spill Pictures: Birds, Fish, Crabs Coated.)

Published July 5, 2010

Buried Ribbons

Photograph by Chris Combs, National Geographic

Buried oil from the Deepwater Horizon spill, such as the layer exposed here by one of the Pensacola Beach, Florida, digs on July 1, could become something of a recurring problem on Gulf Coast beaches if future harsh whether erodes beaches, revealing what lies beneath.

"You can go to a beach and say the beach is clean, and then a year later a storm hits and you find out that the beach is still polluted," said Michel Boufadel, who's studied the lingering oil from the 1989 Exxon Valdez tanker spill in Alaska.

It's like "getting a new spill" with every storm, said Boufadel, chair of Temple University's Department of Civil and Environmental Engineering in Ambler, Pennsylvania.

Published July 5, 2010

Oil Researchers

Photograph by Chris Combs, National Geographic

University of South Florida coastal geologist Ping Wang, who led the Pensacola Beach digs, stands amid beach-top tarballs and tar mats with team member Stoddard Pickrel (background) on July 1.

"This time, we were lucky," said Wang, referring to relatively soft treatment from Hurricane Alex, which made landfall late on June 30 on northern Mexico's Gulf Coast. With Alex's path hundreds of miles to the east, the storm's seawater surges had been relatively small along Florida's Gulf coast. (See Gulf of Mexico map.)

But future, stronger hurricanes could push much more oil onto Pensacola Beach and the nearby Gulf Islands National Seashore, which includes sites in both Florida and Mississippi.

Published July 5, 2010

Surface Oil

Photograph by Chris Combs, National Geographic

Tar balls and liquid oil from the Gulf spill taint Florida's Pensacola Beach on July 1. Exposed oil, though, may be the least of the worries.

Even without cleanup crews, surface oil disappears fairly quickly as oxygen, sunlight, and oil-eating microbes break it down. Buried oil can persist much longer, particularly deep down, where oxygen is in short supply.

"If [oil's] buried and you have a five-year-old out here next summer building a sand castle and they uncover a layer of tar and oil, that's not going to be good," said Tiffany Roberts, a University of South Florida Ph.D. student.

Contact with oil can cause skin irritation, and inhaling evaporated oil particles may cause nausea, headache, and dizziness—ailments already reported by some Gulf oil spill cleanup workers, according to the U.S. Department of Health and Human Services.

Published July 5, 2010

Searching for Oil

Photograph by Chris Combs, National Geographic

Combing Pensacola Beach, Florida, on July 1, University of South Florida coastal geologists continue their search for hidden oil—and for patterns in the swirling, light brown oil stains at the surface (pictured).

By studying how oil is distributed atop the beach, the team may find a way to predict the locations of buried oil, so the toxic substance can be more easily extracted, said Tiffany Roberts, a Ph.D. student at the University of South Florida.

Right now cleanup crews are "dealing with the immediate," Roberts said. Eventually "we've got to figure out what's below."

Published July 5, 2010