<p>University of South Florida coastal geologists (left to right) Stoddard Pickrel,&nbsp;Katie Brutsché, and&nbsp;Jun Cheng dig into a beach near <a href="http://maps.nationalgeographic.com/map-machine#s=r&amp;c=30.332462285442336, -87.142344&amp;">Pensacola Beach, Florida (map)</a>, on Thursday. It didn't take long for the scientists to strike black gold.</p><p>During a series of digs, oil patties and tarballs were found just beneath beaches dirtied by the <a id="nis6" title="Gulf of Mexico oil spill" href="http://news.nationalgeographic.com/news/gulf-oil-spill-news/">Gulf of Mexico oil spill</a>. 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.</p><p>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.</p><p>(See <a id="rknz" title="&quot;Oil Found in Gulf Beach Sand, Even After Cleanups.&quot;" href="http://news.nationalgeographic.com/news/2010/07/100702-gulf-oil-spill-beaches-florida-nation/">"Oil Found in Gulf Beach Sand, Even After Cleanups."</a>)</p><p><em>—Adapted from a story by Christine Dell'Amore in Pensacola Beach, Florida, and Gulf Islands National Seashore</em></p>

Pensacola Beach

University of South Florida coastal geologists (left to right) Stoddard Pickrel, Katie Brutsché, and Jun Cheng dig into a beach near Pensacola Beach, Florida (map), on Thursday. It didn't take long for the scientists to strike black gold.

During a series of digs, oil patties and tarballs were found just beneath beaches dirtied by the Gulf of Mexico oil spill. 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.

(See "Oil Found in Gulf Beach Sand, Even After Cleanups.")

—Adapted from a story by Christine Dell'Amore in Pensacola Beach, Florida, and Gulf Islands National Seashore

Photograph by Chris Combs, National Geographic

Gulf Spill Pictures: Toxic Oil Found Just Under Beaches

Even "clean" patches of beach along the Gulf of Mexico harbor unsafe oil just beneath the surface, as new pictures from Florida show.

DON'T MISS THE REST OF THIS STORY!
Create a free account to continue and get unlimited access to hundreds of Nat Geo articles, plus newsletters.

Create your free account to continue reading

No credit card required. Unlimited access to free content.
Or get a Premium Subscription to access the best of Nat Geo - just $19
SUBSCRIBE

Read This Next

'World’s worst shipwreck' was bloodier than we thought
World’s first ultrasounds of wild manta rays reveal a troubling truth
Titanic was found during secret Cold War Navy mission

Go Further

Subscriber Exclusive Content

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet