New Orleans Sinking Faster Than Thought, Satellites Find

<< Back to Page 1   Page 2 of 2

Key infrastructure like roads and hospitals may also be far lower than previously believed, putting them at greater risk of future flooding, Dokka said.

What's Causing New Orleans to Sink?

While scientists agree that parts of New Orleans are sinking, they don't agree on the rates or the root causes of the subsidence.

"There is a raging debate on rates of subsidence, how you measure it, and what's really happening," said University of Texas at Austin geologist Charles Groat, former director of the U.S. Geological Survey.

Groat explains that understanding this process is critical, but answers have proven elusive.

Subsidence has been attributed to geological processes, the weight of aboveground development, and the withdrawal of oil, gas, and water from shallow underground reservoirs.

(See a 2004 National Geographic magazine feature on New Orleans' vanishing coastline.)

"Members of the scientific community have squared off against each other in polite and not-so-polite terms," Groat said.

Areas built on reclaimed marshland, like much of New Orleans, may be particularly susceptible to continued subsidence, he explained.

"All [scientists] are in agreement that the subsidence issue is a huge one. Combined with sea level rise, it's a supreme challenge in low-lying coastal areas and a key part of any future plans for the [Gulf] Coast."

The study's authors hope that their findings will cast more light on a critical issue.

"There's an interagency group studying why the levee system failed, and a [National Academy of Sciences] report that came out, but neither of these really dealt with subsidence in any meaningful way," Dokka said.

"Engineers need to understand more about geology. Maybe this will help them."

Free Email News Updates
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).

<< Back to Page 1   Page 2 of 2


SOURCES AND RELATED WEB SITES

ADVERTISEMENT

NATIONAL GEOGRAPHIC'S PHOTO OF THE DAY

NEWS FEEDS     After installing a news reader, click on this icon to download National Geographic News's XML/RSS feed.   After installing a news reader, click on this icon to download National Geographic News's XML/RSS feed.

Get our news delivered directly to your desktop—free.
How to Use XML or RSS

National Geographic Daily News To-Go

Listen to your favorite National Geographic news daily, anytime, anywhere from your mobile phone. No wires or syncing. Download Stitcher free today.
Click here to get 12 months of National Geographic Magazine for $15.