Pictures: Venice Flood Makes a Swimming Pool of St. Mark's

Off the Deep End?
Photograph by Luigi Costantini, Associated Press
Floods in Venice usually mean breaking out the waders, but a few adventurous souls in St. Mark's Square threw in the towel Sunday and stripped down to swimsuits.
It's normal for Italy's "eternal city" to flood in winter, but Sunday's 5-foot (1.5-meter) inundation is the sixth highest since record-keeping began in 1872, according to the Reuters news service. (Interactive map: See how much of Venice floods at different water heights.)
"Usually flooding occurs when there is high tides and rain." Recently "strong winds from the south further enhanced the high-tide conditions," explained Shimon Wdowinski, a geophysicist at the University of Miami.
Most parts of Venice don't flood during the acqua alta ("high water"), but on Monday three-quarters of the city was underwater. As of Tuesday, the water level has begun to recede, but it may take a while, Wdowinski said. "Venice sits in a lagoon that has three outlets to the Adriatic Sea. In cases of heavy rain, like now, it takes time for the water to flow out."
A barrier to protect the city from repeated winter flooding—known as the MOSE project —is due to be finished by 2014. Until then, "there's not much that can be done," Wdowinski said. (See "Injections Could Lift Venice 12 Inches, Study Says.")
—Ker Than
Published November 13, 2012
Diving Lesson
Photograph by Luigi Costantini, Associated Press
Days before Venice floodwaters reached their current record levels, a woman and child play in St. Mark's Square on October 27. While tourists in the lagoon city may be taking the unusually high tides in stride, related flooding has claimed lives outside of Venice. In Tuscany two men and a woman died when their car fell off a collapsed bridge on Tuesday.
Published November 13, 2012
Early Departure?
Photograph by Luigi Costantini, Associated Press
A tourist shoulders her suitcase in Venice's St. Mark's Square on Sunday. (Travel tips: Venice must-dos.)
On average, the high tides submerge the lowest 14 percent of Venice four times a year, but this past weekend's flood levels affected 70 percent of the city. During floods, Venice erects several miles of wooden walkways, called passerelle, across the city, and many hotels keep galoshes on hand.
Published November 13, 2012
Wet Bar
Photograph by Manuel Silvestri, Reuters
People dressed in rain gear sit on chairs in a flooded St. Mark's Square in Venice earlier this month. (See National Geographic pictures of "vanishing Venice.")
The MOSE project, sometimes called "Project MOSES," could help reduce flood damage. Begun in 2003 and slated for completion in 2014, MOSE will string four giant barriers made of hollow steel floodgates across the three inlets to Venice's lagoons.
When unusually high tides threaten to flood the city, air will be pumped into the gates to make them buoyant. The gates will rise, sandbagging the city against the rising tide. When the tide recedes, water will flow back into the gates, causing them to lower.
Published November 13, 2012
Rising Tide Lifting All Boats
Photograph by Manuel Silvestri, Reuters
During this month's floods, a kayak glides over a barrier at the edge of St. Mark's Square that would normally stop the boat cold.
Venetian flooding could someday be buffered by Project MOSES, but the sea gates aren't the only options under review.
Other scientists have suggested injecting billions of gallons of seawater into porous sediments beneath the island city, inflating them and raising Venice by as much as a foot (30 centimeters) over a period of several years.
Proponents of this idea say that it could compliment the MOSE project and reduce the number of times MOSE would have to be used from 35 times a year to 4.
While subsurface fluid injection has been used by oil companies to raise land in California and Canada, the technique has never been tried on a city, Wdowinski said.
"It's a very interesting idea ... but it could cause structural damage to the city," he added. "They'll want to do a test site before trying it on Venice."
Published November 13, 2012
First Responders
Photograph by Manuel Silvestri, Reuters
Prior to Venice's record flooding this past weekend, nurses carry a man on a stretcher on November 1.
In the same way Hurricane Sandy, which devastated portions of the U.S. eastern seaboard last month, was strengthened by its merger with another storm, the flooding in Venice this weekend was made worse by the combination of two large weather systems, meteorologists say.
According to the Washington Post, a large area of low pressure over the Mediterranean Sea combined with high pressure over the Balkans to funnel wind and water up the Adriatic Sea, producing torrential rains in and around Venice. (Hurricane Sandy Pictures: Floods, Fire, Snow in the Aftermath.)
Published November 13, 2012
Under Cover
Photograph by Manuel Silvestri, Reuters
A man ferries a woman on his back through flooded streets in Venice on Sunday.
As was the case with Hurricane Sandy, some scientists have implicated climate change in the dangerous flooding in northern Italy this past weekend. According to Reuters, Italy's environment minister, Corrado Clini, has insisted global warming is responsible.
Published November 13, 2012
Open During Destruction
Photograph by Manuel Silvestri, Reuters
Apparently protected from record floodwaters, a man rests in a Venice shop Sunday. The annual floods are made worse by the fact that the city is currently sinking about 0.08 inch (2 millimeters) per year, according to a study co-authored by Wdowinski that was published in the journal Geochemistry, Geophysics, Geosystems earlier this year.
Published November 13, 2012
Life on Hold
Photograph by Manuel Silvestri, Reuters
A woman stands atop a bench to escape rising floodwaters in Venice on Sunday. (Venice quiz: How well do you know the eternal city?)
Not only is Venice sinking at a slow-but-steady rate, but the surrounding Adriatic Sea is swelling, scientists say. The local sea level is predicted to rise by perhaps a foot (30 centimeters) by the end of this century, hydrologist Giuseppe Gambolati told National Geographic News in 2011.
Published November 13, 2012
No Boots? No Problem.
Photograph by Manuel Silvestri, Reuters
With plastic bags tied around their legs, tourists strolled through Venice on Sunday.
Scientists predict that Venice will flood more frequently as sea levels rise and storms become more intense due to global warming. Climate change computer models predict that "the pattern of the rain will change," the University of Miami's Wdowinski said. "We'll have more of these strong events."
(See National Geographic magazine's "Vanishing Venice.")
Published November 13, 2012
A Walk to Remember
Photograph by Manuel Silvestri, Reuters
High floodwaters in Venice this weekend made the water levels in the city's canals and on the streets about even. (See pictures of Venice's Grand Canal.)
Even under the worse case climate change scenario, Venice won't become completely drowned anytime soon, scientists say. "That would require a sea level rise of about 30 feet [9 meters], and that won't happen in the next century," Wdowinski said.
More: Explore Charlie Chaplin's Venice >>
Published November 13, 2012