Sadly, this is not an April Fool's prank. We've long known that the city of Venice is slowly sinking into its own watery grave. While city officials thought they had halted Venice's descent, it turns out that the city is still sinking — and five times faster than originally believed.
While some coastal regions of the world are concerned with rising sea levels, Venice has an additional problem: the city is settling. Centuries of building has caused the ground underneath to compact, and pumping groundwater from beneath the city may have also contributed to the city's diminishing stature. But it appears that natural causes are likely to blame as well. The Adriatic tectonic plate subducts nearby, lowering the city's elevation. After groundwater pumping was ceased in a bid to stabilize the ground, studies in the 2000s reported that the city was no longer sinking.
However, a recent report from Scripps Institution of Oceanography has found that the city is still sinking, and more quickly than was originally reported:
"Venice appears to be continuing to subside, at a rate of about 2 millimeters (.07 inches) a year," said Yehuda Bock, a research geodesist with Scripps Institution of Oceanography at UC San Diego, and the lead author of the new research paper on the city's downward drift. "It's a small effect, but it's important," he added. Given that sea level is rising in the Venetian lagoon, also at 2 millimeters per year, the slight subsidence doubles the rate at which the heights of surrounding waters are increasing relative to the elevation of the city, he noted. In the next 20 years, if Venice and its immediate surroundings subsided steadily at the current rate, researchers would expect the land to sink up to 80 millimeters (3.2 inches) in that period of time, relative to the sea.
Although the changes have been small, Venice has experienced a noticeable increase in flooding. Scripps notes that, in addition to the flood barriers Venice has already erected, officials will have to find a way to combat the region's soil compaction.
Photo by billandcathy.