Officials first addressed the problem decades ago when they learned that centuries of building, along with pumping groundwater from underneath the city, caused subsidence. (Subsidence is the gradual caving in or sinking of a piece of land.)
The study, published on March 28 by the Geochemistry, Geophysics, Geosystems Journal, showed that continued subsidence is due to natural forces. Researchers from Scripps, the University of Miami and a company from Milan named Tele-Rilevamento Europa assembled the data.
The team used a combination of GPS data and interferometric synthetic aperture radar data (InSAR).
InSAR uses radar and satellites to generate maps of the earth’s surface, and look for deformations or elevations; it is generally used to measure earthquakes, landslides and volcanic activity.
The report used the combined analysis from five different stations in Venice from 2001-11.
It said that the city continues to sink at a rate of one to two millimeters per year.
In addition, the data revealed that the city is sinking slightly toward the east due to plate tectonics.
The GPS results indicate a general eastward tilt in subsidence due to the Adriatic plate sliding beneath the Apennines mountains.
“The city of Venice asked us to start monitoring the sinking using GPS technology that we had developed here in California,” Scripps researcher and geodesist Yehuda Bock said. “[We were] commissioned by the group to help them build GPS monitoring stations to look at the data over the long term, to look for subsidence in the city.”
Bock said that Venice’s coastal regions have been affected by storms and rising sea levels predicted by global warming models.
He added that Venice has dealt with tidal-induced seasonal flooding every year.
In a March 20 article from ouramazingplanet.com article featuring Dr. Bock, he explained that floods are a big problem along Venice’s canals.
Often, Bock said, residents use wooden planks to navigate floodwaters in large parts of the city during storms throughout the year.
The article stated the city of Venice has created a multibillion-dollar effort to install flood protection walls that can be raised to block incoming flood waters.
Bock said that the city has created these preventive methods to protect Venice from overall rising sea levels due to climate change.
“We just supplied information about the subsidence in the area,” Bock said. “They have to use and take that into account in their engineering implementation.”
