Is Venice, Italy, Really Sinking?

By Susanna Redmer on March 2 2020 in Society

Floods in Venice. Image credit: Paula Kaspar from Pixabay
Floods in Venice. Image credit: Paula Kaspar from Pixabay
  • Venice is sinking at a rate of 1mm per year.
  • There are 118 islands in the Venice Lagoon.
  • Venice is constructing a gate to keep out water that might not even work.

Venice, Italy, is sinking at the alarming rate of 1 millimeter per year. Not only is it sinking, but it is also tilting to the east and battling against flooding and rising sea levels. Venice is in northeast Italy and was built on top of sediments from the Po River. Venice was originally founded as a series of 118 islands separated by canals with 400 bridges that link them. The islands sit in the Venetian Lagoon and make up this beautiful area.

Why Is Venice Sinking?

Venice is primarily sinking because of plate tectonics. Venice sits on top of the Adriatic Plate. This plate is subducting under the Apennines Mountains. Subducting is when the edge of a plate on the Earth's crust moves sideways and downwards under another plate. This process is causing this city to lose elevation. The compacting of the sediments underneath Venice also plays a role in the city sinking. A team of researchers from the University of Miami found that Venice was tilting. The western part is higher than eastern parts.

Past History Of Sinking

In the last 1,000 years, Venice has sunk around 7 centimeters or 2.75 inches. However, during the 20th century, Venice sunk about 9.44 inches. Years ago, researchers noticed that pumping groundwater from underneath the city was causing Venice to sink at a faster rate. Officials stopped the groundwater pumping, but 118 islands that are in Venice’s Lagoon are still sinking. Sinking in the lagoon’s northern section is happening about 2 to 3 millimeters per year. Southern lagoons are sinking about three to four millimeters per year. 

Venice has also been battling rising water levels since the 5th century. The city floods many times a year, with the worst flooding happening between October and late winter. Residents and visitors to the city walk on wooden planks during that time. Some high-end hotels even offer boots to their guests.

Acqua Alta

Venice experiences a phenomenon called “acqua alta.” Acqua Alta happens when the Adriatic Sea’s high tides mix with a storm. If there is a storm over open water, it pulls the surface of the water forward to create a dome with it. The water combines with strong winds and makes a surging storm tide. The water will then flood an area like Venice.

Global Warming As A Catalyst

Venice hand sculpture to remind of the threat of climate change induced sea-level rise. Image by Pixaline from Pixabay 

Global warming is also a factor. Melting polar ice caps have risen sea levels. Coastal towns and islands have felt the brunt of this. Underwater sea gates are being constructed to keep out sea waters. The project is estimated to cost around 2 or 3 billion euros, but it is not clear if this solution will work in the long-term.

Venice is a beautiful city that has many historical places that attract tourists and are in the heart's it’s people. Venice is well known for its ornate glass work, which is called Venetian glass. The carnival of Venice is held every year and attendees wear Venetian masks. Boats, water taxis, and gondolas travel on Venice's waters. Despite it’s sinking and flooding problems, Venice is one of the most beautiful cities on earth.

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