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. In the last 1, years, Venice has sunk around 7 centimeters or 2. However, during the 20th century, Venice sunk about 9. Years ago, researchers noticed that pumping groundwater from underneath the city was causing Venice to sink at a faster rate. Southern lagoons are sinking about three to four millimeters per year. Venice has also been battling rising water levels since the 5 th century.
Twentieth-century industry worsened things by pumping out massive amounts of groundwater from the aquifer beneath the lagoon for nearly 50 years before the government stopped the practice in the s. In the last century, Venice has sunk by about nine inches. Meanwhile, the waters around Venice are rising, a phenomenon that's especially apparent in winter.
The notorious acqua alta happens when an unusually high tide combines with strong sirocco winds and a storm. In November a huge storm the same one that famously flooded Florence raised Venice's water level to more than six feet above the norm. Although tides are minuscule in the Mediterranean, the narrow, shallow Adriatic Sea has about a three-foot tidal range. When a storm — an area of low pressure — travels over a body of water, it pulls the surface of the water up into a dome.
As strong sirocco winds from Africa blow storms north up the Adriatic, they push this high water ahead of the front, causing a surging storm tide. Add to that the worldwide sea-level rise and it makes a high sea that much higher.
If the acqua alta appears during your visit, you'll see the first puddles in the center of paved squares, pooling around the limestone grates at the square's lowest point. These grates cover cisterns that long held Venice's only source of drinking water. That's right: Surrounded by the lagoon and beset by constant flooding, this city had no natural source of fresh water.
For centuries, residents carried water from the mainland with much effort and risk. According to The Guardian, it's only the sixth recorded time the church has flooded in the last years, but the fourth in the last 20 years.
Venice is sinking, and this time it may go under. Venetians have always recognized that human choices would shape their relationship with the natural world.
The sixth-century Roman statesman Cassiodorus described the Venetians gorging themselves on fish, harvesting salt, and living in "scattered homes, not the product of Nature, but cemented by the care of man into a firm foundation. Rather, as the French historian Elizabeth Crouzet-Pavan has shown , Venetians knew that the ecology of their lagoon was fragile and that either too much or not enough water flowing in or out could spell their destruction.
They build up the thin islands that sheltered the lagoon. They engaged in complex hydrology projects to shift the flow of rivers. They watched as the neighboring city of Torcello collapsed in the mud, plague-ridden, malarial swamp. Italian council is flooded immediately after rejecting measures on climate change. I lived in Venice during the fall and winter of , residing in a little apartment on the Street of Paradise, above an antique bookshop, right by the church of Santa Maria Formosa the beautiful.
I was studying how medieval Venetians told stories about their city, building rich narratives that linked the city's destiny to complicated networks of trade and culture that stretched across the Adriatic and Mediterranean Seas. Every day I would walk down streets that followed medieval paths and work with both textual and visual evidence in a library across from the great Basilica.
Often I would wind my way through crowds of tourists and pigeons to the "prayer" door in the church, chatting with the guards as I made my way inside to stare up at gold mosaics. How long until the great church is only accessible by boat, if at all? Read More. Like medieval Venetians, the modern ones have turned to massive civic projects in an attempt to hold back the tide, patterning its Project Moses on similar works in Holland.
Moses, a linked system of 78 gates , was proposed in the s. Work began in Corruption scandals and incompetent management delayed completion, but it's scheduled to be fully operational by I worry, as do others , that at best a fully operational Project Moses would just buy time, but one cannot simply build a wall to stop the ever-rising waters and the fiercer weather caused in our warming world.
0コメント