The Italian Almanac


Still Sinking

Venice is still sinking and the foundation is tilting slightly eastward, a new study has found. Despite previous studies that showed that subsistence had leveled off, a forthcoming article in the journal Geochemistry, Geophysics, Geosystems shows Venice to be sinking on average of one to two millimeters per year.

Venice's 117 islands are also slipping deeper into the lagoon, with those in the north dropping at a rate of two to three millimeters per year and those in the south at three to four. The study also found that Venice is listing slightly eastward, meaning the western side is higher than the rest, a previously unnoticed phenomenon the researchers detected using a combination of GPS measurements and data from space-borne radar (InSAR) from 2000 to 2010.

High tides routinely wash over the city's banks flooding its streets and squares. The reasons Venice is sinking are both natural and man-made. Decades of pumping groundwater caused significant damage to the delicate foundation before the practice was called off. Weather experts say the high-water threat has been increasing in recent years as heavier rains have hit northern Italy. Other possible explanations for the phenomenon include the sea floor rising as a result of incoming silt and gas extraction in the sea off Venice undermining the islands.

According to the new study, plate tectonics is also to blame as the Adriatic plate is sliding beneath the Apennine Mountains, causing the area to drop in elevation. Scientists have conceived various ways of warding off the waters since a catastrophic flood in 1966 and a system of moveable flood barriers called MOSE is near completion after years of polemics.