Medieval Earthquake Moved River 12 Miles

The Po, the longest river in Italy, has shifted northward about 12 miles (20 kilometers) between the towns of Guastella and Ficarolo over the past 2,800 years, researchers reported July 20 in the Journal of Geophysical Research: Solid Earth. This shift likely happened in spurts, forced by quakes.

The 1570 temblor caused a 4- to 6-inch (10 to 15 centimeters) uplift of the right flank of the river and resulted in a major one-time shift of the final portion of the waterway, according to geoscientists Livio Sirovich and Franco Pettenati of the National Institute for Oceanography and Experimental Geophysics (OGS) in Trieste. As a result of the quake, the river’s delta moved 25 miles (40 kilometers) north, to its current position.

The 1570 quake was a 5.8-magnitude event and caused widespread damage in the city of Ferrara. At the time, Pope Pius V blamed God’s wrath for the destruction, because the city was a refuge for Jews. The damage prompted Italian architect Pirro Ligorio to invent the first buildings designed to withstand earthquakes, according to Italian historians.