The University of Pisa, one of the partners, compares it to a zipper coming open in its announcement<\/a>. According to Pisa, the peeling began about 10 million years ago. Today it is active beneath the highest parts of the chain.<\/p>\n\n\n\n Tavani asks readers to picture the crust as a stack of layers, not one rigid block. In the Florence university statement<\/a>, translated from Italian, he said the deepest part “is progressively separating from the upper part, dragged downward together with a portion of the Earth’s mantle.”<\/p>\n\n\n\n Coauthor Paola Vannucchi, who teaches in the same department, added that the zipper opens step by step, from west to east.<\/p>\n\n\n\n For millions of years, two linked motions shaped central and southern Italy. The Tyrrhenian Sea basin opened to the west. Farther east, the crust was squeezed, folded and stacked into the Apennines, in a system driven by subduction<\/a>, where one plate dives beneath another.<\/p>\n\n\n\n Then, about 2 million years ago, the Tyrrhenian opening largely stopped and the squeezing slowed sharply, the Florence statement explains. Even so, the Apennines still shake. They still stretch sideways and rise along their spine.<\/p>\n\n\n\n The paper’s abstract answers that puzzle head on: “lower-crustal delamination is presently the primary geodynamic driver of Apennine tectonics and seismicity.”<\/p>\n\n\n\n Reviewers asked whether that meant delamination began 2 million years ago. No, the authors wrote back in the peer review file Nature published with the paper. It has worked since about 10 million years ago, next to slab rollback, and only took the lead after 2 million years ago.<\/p>\n\n\n\n To test the idea, the group used three decades of ground GPS measurements<\/a>. They added radar maps from the Sentinel satellites of Europe’s Copernicus program for 2019 to 2023. Italy’s earthquake catalog for 2004 to 2026 and geological cross sections completed the set.<\/p>\n\n\n\n Each data set covers a gap in the others. Satellite radar is blind to north-south motion, but it maps vertical and east-west movement in fine detail. GPS stations give full 3D speeds, though only at fixed points, the authors note.<\/p>\n\n\n\n Sapienza University of Rome, the universities of Pisa and Palermo and the National Institute of Geophysics and Volcanology (INGV) took part. So did the Institute of Marine Sciences in Barcelona.<\/p>\n\n\n\n “The data show that tectonic movements and earthquakes follow a precise geographic organization,” the Florence researchers concluded. Inside the chain, the crust stretches. Toward the Po Plain and the Adriatic Sea, it is compressed, in what the university calls an accordion movement.<\/p>\n\n\n\n In the northern and central Apennines, internal stretching reaches about 0.16 inch (4 millimeters) a year. That is roughly double the 0.08 inch (2 millimeters) of overall spreading between the stable lands on either side.<\/p>\n\n\n\n About 0.08 inch of yearly shortening at the outer front makes up the difference. That is where active thrust faults<\/a> sit.<\/p>\n\n\n\n Up-and-down motion fits the same picture. Florence puts it this way. Where the deep layers come off, the crust on top can rise, and where they stay stuck, the downward pull can make the land sink.<\/p>\n\n\n\n Vannucchi called the result “apparently contradictory,” since some zones stretch while others are compressed.<\/p>\n\n\n\n Half a century ago, Pisa geologists led by Piero Elter described tensional and compressional areas in the northern Apennines. Pisa says they were the first to describe the peculiar tectonics behind the range’s landscape, earthquakes and geologic history.<\/p>\n\n\n\n Pisa’s announcement carries the names of Francesca Meneghini and coauthor Giancarlo Molli. It says the 2026 paper describes and quantifies, with modern techniques, the deep dynamics that Elter’s group sketched in 1975.<\/p>\n\n\n\n A 2014 seismic study led by Claudio Chiarabba had already proposed a retreating separation zone under the northern Apennines, and the new paper cites it.<\/p>\n\n\n\n Florence says plainly that the study does not let anyone predict when or where an earthquake will happen. What it offers is a model for interpreting where active faults lie and how the ground moves.<\/p>\n\n\n\n The peeling front itself is never seen. Its position comes from GPS, radar, quake depths and rock sections. The authors offer their elastic bending model as a first-order tool, and one reviewer judged it too simple for the full, messy physics at depth.<\/p>\n\n\n\n Reviewers also said that computer and lab models had predicted this surface pattern for two decades. The authors reply that in the Apennines, a moving hinge “is for the first time directly resolvable from geodesy.”<\/p>\n\n\n\n The full study was published in Communications Earth & Environment<\/a>.<\/p>\n\n\n\n Photo: University of Florence<\/p>\n","protected":false},"excerpt":{"rendered":" Deep beneath Italy’s Apennine Mountains, the lower crust is peeling away from the rock above it. The split runs along … <\/p>\n![\"Bare](\"https:\/\/www.ecoticias.com\/en\/wp-content\/uploads\/2026\/11\/apennine-limestone-peaks.jpg\")
When the Tyrrhenian stopped opening<\/h2>\n\n\n\n
GPS, Sentinel radar and quakes<\/h2>\n\n\n\n
Stretching inside, squeezing outside<\/h2>\n\n\n\n
Pisa’s 1975 map of the range<\/h2>\n\n\n\n
Quake timing remains unpredictable<\/h2>\n\n\n\n