"Like a zipper": The enormous process along 500 km taking place beneath Italy

A new study explains a unique geological phenomenon in the Apennine mountain range in Italy: heavy layers of the Earth's crust are gradually separating and sinking toward the planet's interior in a process spanning more than 500 kilometers. The phenomenon, known as delamination, creates an "accordion" motion where some areas of the range are stretched while others are simultaneously compressed. Researchers compare it to the opening of an underground zipper.

A new study, led by Dr. Stefano Tavani of the University of Florence, solves a geological puzzle that has occupied scientists for years: why parts of the Apennine mountain range in Italy are stretching while others are contracting at the same time. The answer, published in the journal Communications Earth & Environment, is a process of delamination – heavy, dense layers in the lower part of the Earth's crust and the rock mantle beneath it peel away and detach from the upper layer. The process advances gradually as a wave moving forward over more than 500 kilometers, similar to the opening of a zipper. The researchers combined data from earthquakes, satellite measurements, and scans of the geological boundary line "Moho," and discovered an anomalous strip where the rock structure on the western side overlaps with the structure on the eastern side. In areas where the layers have already sunk, the ground expands at a rate of about four millimeters per year; in areas where the layers are still attached, compression of about two millimeters per year occurs. The scientific community clarifies that there is no cause for concern – this is a natural and extremely slow mechanism.