The Alps are growing for two reasons: On the one hand, the African Plate presses against the Eurasian Plate and the mountains fold up at the boundary. On the other hand, an enormous load has disappeared from the Earth's crust since the end of the peak phase of the last glaciation about 20,000 years ago. Glaciers had dented the crust hundreds of metres, now it is lifting again. Exactly which of these processes took place in which parts of the Alpine region is still not clear.

Researchers led by first author Ajay Kumar from Section 4.5 "Basin Modelling", together with colleagues from Kiel and Mainz, have now found an explanation using models and geodynamic simulations. Although there are still some uncertainties, the picture of the deep subsurface of that region is slowly brightening. They have published their results in the journal Geophysical Research Letters.

According to their findings, subduction no longer takes place under the Alps, i.e. one plate no longer slides under the other. Under the Apennines, which lie south of the Alps and run through large parts of Italy from northwest to southeast, the subduction process is still going on.

Knowledge of the processes underground is not only interesting for geology, but is also very important for the people who live between the Alps and the Apennines. After all, the earth shakes more frequently there and a more precise knowledge of the subsurface helps to assess the earthquake risk.

Read more about the results of the study here.

Original publication: Kumar, A., Cacace, M., Scheck-Wenderoth, M., Götze, H.-J., & Kaus, B. J. P. (2022). Present-day upper-mantle architecture of the Alps: Insights from data-driven dynamic modeling.  Geophysical Research Letters, 49, e2022GL099476. https://doi.org/10.1029/2022GL099476