From the earthquake to the current dynamics of the Western Alps

Mountain ranges are in constant motion. This is the case of the European Alps which, particularly in their western part, are rising by a few mm/year. The paradox ? The western Alps are at the same time characterised by a horizontal extension through the chain, and no longer by shortening as when they were formed. Several geophysical methods make it possible to measure this constant evolution in order to better understand its origin. More specifically, seismotectonics makes it possible to study the movements of the Earth’s crust during earthquakes. Thanks to the joint data from the regional Alpine stations of Résif (Sismalp) and the stations of the French, Italian and Swiss national networks, more than 30,000 earthquakes have been recorded in the Western Alps between 1989 and 2013. Recent work has benefited from this hitherto unprecedentedly accurate catalogue, in order to establish the 3D seismic deformation field of the western Alpine chain, with a view to gaining a better understanding of the drivers of its current dynamics.

To know more about it

Read the full story on the CNRS-INSU website (in French)

Reference : Present-day geodynamics of the Western Alps: new insights from earthquake mechanisms – Marguerite Mathey, Christian Sue, Colin Pagani, Stéphane Baize, Andrea Walpersdorf, Thomas Bodin, Laurent Husson, Estelle Hannouz, and Bertrand Poti. https://doi.org/10.5194/se-12-1661-2021