zoom link https://umontpellier-fr.zoom.us/j/94079278166

The signature of lithospheric strength on seismicity in the Central Andes

In the southern Central Andes (29°S-39°S), the oceanic plate changes the subduction angle between 33°S and 35°S from almost horizontal (< 5° dip) in the north to a steeper angle ( 30° dip) in the south. This region displays remarkable along- and across- strike variations of the tectonic deformation patterns. I will talk about the effects of the long-term yield strength of the lithosphere on the active seismic deformation of the subduction zone bordering this sector of the Andes. By using multiple geophysical approaches and data sources, we constructed the structural, density, thermal and rheological 3D models of the lithosphere. We found that most of the seismicity within the continental plate occurs above the modelled transition from brittle to ductile conditions. In addition, upper-plate seismic deformation spatially correlates with the steepest strength gradients. Our work shows that thermomechanical conditions of the lithosphere could be a key factor influencing seismic deformation in the area.

Mis à jour le 20 novembre 2024