6347 20230203102416.0 10.1038/s41598-022-22752-6 DOI SCART-2023-0112 Ammirati, Jean Baptiste Stress transmission along mid-crustal faults highlighted by the 2021 Mw 6.5 San Juan (Argentina) earthquake 2022 Understanding the mechanisms of crustal deformation along convergent margins is critical to identifying seismogenic structures and assessing earthquake hazards for nearby urban centers. In the southern central Andes (28–33°S), differences in the style of middle to upper-crustal deformation and associated seismicity are highlighted by the January 19th, 2021 (Mw 6.5) San Juan earthquake. We integrate waveforms recorded at regional and teleseismic distances with co-seismic displacements calculated from local Global Navigation Satellite System time series, to re-estimate the source parameters of the 2021 San Juan earthquake, confirming a mid-crustal nucleation depth (21 ± 2 km) and right-lateral transpressional mechanism. Considered alongside decades of seismic observations and geological data, this event provides evidence for retroarc deformation partitioning among inherited basement faults and upper-crustal structures in response to oblique convergence of the Nazca and South American plates. As they may transfer shortening to active upper-crustal faults associated with historically devastating shallower earthquakes, a better understanding of seismogenic basement faults such as the mid-crustal structure activated during the 2021 San Juan earthquake earthquake could help future re-assessment of the seismic risk in western Argentina. NO Mackaman-Lofland, Chelsea Zeckra, Martin Gobron, Kevin Scientific Reports 12 2022 1 Article number: 17939 martin.zeckra@observatory.be https://www.nature.com/articles/s41598-022-22752-6 7333749 http://publi2-as.oma.be/record/6347/files/s41598-022-22752-6.pdf 20893 http://publi2-as.oma.be/record/6347/files/s41598-022-22752-6.jpg?subformat=icon-180 icon-180 9312 http://publi2-as.oma.be/record/6347/files/s41598-022-22752-6.gif?subformat=icon icon published in REFERD