Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Geophysical Research Letters e2025GL114615 [12 p.] tomography seismology subduction zone seismic slip EQUATEUR CHILI AMERIQUE DU SUD PEDERNALES ANTOFAGASTA 2025 fdi:010094399 ENG Geophysical Research Letters 0094-8276 ISI:001536276100001 14 10.1029/2025gl114615 https://www.documentation.ird.fr/hor/fdi:010094399 https://www.documentation.ird.fr/intranet/publi/2025-09/010094399.pdf 52 Horizon (IRD) Seismic velocity models were compared with coseismic slip distributions for two megathrust earthquakes that occurred along the South American subduction zone. By analyzing the distribution of Vp/Vs ratios, we found that seismic anomalies with values higher or lower than the average coincide with the boundaries of the earthquake ruptures. In contrast, the regions characterized by intermediate Vp/Vs values may represent a mechanical "sweet spot" where the physical properties create favorable conditions for sustained rupture propagation. Our methodology, which combines the Vp/Vs distribution and the analysis of coseismic slip models, could reveal the rupture-prone regions and the likely magnitude of potential earthquakes, providing relevant information for seismic hazard assessment. 066 Chili / Équateur