(A) Synthetic structural map of the study area (black box) showing the main tectonic domains mentioned in the text and the course of the Rhône and Ardèche rivers in dotted blue lines. (B) Seismotectonic map of the lower Rhône Valley between the Cévennes Fault and Nîmes Fault. Plotted historical earthquakes are from SisFrance Database (www.sisfrance.net: data from SisFrance, BRGM, EDF, IRSN, 2022), magnitudes from FCAT (Mw catalog − Manchuel et al., 2018). BDFA refers to the Potentially Active Fault Database (Jomard et al., 2017), paleoseismological works reported in Baize et al. (2002) and Bellier et al. (2021).