Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

Additionally, for determining the hazard of surface rupture, the methodology proposed by Boncio (2018) is applied employed. R E S U LT S A N D D I S C U S S I O N Through the analysis of topographic profiles, 265 features were observed, with 191 of them attributable to the recent activity of the FSR (Fig. 2). These features generally exhibit a north-south orientation and extend throughout the Pirque foothills. They were observed in 236 profiles distributed along the piedmont of the Andeanmountain front with some profiles displaying up to 2 features attributable to the activity of the structure. On the other hand, there were 114 profiles where geomorphic features attributable to the FSR activity could not be identified. The observed features suggest that the footprint of the SRF in the landscape is noticeable between the Maipo River and Honda gully, demonstrating its continuity over approximately 18 km on the surface, beneath the Pirque district. The seismic hazard during a major earthquake can be estimated as associated to an earthquake of magnitude ranging betweenMw = 7.1- 7.5, with a surface rupture zone of approximately 380 m width that, theoretically, would accommodate 3 of every 4 ruptures following the general compilation and estimates of Boncio et al. (2018). C O N C L U S I O N S Through the analysis of 350 topographic profiles from high resolution LiDAR data, we observed fault scarps, other deformed surfaces and associated drainage systems allowing for the mapping of the trace of the San Ramón Fault in Pirque, located immediately to the south of Santiago, evidencing the continuity of this fault for at least ∼18 kmmore than previously known (encompassing around 50 km length along the piedmont of the Andes inMetropolitanRegion). The detailed mapping of the SRF indicates that it traverses urbanized sectors with residential areas and critical infrastructure, as well as rural areas without urbanization (Fig 3). Therefore, these results reinforce the need for incorporate it as a risk element in regional and district scales urban regulations (Easton et al., 2022), particularly in Pirque, as revealed by this work, to achieve sustainable development of the communities in the territory, including populated centers. A C K N O W L E D G E M E N T S We thank FONDECYT projects 1230350 and 1190734. Fig. 2: Map of study area showing topographic profiles (black lines) and features observed (red dots: fault scarp; orange dots: fault scarp with anthropogenic influence; yellow dots: bulging; green dots: regional slope change.