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

422 1 2 T H I N T E R N AT I O N A L I N Q U A M E E T I N G O N PA L E O S E I S M O L O G Y , A C T I V E T E C T O N I C S A N D A R C H A E O S E I S M O L O G Y ( PATA ) , O C T O B E R 6 T H - 1 1 T H , 2 0 2 4 , L O S A N D E S , C H I L E PATA Days 2024 K E Y W O R D S Landslides, susceptibility, San Ramon Fault (1) Departamento de Geología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile. *Email: srebolle@ing.uchile.cl Sofía Rebolledo (1) Jaime González (1) Marisol Lara (1) Gabriel Easton (1) LANDSLIDE SUSCEPTIBILITY ASSOCIATED WITH THE SAN RAMÓN FAULT, SANTIAGO ANDEAN FOOTHILLS A B S T R A C T The urban area of Santiago has expanded in last decades to Andean foothills. These areas have geomorphological and geological conditions with potential to be affected by different landslide processes. The accelerations associated with a seismic event in the SanRamon Fault (SRF) could trigger mass movements events, mainly surface landslides and rockfalls on the slopes of the mountain front of Santiago. In this study, we estimate a Susceptibility Index (SI) using an adaptation of a factor weighting methodology from Lara (2007). I N T R O D U C C I O N Andean foothills of Santiago city have geological and geomorphological conditions that make these areas susceptible to different types of landslides (Lara & Sepúlveda, 2010; Lara et al 2018). The San Ramon Fault (FSR), a reverse fault bounding the eastern edge of Santiago, is an active fault that could generate a Magnitude 7.5 earthquake (Ammirati, 2019; Easton et al., 2022). Seismic shaking can trigger landslides of many sizes from small, shallow failures in soil to large, deep rock avalanches (Fan et al., 2019). Their distribution depends on the patterns of incoming seismic waves, geology, and topography, and earthquakes can produce hot spots of high landslide density (Fan et al., 2019). Additionally, Fan et al. (2019) point out that one factor controlling the ground motion is the fault-rupture mechanism. In the case of reverse faults, the density of coseismic landslides or earthquake-