GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.1 GNGTS 2023 Seismically-induced slope instability by 13 January 2001 strong earthquake event (M w 7.7) in El Salvador territory (Central America) C. Faraone 1 , M. Di Clemente 1 , L.A. Castillo Ramos 1,2 , M.L. Rainone 3 , G. Vessia 1 1 University “G. d’Annunzio” of Chieti-Pescara, Department of Engineering and Geology (INGEO), Chieti, Italy 2 University of San Salvador, (UES), Department of Geophysics, San Salvador, El Salvador 3 University “G. d’Annunzio” of Chieti-Pescara, Department of Psychological, Humanistic and Territorial Sciences (DISPUTER), Chieti, Italy Introduction and objectives Within the international cooperation umbrella established between Italy and El Salvador (Central America), the CASTES project (Establecer y desarrollar la carrera de Licenciatura en Ciencias de la Tierra con énfasis en Geología en la Universidad de El Salvador: https://castes.agronomia.ues.edu.sv/ ) has been developing since 2020 with the financial support of AICS (Italian Agency for the Development and Cooperation) and the joined scientific coordination of the University of Palermo and Chieti-Pescara. This project has two main objectives: higher education and research activity related to the seismic hazard assessment and the co-seismic effects evaluation. One of the research objectives is focused on the co-seismic slope instability induced by El Salvador’s seismic activity that causes high human and economic losses. The high seismic hazard is here due to the volcanic and tectonic activity along the intersection of three plates and a subduction zone. Several studies have been developed on the seismicity of El Salvador (Bommer and Rodriguez, 2002; Legrand et al., 2020, among others). This study shows the results of the calculation of permanent displacements (D) values through GIS-based equations at one region within the El Salvador national territory, that is the district of Santa Tecla, located in San Salvador urban area (MASS). The prediction of seismic-induced displacements is related to the strong 13 January 2001 earthquake, an event of M w 7.7 generated at about 40 km offshore to the southern coast of the Pacific Ocean, which caused widespread damages and fatalities throughout much of the country. Utilizing the critical acceleration (a c ), together with seismic proxy parameters (peak ground acceleration PGA, peak ground velocity PGV and Arias intensity I a ) drawn from seismic stations that recorded the13 January 2001 earthquake, the value of the permanent displacements for the area of Santa Tecla have been shown by two empirical equations suggested by Jibson (2007) and Bray and Travasarou (2007). These equations have been drawn from a database collecting a large number of worldwide earthquakes to be used for regional-scale analyses.