Huge Slope Collapses Flashing the Andean Active Orogenic Front (Argentinean Precordillera 31–33°S)

Abstract

The study area is located along the Andean active orogenic front comprising the most seismically active region of Argentina. Main Quaternary deformation is concentrated in this Western central part of the country associated with active faults linked to an intense shallow seismic activity (<35 km depth). During the last 150 years, the region has suffered at least six major earthquakes with a magnitude greater than Ms ≥ 7.0. The focus of this research is to analyse the landslide behaviour along this Andean active orogenic front. To that end, we carried out a landslide inventory along Precordillera (31°–33°S). We analysed type, size, activity grade and other morphological parameters of these landslides. We found huge collapses coincide with traces of active Quaternary faults in this region. However, landslides are clustered being denser splayed in the centre of study area. Furthermore, activity grade of such landslides is higher in this central zone decreasing gradually towards the north and the south. This central area is affected by the Juan Fernandez Ridge which is likely related to higher deformation rate.