## 2 General Setting of the Study Area  
### Geological, Geomorphological, and Climatic Framework  
The landslide under investigation is located in north-western Italy, along the eastern coastal side of the Liguria region and the easternmost portion of the Genoa Province, in a site called Fontane di San Bernardo, which is placed in the hills immediately behind the town of Sestri Levante (Figure 1). From the geological point of view, this sector of Liguria belongs to the north-western segment of the Northern Apennine, a fold-and-thrust belt characterized by terrains referred to as oceanic, transitional, and continental paleogeographic environments. During the Apennine orogenesis, these successions were piled-up to constitute the following main tectonic units (bottom to top): the Tuscan Nappe (i.e., Tuscan Domain), the Canetolo Unit (Sub-Ligurian Domain), the Ottone Unit (External Ligurian Domain), and the Bracco-Val Graveglia, Gottero, and Lavagna units (Internal Ligurids Domain). The latter are included in the so-called Vara Supergroup succession, which is dominantly outcropping in the study area and is characterized by an ophiolitic sequence. This stratigraphic series begins with an ultramafic oceanic basement of the Jurassic Age made up of serpentinized peridotites intruded by gabbros and basalts and is followed by a volcanic sedimentary cover, spanning from late Jurassic to early Cretaceous, consisting of basalts, chaotic breccias, and cherts. The top of the sequence comprises carbonic-siliceous pelagic sediments underlying thick bodies of siliciclastic turbidites deposited from the late Cretaceous up to Paleogene [56]. The geo-structural setting results from the complex tectonic history of the Northern Apennine that, in the study area, is largely dominated by geologic structures connected to the uplift phases, which have progressively thrusted the oceanic successions onto the  
Figure 1: Geographical location of the study area: **(a)** 3D view of the coastal segment of the Sestri Levante municipality (modified from Google Earth); **(b)** detailed 3D view of the Fontane di San Bernardo site where the red line indicates the boundary of the studied landslide (modified from Google Earth). transitional and continental domains. These tectonic stages were responsible for the formation of a sequence of kilometre-scale recumbent folds and overthrusts [56]. This geologic framework has been further complicated by the post-orogenic evolution associated with the formation of the Ligurian Sea that involved distensive phases, active since the late Miocene age and throughout the Plio-Quaternary, producing systems of high-angle normal faults [57]. The geomorphological outline is largely controlled by litho-structural factors [58; 59; 60; 57]. The landscape morphology, in both inland and coastal sectors, along with the pattern of the drainage network, strongly depends on morpho-selective erosion, chiefly connected to the combined role of widespread outcrop of both strong and weak rocks and the arrangement of tectonic structures. In this regard, landforms and deposits are predominantly related to fluvial- and runoff-related processes and mass movements. Nevertheless, weak formations composed of clayey rocks typically produce gentler topography and thicker slope deposits and are generally affected by large landslides [12; 57; 61]. On a more detailed scale, the rocks outcropping at the Fontane di San Bernardo site, and in the surrounding areas, are related to two turbiditic formations belonging to the Internal Ligurian Domain [56], namely the Monte Gottero Sandstones Fm. (GOT--Gottero Unit, Late Campanian--Paleocene) and the Forcella Banded Shales Fm. (FBM--Lavagna Unit, Late Campanian) (Figure 2a,b).