## 2 Study Area  
The study area is close to the Gulf of Corinth which is considered to be a paradigm of an active rift system in Greece (Figure 1; [22]) and is among the fastest extending continental regions in the world [15; 23; 24; 25]. This rift was formed by normal slip on large, E-W striking fault segments that extend the crust of central Greece in a N-S direction. The length of the Corinth rift is 130 km, and the width is 20-40 km. The deepest sea depth is \(\sim\)900 m, and the major peaks of the mountains around the Gulf of Corinth are \(\sim\)2500 m. The south coast of the Corinth rift is uplifting, whereas the north part is subsiding [22; 25; 26; 27; 28]. From space geodesy data (GNSS) we know that the Peloponnese (southern part) moves faster toward the southwest than the Greek mainland (with respect to the \"stable\" Europe; [23; 25; 29]). The net result from this movement is that these two areas move away from each other with an average speed of 1 cm/year while the rate of movement increases from east to west [23; 24]. The onshore active faults have normal kinematics with the main active structures being north-dipping faults visible along the southern coast of the Gulf of Corinth, while the rest are located offshore in the central part of the rift [29; 30; 31; 32]. Moreover, the study area has rugged relief, several rivers flowing in the general N-S direction (Figure 1), many narrow valleys and numerous other erosional landforms such as triangular faceted spurs on the footwall of active faults [33; 34; 35; 36]. Moderate to strong earthquakes occur frequently, inducing additional geological phenomena such as slow and continuous ground displacements in the area [13; 15; 37]. The area of Achaia specifically has been the focus of many studies concerning landslide events and vulnerability in the last decade [13; 14; 21; 38; 39; 40; 41; 42; 43; 44]. The lithological condition of this area is one of the most controlling parameters for landslide occurrence [38; 39]. The higher density of landslide occurrence is in Pliocene and Pleistocene fluvio-terrestrial and clastic flysch formations [39]. The most common triggering mechanisms are the seismicity, the steepness of slopes, heavily fractured rocks in the source areas and heavy rainfall [37; 45]. The artificial and natural parts of the terrain slopes along a road, as well as the hydrographic axes of river networks, are also considered important factors for landslide manifestation [39; 46]. From these common factors [PERSON] et al. [13] proposed two main triggering mechanisms for large mass movements in the area, i.e., the excessive rainfall resulting in high pore pressure in the rocks during these events and strong earthquakes resulting in dynamic loading conditions at the failure surface. Therefore, the increased permeability of the rock formations produced by earthquakes (due to strong ground motion and/or fissuring) together with events or periods of intense rainfall are the main factors for the intensity of landslide events. The bedrock geology of Achaia comprises mainly carbonates (Figure 1b). According to IGME (institute of Geological and Mineral Exploration) maps [47; 48], the study area is part of the Olonos-Pindos geotectonic zone of the Hellenides and mainly comprises limestone, schists and cherts of the Triassic-Jurassic age, covered by thinly bedded limestones with radiolarites of the Cretaceous age. A transition zone overlays the radiolarites, including limestones, shales, cherts and marls, leading to typical flysch sequence sediments of the Upper Eocene [13]. The syn-rift rocks are Pliocene-Quaternary age sedimentary rocks such as marls, sandstones, conglomerates and alluvial fan deposits. In this paper we focus our research on the northern / eastern slopes of Panachaiko mountain, with emphasis on well-known landslide activity near the villages of Krini, Pititsa and the monastery of Agia Eleoussa (Figure 1a). In particular, the area around Krini (elevation 775 m; Figure 1b) mostly consists of the Upper Cretaceous-Paleoocene flysch.