## 2 Study Area
### Study Sites  
In the frame of susceptibility and hazard assessment in the Ionian Islands for highlighting sites of earthquake-related hazards, [PERSON] et al. [82] studied the landslide susceptibility of the Ionian Islands by applying the Analytical Hierarchical Process (AHP) used along with the Weighted Linear Combination (WLC) method in the context of multi-criteria decision analysis for the calculation of the Landslide Susceptibility Index (LSI). Based on the applied methodology and the respective results, it is concluded that the abrupt coastal slopes and scarps in the western part of Lefkada are characterized by high and very high susceptibility to earthquake-triggered landslides (Figure 2b). Indeed, the western coastal part of the island has been heavily affected by landslides triggered by historical and recent earthquakes [64; 79; 83]. In particular, landslides comprising mainly rockfalls have been triggered by earthquakes on:  
* 22 November 1704 (M = 6.3, I = IX). * 22 and 23 March 1783 (M = 6.7, I = X for the event on 23 March). * 14 December 1885 (Ms = 5.7, Mw = 5.1). * 27 November 1914 (M = 6.3, I = IX). * 22 April 1948 (Mw = 6.5, I = IX). * 30 June 1948 (Mw = 6.4). * 14 August 2003 (Mw = 6.2, Ms = 6.4, I = VIII). * 17 November 2015 (Mw = 6.4, I = VIII). Among the areas affected by earthquake-triggered landslides are the coastal areas of Egremnoi and Porto Katsiki (Figure 3), located in southwestern coastal Lefkada [64; 84; 85]. They constitute typical cases of extensive coastal slopes, where the change in morphological slope is so abrupt that almost vertical planes are formed. In addition to faults and joints, the continuous marine and terrestrial erosion processes play an important role in the evolution of these coastal slopes. The geological structure of Egremnoi and Porto Katsiki is similar, as both are composed of Jurassic-Moecene limestone of the Paxoi unit. They are intensively faulted resulting in their disintegration and brecciation, while locally completely pulverized and extremely unstable. They are extremely susceptible to landslides, a fact that has been revealed not only by the landslide susceptibility assessment of [PERSON] et al. [82], but also by the triggering of landslides not only by nearby earthquakes but also by distant earthquakes (Figure 3). Typical examples of landslides induced by nearby earthquakes are the rockfalls and slides caused by the earthquake on 17 November 2015 (Figure 3). In the Egremnoi area, a large mass comprising loose limestone blocks, semi-cohesive scree with limestone breccia and red clay was mobilized during the 2015 earthquake and rolled down towards the adjacent beach, which was almost entirely covered by landslide material [78] (Figure 3a-c). Furthermore, the part of the road network leading to the beach was completely destroyed, and some buildings found on the edge of the slope were at risk of total collapse [86; 87]. As regards the presence of residents and tourists in this area, it was fortunate that the earthquake was generated during the winter season and the beach was empty. In Porto Katsiki, loose brecciated limestone blocks were detached from the abrupt limestone slope and fell on the narrow beach [78] (Figure 3f). It is significant to note that both beaches are amongst the most beautiful and visited in the Mediterranean with thousands of locals and tourists attracted during the summer season staying close to the steep limestone slopes or inside coastal caves. Fortunately, the 2015 earthquake was generated during the winter season with very limited tourist flow in Lefkada and both beaches were totally empty. A typical example of landslides induced in these areas by distant earthquakes comprises the rockfalls triggered in the large coastal slope of Porto Katsiki by the 8 June 2008, Mw = 6.8, Andravida (NW Peloponnese, Western Greece) strike-slip earthquake [88] (Figure 3d). The epicenter was reported at a distance of 110 km southeast of the affected slope.