## 8 Results
### Distribution of Effects on Susceptible Zones
#### 8.3.1 Slope Failures  
Slope failures constituted about 40.8% of the detected effects in the southern Ionian Islands and were the dominant effects triggered by the studied 1953 earthquakes. Slope failures were distributed on several lithologies, which were obtained from the respective neetectonic maps presented in Figure 16. 24 slope failures were generated in post-alpine deposits (49% of the total failures) and 25 in alpine formations of Paxoi and Ionian units (51% of the total failures) (Figure 16a). The majority of slope failures (22 out of 49, 44.9%) were triggered in carbonate rocks, comprising Triassic-Middle Miocene limestones of the Paxoi unit (14 failures, 28.6%) and Jurassic-Cretaceous limestones of the Ionian unit (7 failures, 14.3%) in Cephalonia as well as the Upper Cretaceous limestones of Paxoi unit (1 failure, 2.0%) in Zakynthos (Figure 16b). The next-most affected lithologies are comprised of interglacial deposits of Middle Pleistocene age (8 failures, 16.7%) and scree and talus cones of Middle Pleistocene age (7 failures, 14.3%) (Figure 16b), all located on Cephalonia island. As regards the type of the triggered slope failures, we conclude that the majority were rockfalls (46 failures out of 49, 93.9%), while mixed-types, consisting of slides and rockfalls, were also triggered (3 failures out of 49, 6.1%). Regarding the impacts on the built environment of the southern Ionian Islands, several rockfalls considerably affected buildings in villages, resulting in greater fatalities and injuries. Characteristic examples are Tzanata, Chionata, Plateies and Anninata villages, where rockfalls triggered by the 11 and 12 August earthquakes increased the number of fatalities and injured people; Kourouklata, Valsamata and Kolaitis villages, which were completely destroyed by rockfalls generated by the 12 August 1953 earthquake; as well as Zervata, Katapodata, Atsoupades, where rockfalls induced by the 12 August mainshock caused extensive structural damage to their buildings. Beyond these effects, slope failures affected also the livestock in several villages and vegetation, including mainly olive groves and vineyards. As regards the spatial distribution of slope failures, the landslide susceptibility maps of the Ionian Islands compiled in the frame of the project titled \"Telemachus--Innovative Operational Seismic Risk Management System of the Ionian Islands\" [Priority Axis \"Environmental Protection and Sustainable Development\" of the Operational Programme \"Ionian Islands 2014-2020\"] [52; 53; 54] were used. For the compilation of the maps, various factors were taken into account, which favor the occurrence of slope failures, including slope, aspect, curvature, lithology, proximity to faults, roads and streams, soil thickness and land use. The analytical hierarchy process was used, along with the weighted linear combination method, in the framework of a multiciteria decision analysis for the calculation of the landslide susceptibility index (LSI). The result of this approach is the landslide susceptibility map of the Ionian Islands, shown in Figure 17.  
Figure 16: Pie charts showing the distribution of slope failures triggered by the 12 August 1953 mainshock and its 9 and 11 August foreshocks (**a**) in geological units and (**b**) in geological formations. Figure 17: Comparison of the inventory of slope failures triggered by the August 1953 earthquakes in Cephalonia, Ithaki and Zakynthos with the landslide-susceptibility maps of the islands. By comparing slope failures induced by the studied 1953 earthquakes in the southern part of the Ionian Islands with the respective susceptibility maps for Cephalonia, Ithaki and Zakynthos, it is concluded that the largest percentage of slope failures (42.9%) were generated in zones characterized by high susceptibility (LSI = 42.1-60), while 26.5% of slope failures were induced in zones with moderate susceptibility (LSI = 35.1-42), 26.5% in zones with low susceptibility (LSI = 25.1-35) and 4.1% in zones with very low susceptibility (LSI < 25) (Figures 17 and 18).