## 6 Primary Environmental Effects Induced by the August 1953 Ionian Sea Earthquakes  
### Permanent Surface Deformation in Cephalonia Island  
The main source for inventorying the primary effects of the August 1953 earthquake sequence in the southern Ionian Islands was the multiparametric and interdisciplinary research of [PERSON] et al. [21] and [PERSON] et al. [22]. Based on geomorphological, marine biological and radiometric data, in combination with earlier post-event field surveys and reports [18; 19], they found that the 12 August 1953 earthquake induced primary environmental effects, including permanent surface deformation of tectonic origin and, more specifically, coseismic uplift in the central and northern part of Cephalonia Island. More specifically, it is associated with a 0.3-0.7 m quasi-rigid-body uplift and the westward tilting of the central part of the island [21]. [PERSON] et al. studied systematically the coasts of Cephalonia and Ithaki Islands [21]. Taking into account geomorphological and marine biological observations, along with field data and radiocarbon dating results, they identified uplifted fossil shorelines in several sites of Cephalonia. Moreover, they determined the amount of the coseismic uplift attributed to the 1953 earthquake sequence in several coastal sites along:  
* the eastern coastal part of the Aenos Mt fault block
* the southern and western coasts of Argostoli peninsula
* the western coastal part of the transition zone between the Aenos Mt and the Erisos peninsula. More specifically, coseismic uplift was detected in the following areas (Figure 5):  
* in three sites along the coast located northeast of Ayia Efimia, ranging from 15 to 25 cm
* in several sites along the coast of Sami Bay, extending from Ayia Efimia located northwards to Sami located southwards (uplift ranged from 25 to 60 cm)
* in several sites along the coast of Sami Bay, extending northeastwards of Sami (uplift ranged from 30 to 40 cm)
* along the coast extending from the area located southeastwards of Sami to the area located southeast of Poros (uplift ranged from 50 to 70 cm)
* along the southern coast of the fault block of Argostoli peninsula and, more specifically, along the coast located south of Moussata village (uplift ranged from 30 to 50 c)
* along the western part of Argostoli peninsula (uplift ranged from 30 to 35 cm)
* along the western coastal part of the transition zone between the Aenos Mt and the Erisos peninsula; in particular, uplift in Mytros coastal area ranged from 30 to 70 cm
* Permanent surface deformation was not detected in the western and northern part of the island, and, more specifically, on the Paliki and Erisos peninsulas, respectively. Moreover, [PERSON] et al. conducted an interdisciplinary study along the coasts of the Ionian Islands with scientists from various scientific fields, including geology, geomorphology, marine biology and archaeology [22]. They detected uplifted shorelines strongly related to seismotectonic processes and seismic events during the Holocene. As regards Cephalonia, they detected two vertical movements that have affected the island. The first was generated between 350 and 710 AD and the second in 1953; both resulted in the uplift of the southeastern part of Cephalonia. Figure 5: Sites in Cephalonia and Zakynthos uplifted by the August 1953 earthquakes with the amount of uplift in cm in each site, based on studies conducted by [PERSON] (18), [PERSON] (19), [PERSON] et al. (2011) and [PERSON] et al. (2021). [PERSON] et al. detected coseismic uplift attributed to the 1953 earthquake sequence in Poros port (+0.55 m), in a bay located south of Poros port (+0.50 m), in Skala coastal area (+0.30 m), in Karavomylos (+0.50 m), in the coastal area west of Myrtos (+0.70 m) and in Katavothres (+0.15 m) [22] (Figure 5). Prior to the systematic research of [PERSON] et al. and [PERSON] et al.