## 3 Results
### Spatial Distribution of PGA and PGV
Regarding sub-area 4 (Hydra, Spetses, Figure 4d), the highest PGA value was \(\sim\)220 cm/s\({}^{2}\) and the lowest \(\sim\)170 cm/s\({}^{2}\). The value at the capital of Hydra was \(\sim\)220 cm/s\({}^{2}\), and at the capital of Spetses it was \(\sim\)190 cm/s\({}^{2}\). For Kythira and Antikythira (Figure 4e), the highest PGA value was 290 cm/s\({}^{2}\), which was again identified at Antikythira, and the lowest one was \(\sim\)260 cm/s\({}^{2}\), at the northwestern part of the Kythira Island. The value calculated at the capital of Kythira was \(\sim\)280 cm/s\({}^{2}\). PGV levels were also computed for the five sub-areas for return periods of 475 and 950 years (Figures 5 and 6, respectively). Given that the seismicity parameters were kept the same, the spatial distribution of the values remained similar to that of PGA for both return periods. Starting with the first sub-area, the highest PGV value was estimated at \(\sim\)19.0 cm/s at the western part of Attica's shoreline, whereas the lowest one was \(\sim\)4.0 cm/s at the southeastern edge of Attica. PGV in Athens was 9.0 cm/s. As for the second sub-area,  
Figure 4: The spatial distribution of PGA values for a return period of 950 years for each of the five sub-areas. (**a–e**) explanations as in Figure 3.  
the largest PGV value was \(\sim\)15.5 cm/s at the western edge of the group's shoreline, similar to the previous sub-area's case. The minimum value was \(\sim\)10 cm/s. The calculated value at the capitals of Salamina and Aegina was 13.2 cm/s for both sites. The greatest PGV level computed in the sub-area of Methana and Poros was 13.5 cm/s and the lowest was 9.0 cm/s. At Methana town, the estimated PGV value was 12.8 cm/s and at the capital of Poros it was 11.2 cm/s. In the fourth sub-area (Hydra and Spetses), the highest PGV value was \(\sim\)9.5 cm/s, and the lowest one was 7.0 cm/s. At the capital of Hydra, the value was 9.0 cm/s, and at the capital of Spetses it was 8.4 cm/s. Regarding the last group, the greatest PGV value was \(\sim\)13.0 cm/s, in proximity to Antikythira, and the lowest value was 11.5 cm/s at the northernmost edge of Kythira's shoreline. The PGV value computed at the capital of the latter was \(\sim\)13 cm/s. Concerning the return period of 950 years in the first sub-area, the highest PGV value was estimated at \(\sim\)25.0 cm/s, whereas the lowest value was \(\sim\)5.0 cm/s. PGV in the city center of Athens was computed at 11.0 cm/s. Regarding the second sub-area, the highest PGV value was \(\sim\)20.0 cm/s, whereas the lowest was \(\sim\)15 cm/s. The calculated value for the capitals of both Salamina and Aegina was \(\sim\)18.0 cm/s. The highest PGV value in the sub-area of Methana and Poros was 18.5 cm/s and the lowest was 12.0 cm/s. At Methana  
Figure 5: The spatial distribution of PGV values for a return period of 475 years for each of the five sub-areas. (**a–e**) explanations as in Figure 3.  
town the estimated PGV value was 17.5 cm/s, and at the capital of Poros it was 16.0 cm/s. Concerning the fourth group (Hydra and Spetses), the highest PGV value was \(\sim\)13.0 cm/s, and the lowest was 10.0 cm/s. At the capital of Hydra, the value was 12.5 cm/s, and at the capital of Spetses it was 11.4 cm/s. Regarding the last group, the largest PGV value was \(\sim\)19.0 cm/s at Antikythira Island, and the lowest was 16.5 cm/s at the northernmost edge of Kythira's shoreline. The PGV value in the capital of Kythira was \(\sim\)16.5 cm/s.