## 4 Results and Discussion
### Interpretation of the Observed Ground Deformation  
The maximum \(V_{\text{LOS}}\) away from the sensor (i.e., negative values) that is observed after calibrations is \(-8.5\) mm/year from the PS dataset and \(-18.1\) mm/year from the DS dataset (Figure 6). PS and DS with the strongest movement away from the sensor are located on the eastern flank of the peninsula. Considering the ascending mode-looking geometry and the orientation of the LOS, this could plausibly indicate the occurrence of downslope mass movements. Compared with the topography displayed in Figure 1b, these movements concentrate on the volcanic ranges and gully erosion landforms above the urban settlements of Methana, Kipseli, Agii Teodori and Agios Georgios. Photo interpretation using Google Earth imagery, however, did not highlight changes of specific landforms for the 2012-2019 period. The maximum \(V_{\text{LOS}}\) towards the sensor (i.e., positive values) from the PS dataset is \(+7.5\) mm/year, and that from the DS dataset is \(+3.8\) mm/year (Figure 6). Some values above \(+3.0\) mm/year are observed for very few PS and DS scatterers, mainly located on the western flank of Methana peninsula. These scatterers are, however, characterized by a high uncertainty of their deformation rate (i.e., up to 4.0-5.0 mm/year). Their estimated velocities are therefore not considered as robust as those of other scatterers characterized by higher precision. The northern portion of Methana town is built onto alluvium, and it seems more stable (\(V_{\text{LOS}}=-1.8\) mm/year) than the central zone of the town, which is moving away from the satellite at \(-2.5\) mm/year (Figure 8a), although both zones show velocities within the range of stability. The central zone is built onto volcanosts (Figure 8c), and the southern zone onto limestone (\(-2.9\) mm/year). The southern zone is moving away from the satellite with relatively low \(V_{\text{LOS}}\). Overall, it appears that the majority of the urban area footprint (Figure 8d) is not affected by significant deformation, while somehow, greater rates are found in the suburban zones, as revealed by the DS targets. The deformation scenario at Vathi and Paleokastro (Figure 9a) shows that there is a slight movement away from the satellite also in this sector of the peninsula. Similar to what was observed for Methana town, PS targets in the region indicates that the urban areas have a mean value of \(-0.9\) mm/year, while the DS targets for the suburban and more rural zones show \(-3.1\) mm/year. Annual LOS velocities do not reveal any significant deformation patterns across the sparsely vegetated outcrops at Mavri Petra (Figure 10a), which mostly shows both PS and DS with \(V_{\text{LOS}}\) in the range of \(\pm 3.0\) mm/year and absence of any clear deformation patterns from the sole observation of the annual LOS velocities. However, evidence of seasonal deformation can be detected in the time series at several locations across the peninsula, including at Mavri Petra (Figure 10b) and at many other sites, for instance at Vathi and Paleokastro (Figure 9b) and at Methana town (Figure 8b). However, in the latter, this happens with less prominent amplitudes. The detected seasonal fluctuations at Mavri Petra are significant, both for PS with LOS velocity close to 0 mm/year and for PS with higher LOS velocity. Those displacements have an amplitude of approximately 5 mm and periodicity of 1 year (Figure 10b). Similar amplitudes are found at Vathi and Paleokastro (Figure 9b). The peaks of the fluctuations generally occur in the period October-March, i.e., rainfall season [62]. This suggests the presence of a seasonal component in the deformation behaviour that is potentially influenced by rainfall and overlaps onto the long-term, generally linear, trend observed across the peninsula in 2015-2019.