## 4 Results  
### Synthesis of Strain Results  
#### 4.1.1 Maximum (MaHE) and Minimum (MiHE) Horizontal Extension  
The MaHE and MiHE for the North Aegean Sea region are characterized by a wide range of strain field values. In particular, these parameters demonstrate a heterogeneous strain distribution within the North Aegean Sea region, as depicted in Figure 4a. The MaHE values range from approximately \(-50\) to \(1000\) nano-strain, with the highest value observed in the Thrace region. Similarly, the MiHE values range approximately from \(-1250\) to \(70\) nano-strain [71]. The North Aegean Sea is predominantly characterized by shear, with comparable values of MaHE and MiHE. Moreover, the MaHE and MiHE exhibit an increase in the northwestern region of Turkey, showing a slight NE-SW (MaHE orientation) extension dominance. These results indicate that the crustal dynamics of the North Aegean Trough (NAT) are more complex ranging from \(100\) to \(700\) nano-strain, particularly under a shear setting. At the same time, its extension is oriented in an NNE-SSW to N-S direction [71]. The shear occurrence can also be observed in the North Aegean Basin (NAB), characterized by moderate magnitudes and a gradual transition in an approximately NW-SE extension direction. The NAB exhibits a prevalence of local extension dominance over compaction. The area exhibits a distinct extensional trend in contrast to the adjacent regions, which follows an ENE-WSW direction [71]. The strain regime prevalent in the northern Aegean region, except for the wider Skyros Island area, is the transition from pure to quasi-pure extension. A broad spectrum of strain field values is exhibited in the Stryrom basin region. In particular, the MaHE values show a range of variability from approximately \(-60\) to \(2650\times 10^{-9}\), whereas the corresponding MiHE values demonstrate a range of variability from approximately \(-650\) to \(150\times 10^{-9}\), as depicted in Figure 4b. The primary analysis of  
Figure 4: Maximum (MaHE; blue arrows) and Minimum (MiHE; red arrows) Horizontal Extension in the regions of: (**a**) North Aegean Sea; (**b**) Strymon basin; and (**c**) Thessalian basin. the distribution of the values [17] indicates that the absolute maximum values of both MaHE and MiHE are primarily concentrated along the eastern boundary and the northernmost part of the western boundary of the Strymon basin. Moreover, the analysis of MaHE and MiHE suggests that extension is the dominant process in the study area, resulting in a normal faulting activity. In particular, the Strymon basin exhibits a notable concentration of maximum values at its eastern and northwestern boundaries. At the same time, the high MaHE values of these regions, coupled with exceedingly low absolute values of corresponding MiHE, suggest the prevalence of dip-slip normal faulting activity [17]. The documented data reveals a gradual decrease in both MaHe and MiHE values on either side of the area. Simultaneously, the difference in values between MaHE and MiHE decreases, with MaHE values remaining greater than the corresponding MiHE values. These findings suggest oblique-slip normal faulting activity in the Strymon and the adjacent (e.g., Drama) basins. Additionally, the northwestern part of the Strymon basin exhibits positive values for both MaHE and MiHE, indicating a prevalent, pure extensional setting characterized by normal faulting. Finally, it is worth mentioning that the direction of the MaHE vectors is nearly perpendicular to the strike of the faults and fault zones, thereby providing evidence for the existence of these tectonic structures and their normal faulting characteristics. Focusing on the wider Thessalian basin region, the values show a range of \(-40\) to \(380\) nano-strain, with the extensional regime prevailing as the dominant one (Figure 2a,b) [72]. The MaHE vectors exhibit an approximate N-S orientation in the southern Thessalian basin. This region also displays the most significant values, exceeding \(200\) nano-strain.