## 4 Methods
### Implementation of Triangulation Methodology
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Station** & **Longitude** & **Latitude** & \(\mathbf{V_{E}}\) **(m/yr)** & \(\mathbf{V_{N}}\) **(m/yr)** & \(\mathbf{V_{U}}\) **(m/yr)** & \(\mathbf{\sigma V_{E}}\) **(m/yr)** & \(\mathbf{\sigma V_{N}}\) **(m/yr)** & \(\mathbf{\sigma V_{U}}\) **(m/yr)** \\ \hline SMOL & 24.70587 & 41.57750 & 0.0014 & \(-\)0.0029 & \(-\)0.0005 & 0.0017 & 0.0014 & 0.0034 \\ DUTH & 24.91680 & 41.14021 & \(-\)0.0004 & \(-\)0.0033 & \(-\)0.0004 & 0.0022 & 0.0022 & 0.0034 \\
041A & 22.80240 & 41.16515 & 0.0013 & \(-\)0.0076 & \(-\)0.0042 & 0.0030 & 0.0020 & 0.0039 \\ THSI & 22.95936 & 40.62747 & 0.0007 & \(-\)0.0077 & \(-\)0.0001 & 0.0021 & 0.0017 & 0.0044 \\ AUTI & 23.00372 & 40.56682 & 0.0010 & \(-\)0.0078 & \(-\)0.0019 & 0.0015 & 0.0019 & 0.0040 \\ AFT & 23.43532 & 40.09713 & 0.0005 & \(-\)0.0085 & \(-\)0.0009 & 0.0018 & 0.0019 & 0.0050 \\ SERR & 23.03745 & 41.28591 & 0.0009 & \(-\)0.0056 & 0.0011 & 0.0018 & 0.0019 & 0.0068 \\ PROV & 23.38698 & 41.06844 & 0.0009 & \(-\)0.0059 & \(-\)0.0022 & 0.0018 & 0.0013 & 0.0036 \\ STRA & 23.79077 & 40.52022 & 0.0007 & \(-\)0.0079 & 0.0007 & 0.0021 & 0.0024 & 0.0039 \\
076A & 23.94427 & 40.03895 & 0.0011 & \(-\)0.0067 & 0.0020 & 0.0010 & 0.0060 & 0.0101 \\ SAND & 23.26782 & 41.55056 & \(-\)0.0001 & \(-\)0.0036 & 0.0001 & 0.0009 & 0.0008 & 0.0028 \\ TEIS & 23.55529 & 41.07432 & 0.0009 & \(-\)0.0006 & \(-\)0.0022 & 0.0017 & 0.0013 & 0.0036 \\
037A & 23.90486 & 40.87183 & \(-\)0.0004 & \(-\)0.0047 & \(-\)0.0035 & 0.0036 & 0.0050 & 0.0085 \\ GODE & 23.72928 & 41.57587 & 0.0041 & 0.0005 & 0.0052 & 0.0029 & 0.0020 & 0.0070 \\ NVRK & 23.86973 & 41.33574 & \(-\)0.0037 & \(-\)0.0021 & 0.0008 & 0.0098 & 0.0060 & 0.0098 \\ KAVA & 24.38731 & 40.93380 & \(-\)0.0002 & \(-\)0.0049 & 0.0006 & 0.0016 & 0.0022 & 0.0045 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: East, north, and up velocity components of each GNSS station. 4.2.1. Maximum (MaHE) and Minimum (MiHE) Horizontal Extension  
The parameters of Maximum (MaHE) and Minimum (MiHE) Horizontal Extension are directly related to the identification of active tectonic structures. Particularly, the MaHE parameter indicates the extensional tectonics occurrences (extension in strain terminology), while, on the other hand, the MiHE, which is perpendicular to the MaHE, represents compressional tectonics occurrences (compression in strain terminology). The MaHE and MiHE parameters are interconnected, and, therefore, the three following cases are observed: (i) the coexistence of high MaHE values with low MiHE values, which shows normal dip-slip faulting; the MaHE parameter is perpendicular to the fault or fault zone, (ii) the coexistence of low MaHE values with high MiHE values, which shows reverse dip-slip faulting; the MiHE parameter is perpendicular to the fault or fault zone, and (iii) the coexistence of equal or similar MaHE and MiHE values, which shows strike-slip faulting; both MaHE and MiHE form 45\({}^{\circ}\) with the fault or fault zone. It is noted that the MaHE develops along the major axis of the strain ellipse, as was explained above, while the MiHE develops along the minor axis of the strain ellipse, respectively. The following equations (Equations (3) and (4)) define mathematically the MaHE and MiHE parameters:  
\[\text{MaHE}=(l_{f}-l_{0})/l_{0} \tag{3}\]  
\[\text{MiHE}=(l^{\prime}_{f}-l^{\prime}_{0})/l^{\prime}_{0} \tag{4}\]  
where  
\(l_{f}\): the final length along the strain ellipse major axis,  
\(l_{0}\): the original length along the strain ellipse major axis,  
\(l^{\prime}_{f}\): the final length along the strain ellipse minor axis, and  
\(l^{\prime}_{0}\): the original length along the strain ellipse minor axis. It is mentioned that \(l_{0}=l^{\prime}_{0}\) in case of circle occurrences. 4.2.2. Velocity (V)  
Velocity (V) is associated with the motion of an area, which indicates partially the geotectonic evolution of a larger scale region.