# Stability Analysis of GNSS Stations Affected by Samos Earthquake
## 3 Results and Discussion  
Table 2 represents the 3D (XYZ)oseismic displacements of the GNSS stations along with their uncertainties. As expected, the SAMO GNSS station, located closest to the earthquake's epicenter (as shown in Figure 1), experienced the highest displacement, and CESM, MNTS, IZMI and IKAR follow SAMO. Stability analysis of GNSS stations was first performed by analyzing 3D Cartesian coordinates of the stations the day before and after the earthquake. In the initial iteration, with hypothesis testing, it was determined that the SAMO GNSS station was unstable. The analysis was repeated after excluding SAMO, and the CESM station was found to be unstable. By repeating the same procedure until no unstable stations remained, MNTS, IZMI and IKAR were identified to have significant displacements. Figure 2 displays the hypothesis testing process iterations, represented by various colors and corresponding geometric symbols. The text values of the stations that exceed the critical values, which provide quantitative evidence of substantial movement, indicate that those particular stations have significant displacement. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline
**Agency** & **Long** & **Lat** & **Mag** & **Depth** & **Strike** & **Dip** & **Rake** & **Strike** & **Dip** & **Rake** \\ \hline AFAD & 26.794 & 37.902 & Mw6.9 & 17 km & 95 & 43 & \(-87\) & 270 & 46 & \(-91\) \\ USGS & 26.79 & 37.918 & Mw7.0 & 21 km & 93 & 61 & \(-91\) & 276 & 29 & \(-88\) \\ \hline \end{tabular}
\end{table} 
Table 1: Samos earthquake focal mechanism solutions [22]. \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Station Name** & \(d_{X}\) **(mm)** & \(d_{Y}\) **(mm)** & \(d_{Z}\) **(mm)** & \(\sigma_{dX}\) **(mm)** & \(\sigma_{\Omega Y}\) **(mm)** & \(\sigma_{dZ}\) **(mm)** \\ \hline ASTY & \(-2.43\) & \(-6.82\) & \(-8.84\) & 13.04 & 7.09 & 9.71 \\ AYD1 & \(-1.91\) & \(-3.05\) & 3.14 & 12.23 & 7.30 & 9.65 \\ AYDN & \(-10.11\) & \(-7.58\) & \(-4.17\) & 10.37 & 6.24 & 8.25 \\ AYVL & \(-1.03\) & \(-2.37\) & 6.06 & 8.61 & 4.86 & 7.09 \\ BOZD & \(-7.10\) & \(-6.33\) & \(-0.43\) & 10.62 & 6.65 & 8.42 \\ CESM & \(-21.87\) & \(-26.18\) & 42.38 & 10.37 & 5.79 & 8.19 \\ DIDI & \(0.69\) & \(-2.63\) & \(-6.40\) & 10.70 & 6.25 & 8.18 \\ DIDM & \(-11.65\) & \(-5.50\) & \(-17.56\) & 12.21 & 7.08 & 9.55 \\ IKAR & 23.70 & \(-4.45\) & \(-22.85\) & 11.77 & 6.67 & 9.52 \\ IZMI & \(-24.42\) & 2.06 & 28.47 & 9.74 & 5.64 & 7.75 \\ KALY & \(0.41\) & 0.86 & \(-12.33\) & 12.07 & 6.77 & 9.07 \\ KIKA & \(-2.83\) & 0.03 & 4.24 & 9.36 & 5.84 & 7.88 \\ LESV & \(-6.94\) & \(-4.53\) & 6.66 & 12.38 & 6.78 & 9.99 \\ MNTS & \(-31.72\) & \(-11.77\) & 35.76 & 9.26 & 5.27 & 7.32 \\ MYKN & \(0.25\) & \(-2.00\) & \(-2.07\) & 10.42 & 5.35 & 7.76 \\ NAXO & \(-2.06\) & \(-6.09\) & \(-4.14\) & 11.04 & 5.74 & 8.15 \\ PAMU & \(-15.35\) & \(-9.92\) & \(-10.72\) & 11.88 & 7.59 & 9.86 \\ PRKV & \(-4.30\) & \(-3.69\) & 3.45 & 8.99 & 4.98 & 7.35 \\ RODO & \(1.44\) & \(-6.55\) & \(-0.03\) & 13.54 & 8.46 & 10.18 \\ SALH & \(-6.01\) & \(-3.89\) & \(-0.97\) & 10.72 & 6.21 & 8.41 \\ SAMO & \(290.44\) & \(75.35\) & \(-236.92\) & 13.79 & 8.03 & 11.05 \\ \hline \end{tabular} \(d_{X}\), \(d_{Y}\) and \(d_{Z}\) are displacements in the \(X\), \(Y\) and \(Z\) components; \(\sigma_{dX}\), \(\sigma_{dX}\) and \(\sigma_{dZ}\) are standard deviation values for the displacement in the \(X\), \(Y\) and \(Z\) components.  
\end{table} 
Table 2: Coseismic XYZ displacements and st. deviations derived from GNSS measurements. In Figure 2, all iterations are presented simultaneously. All station data used in the first iteration are indicated by red triangles. Following the first iteration, the SAMO station was removed; therefore only the first-iteration T values for that station are available with red triangles. For the second iteration, all stations are denoted by stars. In the second iteration, the CESM station was found to be unstable, exceeding the critical value, and was therefore removed.