## 2 Materials and Methods
The topography of the study area has been derived from the ETOPO1 model [40]. The depth of the 3D model has been set to the MOHO discontinuity depth. In addition, the model is created from three different layers in the vertical direction: upper crust, middle crust, and lower crust. The crusts and MOHO discontinuity depth values of the study area have been obtained from the Litho1.0 model [41]. The model boundaries have been chosen according to the distribution of GNSS stations located in the region [42], and Figure 6 map boundaries represent the 3D model edges. Figure 5: Processing inputs for the FEM model. Figure 6: Main Marmara Fault and GNSS stations used for FEM modelling (GF: Ganos Fault, TS: Tekirdag Segment, CeS: Central Segment, KS: Kumburgaz Segment, CiS: Cinarck Segment, IF: Izmit Fault. Left bottom corner coordinates: latitude: 26\({}^{\circ}\).10, longitude: 39\({}^{\circ}\).20. Upper right corner coordinates: latitude: 30\({}^{\circ}\).90, longitude: 41\({}^{\circ}\).75). The Poisson's ratio and Young's modulus have been calculated from velocities of P and S seismic waves that have been obtained from the Litho1.0 model [41] using Equations (6)-(9), and the density values have been obtained from the model directly. First, the Lame parameters have to be calculated using the following formulae:  
\[\mu=V_{S}^{2}\times\ \rho \tag{6}\]  
\[\lambda=V_{P}^{2}\times\rho-2\ \times\ V_{S}^{2}\times\ \rho \tag{7}\]  
where \(\mu\) is the shear or rigidity modulus, \(\lambda\) is the Lame's first parameter [43; 44], \(\rho\) is the density, and \(V_{P}\) and \(V_{S}\) are the seismic velocities. Then, the values of Young's modulus (E) and Poisson's ratio (v) to be used for material identification can be calculated using Equations (3) and (4) [45; 46]. \[\text{E}=\mu\times(3\ \lambda+2\ \mu)/(\lambda+\mu) \tag{8}\]  
\[\
u=\lambda/(2\times(\lambda+\mu)) \tag{9}\]  
In fact, since the same parameters have been used in all scenarios, any value in the literature could be used as a material parameter. The material parameters used in the study are given in Table 1.  
Frictional contact has been defined between fault surfaces. In studies conducted in the literature, friction coefficients in the range of 0.02-0.05 were used for the North Anatolian Fault [32; 47; 48; 49]. It has been stated that the values used in this range give the best model results. The friction coefficient has been chosen to be 0.05. Three-dimensional geometry was created using the fault geometry used in the [PERSON] [39] study, determined model boundaries, crustal layers, and topography. The visual appearance of this created 3D geometry in ANSYS software is given in Figure 7. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **Mean Depth (m)** & **Density (kg/m\({}^{3}\))** & \(V_{P}\) (m/s)** & \(V_{s}\) (m/s) & **E (GPa)** & \(\
u\) \\ \hline \hline  & \multicolumn{6}{c}{Upper Crust} \\ \hline Northern Part & & 2783.202 & 6171.798 & 3595.387 & 89.452 & 0.243 \\ \hline Middle Part & 14,884 & 2755.755 & 6130.727 & 3568.524 & 87.296 & 0.244 \\ \hline Southern Part & & 2673.685 & 5951.101 & 3463.532 & 79.792 & 0.244 \\ \hline  & \multicolumn{6}{c}{Middle Crust} \\ \hline Northern Part & & 2870.239 & 6560.122 & 3789.549 & 103.013 & 0.250 \\ \hline Middle Part & 25,783 & 2806.795 & 6374.402 & 3690.362 & 95.405 & 0.248 \\ \hline Southern Part & & 2737.393 & 6239.372 & 3607.668 & 88.990 & 0.249 \\ \hline  & \multicolumn{6}{c}{Lower Crust} \\ \hline Northern Part & & 2991.605 & 7000.578 & 3899.408 & 116.004 & 0.275 \\ \hline Middle Part & 35,581 & 2894.723 & 6703.498 & 3676.326 & 100.542 & 0.285 \\ \hline Southern Part & & 2833.714 & 6626.517 & 3692.061 & 98.492 & 0.275 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Material properties of crust layers (E and \(\
u\) calculated using Equations (6)–(9); the other parameters were revealed from the Litho 1.0 model [41]).