# Compatible Ground Motion Models for South Korea Using Moderate Earthquakes
## 2 Materials and Methods
### Earthquake Data Sources
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Station**} & \multirow{2}{*}{**V\({}_{\text{S30}}\) (m/s)**} & **Station** & **V\({}_{\text{S30}}\) (m/s)** & **Station** & **V\({}_{\text{S30}}\) (m/s)** & **Station** & **V\({}_{\text{S30}}\) (m/s)** \\ \hline AJD & 660 \({}^{\text{*}}\) & DOKDO & 704 \({}^{\text{*}}\) & HWSB & 1264 & MGB & 680 \({}^{\text{*}}\) & TJN & 584 \({}^{\text{*}}\) \\ BBK & 601 \({}^{\text{*}}\) & DUC & 463 \({}^{\text{*}}\) & IBA & 556 & MKL & 660 \({}^{\text{*}}\) & UNI & 524 \\ BGD & 512 \({}^{\text{*}}\) & GCN & 544 \({}^{\text{*}}\) & JJB & 580 \({}^{\text{*}}\) & MRD & 416 \({}^{\text{*}}\) & WDL & 306 \\ BOG & 475 \({}^{\text{*}}\) & GHR & 544 & JRB & 641 \({}^{\text{*}}\) & MUN & 545 \({}^{\text{*}}\) & WID & 530 \({}^{\text{*}}\) \\ BRN & 427 \({}^{\text{*}}\) & GKP1 & 438 \({}^{\text{*}}\) & JSB & 618 \({}^{\text{*}}\) & NPR & 478 \({}^{\text{*}}\) & YIN & 632 \({}^{\text{*}}\) \\ BRS & 466 \({}^{\text{*}}\) & GKP2 & 847 & JUC & 459 \({}^{\text{*}}\) & GJR & 1092 & YKB & 736 \({}^{\text{*}}\) \\ CGD & 638 \({}^{\text{*}}\) & GRE & 505 \({}^{\text{*}}\) & KIP & 518 \({}^{\text{*}}\) & PCH & 559 \({}^{\text{*}}\) & YPD & 482 \({}^{\text{*}}\) \\ CGU & 581 \({}^{\text{*}}\) & GSU & 1333 & KJM & 301 \({}^{\text{*}}\) & PKNU & 313 \({}^{\text{*}}\) & YSB & 533 \({}^{\text{*}}\) \\ CHNB & 659 \({}^{\text{*}}\) & HAK & 631 \({}^{\text{*}}\) & KMC & 698 \({}^{\text{*}}\) & POHB & 562 \({}^{\text{*}}\) & YSUK & 166 \\ CHS & 672 \({}^{\text{*}}\) & HCH & 599 \({}^{\text{*}}\) & KNUC & 338 & POSB & 539 \({}^{\text{*}}\) & YSUM & 899 \\ CRB & 859 & HDB & 587 \({}^{\text{*}}\) & KNUD & 791 \({}^{\text{*}}\) & SIG & 625 \({}^{\text{*}}\) & - & - \\ DES & 642 \({}^{\text{*}}\) & HKU & 506 & KSA & 615 \({}^{\text{*}}\) & SND & 772 \({}^{\text{*}}\) & - & - \\ DKJ & 615 \({}^{\text{*}}\) & HSB & 914 & MAK & 642 \({}^{\text{*}}\) & SNU & 718 \({}^{\text{*}}\) & - & - \\ \hline \hline \end{tabular} \({}^{\text{*}}\) derived value [37].  
\end{table} 
Table 2: Ground motion recording stations operated by KIGAM with measured V\({}_{\text{S30}}\). velocity version of the ground motion data. Acceleration ground motions were computed as the derivative of the velocity data. Table 3 summarizes the raw ground motion data processing parameters. With the resultant ground motions, 5% damped acceleration response spectral ordinates for periods, T = 0.02, 0.2, 1.0, and 10.0 s were estimated for comparison with PEER GMMs. There are several reasons for selecting these periods. The reason for selecting T = 0.2 s as a basis of comparison is because it is a compromise between the acceleration and velocity-sensitive period ranges, while T = 1.0 s is a compromise between the velocity and displacement-sensitive period ranges. Additionally, spectral ordinates at and near T = 0.2 and 1.0 s generally control practical response spectra design [38; 39]. A period of T = 0.02 s was selected in lieu of a peak ground acceleration (PGA) estimation because some GMMs use short periods, typically below 0.05 s, as representative of PGA and that PGA is not generally used in practical design. Using the same logic, peak ground velocity was not considered because it is also not very prominent nor frequent in design practice. Nonetheless, estimations for PGA and at T = 0.02 s are not significantly different. A long period of T = 10.0 s was selected for displacement-based interests. The two orthogonal horizontal recordings, i.e., E and N, were projected onto a single azimuth given by an increment of rotation angle across 1\({}^{\circ}\) to 180\({}^{\circ}\). A 5% damped elastic acceleration response spectrum (SA) was estimated for each rotation angle increment with the median across all SA at a specific period denoted as Rot50 [40]. Note that this implies not all Rot50 will come from the same azimuth.