## 3 Results  
### Site Effect Curves of the Translational and Rotational Motion  
Based on the geological profiles (Figure 1d,f), the theoretical HVSR curves were estimated for the IMI and PLA stations as the first step of the analysis. The investigation of local geology allowed us to assess the two-layered geophysical models for both stations. The parameters required to estimate the theoretical HVSR curve are shown in Table 2, containing values of the shear wave velocities (Vs), densities, attention coefficient, and the thickness of the resonant (soft) layer. The velocities in the resonant layer were found in the research performed in the same area [9], where the MASW technique was applied to recognize Vs30. For the IMI station, the Vs30 = 400 m/s value was used in the calculation. In the case of PLA, the average Vs value up to 20m was set as 340 m/s. The thickness of the resonant layer in the IMI station corresponded to the complex of loose Quaternary deposits and strongly weathered Triassic hydrocarbons, which reached a thickness of over 60 m. The basement velocities were arbitrarily assumed [48], Table 2. The theoretical calculation of the site effects allowed us to estimate the amplification coefficients as 6.4 and 4.7 with corresponding resonance frequencies of 1.65 Hz and 4.25 Hz for the IMI and PLA stations, respectively. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \multirow{2}{*}{**Station**} & **Vs** & **Vs** & **Density** & **Density** & **Attenuation** & **Thickness** & **Max (H/V)** & **f\({}_{0}\) [Hz]** \\  & **Basement** & **Resonant** & **Basement** & **Resonant** & **Factor** & **[m]** & **Max (H/V)** & **f\({}_{0}\) [Hz]** \\  & **[m/s]** & **[m/s]** & **[g/cm3]** & **[g/cm3]** & **[g/cm3]** & **[m]** & **Max (H/V)** & **f\({}_{0}\) [Hz]** \\ \hline IMI & 3800 & 400 & 2.5 & 1.8 & 0.05 & 62.0 & 6.4 & 1.65 \\ \hline PLA & 2200 & 340 & 2.1 & 1.8 & 0.05 & 20.0 & 4.7 & 4.25 \\ \hline \end{tabular}
\end{table} 
Table 2: Parameters of two-layered geophysical models and theoretical site effects. The spectral ratios were estimated according to the SESAME criteria [35]. Each seismic record of 130 events was processed similarly. However, the difference between the process parameters was connected with the values of predicted resonance frequency and, therefore, the number of significant cycles, according to the SESAME criteria. As mentioned above, the number of significant cycles should exceed 200. Thus, in the case of the IMI station, the calculation was carried out under the assumption of the expected 1.65 Hz resonance frequency and windowing of the signals in a 5 s long time series (50 windows per signal). The calculation in the case of the PLA station was performed considering the expected 4.25 Hz resonance frequency and windowing the signals in a 3 s long time series (50 windows per signal). The empirical amplification and resonance frequency were found for average horizontal, EW, and NS directions. Subsequently, the arithmetic average was calculated from all events (Figures 4 and 5). The ratio curves of the IMI station records allowed us to distinguish two general HVSR peaks and two TRSR peaks (Table 3). The first maximum was observed at frequencies ranging from 1.4 Hz to 1.6 Hz for translation and at 1.8 Hz for rotation. The second maximum of translation occurred at frequencies ranging from 2.2 Hz to 2.4 Hz, while for rotation, it ranged from 4.4 Hz to 4.6 Hz. The analysis of the PLA station records allowed to distinguish only one general HVSR peak and one TRSR peak (Table 3), observed at frequencies ranging from 4.2 Hz to 5.8 Hz for translation and 5.4 Hz to 5.8 Hz for rotation. Each of the spectral ratios for all 130 seismic events satisfied the first, second, and third rules concerning the criteria of reliable HVSR estimations. Consequently, according to the satisfied criteria of time-window length and the number of windows, dividing peak values of the seismic signals by the estimated amplification coefficient was allowed.