## 3 Description of Seismometric Data  
The subject of the analysis was seismometric data from a mining area characterized by a very high level of induced seismicity. The analyzed tremors were recorded from 2009 to 2020 at a single measuring station. The surface distribution of tremors along with the location of the seismometric station is shown in Figure 2.  
A surface seismic station ARP 2000 was installed in the analyzed area, consisting of triaxial accelerometers with a frequency range between 0.5 and 100 Hz and a sampling rate of 500 samples per second. The dynamic range for processing and recording is 90 dB. The station is synchronized with a GPS unit, yielding a very precise recording time accuracy, on the order of microseconds. The equipment is serviced and periodically calibrated by its manufacturer. Measurement accuracy is better than 0.0001 m/s\({}^{2}\). The system detects vibrations of mining, seismic or communication origins and transmits them digitally via radio to a processing centre. A PC, which is the processing centre, is allowed to record, archive, and process the registered data. The logger software periodically generates status data and sends it to the processing centre.  
Information on seismic event locations and seismic energy were collected by an underground seismic network installed in the coal mine. The location of underground stations is periodically optimised to ensure that the exact locations of tremors are acquired.  
Table 1 presents basic positional statistics on the distribution of source energy, epicenter distances, as well as PGA values of the considered tremors.  
Analyzing the distribution of PGAs, it should be noted that 89% of all resultant components of horizontal vibration accelerations did not exceed a value of 0.045 m/s\({}^{2}\), while more than 96% did not exceed a value of 0.090 m/s\({}^{2}\). Only 1.8% of the investigated accidental components of horizontal ground vibration accelerations exceeded a value of 0.135 m/s\({}^{2}\), and only 0.5% exceeded a value of 0.225 m/s\({}^{2}\). Table 2 presents the distribution of the logarithms of the energy of the recorded shocks. It can be seen that shocks with energies in the energy range from 3.1 \(\times\) 10\({}^{4}\) J to 1.3 \(\times\) 10\({}^{5}\) J dominate. The energies of more than 900 recorded seismic phenomena exceeded a value of 5.5 \(\times\) 10\({}^{5}\) J while about 70 shocks were characterized by energies of no less than 1.0 \(\times\) 10\({}^{7}\) J.  
The epicenter of the tremor with the highest energy, at 3.0 \(\times\) 10\({}^{9}\) J, was located about 2420 m from the measuring station. This tremor caused ground vibration accelerations of 0.22 m/s\({}^{2}\). A maximum ground vibration acceleration of 0.455 m/s\({}^{2}\) was caused by a tremor with an energy of 1.0 \(\times\) 10\({}^{7}\) J. The epicenter of this tremor was located about 1297 m from the measuring station.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**Parameter**} & \multicolumn{6}{c}{**Descriptive Statistics**} \\ \cline{2-6}  & **Minimum** & **Quartile** & **Median** & **Quartile** & **Maximum** \\  & **First** & **Median** & **Third** & **Maximum** \\ \hline E & 100 J & 40 kJ & 90 kJ & 500 kJ & 3 GJ \\ R & 36 m & 1025 m & 1563 m & 2115 m & 7978 m \\ a & 0.0007 \(\frac{\mathrm{m}}{\mathrm{s}^{2}}\) & 0.0079 \(\frac{\mathrm{m}}{\mathrm{s}^{2}}\) & 0.013 \(\frac{\mathrm{m}}{\mathrm{s}^{2}}\) & 0.024 \(\frac{\mathrm{m}}{\mathrm{s}^{2}}\) & 0.445 \(\frac{\mathrm{m}}{\mathrm{s}^{2}}\) \\ \hline \end{tabular}
\end{table}
Table 1: Basic descriptive statistics of energy, distance and vibration acceleration.  
Figure 2: Distribution of the epicenters of the tremors along with the location of the measuring station.