## 2 Materials and Methods
### General Characteristic of Seismic Activity and Rockburst Hazard
The reason why these particular events were selected for further analysis can be explained \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Year** & **10\({}^{3}\) J** & **10\({}^{4}\) J** & **10\({}^{5}\) J** & **10\({}^{6}\) J** & **10\({}^{7}\) J** & **10\({}^{8}\) J** & **\(\Sigma\)N [–]** & \(\Sigma\)E [J]** & \(\Sigma\)E\({}_{\rm w}\)/N\({}_{\rm w}\) [J]** \\ \hline
1 st & 15 & 10 & 6 & 2 & 1 & 1 & 35 & 2.63 \(\times\) 10\({}^{8}\) & 2.62 \(\times\) 10\({}^{7}\) \\ \hline
2 nd & 96 & 40 & 19 & 10 & 4 & – & 169 & 1.25 \(\times\) 10\({}^{8}\) & 3.73 \(\times\) 10\({}^{6}\) \\ \hline
3 rd & 164 & 62 & 36 & 13 & 7 & 1 & 283 & 3.46 \(\times\) 10\({}^{8}\) & 6.04 \(\times\) 10\({}^{6}\) \\ \hline
4 th & 234 & 87 & 30 & 18 & 3 & – & 372 & 1.58 \(\times\) 10\({}^{8}\) & 3.04 \(\times\) 10\({}^{6}\) \\ \hline
5 th & 241 & 92 & 39 & 15 & 9 & – & 396 & 2.70 \(\times\) 10\({}^{8}\) & 4.22 \(\times\) 10\({}^{6}\) \\ \hline
6 th & 162 & 56 & 20 & 5 & 5 & 1 & 249 & 2.91 \(\times\) 10\({}^{8}\) & 9.32 \(\times\) 10\({}^{6}\) \\ \hline \(\Sigma\)/av. & 912 & 347 & 150 & 63 & 29 & 3 & 1504 & 1.45 \(\times\) 10\({}^{9}\) & 5.89 \(\times\) 10\({}^{6}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Mining-induced seismicity in panel XVII/1 (in the first six years). Figure 4: Number of seismic events in the energy class (\(\geq\)10\({}^{3}\) J). by specific conditions of their occurrence and the unusual nature and scale of impacts, offering us a better insight into the issue. In both cases, the impacts would be revealed as floor upheaving, sidewalls sliding and stope failure or fracturing of the immediate roof, yet the scale and scope of impacts produced by the rockburst in Year 3 seem disproportionately high in relation to the seismic energy of triggering tremors. That the impacts were really extensive is evidenced by the amount of 41,000 Mg of ore produced without any blasting while implementing the mitigation measures and restoring the normal operations in the mine workings. In regard to the event registered in December in Year 6, its impacts were regarded as proportional to the tremor energy (in the conditions prevailing in LGCD), yet in this case the epicentre was located nearby the fault with the downthrow of 3-5 m, traversing the panel diagonally, this aspect merited a thorough analysis. In regard to mining-induced seismicity in all mines within the LGCD copper district, there appears to be a straightforward relationship between the number of seismic events and the number of impact-exerting events: the higher the energy of the seismic event, the larger the probability that a rockburst/rock de-stressing should occur. Statistics compiled over the 6 years of mining operations reveal that seismic events exerting serious impacts (rockbursts and de-stressing events) would be triggered by tremors of \(10^{6}\) J (-2%), tremors in the energy class \(10^{7}\) J (-21%), tremors in the class \(10^{8}\) J (-87%) and, finally, tremors of \(10^{9}\) J (100%). Considering the previous mining-induced seismicity (Table 2) and mining and geological conditions in the panel XVII/1 (Figure 3), it is unreasonable to expect a decrease in seismic activity while mining operations continue, and the occurrence of an event exerting serious impacts cannot be precluded whilst the current mining methods and technologies are still employed. That this hypothesis is true is evidenced by high rockburst risk levels subsisting during mining operations in the neighbouring panels XVII/2, XVII/3, XVI/1 and XVI/2, associated with high-energy seismicity.