Influence of Watering of Khibiny Mountains on the Earthquake-Size Distribution

According to the long-term earthquake statistic and the data of monitoring of water inflows carried out at the apatite-nepheline deposits of the Khibiny massif, the authors have revealed a statistically significant decrease in the b-values of the Gutenberg-Richter law during the period of high watering (May–October) compared with the period of low watering (November–April). A sharp increase in seismicity (a-value of the Gutenberg-Richter law) with the beginning of the watering increase in the deposits of the Khibiny massif caused by the melting of snow accumulated over the winter is demonstrated. A decrease in the strength of rocks and the dilatancy of cracks due to the influence of additional pore pressure can serve as an explanation for the dependence of the seismic regime on the change in the level of watering of the rocks.