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

Influence of Rock Watering on Post-Seismic Activity: A Study on the Khibiny Massif

“…Due to its commercial development, seismic monitoring has been carried out at the fields of the Khibiny massif since the late 1980s, and since 2002, regular measurements of water inflow have been carried out at depths comparable to the depths of seismic events (for more details refer to the section "Research area and materials"). In addition, previous studies have revealed a significant influence of watering of the rock on the seismicity of the Khibiny fields [Kozyrev et al, 2021;Zhukova, 2015;Zhukova et al, 2023]. In particular, Zhukova et al [2023] showed a significant decrease in b-value during the high watering period of the Khibiny massif, from May to October, compared to the low period from November to April.…”

“…In addition, previous studies have revealed a significant influence of watering of the rock on the seismicity of the Khibiny fields [Kozyrev et al, 2021;Zhukova, 2015;Zhukova et al, 2023]. In particular, Zhukova et al [2023] showed a significant decrease in b-value during the high watering period of the Khibiny massif, from May to October, compared to the low period from November to April. In this paper, we will find out whether watering of the rock affects the parameters of post-seismic activity.…”

“…Using the data of long-term monitoring of seismicity and observations of water inflows in the fields of the Khibiny massif, it was revealed that the values of the parameter b a of the distribution of magnitudes of triggered events (M a = M − M m ) virtually do not change in different periods of watering of the massif. In [Zhukova et al, 2023] it was demonstrated that the influence of watering on the b-value of the distribution of magnitudes of all seismic events is significant (Figure 7). The b significantly decreases in May (the beginning of high watering period) and maintains its lowered value virtually throughout the entire high-watering period until the end of September.…”

“…There are experimental [Board et al, 1992;Kartseva et al, 2022] and field data [Hainzl et al, 2006[Hainzl et al, , 2013Heinicke et al, 2017;Maystrenko et al, 2020;Smirnov et al, 2022;Talwani, 1997;Vorobieva et al, 2020;Zoback and Harjes, 1997] on the influence of moisture content of the geologic material on the parameters of the seismic regime for natural (tectonic) and induced seismicity. The key result of these studies is the increase in seismicity during elevation of pore fluid pressure and the "lubrication" effect due to the increase in the amount of liquid penetrating into the medium caused either by the changes in the reservoir level [Smirnov et al, 2022;Talwani, 1997], or by heavy rainfalls [Hainzl et al, 2006[Hainzl et al, , 2013Heinicke et al, 2017;Maystrenko et al, 2020], or by snowmelt in spring [Zhukova et al, 2023], or by direct liquid injection for extraction of hydrocarbons [Vorobieva et al, 2020;Zoback and Harjes, 1997].…”

“…Porosity and moisture content of rock play a significant role in this process. At the same time, the increase in seismicity during the growth of moisture content is manifested in both the growth in the number of earthquakes and the reduction of the b-value of the Gutenberg -Richter magnitude distribution [Smirnov et al, 2013[Smirnov et al, , 2022Zhukova et al, 2023], which reflects an increase in the proportion of strong earthquakes.…”