Features and Factors of Time Variations in Hydrogen Release at Lovozersky Rare-Metal Deposit (Kola Peninsula)

The paper presents the results of a long-term (52 months) monitoring of molecular hydrogen release from the rocks of the Lovozero Massif. Observations are performed in an underground mine with the help of a portable highly sensitive gas analyzer developed at the National Research Nuclear University MEPhI. The strong variability (of 0.7 to 303 ppm) of the dynamics of the volume concentration of hydrogen (phi H-2) is established. The main elements of the structure of the time series obtained consist of the fact that they have quite sustained and long intervals of low background concentrations, low-amplitude excesses of various durations, and short (usually high-amplitude) bursts. Seasonal and off-season periodic and other cyclic components in the structure of the series are identified. It is shown that the most important factors determining the dynamics of phi H-2 are barogenic (variation in the atmospheric pressure) and technogenic (technological explosions). Possible mechanisms of gas release are considered.