RESULTS OF SHORT-TERM MONITORING OF HELIUM CONTENT AND GENERALIZED INDICATORS IN THE UNDERGROUND WATERS OF THE ALTAI MOUNTAINS
The relevance of the work is caused by the need to improve the methods for monitoring the characteristics of groundwater and their changes in the seismically active regions of the Altai Republic. Groundwater is an indicator of seismic processes and they react to changes in the stress-strain state of rocks in the zones of foci of upcoming tectonic earthquakes. The aim of the work is to identify short-term changes in the helium content and generalized hydrogeochemical indicators in the previously identified highly dynamic groundwater monitoring facilities of the Altai Republic in relation to the search for precursors of strong seismic events. Research methods. The work is based on the results of daily monitoring of groundwater in the Altai Republic, which was carried out in January-March 2021 at two observation points for temperature conditions and the qualitative composition of groundwater - well and a column - of the Territorial Center «Altaigeomonitoring». Results. For the first time on the territory of Gorny Altai, a study was made of the dynamics of generalized geochemical characteristics and helium content in groundwater and their short-term (1-3 days) changes due to earthquakes were shown. For this study, we used two groundwater observation points located in Gorno-Altaisk (street water fountain) and in the village Stariy Beltir (borehole) distant from each other of more than 200 km. These monitoring points were chosen due to the fact that a significant change in the characteristics of groundwater was recorded there during the preparation and course of seismic events in the region. The work gives a characteristic of the seismic setting of the Altai-Sayan region during the monitoring period. To identify the dynamics of the helium content and generalized geochemical indicators of groundwater in the period of January 14-February 23, 2021, we carried out sampling. The sampling results showed that the monitoring point Stary Beltir, located in the fault zone near the epicentral zone of the Chuya earthquake (2003), is characterized by a high sensitivity to changes in both generalized groundwater characteristics and a high degree of helium content response to earthquakes. At the same time, the seismic events closest to them are reflected in the presented groundwater monitoring points. The chosen monitoring points in some cases do not overlap each other and react mainly to the nearest earthquakes, including weak ones. The most dynamic response to earthquakes was noted in helium, pH, Eh, and temperature.