Groundwater responses on the east european platform to earthquakes in myanmar and the central trans-asian seismic belt

Seismic activity can dramatically impact regional groundwater systems. Mechanisms of groundwater reaction to the passage of seismic waves are poor understood. We explored the responses of natural and natural–anthropogenic aquifers on the East European Platform to earthquakes that occurred in the central Trans-Asian Seismic Belt and Myanmar. Hydrogeological monitoring was performed at two test sites beginning in 2009 (Mikhnevo) and 2019 (Gubkin). The Mikhnevo site is located along the northeastern edge of the Prioksko–Terrasny Nature Reserve. The Gubkin test site is located on the eastern outskirts of the town of Gubkin in the Belgorod District, where iron ore deposits exhibiting the Kursk Magnetic Anomaly (KMA) are being developed. The maximum variation in water level following the M7.9 Myanmar earthquake on March 28, 2025, was 37 mm in the weakly confined aquifer under natural conditions at the Mikhnevo site with an epicentral distance of 6100 km. Under the technogenically disturbed conditions of the Gubkin site, the same value did not exceed 4 mm in the confined aquifer at a distance of 5950 km. Our data obtained in 2014-2025 confirmed the previously established fact that groundwater response intensity depends on aquifer permeability and type. High amplitude responses were observed in the сarboniferous reservoir, which displayed relatively high transmissivity. The dependence of dynamic oscillations in water level on particle velocity was approximated for this weakly confined aquifer using a linear function. Synchronous hydrogeological responses to the onset of shear S- and SS-waves before variations in water level produced by the passage of surface waves were observed in the reservoir–well system when seismic energy density exceeded 3 × 10⁻⁵ J/m³. In the confined aquifers, which displayed lower filtration parameters, similar coseismic oscillations were observed only during the passage of surface waves at the same seismic energy. Further analysis of hydrogeological responses to seismic activity recorded allowed us to trace the responses of groundwater on the East European Platform to Trans-Asian earthquakes. We consider the anisotropy of crack-porous aquifer to be the main factor that governs variations in pore pressure of the reservoir-well system under seismic impact.