SURFACE DEFORMATION MONITORING IN EPICENTRAL ZONES OF UNDERGROUND NUCLEAR EXPLOSIONS USING GEODETIC METHODS

Abstract

This study examines geodetic monitoring of ground surface deformation in epicentral zones of underground nuclear explosions at the former Semipalatinsk Test Site. Underground nuclear explosions significantly alter geological structures and can lead to long-term deformation processes affecting the Earth's surface. The research focuses on the Balapan testing area, where underground nuclear tests were conducted in deep boreholes. A geodetic observation network consisting of several benchmarks was established to monitor vertical displacements of the ground surface. High-precision leveling observations were performed using digital geodetic instruments in order to detect small elevation changes. Monitoring results indicate that measurable deformation processes continue to occur in epicentral zones even decades after underground nuclear explosions. The analysis of monitoring data shows gradual subsidence of the ground surface around the crater zone caused by long-term geomechanical processes within the rock mass. The obtained results demonstrate the importance of long-term geodetic monitoring for understanding post-explosion geodynamic processes and for assessing environmental safety in former nuclear testing territories.