ASSESSMENT OF SEISMOTECTONIC DEFORMATIONS IN ALMATY BASED ON INSAR MONITORING DATA

Abstract

The study presents the results of ground deformation monitoring in Almaty for the period 2017–2023 using the SBAS-InSAR method and Sentinel-1 satellite data. The scientific novelty of the research lies in the application of the Small Baseline Subset (SBAS) algorithm for the quantitative assessment of vertical and horizontal displacement rates under conditions of complex terrain and dense urban development. It was established that the city's deformation field is strongly controlled by active faults (the Zailiysky Fault, the Almaty Fault, and others). Three characteristic zones were identified: subsidence (Block 1), uplift (Block 2), and mixed deformation (Block 3). Maximum negative trends (−57 mm/year) were recorded in the foothill areas, which, in combination with seismic microzonation data, indicate zones of increased geodynamic risk. Five cases of deformation affecting buildings and bridges with cumulative subsidence trends were identified. The results confirm the high activity of tectonic structures within the city limits, highlighting the need to integrate InSAR data into urban risk assessment systems and construction regulations.