Abstract
Introduction We quantify temporal variations of geoid heights (Δ N ) across Kazakhstan during 2019–2024 using satellite gravimetry, and relate these changes to recent extreme hydrological and seismic events. Methods Monthly Δ N fields were derived from GRACE-FO–based global geopotential models. We applied seasonal-trend decomposition to isolate seasonal and long-term components, mapped linear trends, and assessed 2024 mass-change anomalies. Consistency checks included correlations with Caspian Sea water-level records and a preliminary comparison between Δ N and ellipsoidal height changes from five continuous GPS stations within the study area. Results Δ N exhibits a clear seasonal cycle with amplitudes up to ∼3.5 mm. A persistent decline in geoid heights during 2019–2022 is observed along the Caspian Sea coast, reaching rates of up to −1.57 mm yr −1 . In 2024, mass anomalies associated with seismic and hydrological events interrupted this decline. Δ N correlates strongly with Caspian Sea level variations (r = 0.91). GPS–GRACE-FO comparisons show an inverse seasonal pattern, consistent with mass-loading effects. Discussion/conclusions GRACE-FO robustly captures regional, mass-related geoid variability over Kazakhstan. The results support applications in geodetic infrastructure maintenance, hazard assessment and early warning, and climate-impact analysis. They also provide inputs relevant to the realization of the International Height Reference Frame by accounting for time-variable gravity in Central Asia.