Mud volcanoes are dynamic surface expressions of deep over pressured fluids and gases, requiring precise monitoring to understand their behavior and related hazards. This study investigates ground deformation at the Tang Mud Volcano in southeastern Iran using the Small Baseline Subset (SBAS) InSAR technique applied to 16 Sentinel-1 IW SLC images acquired from December 31, 2023, to December 13, 2024.
Data were processed using the GMTSAR toolbox under a Linux environment, supported by SNAP and GMT. Both Ascending and Descending tracks were analysed to validate deformation signals across viewing geometries. Interferometric analysis included co-registration, baseline estimation, interferogram generation, Goldstein filtering, phase unwrapping, and time-series inversion using Singular Value Decomposition (SVD). Coherence and standard deviation maps ensured data quality.
Results show minimal displacement at the main vent (P1), with cumulative deformation limited to approximately +5 mm, indicating a stable structure. In contrast, a nearby flank area (P2) experienced significant uplift (~+47 mm), suggesting active subsurface processes such as fluid migration or sediment extrusion. Despite the relatively stable behavior observed at the Tang mud volcano itself, the adjacent areas demonstrated significant uplift of up to 6 cm. This level of deformation, occurring over a one-year observation period, highlights the geodynamic activity in parts of the Kahir region. Velocity maps revealed localized deformation rates in mm/year, correlating with fault structures and internal pressure variations.
Time-series analysis highlighted contrasting deformation trends at P1 and P2. The integrated interpretation confirms the effectiveness of SBAS-InSAR in detecting subtle, spatially variable deformation and enhances understanding of the volcano’s internal dynamics. These findings provide valuable insight for geohazard assessment and long-term monitoring of mud volcanoes in tectonically active regions.