Far-Field Seismic Triggering Effects on Faults and Mud Volcanoes in Azerbaijan: Insights from InSAR and GNSS Results

Azerbaijan is well-known for its hydrocarbon-rich subsurface geology, which hosts numerous mud volcanoes interacting with complex tectonic settings. Mud volcanoes, constant sources of methane gas, mud, and other hydrocarbons, are not just natural wonders but also crucial indicators of geological processes. The geological setting, characterized by rapid eruptions, overpressured reservoirs, and complex fault networks, presents a unique environment to explore the interactions between tectonic and volcanic processes. We have analyzed an extensive long-term InSAR time series using Sentinel-1 data from January 2017 to October 2024 to examine the complex deformation processes and mud volcano activity in the region. Detailed and comprehensive analyses used both Ascending and Descending tracks and applied the ISCE2 and MintPy software to process the InSAR time series. We used over 230 scenes and created nearly 700 interferograms for each track. DEM and atmospheric corrections were applied from SRTM1 and ERA5, respectively. Our key findings reveal far-field dynamic deformation effects along the faults and at major mud volcanoes, including Ayazakhtarma and Akhtarma-Pashaly. Notably, the February 2023 Türkiye Kahramanmaraş earthquakes (Mw 7.8 and 7.6) triggered widespread deformation, reactivating fault systems and nearly all monitored mud volcanoes. This far-field triggering effect persisted for months, indicating prolonged subsurface adjustments and emphasizing the responsive nature of mud volcanoes to seismic events. Additionally, GNSS station data from two continuous stations in the study area, which provided precise and continuous ground deformation measurements, further validated the findings, showing clear evidence of dynamic triggering effects. These complementary datasets, GNSS and InSAR, provide a robust framework for understanding the complex geophysical processes. Results highlight the essential role of mud volcanoes as indicators of subsurface fluid migration and tectonic stress. This examination provides critical insights into the conduct of hydrocarbon-rich regions under seismic influences, with significant implications for seismic hazard assessment and tectonic studies. By integrating geodetic analysis with geological interpretations, this work highlights the importance of monitoring tectonically active, hydrocarbon-rich zones like Azerbaijan to understand natural hazards and subsurface processes.