Geochemical Characteristics of Soil Gases in the Keping Fault Zone, Southwestern Tian Shan, Northwestern China

This study selected seven soil gas (Rn, H 2 ) measurement lines across Keping fault zone at the front of the Keping block in southwestern Tianshan. By integrating these measurements with InSAR techniques, we investigated the temporal and spatial characteristics of soil gases along the fault zone and analyzed the coupling relationship between soil gas geochemistry and tectonic activity. The average concentration variation characteristics of seven measurement lines, analyzed concurrently, along with the InSAR cross‐fault profile data, collectively identified three soil gas measurement lines that more effectively reflect the regional tectonic stress features. Furthermore, the maximum anomaly contrast ( I gas ) of soil gases for three key soil gas measurement lines exhibited a clear pattern of pre‐earthquake increase, followed by a significant post‐earthquake decrease returning to background levels during three moderate to strong seismic events in the vicinity of the study area. These temporal and spatial features indicate that the three lines possess geochemical sensitivity.