Revealing Blind Faults Through High‐Resolution Imaging of Shallow Structures: A Case Study on Chenghai Fault, Yunnan, China

Abstract Blind faults pose significant seismic hazards because they remain hidden beneath the surface and are often unrecognized until they generate large earthquakes. High‐resolution shallow velocity models are essential for imaging these blind structures. We analyze seismic data from a dense linear array across the Chenghai Fault, buried beneath a thick basin in Yunnan, China. First, we obtain a high‐resolution shallow velocity model using surface wave tomography with a three‐station‐interferometry‐based denoising technique. Then we correct teleseismic S‐wave delays with this model, and reveal a bi‐material interface associated with the buried fault. Compared with previous regional tomography, the across‐fault velocity contrast offers a higher‐resolution view of the buried bi‐material interface. These results highlight the importance of high‐resolution shallow velocity models for detecting and characterizing blind faults. The model can be further exploited to remove wave propagation effects in shallow structures, aiding high‐resolution imaging of blind faults in future studies.