An integrated approach to unravel gas hydrates in the complex permafrost of the Tso Co area, Qiangtang Basin, China

Gas hydrate accumulations in high-altitude permafrost settings remain notoriously difficult to characterize seismically, yet they hold significant resource potential This study addresses key technical challenges in seismic exploration for gas hydrates in the permafrost of the Tso Co area, Qiangtang Basin, Tibetan Plateau, including low signal-to-noise ratio, complex static corrections, and difficult structural imaging. An integrated acquisition, processing, and interpretation workflow was developed to provide a high-precision seismic detection system suited to plateau permafrost conditions. A wide-line high-density geometry, combined with a low-frequency vibrator source with a sweep frequency of 1.5–96 Hz and point-receiver technology, enhanced low-frequency penetration and raw-data fidelity. Data processing used pseudo-three-dimensional wide-line tomographic static correction and global-optimization residual static correction to resolve high-frequency static distortions through iterative refinement. A multi-domain, stepwise, amplitude-preserving denoising workflow effectively suppressed high-energy noise, including surface waves and linear interference. Refined velocity modeling based on the Dip Moveout velocity field and finite-difference time migration achieved accurate positioning of complex structures. High-quality seismic profiles reveal alternating depression-uplift structural frameworks and major fault systems. The base of the permafrost layer shows a low-frequency, high-amplitude reflection of 10–35 Hz, with varying thickness (30–140 m). Ultra-low-frequency (5 Hz) relative impedance highlights permafrost distribution and indicates hydrate potential zones concentrated along faults, demonstrating structural control on gas migration. Low-frequency amplitude anomalies provide a reliable regional indicator for hydrate exploration.