Quantifying Crustal Seismic Attenuation Across Continental China: A Comprehensive Coda‐Wave Tomography From Ambient Noise Correlations

Abstract

Ambient noise cross‐correlation has emerged as a key technique in low‐frequency seismology, enabling coda‐attenuation measurements at frequencies difficult to access with traditional earthquake‐based approaches, especially in regions with insufficient seismicity. This work establishes the first comprehensive coda‐wave attenuation tomography of continental China across the 3–30 s period band, utilizing Empirical Green's Functions retrieved from ambient noise cross‐correlations, with attenuation measured from the Rayleigh‐wave coda. By applying a bound‐constrained Gauss‐Newton inversion scheme, we derive a high‐resolution frequency‐dependent Qc model that reveals pronounced lateral variations in crustal attenuation. Our tomographic results demonstrate a systematic relationship between attenuation structure and major tectonic blocks: prominent high‐attenuation anomalies correlate with sedimentary basins and active tectonic zones, whereas stable cratonic regions exhibit consistently elevated Qc values. These spatial patterns show a strong correspondence with active fault systems and modern seismicity distributions, thereby providing new constraints on regional tectonic processes and vital insights for seismic hazard assessment. Collectively, the Qc model presented in this study establishes a robust reference for investigating crustal heterogeneity throughout continental China, effectively complementing existing seismic velocity models to advance the integrated interpretation of the region's complex tectonic architecture.