Seismic Attenuation Reveals Fault and Forearc Structure Across the Subduction‐Collision Transition in Southern Taiwan

Abstract The Southern Array for the Lithosphere and Uplift of Taiwan Experiment (SALUTE) provides a new window into the subduction‐collision transition zone in southern Taiwan, where the Eurasian Plate‐Luzon Arc convergence drives intense orogeny and crustal deformation. Using dense P ‐ and S ‐wave spectral amplitude data recorded by SALUTE and a quality factor ( Q ) tomography, we image attenuation structures with improved clarity of features. Results delineate sharp attenuation contrasts across major faults, reflecting juxtaposition of distinct lithological domains, and broad low Q and Q P / Q S anomalies within internally deformed regions not resolved by velocity tomography. Our models closely match mapped fault geometries and, for the first time, unravel the offshore forearc block as a northward‐dipping (∼15°), narrowing low‐ Q P volume and the spatial coincidence of low Q and Q P / Q S anomalies with tectonic tremor, which highlight the diagnostic value of attenuation imaging for fault‐related hazards, forearc deformation, fluid‐facilitated processes, and orogenic dynamics in southern Taiwan.