Seismic Attenuation Reveals Fault and Forearc Structure Across the Subduction‐Collision Transition in Southern Taiwan
Journal
Geophysical Research Letters
Journal Volume
53
Journal Issue
8
ISSN
0094-8276
1944-8007
Date Issued
2026-04-18
Author(s)
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 QP/QS 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-QP volume and the spatial coincidence of low Q and QP/QS 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.
Subjects
SALUTE
seismic attenuation
southern Taiwan
subduction-collision transition
tomography
Publisher
American Geophysical Union (AGU)
Type
letter