*Earthquake hazard analysis, *Thrust faults (Geology), *Earthquakes, *Earth sciences, *Strains & stresses (Mechanics), *Earthquake aftershocks

We conducted a comprehensive seismotectonic study of the 2025 Dapu earthquake sequence in Taiwan, using densely distributed temporary seismic stations in a total number of 39, at the epicentral area. The ML 6.4 mainshock occurred in the foothills of southwestern Taiwan, an area characterized by a series of imbricate folds and thrust faults. Based on the relocated hypocenters, focal mechanisms, and stress inversions analyses, we identified two distinct aftershock distributions: one aligned with westward-dipping faults and another exhibiting an eastward-dipping distribution dominated by thrust faulting. Our finding suggests that the rupture process of the Dapu earthquake sequence can be explained by a conjugate fault rupture model and a triggering mechanism that accounts for the observed spatial characteristics. This interpretation is supported by detailed focal mechanism solutions that indicates complex fault interactions during the sequence. By evaluating the distribution of strong earthquakes in the areas surrounding this seismogenic zone, this study provides insights for refining regional seismic hazard assessment, ultimately contributing to improved pre-disaster planning and post-event response efforts. Highlights: The seismogenic structure of the 2025 Dapu earthquake. Detecting seismic events from dense array. Complex fault system in the highly fractured zone. [ABSTRACT FROM AUTHOR]

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