Work

Seismic imaging of the crust and upper mantle beneath Taiwan using full-waveform inversion of teleseismic body waves

Year: 2026

Type: article

Abstract: Taiwan, situated at the convergent boundary between the Eurasian and Philippine Sea plates, is characterized by complex arc–continent collision and active orogenic processes. Previous seismic tomography studies have imaged key lithospheric structures, but ambiguities persist regarding slab morphology and near-surface structures. Here, we present new three-dimensional tomographic models of density, VP, VS, and VP/VS for Taiwan, obtained by inverting complete teleseismic P and SH waveforms using full-waveform inversion (FWI). The resulting models resolve the aseismic segment and detachment of the subducting Eurasian slab, revealing a slab gap north of 23.6°N at depths greater than 130 km, which accommodates the northwestward subduction of the Philippine Sea Plate. Crustal thickening and the formation of a deep crustal root beneath the Central Range are clearly imaged. High VP/VS in the lower crust suggests elevated fluid content from dehydration of the Eurasian slab. Improved shallow depth imaging reveals prominent velocity anomalies associated with active faults, sedimentary basins, and volcanic systems, including magma reservoirs beneath the Tatun Volcano Group and Turtle Island in northern Taiwan. These new constraints provide insights into the tectonic evolution, slab dynamics, and orogenic processes in Taiwan, and highlight the potential of teleseismic FWI for lithospheric imaging.

Source: Tectonophysics

DOI: 10.1016/j.tecto.2026.231301

Authors: Li-Yu Kan, Hao Kuo-Chen, Sébastien Chevrot, Vadim Monteiller