11:15 〜 11:30
[SSS05-09] Lithospheric Structure and Deformation in Southern Taiwan from SALUTE Seismic Observations
キーワード：receiver function, CCP stacking, seismic discontinuity, shear wave splitting, continental lithosphere subduction, arc-continent collision
The Southern Array for the Lithosphere and Uplift of Taiwan Experiment (SALUTE) is an amphibious seismic initiative designed to investigate the lithospheric structure and dynamics of southern Taiwan and its eastern offshore region. This area, located at the juncture of Eurasian Plate subduction and Luzon Arc collision, is key to understanding the spatiotemporal evolution of the Taiwan orogen. The project integrates multi-faceted, array-based seismic imaging, tomography, and modeling to comprehensively examine the crust-mantle system in this critical transition zone.
Here, we present findings from earthquake datasets recorded since October 2021 by the SALUTE array, which consists of 31 closely spaced broadband land stations and 11 ocean-bottom seismometers (OBSs) arranged in a cross-shaped configuration. Here, we present major findings from earthquake datasets recorded since October 2021 by the SALUTE array, consisting of 31 closely spaced broadband land stations and 11 ocean-bottom seismometers (OBSs) arranged in a cross-shaped configuration. Teleseismic P receiver function (RF) analysis and Common Conversion Point (CCP) stacking reveal significant subsurface seismic discontinuities. Our results show that the Eurasian continental crust beneath western Taiwan is relatively thin (~25 km), suggesting a history of rifting and extension preceding subduction. A ~10 km Moho offset near the Chaochou Fault (CCF) indicates differential crustal thickening across the collision boundary. Additionally, weak and intermittent P-to-S conversions from the subducted Eurasian slab beneath eastern Taiwan suggest that serpentinization effects or a steep slab geometry may affect its detectability. A 70 km-deep, 35 km-wide oceanic-continent boundary (OCB) beneath eastern Taiwan marks the transition from the Eurasian continental crust to the South China Sea oceanic lithosphere. Furthermore, SKS/SKKS splitting analysis provides insights into lithospheric deformation and asthenospheric mantle flow, revealing intricate anisotropic patterns resulting from the interaction of the oppositely subducting Eurasian Plate and Philippine Sea Plate.
Here, we present findings from earthquake datasets recorded since October 2021 by the SALUTE array, which consists of 31 closely spaced broadband land stations and 11 ocean-bottom seismometers (OBSs) arranged in a cross-shaped configuration. Here, we present major findings from earthquake datasets recorded since October 2021 by the SALUTE array, consisting of 31 closely spaced broadband land stations and 11 ocean-bottom seismometers (OBSs) arranged in a cross-shaped configuration. Teleseismic P receiver function (RF) analysis and Common Conversion Point (CCP) stacking reveal significant subsurface seismic discontinuities. Our results show that the Eurasian continental crust beneath western Taiwan is relatively thin (~25 km), suggesting a history of rifting and extension preceding subduction. A ~10 km Moho offset near the Chaochou Fault (CCF) indicates differential crustal thickening across the collision boundary. Additionally, weak and intermittent P-to-S conversions from the subducted Eurasian slab beneath eastern Taiwan suggest that serpentinization effects or a steep slab geometry may affect its detectability. A 70 km-deep, 35 km-wide oceanic-continent boundary (OCB) beneath eastern Taiwan marks the transition from the Eurasian continental crust to the South China Sea oceanic lithosphere. Furthermore, SKS/SKKS splitting analysis provides insights into lithospheric deformation and asthenospheric mantle flow, revealing intricate anisotropic patterns resulting from the interaction of the oppositely subducting Eurasian Plate and Philippine Sea Plate.