Crustal Velocity Variation of the Western Philippine Sea Plate from TAICRUST OBS/MCS Line 23

The aims of this research are to understand the deformation of the shallow structures (< 6 km depth), the crustal velocity variation of the western Philippine Sea Plate (PSP) and their relation to the arc-continent collision using Ocean Bottom Seismometers (OBS) and a multi-channel seismic (MCS) survey (together known as TAICRUST) offshore southeastern Taiwan. A seismic line, Line 23 which covers the Luzon Arc, the Huatung Basin, the Taitung Canyon and the western edge of the Gagua Ridge, is investigated. Prominent reflected and refracted arrivals form the sediment, the oceanic basement and the Moho can be seen in the OBS data. By applying the travel-time inversion of the stacked MCS data and the OBS data, the velocity-depth model is built sequentially from the shallow to the deep structures. Low RMS travel-time error and numerous travel-time picks demonstrate the accuracy and the high resolution of the model, respectively.