摘要： •8 OBSs and 14 inland stations were used to analyze the seismic features.•9 focal mechanisms were determined based on the first arrivals motion.•Two main borders along east Taiwan were defined based on relocated earthquakes.•The underthrusted arc/fore-arc forms the transition from collision to subduction.•The arc/for-arc deformation occurred mainly in the marine area. Located at the arc-continental collision region between the Eurasian (EP) and Philippine Sea Plates (PSP), Taiwan is usually considered to have a complex tectonic environment, particularly along the eastern coast of the island. To gain a better understanding of the geological evolution of the east Taiwan area, the data from 8 Ocean Bottom Seismometers (OBS) acquired during the Across Taiwan Strait Explosion Experiment in 2012 and 14 inland seismic stations were used to determine a more detailed and accurate distribution of marine earthquakes. Based on the 333 relocated earthquakes and available geophysical data, we suggest two main tectonic boundaries for eastern Taiwan. South of 23.25°N, the homogeneous distribution of earthquakes in the crustal portion for both the inland and offshore areas suggests an ongoing collisional process. North of this location, between approximately 23.25°N and 23.8°N, the abrupt increasing of seismicity depth infers that the underthrusted arc/fore-arc material is deforming due to the collisional compression at depth. In this segment, the subsidence of the arc/fore-arc area determines the transition from collision to subduction. North of 23.8°N, the northwestern dipping PSP is well illustrated by the seismicity both onshore and offshore, indicating a dominant subduction process. 出版者： Elsevier Ltd 出版日期： 2016-10-01 出處： Journal of Asian earth sciences, 2016-10, Vol.128, p.149-157 資源來源： Elsevier ScienceDirect Journals Complete 版權： 2016 Elsevier Ltd 識別號： ISSN: 1367-9120 識別號： EISSN: 1878-5786 識別號： DOI: 10.1016/j.jseaes.2016.07.008
