Deep structure beneath eastern China from teleseismic P-wave tomography

A detailed three-dimensional P-wave velocity structure of the crust and the upper mantle beneath eastern China was determined by applying teleseismic tomography to 12078 high-quality P-wave arrival times from 9802 teleseismic events recorded by 652 broadband stations of seismic networks. The tomographic image shows that obvious low P-wave velocity (low-Vp) anomalies exist under Datong volcano, Wudalianchi volcano, Guangdong Province，Bohai Gulf and Yangtze block. Significant high-Vp zone of Sichuan basin and low-Vp zone of Yangtze block are also fairly evident in images of vertical cross-sections of P-wave tomography. The collision-driven, large-scale lateral mantle flow under eastern China may help explain the broad and dispersive mantle upwelling under eastern China. The subduction of Pacific plate is only one of the mantle upwelling causations.