Fig. 9

P-wave tomography images along the upper boundary of the subducting Pacific slab in the forearc region. a Zhao et al. (2009), b Zhao et al. (2011), c Huang and Zhao (2013), and d Liu and Zhao (2018). In a, the tomography image along the NE Japan land region represents the central part of the mantle wedge (Zhao et al. 2009), while the blue dashed line indicates a low Vp region at the top of the plate boundary of Mochizuki et al. (2005)