Pacific plate

Pacific plate unified based on the velocity structures by seismic tomography, seismicity, focal mechanisms.

Figure 1. Depth contour map of the upper boundary of the Philippine Sea and Pacific slabs. PDF

Please refer to PHS about the Philippine Sea slab.

Pacific plate: Data of Hokkaido district - northern Tohoku district¹, northern - southern Tohoku district², and Kanto district - northern Izu arc³ are compiled. Broken blue line denotes the northeastern limit of the Philippine Sea slab⁴. Blue masked area denotes the contact zone between the Philippine Sea and Pacific slabs³. Arrow indicates direction of plate motion of the Philippine Sea and Pacific plates relative to the continental (Eurasian, Amurian, and Okhotsk) plate⁵.

*Note:
The plate configuration reflects the depth of the trench. Therefore, the trench almost accords with the iso-depth contour of 10 km at deep Izu-Bonin trench. Depth contour of 0 km on the Pacific plate is a temporary thing in the illustration.

References

Kita, S., T. Okada, A. Hasegawa, J. Nakajima, and T. Matsuzawa (2010), Anomalous deepening of a seismic belt in the upper-plane of the double seismic zone in the Pacific slab beneath the Hokkaido corner: Possible evidence for thermal shielding caused by subducted forearc crust materials, Earth Planet. Science Lett., 290, 415-426.
Nakajima, J., and A. Hasegawa (2006), Anomalous low-velocity zone and linear alignment of seismicity along it in the subducted Pacific slab beneath Kanto, Japan: Reactivation of subducted fracture zone?, Geophys. Res. Lett., 33, L16309, doi: 10.1029/2006GL026773.
Nakajima, J., F. Hirose, and A. Hasegawa (2009), Seismotectonics beneath the Tokyo metropolitan area, Japan: Effect of slab-slab contact and overlap on seismicity, J. Geophys. Res., 114, B08309, doi:10.1029/2008JB006101.
Uchida, N., J. Nakajima, A. Hasegawa, and T. Matsuzawa (2009), What controls interplate coupling?: Evidence for abrupt change in coupling across a border between two overlying plates in the NE Japan subduction zone, Earth Planet. Sci. Lett., 283, 111-121.
Wei, D., and T. Seno (1998), Determination of the Amurian plate motion, in "Mantle dynamics and plate interactions in East Asia", Geodynamics. Series, 27, ed. by M. F. J. Flower, S. L. Chung, C. H. Lo, and T. Y. Lee, pp. 337-346, AGU, Washington D. C.