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Figure 2 | Earth, Planets and Space

Figure 2

From: Strike-slip motion of a mega-splay fault system in the Nankai oblique subduction zone

Figure 2

Seismic profile, P-wave seismic velocity, normalized pore pressure ratio, and S-wave velocity anisotropy. (a) Seismic profile across the Kumano transect (CDEX-3D). The locations of faults discussed in this paper (e.g., WBSF) are described in this panel. A low reflectivity zone occurs beneath the WBSF. (b) P-wave seismic velocity estimated from waveform tomography (WT; Kamei et al. 2012; Kamei et al. 2013) overlaid on the reflection seismic profile. The seismic velocity shown in this figure is de-trended from the dominant 1D velocity-depth trend defined in Kamei et al. (2013). Low P-wave velocity is observed within the accretionary prism beneath the WBSF. (c) Normalized pore pressure ratio (Tsuji et al. 2014), defined by λ* = (Pf − Phf)/(Pc − Phf) where Pc is the confining pressure, Pf is the pore pressure, and Phf is the hydrostatic pressure. Overpressure and well-developed fractures cannot be distinguished, as described in Tsuji et al. (2014). (d) S-wave velocity anisotropy (Tsuji et al. 2011a), defined by (Vs,fast − Vs,slow)/Vs,fast where Vs,fast is the S-wave velocity for the fast-polarization direction and Vs,slow is the velocity for the slow-polarization direction. (e) S-wave velocity difference between trench-parallel direction Vs,tp and trench-normal direction Vs,tn.

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