Examples of geophysical subduction profiles. (A) P wave attenuation tomography in the Tonga/Lau system (after Pozgay et al. 2009). Circles are earthquakes. (B) Seismic velocity contrast profile created using teleseisms. (C) Electromagnetic profiles of the Cascades (Rondenay et al. 2008; Evans et al. 2013). Labels A, B, and C correspond to possible fluid accumulation areas (forearc and backarc conductors). See text for details.