High Quality Content by WIKIPEDIA articles! A Wadati–Benioff zone (also Benioff–Wadati zone or Benioff zone or Benioff seismic zone) is a deep active seismic area in a subduction zone. Differential motion along the zone produces deep-seated earthquakes, the foci of which may be as deep as about 700 kilometres (430 mi). They develop beneath volcanic island arcs and continental margins above active subduction zones. They can be produced by slip along the subduction thrust fault or slip on faults within the downgoing plate, as a result of bending and extension as the plate is pulled into the mantle. The deep earthquakes along the zone allow seismologists to map the three-dimensional surface of a subducting slab of oceanic crust and mantle. The angle of dip of the zone is the same as that of the subducting slab.