What is the name of the deepest earthquake zone created by a sinking tectonic plate?

The Wadati–Benioff zone is the dipping zone of earthquakes created by a sinking tectonic plate.

It forms at a subduction boundary, where oceanic lithosphere descends into the mantle beneath another plate. Earthquakes can occur from near the trench to depths of roughly 700 kilometres, tracing the descending slab through the mantle. Their pattern helps scientists map plate geometry below the surface.

The zone is named for Japanese seismologist Kiyoo Wadati and American seismologist Hugo Benioff, whose work independently documented deep earthquake patterns. Shallow earthquakes occur near the plate boundary, while intermediate and deep events follow the slab downward.

Not every earthquake at a subduction zone lies exactly on one plane, and earthquakes deeper than about 700 kilometres are rare. The zone is therefore a seismic expression of subduction, not the name of the trench itself.