1. A reference to a region that is prone to seismic activity.
2. The base of the seismogenic zone is the top of the more ductile asthenosphere (the ductile part of the earth just below the lithosphere, including the lower mantle which is about 180 km thick).
3. Capable of generating earthquakes.

Many of the world’s most disastrous earthquakes and volcanic eruptions take place at subduction zones, or areas under the ocean where one tectonic plate collides with another, sending sections of Earth’s crust down into the mantle.

The deep layers of seismic activity in these areas are called Wadati-Benioff zones and can be found as deep as 700 km.

Some areas are known to host parallel planes of seismicity referred to as double Benoiff zones, or DBZs, but these have been thought to be rare.

Analysis of global seismicity catalogs and characterization of the layer separation at 16 subduction zones revealed two parallel seismic strips, rather than a single broad zone, in most cases.