Subduction

In plate tectonics a subduction zone is a region where one plate (the lower plate or slab) moves under another (the upper plate) and sinks into the mantle beneath it. This process results in a convergent movement of the two involved plates which is known to generate earthquake ruptures of different types. These ruptures are classified according to the part of the subduction zone where they occur. Interface ruptures are those that occur at the contact between the two plates; intraslab ruptures are those that occur within the slab; outer-rise ruptures also occur within the slab but in the region in front of the trench or the tip of the accretionary wedge; and splay ruptures which are those that propagate from the slab interface into the upper plate.