This volcanic arc delineates the boundary between the Pacific and North American tectonic plates. A subduction zone ... the volcano's throat and causes explosive eruptions when magma again ...

There is a 10% chance of Auckland suffering a volcanic eruption in the next 50 years ... predicted should a magnitude 9.1 Hikurangi subduction zone earthquake and subsequent tsunami take place.

Slab pull occurs where older, denser tectonic plates sink into the mantle at subduction zones. As these older sections of plates sink, newer and less dense sections of plate are pulled along behind.