Fabio Crameri
Subduction initiation events during the past 100 Ma collected in the Subduction-zone initiation (SZI) Database 1.0.

' Subduction zone initiation '

(SZI) is the initiation of new, independent subduction zone in the presence of ongoing ocean-plate tectonics. More specifically, it is the onset of downward plate motion forming a new slab, which later evolves into a self-sustaining subduction zone. - Crameri et al. (2020, Nature Comms.)

It is distinguished from:

  • ' Subduction initiation (SI) '
    is the initiation of subduction (i.e., the sinking of oceanic plates into the mantle) in the absence of pre-existing subduction zones anywhere else on the planet.

While SZI describes the initiation of a feature (i.e., a subduction zone), SI describes the initiation of a process (i.e., subduction). As such, SZI and SI are describing two strongly different aspects of the ocean-plate tectonics, and must therefore be clearly distinguished from each other.

For more information, a universal glossary, and an online discussion forum, go to SZIdatabase.org.