Subduction is a geological method that gets a place at convergent boundaries of tectonic plates where one plate passes under another and is bound or falls due to gravity into the covering. When subduction zone earthquakes hit, Earth's shell flexes and locks like a cleared spring. For earthquakes bigger than a size 7.5, this can create a tsunami, a large sea tide, by quickly moving the seafloor. However, not all subduction zone earthquakes will generate tsunamis.
