At a subduction boundary, there are two key features that bound to form namely a deep ocean trench and a volcanic arc.
Subduction boundary or zone is formed when two tectonic plate converge and one plate is thrust beneath the other.
The deep ocean trench occurs where the oceanic plate bends downward below the other plate.
Volcanic arc is a chain of volcanoes, all concurrently active, that form on the overriding plate.
Powerful earthquakes and earth tremors usually occur at the subduction boundary.
