What geological process occurs when one tectonic plate moves under another?

The geological process that occurs when one tectonic plate moves under another is known as subduction. This process typically happens at convergent plate boundaries, where an oceanic plate collides with either another oceanic plate or a continental plate. The denser oceanic plate is forced beneath the lighter plate into the mantle, where it begins to melt.

Subduction zones are characterized by deep ocean trenches, volcanic arcs, and earthquake activity, as the movement of the plates creates significant geological stress and leads to the formation of various geological features. The melting of the subducted plate can generate magma, which can lead to volcanic eruptions on the overlying plate.

While other processes are related to tectonic activity, they do not specifically describe the scenario of one plate moving beneath another. Spreading refers to the movement of tectonic plates away from each other, often occurring at mid-ocean ridges. Transforming describes the lateral movement of plates sliding past one another, which does not involve one plate being forced underneath another. Convergence refers to the broader category of tectonic interaction where plates move toward each other, but it alone doesn't specify the subduction process. Thus, subduction is the most precise term that directly describes the movement of one plate beneath