What geological process involves tectonic plates slipping under one another?

Subduction is the geological process where one tectonic plate moves under another and sinks into the mantle as the plates converge. This occurs when an oceanic plate meets either another oceanic plate or a continental plate, leading to the formation of deep ocean trenches and volcanic arcs. The intense pressure and temperature conditions associated with subduction can lead to significant geological phenomena, including earthquakes and the formation of mountain ranges.

Other options, while related to geological processes, do not describe the action of tectonic plates sliding beneath one another. Subterranean refers to something existing or occurring under the ground, which does not specifically relate to tectonic activity. Convection is a process that involves the movement of fluid caused by temperature differences, often within the Earth's mantle but not specifically referring to plate interactions. Transformation does not accurately encapsulate the dynamics of subduction, as it may refer more generally to changes in form or structure rather than the specific interaction of tectonic plates.