A subduction zone is a geological area where one tectonic plate moves under another and sinks into the Earth's mantle. This process occurs at convergent plate boundaries, where the denser oceanic plate is typically forced beneath a lighter continental plate. Subduction zones are often associated with volcanic activity and the formation of mountain ranges. These zones can lead to significant geological events, such as earthquakes and the creation of deep ocean trenches. Notable examples of subduction zones include the Cascadia Subduction Zone off the coast of North America and the Japan Trench near Japan.