Subduction zones are areas where one tectonic plate moves under another and sinks into the Earth's mantle. This process occurs at convergent boundaries, where two plates collide. The descending plate, often an oceanic plate, creates deep ocean trenches and can lead to volcanic activity as it melts and releases magma. These zones are significant for their role in the Earth's geology. They are responsible for creating mountain ranges, earthquakes, and volcanic eruptions. Notable examples of subduction zones include the Cascadia Subduction Zone in the Pacific Northwest and the Japan Trench off the coast of Japan.