The Mariana Trench<span> is part of the Izu-Bonin-</span>Mariana<span>subduction system that forms the boundary between two </span>tectonic plates<span>. In this system, the western edge of one </span>plate<span>, the Pacific </span>Plate<span>, is subducted (going under) beneath the smaller </span>Mariana Plate<span> that lies to the west.</span>
