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>
The Tropic of Capricorn (or the Southern Tropic) is the circle of latitude that contains the subsolar point on the December (or southern) solstice. It is thus the southernmost latitude where the Sun can be directly overhead. Its northern equivalent is the Tropic of Cancer.
