Deep ocean trenches are some of the deepest parts of the Earth's oceans, formed by the movement of tectonic plates. These trenches can reach depths of over 36,000 feet, with the Mariana Trench being the deepest known. They are typically found at convergent plate boundaries, where one tectonic plate is forced under another. These underwater features play a crucial role in the Earth's geology and ecosystems. They are home to unique organisms that have adapted to extreme pressure and darkness. The trenches also influence ocean currents and are important for understanding the planet's climate and geological processes.