What is an underwater trench?

An underwater trench is a deep, narrow depression in the ocean floor, often formed by tectonic plate movements, such as subduction, where one plate moves beneath another. These trenches are the deepest parts of the ocean and can reach depths of over 10,000 meters. They play a crucial role in the Earth's geology and ecology, serving as habitats for unique marine life and influencing ocean currents and climate. Notable examples include the Mariana Trench and the Tonga Trench.