マリアナ海溝
Its mean depth is . Challenger Deep in the Mariana Trench, located in the western north Pacific, is the deepest point in the world, reaching a depth of . The Pacific also contains the deepest point in the Southern Hemisphere, the Horizon Deep in the Tonga Trench, at . The third deepest point on Earth, the Sirena Deep, is also located in the Mariana Trench.