Mariana Trench is located in the ocean floor of

The Mariana Trench is the deepest oceanic trench on Earth, located in the floor of the western Pacific Ocean [4]. It is a crescent-shaped depression formed by the tectonic subduction of the Pacific Plate beneath the smaller Mariana Plate [1]. Geographically, it lies east of the Philippines and the Mariana Islands, and southwest of Guam [3]. The trench spans approximately 2,550 kilometers in length and contains the Challenger Deep, which is the deepest known point in the world's oceans, reaching depths of approximately 10,935 to 11,034 meters [2]. While the Pacific Ocean contains a majority of the world's deep-sea trenches along its margins, the Mariana Trench specifically occupies the western North Pacific region [4].

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 8: Convergent Boundary > The Mariana Trench or Marianas Trench > p. 115
2. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 31: Ocean Relief > Oceanic Deeps or Trenches > p. 482
3. [4] https://www.britannica.com/place/Mariana-Trench
4. [2] https://www.ncei.noaa.gov/news/planet-postcard-mariana-trench