Which ocean contains the Mariana Trench, the deepest known oceanic trench?

The Mariana Trench, the deepest known oceanic trench, lies in the Pacific Ocean.

It is located east of the Mariana Islands, near the boundary where the Pacific Plate is forced beneath the Mariana Plate. This process, called subduction, formed the long, curved depression in the seafloor. The trench’s deepest point is Challenger Deep, whose measured depth is about 10,935 metres, although values vary slightly by survey method.

The first confirmed crewed descent to Challenger Deep took place in 1960, when Jacques Piccard and U.S. Navy lieutenant Don Walsh reached the bottom in the bathyscaphe Trieste. Filmmaker and explorer James Cameron made a solo descent in 2012.

The trench is in the Pacific, not the Atlantic or Indian Ocean. Its extreme pressure, darkness, and near-freezing temperature make exploration difficult, yet scientists have found organisms adapted to these conditions. The Mariana Trench is part of the Pacific’s broader system of deep ocean trenches and island arcs.