Which ocean trench contains Challenger Deep, the deepest known point on Earth?

The Mariana Trench contains Challenger Deep, the deepest known point on Earth.

The trench lies in the western Pacific Ocean east of the Mariana Islands, where the Pacific Plate is forced beneath the smaller Mariana Plate. This subduction process created a long, curved depression in the seafloor. Challenger Deep, at the trench’s southwestern end, reaches nearly 11,000 meters below sea level, although precise measurements vary by survey and instrument.

The deepest area was named after HMS Challenger, whose expedition made the first systematic deep-ocean soundings there in 1875. In 1960, Jacques Piccard and Don Walsh descended in the bathyscaphe Trieste, becoming the first people to reach Challenger Deep. James Cameron made a solo descent in 2012.

“Deepest point” does not mean the entire trench has one uniform depth. Challenger Deep consists of several basins, and modern sonar and submersible missions continue refining its measurements. Even under extreme pressure, microbial life and other organisms have been found in the surrounding hadal environment.