The Mariana Trench or Marianas Trench is the deepest part of the world's oceans. It is located in the western Pacific , to the east of the Mariana Islands.
The trench is about 2,550 kilometres long with an average width of 69 kilometres.
It reaches a maximum-known depth of 10,994 metres at a small slot-shaped valley in its floor known as the Challenger Deep, at its southern end, although some unrepeated measurements place the deepest portion at 11,034 metres