The
Mariana Trench or
Marianas Trench is the
deepest part of the
world's oceans. It is located in the western
Pacific Ocean, to the east of the
Mariana Islands. The trench is about long but has an average width of only . It reaches a maximum-known depth of 10,994 m (± 40 m) or 6.831 mi (36,070 ± 131 ft) 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 .