The
Mariana Trench (or
Mariana's Trench) is the deepest part of the world's
oceans, and the deepest location on the surface of the
Earth's crust. It has a maximum depth of about 11&_160;km (6.8&_160;mi), and is located in the western North
Pacific Ocean, to the east and south of the
Mariana Islands, near
Guam.
The trench forms the boundary between two tectonic plates, where the Pacific Plate is subducted beneath the Philippine Plate. The bottom of the trench is farther below sea level than Mount Everest is above it (8,848m/29,028ft). At the bottom, the water column above exerts a pressure of 108.6&_160;MPa, over one thousand times the standard atmospheric pressure at sea level.
The trench was first surveyed in 1951 by the Royal Navy vessel Challenger, which gave its name to the deepest part of the trench, the Challenger Deep.[1] Using echo sounding, the Challenger II measured a depth of 5,960 fathoms (10,900 metres, 35,760 ft) at 11°19'N, 142°15'E.[2]
In 1957, the Soviet vessel Vityaz reported a depth of 11,034 meters (36,200&_160;ft), dubbed the Mariana Hollow.[3] (Although this claim was made by the Soviets in 1957, the finding has not been repeated by subsequent mapping expeditions using more accurate and modern equipment.[citation needed])
