Mariana Trench
The Mariana Trench is an oceanic trench located in the western Pacific Ocean, about 200 kilometres (124 mi) east of the Mariana Islands; it is the deepest oceanic trench on Earth. It is crescent-shaped and measures about 2,550 km (1,580 mi) in length and 69 km (43 mi) in width. The maximum known depth is 10,984 ± 25 metres (36,037 ± 82 ft; 6,006 ± 14 fathoms; 6.825 ± 0.016 mi) at the southern end of a small slot-shaped valley in its floor known as the Challenger Deep.[1] The deepest point of the trench is more than 2 km (1.2 mi) farther from sea level than the peak of Mount Everest.[a]
"Marianas Trench" redirects here. For the Canadian band, see Marianas Trench (band).
At the bottom of the trench, the water column above exerts a pressure of 1,086 bar (15,750 psi), more than 1,071 times the standard atmospheric pressure at sea level. At this pressure, the density of water is increased by 4.96%. The temperature at the bottom is 1 to 4 °C (34 to 39 °F).[4]
In 2009, the Mariana Trench was established as a US National Monument.[5]
One-celled organisms called monothalamea have been found in the trench at a record depth of 10.6 km (35,000 ft; 6.6 mi) below the sea surface by researchers from Scripps Institution of Oceanography. [6] Data has also suggested that microbial life forms thrive within the trench.[7][8]
Etymology
The Mariana Trench is named after the nearby Mariana Islands, which are named Las Marianas in honor of Spanish Queen Mariana of Austria. The islands are part of the island arc that is formed on an over-riding plate, called the Mariana Plate (also named for the islands), on the western side of the trench.
Possible nuclear waste disposal site
Like other oceanic trenches, the Mariana Trench has been proposed as a site for nuclear waste disposal[52][53] in the hope that tectonic plate subduction occurring at the site might eventually push the nuclear waste deep into the Earth's mantle, the second layer of the Earth. However, ocean dumping of nuclear waste is prohibited by international law.[52][53][54] Furthermore, plate subduction zones are associated with very large megathrust earthquakes, the effects of which are unpredictable for the safety of long-term disposal of nuclear wastes within the hadopelagic ecosystem.[53]