hemalsilva
01-21-2010, 10:02 PM
The Mariana Trench (or Marianas Trench)
The Mariana Trench (or Marianas Trench) is the deepest known part of the world's oceans, and the lowest elevation of the surface of the Earth's crust. It is located in the western Pacific Ocean, to the east of the Mariana Islands. The trench is about 2,550 kilometres (1,580 mi) long but has a mean width of only 69 kilometres (43 mi). It reaches a maximum depth of about 11,033 metres (36,200 ft) at the Challenger Deep, a small slot-shaped valley in its floor, at its southern end.
Part of the Izu-Bonin-Mariana Arc system, the trench forms the boundary between two tectonic plates, where the western edge of the Pacific Plate is subducted beneath the small Mariana Plate. Because the Pacific plate is the largest of all the tectonic plates on Earth, crustal material at its western edge has had a long time since formation (up to 170 million years) to compact and become very dense; hence its great height-difference (which translates to water depth) relative to the higher-riding Mariana Plate, at the point where the Pacific Plate crust is subducted (is forced down beneath the other). This deep area is the Mariana trench proper. The movement of these plates is also responsible for the formation of the Mariana Islands.
At the bottom of the trench, where the plates meet, the water column above exerts a pressure of 108.6 megapascals (15,750 psi), over one thousand times the standard atmospheric pressure at sea level. If Mount Everest, the highest mountain on Earth at 8,848 metres (29,030 ft), were set in the deepest part of the Mariana Trench, there would be 2,076 metres (6,810 ft) of water left above it.
http://upload.wikimedia.org/wikipedia/commons/thumb/1/1b/Marianatrenchmap.png/250px-Marianatrenchmap.png
http://farm1.static.flickr.com/49/157436392_79e1eff8fc_o.jpg
The Mariana Trench (or Marianas Trench) is the deepest known part of the world's oceans, and the lowest elevation of the surface of the Earth's crust. It is located in the western Pacific Ocean, to the east of the Mariana Islands. The trench is about 2,550 kilometres (1,580 mi) long but has a mean width of only 69 kilometres (43 mi). It reaches a maximum depth of about 11,033 metres (36,200 ft) at the Challenger Deep, a small slot-shaped valley in its floor, at its southern end.
Part of the Izu-Bonin-Mariana Arc system, the trench forms the boundary between two tectonic plates, where the western edge of the Pacific Plate is subducted beneath the small Mariana Plate. Because the Pacific plate is the largest of all the tectonic plates on Earth, crustal material at its western edge has had a long time since formation (up to 170 million years) to compact and become very dense; hence its great height-difference (which translates to water depth) relative to the higher-riding Mariana Plate, at the point where the Pacific Plate crust is subducted (is forced down beneath the other). This deep area is the Mariana trench proper. The movement of these plates is also responsible for the formation of the Mariana Islands.
At the bottom of the trench, where the plates meet, the water column above exerts a pressure of 108.6 megapascals (15,750 psi), over one thousand times the standard atmospheric pressure at sea level. If Mount Everest, the highest mountain on Earth at 8,848 metres (29,030 ft), were set in the deepest part of the Mariana Trench, there would be 2,076 metres (6,810 ft) of water left above it.
http://upload.wikimedia.org/wikipedia/commons/thumb/1/1b/Marianatrenchmap.png/250px-Marianatrenchmap.png
http://farm1.static.flickr.com/49/157436392_79e1eff8fc_o.jpg