The Challenger Deep Revised

The Mariana Trench is the deepest place on Earth. It is located to the east of Mariana Islands, running for about 2550 kilometers but has a mean width of only 69 kilometers.

The deepest point, known as the Challenger Deep, which had hitherto been measured at 10919 meters, is now estimated to be 10994 meters.

To put the figures into perspective;
The tallest mountain in the world, Mount Everest, is only 8848 meters.
The world record for scuba diving is 330 meters.

Image: whoi.edu

Let's do some calculation.

Water pressure, P is given by hρg 

since h = 10994 m, g = 9.81 m/s^2, and  ρ = 1097 kg/m^3

Therefore P = 110763120.78 Pa, or 110.7 MPa.

So it's really cold and pressurized down there. One might not expect to see any living organism here until they set their eyes on something glittering in the dark--the Angler Fish!
There are also other organism here, for example the Vent Crab, and bacterias. Lots of them. These animals are kept alive probably by hydrothermal vents, which release hydrogen sulfide and other minerals, as well as heat.

Pretty cool isn't it?



Malcolm
info:
http://deepseanews.com/2011/12/deepest-trench-now-with-more-deep/