Mariana Trench

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 2,550 kilometres (1,580 mi) long with an average width of 69 kilometres (43 mi). 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 theChallenger Deep, at its southern end, although some unrepeated measurements place the deepest portion at 11,034 metres (36,201 ft).

At the bottom of the trench the water columnabove exerts a pressure of 1,086 bars (15,750 psi) (over 1000 times the standard atmospheric pressure at sea level). At this pressure, the density of water is increased by 4.96%, making 95 litres of water under the pressure of the Challenger Deep contain the same mass as 100 litres at the surface. The temperature at the bottom is 1 to 4 °C.

[PDF] Fangtooth fish

Unknown sea creature

Frilled Shark

Barreleye

Dragonfish

Hatchetfish

Footballfish

Sea Nut

Dumbo Octopus

Ping-Pong Tree Sponge

Picture Source: Collected from Internet