what is the deepest part of the ocean floor?

Answer 1

Mariana Trench-maximum depth of 10.9 km, 6.77 mi
The Mariana Trench is located in the Pacific Ocean, just east of the 14 Mariana Islands (11"21' North latitude and 142" 12' East longitude ) near Japan. As you probably already know, it is the deepest part of the earth's oceans, and the deepest location of the earth itself. It was created by ocean-to-ocean subduction, a phenomena in which a plate topped by oceanic crust is subducted beneath another plate topped by oceanic crust.

The deepest part of the Mariana Trench is the Challenger Deep, so named after the exploratory vessel HMS Challenger II; a fishing boat converted into a sea lab by Swiss scientist Jacques Piccard.

Answer 2

The Marianas Trench in the western part of the Pacific Ocean at 36,198 feet.

Answer 3

http://en.wikipedia.org/wiki/Mariana_Trench
http://www.marianatrench.com/mariana_trench-oceanography.htm
http://geology.com/records/deepest-part-of-the-ocean.shtml

6.77 miles deep, about 16,000 psi at depth.