Deepest Part of the Ocean / Deepest Ocean Trench

The Greatest Ocean Depth:

Challenger Deep in the Mariana Trench is the deepest point in Earth's oceans. The bottom there is 10,924 meters (35,840 feet) below sea level. If Mount Everest, the highest mountain on Earth, were placed at this location it would be covered by over one mile of water. The Challenger Deep is named after the British survey ship Challenger II, which discovered this deepest location in 1951. It was first explored by Nereus, a deep-sea robotic vehicle designed by scientists at the Woods Hole Oceanographic Institution in 2009.

Map of the Mariana Trench - Deepest Point in Earth's Oceans - Image by CIA

Why is the ocean so deep here?

The Mariana Trench is located at a convergent plate boundary. Here two converging lithospheric plates collide with one another. At this collision point, one of the plates descends into the mantle. At the line of contact between the two plates the downward flexure forms a trough known as an ocean trench. An example of an ocean trench is shown in the diagram below.

USGS Image.