Book 12, Question 57
Why Is the Mariana Trench So Deep?
The Mariana Trench is the deepest place in the whole ocean! It is nearly 11 kilometers straight down. That is deeper than Mount Everest is tall.
More fun facts
- Challenger Deep, the deepest part of the Mariana Trench, is about 11,000 meters (36,000 feet) down.
- The trench is about 2,550 kilometers (1,580 miles) long.
- It marks a subduction zone where the Pacific Plate dives under the Philippine Plate.
- The western Pacific has some of the oldest seafloor in the world, about 180 million years old.
- Old seafloor is cold and dense, so it settles lower.
- Many other deep trenches are more filled with sediment.
Sources: NOAA, NOAA, National Geographic
Questions kids ask
Why is old seafloor deeper?
As it ages it cools and gets denser, so it sinks lower.