So much of the ocean floor is an unknown region of the earth because it is so large and so deep that explorers haven't had the time and equipment to discover more of it. Also, the ocean is CONSTANTLY changing.
We don't yet have the technology available to regularly go down that far. The technology we do have is very expensive, and not very efficient.
The Arctic is still not explored because it is hard to survive there for so long because someone will get sick or even die
The technology to allow humans to reach extreme ocean depths is relatively recent.
The crust contains the ocean floor and also the continents on Earth.
the continental Margin, Ocean Basin Floor and Mid-Ocean ridge :D
Trench
fissure
When the old ocean floor is destroyed, it goes to Earth's mantle.
Ocean Crust.
what other ocean floor feature is fromed by movement of earth's plates
butt
At the ocean floor.
The abyssal zone is the region of the deep ocean that is just above and on the ocean floor.
The Sea Floor
It is the Pacific Ocean.