Abyssal Plain

ocean · deep sea · geology

Super deep underwater. Abyssal plains sit 3,000 to 6,000 meters (10,000 to 20,000 feet) below the ocean surface, so deep that sunlight never reaches them.

Cover half the planet. These vast underwater flatlands make up more than 50% of Earth's entire surface, yet most people have never heard of them.

Smooth like glass. Abyssal plains are among the flattest and smoothest places anywhere on Earth because they are covered with layers of soft sediment that settled there over millions of years.

Between giant features. They lie between the foot of a continental rise (where the ocean floor rises toward the continent) and a mid-ocean ridge (an underwater mountain range where new ocean floor is created).

Barely explored. Because they're so deep and vast, scientists have explored abyssal plains less than they've explored the surface of the Moon.