What is the name of the deepest zone of the ocean, below 6,000 meters?

The deepest zone of the ocean, below roughly 6,000 meters, is the hadal zone. It is also called the hadopelagic zone and is found mainly inside the deep, narrow trenches created where tectonic plates descend beneath one another.

The hadal zone is completely dark, cold, and subjected to enormous pressure. Most of its food arrives from above as marine snow—falling organic particles—or as larger remains that sink into the trenches. Scavenging amphipods, sea cucumbers, worms, microbes, and other organisms have adaptations for these extreme conditions.

The name “hadal” refers to Hades, the ancient Greek underworld. Scientists began distinguishing this environment from the abyssal zone in the 1950s after expeditions detected differences in life and conditions at depths of about 6,000 to 7,000 meters.

The abyssal zone generally occupies depths from about 3,000 to 6,000 meters, so it is not the deepest zone. The photic zone is near the surface and receives sunlight, while the bathyal zone lies considerably higher in the water column.