A vocabulary of landscape — a landscape of words
1469 entries
hadal
Hadal describes the deepest zone of the ocean, everything below about 20,000 feet, which in practice means the trenches. It is a small fraction of the seafloor by area but it accounts for the deepest 45 percent of the ocean’s depth range. The pressure at the bottom of the Mariana Trench is over a thousand times what it is at the surface, and there is still plenty living down there: amphipods, snailfish, sea cucumbers, and bacteria.
Etymology
The word is named for Hades, the Greek underworld and the god who ruled it.
Notes
The trenches are not one habitat but many. Each is effectively an island, isolated from the others by miles of shallower seafloor, so species in one trench are frequently found in no other. Snailfish have been filmed at over 26,000 feet, and there appears to be a hard limit near 27,000 feet set by the chemistry that keeps proteins working under pressure.