Where Is the Hadal Zone?

The hadal zone (from Hades, the Greek underworld) is the deepest layer of the ocean, beginning at 6,000 metres and extending to the bottom of oceanic trenches — the deepest being the Mariana Trench at 10,994 metres. There are about 33 hadal habitats worldwide, almost all located along the "Ring of Fire" where tectonic plates subduct. Conditions are extreme: total darkness, near-freezing temperatures, and pressures exceeding 600 atmospheres. Yet life persists: amphipods, sea cucumbers, polychaete worms, and microorganisms thrive in the hadal zone. These organisms have evolved specialised proteins and cell membranes to withstand the crushing pressure.