Episode 305-The Abyss

Like every part of our planetary geography, oceans have identifiable regions. Beginning at the beach and gradually dropping to about 650 feet is the continental shelf. This shallow region of the ocean is called the sunlit or Epiplagic zone. From sunlight we move into the beginnings of oceanic darkness: we leave the continental shelf and step onto the much steeper continental slope where we enter the twilight or Mesopelagic zone, which descends to about 4,000 feet—the better part of a mile. Here, light from the surface disappears. We continue in darkness down the continental slope into the midnight or Bathypelagic zone, all the way to 13,000 feet—a crushing depth of nearly two miles. But we’re nowhere near the bottom yet. At 13,000 feet, the slope begins to level as it becomes the continental rise on its way to the sea floor, at about 20,000 feet. This is the Abyss, or the Abyssopelagic zone, the dwelling place of creatures that are the stuff of nightmares. Even their names conjure darkness: gulper eels. Angler fish. Vampire squid. Coffinfish. But this is still not the deepest part of the ocean. That honor goes to the Hadal zone, named after Hades, the underworld. These are the ocean’s deep trenches, and they descend to unimaginable depths of nearly 37,000 feet. Mount Everest could be dropped into these canyons and its peak would lie under deep water. In this program, we look at these deep regions, at the organisms that lives there, and at the sounds of the deep.