An article in Discover for last December has a very interesting article about scientific exploration of hydrothermal vents in Indian ocean, five miles below the surface. Which reminded me of a word I accidentally found in dictionary:"hadal" designating or of the ecological zone (hadal zone) of the ocean floor trenches below c. 3,300 fathoms (c. 6,000 m)

How in Hades would I know how it is pronounced? Hey, deez is a joke.