1001 Space Earth Nature History Human World Science and Technology Chemistry Materials Force and Energy Heat and Light Electricity and Magnetism Industry Machines Electronics and Computers Cars and Trucks Railways Ships Aircraft Fishing and Agriculture Undersea Exploration

Choose a Page:What creatures live at the bottom ...Who invented the submarine?*How deep is the ocean?*What is a submersible?How deep have humans dived?Who owns treasure found on the sea...How are submersibles controlled?Are there any useful minerals on t...What does SCUBA stand for?How is the depth of the sea measured?What are the bends?How did early diving suits work?How does a modern diving suit work? How deep is the ocean? The average depth of the world's oceans is 3,360 metres. They cover 71 percent of the earth's surface, an area of 139 million miles² (360 million km²). The largest ocean is the Pacific, with an average depth of 4,270 metres. The deepest part of the oceans, at 10,924 metres, is the Marianas Trench in the Pacific. The trench is so deep that an object dropped into the water at the surface would take over an hour to fall to the bottom. The ocean depths have been called inner space because we probably know less about them than we do about outer space.   Previous: Back Book: 1001 Section: Science and Technology Chapter: Undersea Exploration