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 is the depth of the sea measured? The chief method is echo-sounding. The sounder directs an ultrasonic signal at the sea bed and measures the time it takes for an echo to return. From this measurement, and a knowledge of the speed of sound in water, the depth can be calculated.   Previous: Back Book: 1001 Section: Science and Technology Chapter: Undersea Exploration