Ocean Soundings Ocean Soundings Model the ocean floor in a shoe box and take depth measurements. Discuss how oceanographers use remote sensing to learn about the ocean. Satellites are useful in tracking sea surface temperatures and currents, but they cannot penetrate below the ocean surface.
New technology does allow satellites to infer the depth of the ocean.
Sonar uses sound waves reflecting back from objects to track schools of fish, locate submerged submarines, and map the ocean floor. Demonstrate how sonar works by placing a glass pie plate filled with water onto an overhead projector so that the image of the water projects onto a screen. Let one drop of water from an eyedropper fall into the middle of the pie plate from a height of 6-12 inches above the plate. This will create a wave that radiates outward from the middle of the plate and bounces back from the sides, simulating how sonar reflects sound waves back from objects. Explain that until the invention of sonar during World War II, oceanographers mapped the depths of the ocean by dropping a weighted plumb line over the side of a ship and measuring the length of rope that was let out.