The Ocean FloorThe Ocean Floor

SonarSonar

Part 1 Part 1

SonarSonar

Sonar- Stands forSonar- Stands for sosoundund nanavigation andvigation and rranginganging Sonar was first developed by British naval Sonar was first developed by British naval

scientists in 1921. Later it was used in times of scientists in 1921. Later it was used in times of warfare.warfare.

More commonly sonar is used to measure the More commonly sonar is used to measure the distance from the ocean’s surface to the bottom.distance from the ocean’s surface to the bottom.

Sonar has also been used on land. Pulses sent Sonar has also been used on land. Pulses sent through soil can identify different layers of soil and through soil can identify different layers of soil and rock as well as locate natural gas and oil!rock as well as locate natural gas and oil!

How does it work?How does it work?

A sonar device emits sound waves into the A sonar device emits sound waves into the ocean from the surface. When the impulses ocean from the surface. When the impulses strike the bottom they return to the ship strike the bottom they return to the ship carrying the sonar device in the form of an carrying the sonar device in the form of an echo. It then computes the depth of the echo. It then computes the depth of the ocean at that point. The longer it takes for ocean at that point. The longer it takes for the echo to return the deeper the ocean the echo to return the deeper the ocean floor is!floor is!

Do the Math!Do the Math!

Scientists know that sound waves travel Scientists know that sound waves travel through the water at 1,530m/s.through the water at 1,530m/s.

If it takes an impulse 6.60s to travel from the If it takes an impulse 6.60s to travel from the ship to the ocean floor and back again, how ship to the ocean floor and back again, how deep is that part of the ocean?deep is that part of the ocean?

AnswerAnswer1,530 m/sX6.60 s

10,098 m10,098 m 2

= 5,049 m

MappingMapping

Sonar has allowed scientists to accurately Sonar has allowed scientists to accurately map the ocean floor. As a result many map the ocean floor. As a result many interesting discoveries have been made. interesting discoveries have been made. Including abysses 10,600 m deep (6.3 Including abysses 10,600 m deep (6.3 miles), and mountains higher than Mt miles), and mountains higher than Mt Everest the tallest mountain on land at Everest the tallest mountain on land at 8,848m (29,198 ft).8,848m (29,198 ft).