Describe the factors that affect the distance and the rate at which sound travels in the ocean. Would you expect sound to travel faster through warm or cold water? Shallow or deep? Why?

Answer 1

Sound is a form of energy transmitted by rapid pressure changes in an elastic medium. Like light, sound intensity decreases as it travels through the ocean due to scattering and absorption. However, sound can travel much greater distances through water than light. The speed of sound in seawater is about 1,500 meters per second, which is 5 times faster than in air. The speed of sound increases as temperature and pressure increases. Therefore, sound travels fast in warm surface waters and decreases with depth due to decreasing temperature. However, below about 1,000 meters, the effect of increasing pressure offsets temperature influences, causing the speed of sound to increase. The zone at which sound travels slowest (˜1,000 meters) is called the minimum velocity layer. Sound can travel very far distances in this layer because sound waves generated in this layer are refracted toward layers of lower velocity, causing them to stay within this zone.