Which technique studies ocean structure by emitting low-frequency sound pulses to detect variations in water temperature, salinity, and movement below the surface?

Which technique studies ocean structure by emitting low-frequency sound pulses to detect variations in water temperature, salinity, and movement below the surface?

• A. Water Vapor
• B. Acoustical Tomography
• C. Antarctic Bottom Water
• D. Tropical Cyclone

Answer: (B)

This question examines how oceanographers map subsurface structure using sound. Acoustical tomography involves emitting low-frequency sound pulses and recording how they travel through the water with arrays of receivers. The speed of sound in seawater depends on temperature, salinity, and pressure, so variations in these properties change travel times and the paths the sound takes. By sending pulses along many routes and solving an inverse problem, scientists can reconstruct images of temperature, salinity, and water movement below the surface. This makes it the right technique for studying how the ocean’s interior is structured and varies over time. Water Vapor is an atmospheric component, not a method for probing the ocean interior. Antarctic Bottom Water is a deep-water mass, not a technique. A Tropical Cyclone is a weather system, not a method for imaging subsurface ocean structure.

This question examines how oceanographers map subsurface structure using sound. Acoustical tomography involves emitting low-frequency sound pulses and recording how they travel through the water with arrays of receivers. The speed of sound in seawater depends on temperature, salinity, and pressure, so variations in these properties change travel times and the paths the sound takes. By sending pulses along many routes and solving an inverse problem, scientists can reconstruct images of temperature, salinity, and water movement below the surface. This makes it the right technique for studying how the ocean’s interior is structured and varies over time.

Water Vapor is an atmospheric component, not a method for probing the ocean interior. Antarctic Bottom Water is a deep-water mass, not a technique. A Tropical Cyclone is a weather system, not a method for imaging subsurface ocean structure.