Which instrument uses earthquake waves to map Earth's interior?

Which instrument uses earthquake waves to map Earth's interior?

• A. Barometer
• B. Seismograph
• C. Thermometer
• D. Anemometer

Answer: (B)

Using earthquake waves to study Earth's interior relies on recording how those waves move through the planet. A seismograph captures the ground motion produced by seismic waves as they travel, and by looking at when these waves arrive at many stations and how their paths bend or slow down, scientists can infer the different layers inside Earth. The speeds and directions of waves change at boundaries between crust, mantle, and core, and the fact that certain waves cannot travel through liquids helps identify features like the liquid outer core. In short, the seismograph is the instrument that gathers the data needed to map what lies beneath the surface. The other instruments measure atmospheric conditions—air pressure, temperature, and wind—not seismic waves, so they don’t map Earth’s interior.

Using earthquake waves to study Earth's interior relies on recording how those waves move through the planet. A seismograph captures the ground motion produced by seismic waves as they travel, and by looking at when these waves arrive at many stations and how their paths bend or slow down, scientists can infer the different layers inside Earth. The speeds and directions of waves change at boundaries between crust, mantle, and core, and the fact that certain waves cannot travel through liquids helps identify features like the liquid outer core. In short, the seismograph is the instrument that gathers the data needed to map what lies beneath the surface. The other instruments measure atmospheric conditions—air pressure, temperature, and wind—not seismic waves, so they don’t map Earth’s interior.