Question

How do scientists study the layers of the Earth if they cannot directly observe them?

Group of answer choices

By analyzing seismic waves

By looking at stars

By studying surface rocks

By observing weather patterns

Answer 1

By analyzing seismic waves.

Seismic waves from earthquakes and explosions travel through Earth and change speed and direction depending on the material they pass through. Geologists use arrival times, reflections, refractions and shadow zones of P- and S-waves to map the crust, mantle, solid inner core and liquid outer core.