Scientists work out the layered structure of Earth's interior mainly by measuring what?
- Seismic waves passing through it
- Ocean currents flowing over it
- Sunlight reflecting off it
- Magnetic storms above it
Show answer and solution
Correct answer: A. Seismic waves passing through it
1. No one can drill deep enough to see the inside of a planet directly.
2. Waves from earthquakes travel right through the interior and change speed in each material.
3. Recording those seismic waves at many stations builds a picture of the layers they crossed.
4. Nothing at the surface, such as ocean currents or sunlight, carries information from that depth.
_Source: OpenStax Astronomy (CC BY 4.0), section 8.1 The Global Perspective_