alleryStart learning →Scientists work out the layered structure of Earth's interior mainly by measuring what?
ASeismic waves passing through it
BOcean currents flowing over it
CSunlight reflecting off it
DMagnetic storms above it
Answer & 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_
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