How do scientists determine when one layer of the earth begins and ends?

1 Answer
Apr 10, 2016

It is done with seismic measurements.


When seismic waves travel through the Earth, every boundary between different layers results in reflection off the boundary and refraction through it. Seismologists can infer how the waves are reflected and refracted from their measurements, and thus infer where the boundaries are as well as the differences between the layers.