How do scientists learn about the Earth's mantle?

The main way is by studying seismic (earthquake) waves passing through the mantle. These waves move at different velocities depending on the nature of the wave and the nature of the rock or magma they are passing through. read more

Scientists learn about the layers deep within the Earth's crust by studying how seismic waves travel through the Earth. If there is an earthquake somewhere, seismographs in many locations will record it. read more

Explain two ways that the movement of Earth's plates changes the surface of Earth. read more