Structures of the Earth - Evidence

Exists because of an iron, liquid outer core that functions like an electromagnet.

Historical changes in magnetic field orientation confirm the liquid outer core model.

Mantle rock is ejected as magma from volcanoes.

Kimberlites are mantle rock that was injected into cracks and lifted to the surface.

Stony and iron meteorites reveal mantle and core materials.

Show how minerals change under pressure.

Along with rock evidence, these inform us about pressures inside Earth.

S-waves do not go through liquids. Since they do not go into the outer core, they reveal that the outer core is liquid. S-waves stop there.

P-waves refract when density and state (solid to liquid) change, creating "shadow zones" on Earth's surface where no seismic waves appear.