How do scientist know what deep layers are made of earth?

Answer 1

They study the layers by seeing how seismic waves travel through the earth. By the time of the arrival, and how the frequencies of the waves are arranged within each set they can tell things about the density and other things about the layers.

Answer 2

Geologists use different types of evidence to create theories about different layers of the Earth.

Firstly, for crustal rock, we can simply drill down or use seismic surveys to see what rocks are in the crust, so are confident that the crust is definately made of these rocks.

The mantle however is harder to get to, and one method geologists use to find out the composition of the mantle is the use use of Kimberlite Pipes. Kimberlite Pipes are deep pipes which eject material directly from the mantle, giving some suggestions as to what it is made up of. However no one knows for sure if this is the complete composition of the mantle, and the lower mantle for sure hasn't been touched.

The inner core and outer core of the Earth have thought to be composed of a nickel-iron alloy, as well as some silicate minerals (eg O, K, Al etc) being in the outer core. This has been theorised by the use of metallic meteorites. Geologists suggest that meteorites form in exactly the same way that the Earth has, ie the denser metallic minerals when molten sunk to the middle of the Earth, and the less dense, silicate minerals rose to the surface. Studying the centre of fallen or orbiting meteorites has helped create theories about these deep layers of the Earth.

Hope this helps :)

Answer 3

Through the use of seismometers and the knowledge they have of convection currents.

Answer 4

Seismology: the study of seismic activity.

Answer 5

seismic waves.

Answer 6

Reflection and refraction seismology.

Answer 7

im cave mn stv isay so