What provides us with knowledge about the interior of the earth?

Question

This is earth science. I'm needing some help. Give me the answers!

Answer 1

for starters

0) Digging/going down mines, though that doesn't get very far!!!

1) Seismic waves from earthquakes - they spread through the Earth and are picked up by seismographs all over the world - there are 2 types that travel through, p-waves and s-waves, but the 2 types are not picked up all over; s-waves don't travel through liquids.

2) Lab investigations of the materials that are likely to be within the earth, under appropriately high temperatures and pressures

Putting the results of these together has built up a model of a thin crust, mantle, liquid outer core and solid inner core.

You may want to search for terms like:
seismology, body wave, shadow zone, p-wave (promary wave), s-wave (secondary wave)

Answer 2

1) Seismic Energy from Earthquakes. Time it takes to travel from one point on the earth to another, for example around the world, gives us hints on the velocity of the materials in the earth, as it's faster for the waves to go straight through the earth than to go around the surface of the earth

2) Magnetic Field. Provides us some hints on how the earth is made up because it generates a magnetic field, and how the field is oriented, so we know metallic content in the core.

3) Astronomy - We know how fast we're orbiting, how far we are from the sun, etc., so can use this information to determine mass of the earth. Knowing depth of certain layers from seismic investigation (point 1), we can now assume masses for the materials, and estimate volumes of material and density of the materials that make up the earth.

4) Kimberlites and spreading ridges. We can sample materials that are formed at the centre of the earth (or at least deep in the earth) and that are rapidly extruded to the surface of the earth, so can get an idea of the chemical makeup of the centre of the earth.

With all this information, scientists are able to estimate the makeup of the earth, chemical composition, density, velocity, thickness of layers, etc. They continue today to refine their thoughts on all of these.

Answer 3

The answer is Geography.