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You may find the Earth Science Reference Tables here.

Background

The Earth contains the following layers (spheres) or boundaries:

Crust - continental crust and oceanic crust

Mohorovicic Discontinuity (Moho) – the boundary between the crust and the Mantle

Mantle - forms three quarters of the volume of the Earth and two thirds of its weight. It can be divided into four spheres:

     lithosphere (cool and rigid)

     asthenosphere (hot, partially melted) 150 km thick on average

     mesosphere (transition region or middle mantle, but sometimes used for the entire mantle = deep mantle)

     lower mantle

D" layer - Dee Double Prime - most dynamic and active zone, although it is very thin, and the thickness is extremely

                                             variable

Core - can be divided into two regions

     a liquid outer core

     a solid outer core

The following chart is from page 10 of the ESRT's; use it to answer the questions below.

1. How deep below the surface is the outer core?

2. How thick is the mantle?

3. List the four (4) main layers of the Earth from thinnest to thickest (include the asthenosphere as part of the mantle.)

a. _________________________

b. _________________________

c. _________________________

d. _________________________

4. What is the temperature of the Earth at a depth of 5,000 km?

5. At what depth is the temperature believed to be 3000º C?

6. What information from the diagram supports the belief that the outer core in liguid?

7. Describe the relationship between pressure and depth within the Earth.

8. What is the approximate density of the Continental crust?

9. What is the approximate density of Oceanic crust?

10. Describe the changes in density as depth within the Earth increases.

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