1. Look for patterns in these pictures of the inside of the Earth:
The Layers of the Earth
Look for patterns in these pictures of the inside of the Earth:

3. Why are there distinct layers of the Earth?
How are they different?
Depth
Temperature
State, (solid liquid or gas?)
Composition, (Iron? Aluminum?)

4. Layers of the Earth Inner Core Outer Core Mantle Crust Solid Liquid
State
Solid
Liquid
“Play-Dough”
Components
Iron, Si, C
Iron, Nickel
MgO & SiO2
Si, Alum.
Distance from Surface (km)
6000 (very centre of the earth)
5000
3000 35
Temp.
o Celsius.
5400
4000
2500
<60

5. The thickness of the crust varies:
35 km thick
7 km thick

6. How do Scientists know so much about “the centre of the earth?”
Direct Evidence:
Earth’s magnetic field suggests the presence of iron;

7. More Direct Evidence:
The lava from volcanoes shows us what’s below the surface.

8. Indirect Evidence:
Scientists can infer that the core is solid by measuring seismic waves.
Try this:
Create…
1) S-waves by moving a slinky side to side;
2) P-waves by pushing the slinky.

9. Scientists create S and P waves at one point on the crust, and measure where they “come out” on the other side.
Some seismic waves don’t travel through liquids, so when they don’t show up on the other side of the earth, it suggests there is liquid down there.

10. More Indirect Evidence:
The melting points of the minerals, (Iron, Silicon, Aluminum, etc.) suggest the temperatures of the layers.

11. Some Melting Points, (degrees Celsius):
Iron: 1535
Carbon: 3600
Magnesium: 670
Nickel: 1452
Silicon: 1420

12. Use the table on the screen to complete the worksheet.