1. 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 MantleCrust StateSolidLiquid“Play-Dough”Solid Components Iron, Si, C Iron, Nickel MgO & SiO 2 Si, Alum. Distance from Surface (km) 6000 (very centre of the earth) 5000300035 Temp. o Celsius. 540040002500<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: Direct Evidence: Earth’s magnetic field suggests the presence of iron; Earth’s magnetic field suggests the presence of iron;

7. More Direct Evidence: The lava from volcanoes shows us what’s below the surface. 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. Scientists can infer that the core is solid by measuring seismic waves. Try this: Try this: Create… Create… 1) S-waves by moving a slinky side to side; 1) S-waves by moving a slinky side to side; 2) P-waves by pushing the slinky. 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. 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. The melting points of the minerals, (Iron, Silicon, Aluminum, etc.) suggest the temperatures of the layers.

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

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