1. 4.1 Reading Notes

2. 1. What prevents geologists from directly exploring Earth’s interior?
It’s too dangerous
The conditions are too extreme
It’s IMPOSSIBLE

3. Geologists use direct evidence from __________ to learn about Earth’s interior.
Rock Samples

4. 3. Geologists learn about Earth’s interior using indirect evidence from ___________.
Seismic waves

5. True or False: Geologists are able to drill to the center of Earth.

6. 5. Seismic waves reveal the structure of Earth through their ___________ and ____________.
Speed
paths they travel

7. Seismic
________ waves are produced by earthquakes.

8. 7. What are the three main layers that make up Earth?
Crust
Mantle
Core

9. 8. Which layer forms Earth’s outer skin?
The crust

10. Which type of dark-colored rock makes up most the oceanic crust?
Basalt

11. 10. What is the name of the light-colored rock that makes up most of the continental crust?
Granite

12. 11. Describe the following:
Lower mantle-
Solid material beneath the asthenosphere
Lithosphere-
A rigid layer- includes upper part of the mantle and crust
Asthenosphere-
The soft layer below the lithosphere.
Part of the mantle that can bend like plastic.

13. 12. About how many kilometers thick is the mantle?
3,000

14. 13. Name two types of metals that make up the Earth’s outer core.
Iron and nickel

15. Describe how a compass needle aligns itself.
It aligns itself with the lines of force in Earth’s magnetic field.

16. Direct Evidence- Something that you can actually hold in your hand or touch, hear with your ears or see with your own eyes.

17. Indirect Evidence-Something that you can’t actually touch, but you can learn from its results.

18. How does the temperature change from the surface to the center of the earth?
The temperature remains the same from the surface to about 20 meters down. After that, the temperature rises rapidly for many kilometers.

19. How does the pressure change from the surface to the center of the earth?
The pressure from the weight of rock increases as you travel from the crust towards the mantle and core.

20. What creates Earth’s Magnetic Field?
Movements in Earth’s outer core create Earth’s Magnetic field.