READ THE FOLLOWING QUESTIONS, THEN ANSWER WHILE WATCHING THE VIDEO, THEN COMPARE ANSWERS AFTER THE VIDEO.

1. Most evidence about the interior of the Earth is indirect, because:

2. The deepest drilling has only penetrated about ______________ , and

the Earth is _____________________ to the center.

3. The deepest well now being drilled penetrates rocks at pressures and temperature that are:

4. What two things happen when seismic waves change speed when the cross boundaries between materials with different densities or composition?

5. How is the use of seismic vibrations similar to the way that x-rays and ultrasound are used to provide a picture of the inside of the human human body?

6. List the parts of the Earth from outside to interior:

7. How big is the core of the Earth?

8. List two ways that the continental and oceanic crusts are different:

9. What little, if any, direct evidence is there about the rocks of the lower crust and upper mantle?

10. P-waves will travel through ______________________, s-waves

only go through __________.

11. The ____________ of p-waves that travel through the center of

the planet indicates the size of the _______________ .

12. The disappearance of s-waves indicates:

13: The way that ___________ pass through the core provides

evidence that the inner core is _____________ .

14. The cores of the planet are probably made of:

15. What does the presence of Earth's strong magnetic field indicate about the movement of cores?

16. The magnetic field deflects most of the charged particles coming from the Sun. What do you think would happen if the magnetic field weakened, then reversed in the next thousand years?

OTHER QUESTIONS (your text may help):

17. The timing of the arrival of seismic waves from earthquakes indicates increasing density of the rock toward the center of the planet. What two things would cause this?

18. The solid mantle is the largest part of the planet. Even though its width is a little less than the cores (mantle is 2865 km thick, core radius is 3470 km) why is the mantle volume greater than the volume of the cores?

19. Reflection and refraction of seismic waves indicates a distinct boundary between the crust and the mantle, called:

20. Slowing of the waves in one part of the mantle indicates a soft, almost liquid layer called the asthenosphere. What does "astheno" mean?

21. The upper, rigid portion of the mantle together with the crust is called the lithosphere. What does "litho" mean?