Name _________________________________
13.
Period _____
Code # _____
How do seismologists locate the epicenters of earthquakes?
14. What is the function of the Time - Travel Graph found in the Earth Science Reference Table?
15. What are the relationship between distance from focus and the time delay between P- and S-Waves?
16. What is meant by origin time?
17. What two things are needed to determine the origin time ?
a) ______________________________________________
b) ______________________________________________
18.
How do scientists study the interior of the Earth?
Scientists have discovered that earthquake waves penetrate Earth. The study of these waves provides scientists
with valuable information about the structure of the interior of our planet.
19.
Describe the thickness of the crust.
20. What is the composition of the continental crust?
21. What is the composition of the oceanic crust?
22. Why do earthquake waves suddenly increase in speed as they travel towards Earth's center?
Waves increase in speed as they cross an interface, or boundary between the rocks of the crust and a denser
layer beneath it.
23. What is the name given to the interface between crust and mantle?
24.
How far does the mantle extend into the Earth?
25.
How was the mass of the Earth determined?