2. From RegentsEarth.com

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5. Back The point on the earth’s surface directly above the focus is called the............ Ques. #1 Epicenter Ans.

6. What is the minimum number of seismic stations required to find the location of an earthquake? Back Ques. #2 Ans. 3

7. What are the two most important differences between P waves and S waves? Back Ques. #3 Ans. P waves are faster S waves cannot travel through the liquid outer core.

8. Earthquakes on the ocean floor may generate destructive waves called.............. Back Ques. #4 Ans. Tsunamis

9. If a seismic station receives neither P nor S waves from a particular earthquake it is probably because that station is in a.............. Back Ques. #5 Ans. Shadow zone

10. What is the temperature at the interface between the mantle and the outer core? Back Ques. #6 About 5000°C Ans.

11. Which location is the epicenter of this earthquake? Back Ques. #7 Ans. Location D

12. How far from the epicenter was the seismic station that recorded this seismogram? Back Ques. #8 Ans. About 1800 km

13. What kind of boundary is shown in the diagram? Back Ques. #9 Ans. A transform boundary

14. What is the pressure at a depth of 5000 km inside the earth? Ques. #10 Back Ans. About 3 million atm.

15. P waves arrive at a seismic station at 2:48:00. S waves from the same earthquake arrive at the same station at 2:53:40. How far from the epicenter is the seismic station? Back Ques. #11 Ans. About 4000km

16. Explain why a seismic station might receive P waves but not S waves from a particular earthquake. Back Ques. #12 Ans. The S waves could not travel through the liquid outer core to reach the station.

17. These seismograms are all from the same earthquake but they were recorded at different seismic stations. Which station was closest to the epicenter? Back Ques. #13 Ans. Station C. The arrival times of the P & S waves are closest together.

18. What is the density of the earth’s outer core? Back Ques. #14 Ans. 9.9 - 12.1 g/cm 3

19. How far will P waves travel in 11 minutes 20 seconds? Back Ques. #15 Ans. About 8000 km

20. It takes P waves 4 minutes to reach a seismic station. How long will it take S waves from the same earth- quake to reach the same station? Back Ques. #16 Ans. 00:12:40 (12 min. 40 sec.)

21. About how many kilometers thick is the inner core? Back Ques. #17 Ans. About 2300 km

22. A seismic station is 2000km from the epicenter of an earthquake. P waves arrive at 2:43:00 PM. At what time will S waves from that earthquake arrive at the station? Back Ques. #18 Ans. 2:46:20 PM

23. Back Ques. #19 Ans. 2600 km How far from the epicenter was the seismic station that recorded this seismogram?

24. How far from the epicenter was the seismic station that recorded this seismogram? Back Ques. #20 Ans. 2200km

25. A seismic station is 6000km from the epicenter of an earthquake. If S waves arrived at 4:29:00 AM, at what time did P waves from the same earthquake arrive? Back Ques. #21 Ans. 4:21:20 AM (7min. 40 sec. before the S waves arrived)

26. In which 2 zones in the earth is the temperature higher than the melting point of the rock? Back Ques. #22 Ans. The Asthenosphere (plastic mantle) and the outer core.

27. A seismic station is 5600km from the epicenter of an earthquake. If P waves arrive at 5:59:00 PM, what is the time of origin of the quake (what time did it occur)? Back Ques. #23 Ans. 5:50:00 PM

28. P waves arrive at a seismic station at 1:32:20 AM. S waves from the same earthquake arrive 8 minutes and 20 seconds later. At what time did the earth- quake occur? (what is it’s time of origin) Back Ques. #24 Ans. 1:20:00 AM

29. Back Ques. #25 Ans. Location D (S waves absorbed by outer core) Which location would not receive both P and S waves from this earthquake?

30. State two differences between continental and oceanic crust. Back Ques. #26 Ans. Continental crust: less dense, thicker, granitic Oceanic crust: more dense, thinner, basaltic

31. Where do earthquakes and volcanoes generally occur. Back Ques. #27 Ans. In specific zones (or belts) in the crust. These correspond to plate boundaries.

32. Which of the following graphs correctly represents the relationship between earthquakes and volcanoes? Back Ques. #28 Ans. #1 1234

33. P waves arrive at a seismic station 10 minutes before the arrival of S waves. How far from the epicenter is the seismic station? Back Ques. #29 Ans. 8800 km

34. How many times stronger is a magnitude 7 earthquake than a magnitude 3 earthquake? Back Ques. #30 Ans. 10,000 times stronger 7 minus 3 = 4 which is really 10 4 which is 10,000

35. YOU’RE A WINNER! P waves can go through the earth’s core but S waves cannot.