1. Chapter 12 Study Notes Earthquakes

2. 1 A ____ wave is a seismic wave that travels through the _____ of the earth. –body –interior

3. 2 A _______ is a small earthquake that may precede a ______ earthquake. –foreshock –larger

4. 3 A modern _______ consists of _____ sensing devices. –seismograph –three

5. 4 A ______ ______ is an area in which strong earthquakes have occurred in the ______. –seismic –gap –past

6. 5 A ______ displays earthquake motion ________ by a seismograph. –seismogram –recorded

7. 6 A _______ is an instrument that records the ground _______. –seismograph –vibrations

8. 7 A __________ is an area where no direct ______ _____ from a particular earthquake can be detected. –shadow zone –seismic –waves

9. 8 A ______ wave is a seismic wave that travels along the _______ of the earth. –surface

10. 9 A ______ is a large ocean _____ that forms after a volcanic eruption, underwater earthquake, or landslide. –tsunami –wave

11. 10 As tsunamis move toward shore the waves _______ in _____. –increase –height

12. 11 Before and after an earthquake you should stay _______ and follow ________. –cautious –instructions

13. 12 During a _____ earthquake, buildings may _____ or _______. –major –sway –collapse

14. 13 Earth’s interior affects the _____ and _______ of seismic waves. –speed –direction

15. 14 Earthquake _______ is _________. –prediction –unreliable

16. 15 Earthquakes generally occur at _____ _______ where stress on rocks is the ________. –plate –boundaries –greatest

17. 16 _______ ________is the ______ return of deformed rock to its ________ shape. –Elastic –rebound –sudden –undeformed

18. 17 If you are ______ during an earthquake, you should crouch under _____. –indoors –desk

19. 18 _____ is the amount of _______ caused by an earthquake. –Intensity –damage

20. 19 Intensity ____ on the modified Mercalli scale is described as causing _____ __________. –XII –total –destruction

21. 20 ________ is a measure of the ______ of an earthquake. –Magnitude –strength

22. 21 P _______ are the ______ body waves. –waves –fastest

23. 22 P waves can travel through ______, ______, and _______. –solids –liquids –gases

24. 23 P waves travel _______ through very _____ and not easily _______ materials. –fastest –rigid –compressed

25. 24 S waves can only travel through ______. –solids

26. 25 Scientists find the _______ of an earthquake by comparing the ______ times of P waves and S waves at _____ or more seismograph stations. –epicenter –arrival –three

27. 26 Scientists study ______ ______, ____ ______, and _______ in order to predict earthquakes. –seismic –gaps –rock –changes –foreshocks

28. 27 The _______ of an earthquake is the point on Earth’s _______ directly above the earthquake’s focus. –epicenter –surface

29. 28 The ______ ______ of an earthquake occurs at the _____. –first –motion –focus

30. 29 The _______ _______ scale measures the _________ of an earthquake. –modified –Mercalli –intensity

31. 30 The moment magnitude scale measures the ________ of an earthquake by the _____ size and the ______ that the fault blocks move. –magnitude –fault –distance

32. 31 The _______ _______ scale measures the ________ of large earthquakes the most ________. –moment –magnitude –accurately

33. 32 The Richter scale is based on ________. –magnitude

34. 33 The Richter scale measures the _____ of an earthquake using ______ ______. –magnitude –ground –motion

35. 34 _______ _______, ________, and undersea ________ may all cause a tsunami. –Volcanic –eruptions –earthquakes –landslides

36. 35 When seismologists record ______ times of P waves and S waves at three or more seismograph stations, they are looking for the earthquake’s ________. –arrival –epicenter

37. 36 You can prepare for an earthquake by gathering _____, _____, _______, and a portable _____. –food –water –flashlights –radio

38. The End