Chapter 12 Study Notes Earthquakes

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

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

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

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

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

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

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

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

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

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

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

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

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

14 Earthquake _______ is _________. –prediction –unreliable

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

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

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

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

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

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

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

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

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

24 S waves can only travel through ______. –solids

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

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

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

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

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

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

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

32 The Richter scale is based on ________. –magnitude

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

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

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

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

The End