Name:    Earthquakes -- Chapter 9

True/False  --- Indicate whether the statement is true or false.

1.

Divergent fault boundaries are especially likely to cause earthquakes.

2.

When the kinetic energy build up in a plate exceeds the strength of the rock an earthquake occurs.

3.

The earthquake focus is the point below the surface of Earth where the rock breaks.

4.

Secondary, or S-waves, are only able to travel through liquids inside Earth.

5.

Seismic waves are recorded and measured by an instrument called a seismologist.

6.

The Moment Magnitude scale rates the total energy released by an earthquake.

7.

The Mercalli scale rates earthquakes according to the size of the seismic waves recorded on a seismograph.

8.

The San Andreas fault is an active fault that causes many earthquakes to occur in the city of San Francisco, California.

9.

Secondary, or S-waves cause the rock to move in a side-to-side motion, across the direction of the traveling wave.

10.

An earthquake is a form of stick-slip motion.

Multiple Choice --- Identify the choice that best completes the statement or answers the question.

11.

Which type of plate boundary is most likely to cause earthquakes?
 a. Convergent b. Divergent c. Transform d. Subduction

12.

The energy of an earthquake is spread through Earth’s crust by:
 a. sound waves. b. heat waves. c. Richter waves. d. seismic waves.

13.

The zone on the surface of Earth where the rocks rupture or break open due to an earthquake is called a(n):
 a. focus. b. fault. c. vent. d. stick-slip.

14.

____ is the polished surface of a rock, which is the effect of rock moving against rock along an above-ground fault.
 a. Gliders b. Sureslides c. Slickensides d. Obsidian

15.

The release of built-up ____ causes earthquakes.
 a. potential energy b. aftershocks c. slickensides d. S-waves

16.

The ____ is the location on Earth’s surface directly above the area where rock breaks in the crust in an earthquake.
 a. focus b. epicenter c. fault d. seismic wave

17.

Following an earthquake, small tremors known as ____ can occur, lasting for hours to days after the original quake.
 a. aftershocks b. foreshocks c. seismic shocks d. Richter shocks

18.

What is one way for a fault to occur within a lithospheric plate instead of at its boundaries?
 a. At a mid-ocean ridge. b. When older plates have been incorporated inside newer plates. c. Faults can only occur at boundaries, not within a plate. d. When the lithosphere stays in place after a glacier melts.

19.

Although a plate may be moving as ____, its boundaries behave as though they were made of ____.
 a. a single unit; plastic clay c. several units; plastic clay b. a single unit; many sections d. several units; one section

20.

When a seismic wave reaches Earth’s surface it is known as a(n):
 a. P-wave. b. S-wave. c. surface wave. d. Both b and c

21.

The diagram shows two different sections of a fault. Section A has an average of 4 earthquakes per year. Section B has an average of 1 earthquake every 12 years. Which section would have the stronger earthquakes?
 a. A b. B c. Both A and B would have the same strength d. You can’t determine that without more information

22.

Which of the following is NOT needed for stick-slip motion?
 a. Two bodies that are in contact, but can move. b. Forces that will make the two bodies move. c. A magnetic charge between the two bodies. d. Friction strong enough to stop the two bodies from moving at first.

23.

What information would be most useful in predicting the occurrence of an earthquake at a particular location?
 a. The type of rocks present c. Seismic history b. Climate d. Number of nearby seismographs and seismologists

24.

The fastest type of seismic wave is known as a(n):
 a. P-wave. b. S-wave. c. L-wave. d. None of these

25.

____ are scientists who record and interpret seismic waves.
 a. Paleontologists b. Biologists c. Meteorologists d. Seismologists

26.

____ are typically the slowest type of seismic wave, but they cause the most damage in an earthquake.
 a. P-waves b. S-waves c. Surface waves d. Both b and c

27.

A ____ is an instrument that records and measures the intensity of seismic waves.
 a. seismologist b. seismograph c. polygraph d. seismoscope

28.

At least ____ seismic stations are needed to determine the epicenter of an earthquake.
 a. 2 b. 3 c. 4 d. 5

29.

The distance scale on a map is 1 cm = 10 km. The distance from a seismic station to the epicenter of an earthquake is 50 km. To locate the epicenter, what would be the radius of the circle that is drawn around this station on the map?
 a. 30 cm b. 10 cm c. 20 cm d. 5 cm

30.

If P-waves travel at 7 km/s and S waves travel at 3.6 km/s, how many km/s faster are P-waves?
 a. 10.6 km/s b. 1.94 km/s c. 3.4 km/s d. 25.2 km/s

31.

On the Richter Scale a magnitude 6 earthquake is how many times more powerful than a magnitude 3 earthquake?
 a. 10 times b. 100 times c. 1,000 times d. 10,000 times

32.

The New Madrid Fault is a 250-mile long fault located in what part of the United States?
 a. Northeast b. Southeast c. Midwest d. Northwest

33.

The ____ scale rates earthquakes according to the size of the seismic waves recorded on a seismograph.
 a. Richter b. Moment Magnitude c. Mercalli d. All of these

Figure 9-1

34.

Figure 9-1 shows an earthquake’s seismic waves traveling through the interior of Earth. The wave most likely to be an P-wave is:
 a. wave A. b. wave B. c. Both d. Neither

35.

Figure 9-1 shows the focus of an earthquake and how its seismic waves travel through the interior of Earth. The wave most likely to be an S-wave is:
 a. wave A. b. wave B. c. Both d. Neither

36.

Which of the following could you determine if you knew only the arrival times of P-waves and S-waves from one seismic station?
 a. The direction to the earthquake c. The exact location of the epicenter b. How far underground the earthquake focus is d. The distance to the epicenter

37.

The ____ scale rates the total energy released by an earthquake.
 a. Moment Magnitude b. Richter c. Mercalli d. All of these

Figure 9-2

38.

Assume that P-waves travel through the Earth at 6 km/s. A seismic station records P and S wave arrival times and decides the difference between their arrival is 12 seconds. How far away was the earthquake’s epicenter?  (Note:  Use the formula in Figure 9-2 above [D = r * t] to figure out the answer.)
 a. 18 km b. 72 km c. 6 km d. 144 km

39.

Assume that P-waves travel through the Earth at 6 km/s. A seismic station records P and S wave arrival times and decides the difference between their arrival is 65 seconds. How far away was the earthquake’s epicenter?  (Note:  Use the formula in Figure 9-2 above [D = r * t] to figure out the answer.)
 a. 39 km b. 59 km c. 390 km d. 71 km

40.

Each category in the ____ scale is a rating of the damage suffered by building, ground, and people during an earthquake.
 a. Moment Magnitude c. Mercalli b. Richter d. All of these

41.

What is the term used to describe the process where water enters the spaces between dirt and sand particles in man-made land, and then the "soil" behaves like a liquid and will not support buildings?
 a. solidification b. liquifaction c. plastic flow d. hardening

42.

Ocean waves that can travel thousands of miles from an underwater earthquake site are called ___________
 a. tsunamis b. tidal bores c. rogue waves d. spring tides

43.

In 132 AD Chinese philosopher Chang Heng created an instrument that would predict in which direction an earthquake had occured. The invention was called a ________________.
 a. seismograph b. seismologist c. seismowriter d. seismoscope

44.

The resistance that results from the relative motion of two objects that rub against each other is called _______.
 a. friction b. potential energy c. kinetic energy d. inertia

Figure 9-3

45.

The time difference between the arrival of a P-wave and an S-wave at a seismic station is 30 seconds. How far away is the epicenter? (NOTE: Use the graph in Figure 9-3 to determine your answer.)
 a. 150 km b. 500 km c. 350 km d. 250 km

46.

The time difference between the arrival of a P-wave and an S-wave at a seismic station is 60 seconds. How far away is the epicenter? (NOTE: Use the graph in Figure 9-3 to determine your answer.)
 a. 250 km b. 500 km c. 100 km d. 450 km

47.

The proper human response to an approaching tsunami should be to.....
 a. go out on the beach looking for shells. c. run to higher ground. b. drop, cover, and hold on. d. not to worry -- continue normally.

48.

The proper human response to an earthquake should be to ....
 a. go out on the beach looking for shells. c. run to higher ground. b. drop, cover, and hold on. d. not to worry -- continue normally.

49.

You are a building inspector and have been asked about which building materials to include in a new commercial building. The most important construction material in the choices below is ......
 a. wood b. adobe c. bricks d. steel

50.

The distance scale on a map is 1 centimeter = 25 kilometers. The distance from a seismic station to the epicenter of a recent earthquake is 100 kilometers. To locate the epicenter on a map, you would need to draw a circle around the seismic station that has a radius of .....
 a. 125 cm b. 75 cm c. 25 cm d. 4 cm

51.

DRAWBACK  refers to what part of tsunami understanding?
 a. The movement of trash and broken buildings back out to sea after the tsunami c. The movement of beach water out to sea right before the tsunami strikes b. The increase in height of the surge of water asw it approaches shore. d. The reverse movement of off-shore currents after a tsunami has struck

Matching -- Each letter is used only one time.

Figure 9-4

52.

FOCUS of earthquake.

53.

SEISMIC WAVES spreading out from the underground earthquake.

54.

EPICENTER of the earthquake

55.

Underground FAULT boundary

56.

Surface FAULT boundary