EARTHQUAKES AND EARTHS INTERIOR

Question 1

What is a shadow zone?

Answer 1

an area in the subsurface of the Earth where seismic waves are not seen

Question 2

What rock makes up the oceanic crust?

Answer 2

basalt

Question 3

How can geologists know what the interior of the Earth looks like when we can’t see it?

Answer 3

Geologists use a variety of methods to “see” the interior of the Earth including the study of seismic waves and the magnetic field.

Question 4

Which peripheral hazard of earthquakes caused the damage shown in the photo?

Answer 4

Landslide

Question 5

Aftershocks are usually

Answer 5

much weaker than the mainshock.

Question 6

Which type of wave is a compressional body wave?

Answer 6

P-wave

Question 7

What rock makes up the oceanic crust?

Answer 7

basalt

Question 8

Which of the following is a good technique for building safer structures in an earthquake zone?

Answer 8

Use wood-frame construction.

Question 9

Interpret the travel-time curve shown. Approximately how many minutes elapsed between the arrival of the first P-wave and the arrival of the first S-wave at Station 3?

Answer 9

7

Question 10

The Earth’s magnetic field is thought to be a direct result of ________.

Answer 10

convection in the outer core.

Question 11

The locations of major earthquakes

Answer 11

are usually along plate boundaries.

Question 12

What rock makes up the continental crust?

Answer 12

granite

Question 13

The inner core is ________.

Answer 13

solid.

Question 14

What rock makes up the oceanic crust?

Answer 14

basalt

Question 15

The 2010 Haiti earthquake was so destructive because

Answer 15

of poor construction standards that caused many buildings to collapse.

Question 16

To find the location of an earthquake’s epicenter, you need to calculate the distance from the epicenter to ____ different seismometer stations.

Answer 16

3

Question 17

A tsunami

Answer 17

may be just a broad, gentle swelling out at sea but grows as it approaches shore.

Question 18

The earthquake foci pattern east of Australia and just north of New Zealand indicates which tectonic setting?

Answer 18

Convergent plate boundary

Question 19

One difference between P- and S-waves is that

Answer 19

only P-waves can travel through a liquid.

Question 20

When a fault slips and the rock units on either side return to their original shape by generating vibrations, it is called

Answer 20

elastic rebound.

Question 21

During an earthquake, if the hanging wall slides upward relative to the footwall and if the fault is steep (closer to vertical than horizontal), then the fault is termed a __________ fault. Refer to the following figure for an example of such a feature.

Answer 21

reverse

Question 22

What kind of waves travel with a compressional motion?

Answer 22

P-waves

Question 23

On December 26, 2004, a magnitude 9.3 earthquake generated a tsunami that devastated coastlines on the __________ Ocean.

Answer 23

Indian

Question 24

The Mercalli intensity scale tends to be very subjective and thus is generally only used for historical earthquakes that were near people but were not recorded by seismometers. The Mercalli scale may be considered subjective because it

Answer 24

relies on testimony from people.

Question 25

S-waves are unable to pass through the Earth’s outer core, which indicates that the outer core is

Answer 25

liquid

Question 26

The vast majority of earthquakes occur

Answer 26

along all types of plate boundaries.

Question 27

Generally, which type of earthquake waves travel with the slowest velocity?

Answer 27

surface waves

Question 28

The Modified Mercalli Scale measures what?

Answer 28

the damage caused by an earthquake

Question 29

Vertical motion seismographs record earthquakes by producing a squiggly diagram called a

Answer 29

seismogram

Question 30

The quantity of motion that occurs along a fault is termed

Answer 30

displacement

Question 31

Earthquakes that occur in a band called the __________ can be used to track the motion of subducted oceanic lithosphere.

Answer 31

Wadati-Benioff zone

Question 32

A surface along which rock on opposed sides is offset by an earthquake-induced slip is called a

Answer 32

fault

Question 33

Wet and unconsolidated substrates are uniquely susceptible to __________ during an earthquake.

Answer 33

liquefaction

Question 34

The spot on the surface directly above where the earthquake occurred is called the what?

Answer 34

epicenter

Question 35

Long-term prediction methods include(s)

Answer 35

seismic risk assessment.

Question 36

As a seismologist, you are asked to write a report on the latest earthquake. Your boss want to know the details of the earthquake in terms of damaged caused to the city and surrounding area. In order to get this type of information, which scale would you use?

Answer 36

the Modified Mercalli scale

Question 37

The RIchter Scale measures what?

Answer 37

the largest jolt of energy caused by an earthquake

Question 38

Body waves include

Answer 38

both S- and P-waves.

Question 39

Which of the following does NOT affect the severity of damage from an earthquake?

Answer 39

weather

Question 40

At any point along the surface of any nonvertical fault, as shown in the following figure, the

Answer 40

hanging wall lies vertically above the footwall.

Question 41

The moment magnitude is based on the __________ and __________ of the earthquake.

Answer 41

amplitude; displacement

Question 42

The __________ the earthquake, the LESS severe the damage will be.

Answer 42

farther you are from

Question 43

Which type of waves are shear waves?

Answer 43

S

Question 44

Which type of waves are compressional in nature?

Answer 44

P

Question 45

Earthquakes can often produce __________ by breaking gas lines.

Answer 45

fires

Question 46

Surface waves

Answer 46

produce most of the damage to buildings during earthquakes.

Question 47

The point within Earth where an earthquake takes place is termed the

Answer 47

focus

Question 48

Moderate- and deep-focus earthquakes occur along ONLY

Answer 48

convergent-plate boundaries.

Question 49

Which tectonic setting has the potential to create the largest earthquakes on Earth?

Answer 49

shallow thrust faults associated with a convergent boundary