quiz 7

Question 1

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

Answer 1

Wadati-Benioff zone

Question 2

On December 26, 2004, a magnitude 9.1 earthquake near Sumatra generated a tsunami that devastated coastlines on the …
Ocean.

Answer 2

indian

Question 3

The vast majority of earthquakes occur

Answer 3

along passive margins

Question 4

According to the image below, which seismic wave phase is likely to cause the most damage?

Answer 4

surface wave

Question 5

Making better
_ is the best way to try to prevent earthquake damage.

Answer 5

building and infrastructure

Question 6

Which seismic wave phase causes the ground to roll (surface moving up and down) somewhat like a wave on water?

Answer 6

raleigh wave

Question 7

The… the earthquake, the less severe the damage will be.

Answer 7

farther you are from

Question 8

The seismic moment is defined as

Answer 8

fault area x average slip over that area x resistance to slip or friction

Question 9

According to the moment magnitude scale (Mw), a magnitude 8 earthquake releases about 1,000 times as much seismic strain energy as a magnitude … earthquake.

Answer 9

6

Question 10

The point within Earth where an earthquake first breaks is termed the

Answer 10

focus

Question 11

Long-term earthquake prediction relies on

Answer 11

seismic risk assessment

Question 12

Which of the following is NOT true concerning the long-term forecasting of earthquakes? Long-term “forecasting”:
-works on the principle that zones of past seismicity will be active in the future
-includes the notion of seismic gaps-places where an earthquake is overdue
- is based on past earthquake activity
- is not possible

Answer 12

is not possible

Question 13

Body waves include

Answer 13

both S- and P-waves

Question 14

Periods of intermittent sliding on a fault because of stress release during episodes of slip, followed by stress buildup to the point that the fault is reactivated, is termed

Answer 14

stick-slip behavior

Question 15

what does NOT directly affect the severity of damage from an earthquake?

Answer 15

weather

Question 16

The quantity of motion that occurs along a fault is termed

Answer 16

displacement/slip

Question 17

the larger the … of the surface constrained waves, the most severe the damage will be

Answer 17

amplitude

Question 18

Earthquake __
is a means of deciding where the ground is stable enough to build on in earthquake-prone areas.

Answer 18

zoning incorporated into construction codes for an area

Question 19

a tsunami

Answer 19

a sea wave generated by a displacement of water

Question 20

surface waves ….

Answer 20

produce most of the damage to buildings during earthquakes

Question 21

Seismic retrofitting is the process of

Answer 21

making existing buildings and structures less vulnerable to ground shaking

Question 22

Why do subduction zones have the potential to create the largest earthquakes on Earth?

Answer 22

Subduction zones have very large areas for potential rupture and thus can
produce large earthquakes.

Question 23

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

Answer 23

fault

Question 24

If a fault is nearly vertical in orientation and the two walls of rock on opposite sides slide past one another horizontally, the fault is termed a…
fault.

Answer 24

strike-slip

Question 25

Deep-focus earthquakes occur along only

Answer 25

convergent-plate boundaries

Question 26

Each unit step in the Moment Magnitude scale, Mw

Answer 26

corresponds to an increase in energy released by a factor of 32

Question 27

Which earthquake scale is used to assess the local effects of an earthquake on humans and human-made structures?

Answer 27

Mercalli scale

Question 28

At any point along the surface of any nonvertical fault such as is shown in the figure below, the …

Answer 28

hanging wall lies vertically above the footwall

Question 29

A seismograph records an earthquake which shows a 10-minute interval between the P-wave arrival and the S-wave arrival. How far away from the seismograph station did this earthquake occur?

Answer 29

about 7800 kilometres

Question 30

…. occurs) when earthquakes causes pore pressure to increase, which in turn causes grains in sands and soils to separate and compact.

Answer 30

liquefaction