Deck 4: Earthquake Predictions Forecasts and Mitigation

Question 1

The Loma Prieta earthquake in 1989 occurred on which fault?

A)Hayward
B)Cascadia
C)San Andreas
D)San Jacinto
E)Calaveres

Answer 1

C

Question 2

Early warning systems provide about 10 minutes' warning for populations near the epicenter of an earthquake.

Answer 2

False

Question 3

Modern earthquake forecasts can accurately predict the probability of an earthquake within several years, but do not predict magnitude.

Answer 3

False

Question 4

Windows can seriously weaken a building's ability to withstand an earthquake.

Question 5

Earthquakes are too unpredictable for the time and location of previous earthquakes to help predict future earthquakes.

Question 6

Southern California is at highest risk for very large earthquakes in the United States.

Question 7

The Cascadia Fault, located offshore of the U.S. West Coast, is the dominant earthquake fault in North America.

Question 8

____ is/are NOT effective in earthquake prediction.

A)Changes in groundwater level
B)Increased radon gas detection
C)High fluid pressure in a fault zone
D)Swarms of very small earthquakes
E)Changes in tide heights

Question 9

Older buildings are more likely to survive an earthquake because they have been through earthquakes in the past.

Question 10

Wood frame houses are more likely to withstand earthquake damage than brick houses.

Question 11

The best-known successful prediction of an earthquake was in ____.

A)San Francisco (1989)​
B)Izmit, Turkey (1999)
C)Los Angeles, California (1994)
D)Haicheng, China (1976)
E)Hokkaido, Japan (1998)

Question 12

What is the most likely reason that government agencies might fail to act on an earthquake prediction?

A)Earthquake predictions accurately state the time of the earthquake, but not the intensity.
B)Earthquake predictions accurately state the intensity of the earthquake, but not the location.
C)Emergency measures and evacuation are costly and may be irresponsible if the prediction is inaccurate.
D)Earthquake prediction has never been successful in correctly identifying a danger to life and property.
E)Earthquake predictions can only specify which fault will rupture, not the position along the fault.

Question 13

Faults that generate earthquakes ____.

A)are separated by empty areas free of faults
B)zig-zag across terrain, separating into fault segments at each bend
C)are split into segments by cross faults
D)are separated into segments by sedimentary layers
E)are separated into segments by construction and highways

Question 14

Seismic gaps mark places where earthquakes are unlikely to occur

Question 15

Changes in groundwater level are an effective predictor of earthquakes.

Question 16

The most significant information for predicting high earthquake probability is that a segment of the fault ____.

A)has had the most earthquakes in the recorded past
B)has shown significant, steady movement
C)was the location of the largest recorded earthquake on the fault
D)resides close to a metropolitan area
E)has had very few significant earthquakes in the recorded past

Question 17

A seismic gap is a(n) ____.

A)time period with no earthquakes on a fault, longer than double the recurrence interval
B)an inactive section connecting active parts of a fault
C)part of an active fault that has not had recent earthquakes
D)lack of historical and modern data about a fault system
E)area where blind thrusts are likely to occur

Question 18

Migrating earthquakes are a danger along the ____ Fault.

A)San Andreas
B)North Anatolian
C)Cascadia
D)Hayward
E)San Jacinto

Question 19

One trend that is important in earthquake prediction shows that ____.

A)major earthquakes along a fault tend to occur in groups separated by an inactive interval
B)some faults have migrating earthquakes that start at the center of the fault and proceed in both directions at regular intervals
C)many earthquakes have reliable recurrence intervals which accurately predict the decade of the next major earthquake
D)earthquakes often occur simultaneously at many locations along a fault
E)radon gas emissions and groundwater level are trustable indications that an earthquake is imminent

Question 20

Paleoseismology ____.

A)studies ancient earthquakes but does not help predict earthquakes in modern times
B)relies on the study of fossils of animals killed in major earthquakes
C)improves prediction of earthquakes by extending knowledge before written records
D)is effective in the prediction of the largest earthquakes only
E)relies on old marine sediments, and cannot be used where they are not found

Question 21

The greatest potential for earthquake damage in the near future for the continental United States is in ____.

A)St. Louis, MO
B)Seattle, WA
C)Los Angeles, CA
D)Boulder, CO
E)Portland, OR

Question 22

In EEW systems, EEW stands for "_______________ warning."

Question 23

An area of a fault that has had significantly fewer earthquakes than the areas around it is known as a(n) _______________. (two words)

Question 24

In San Francisco, earthquake hazard is increased for bridges and highways because ____.

A)they use poured concrete without reinforcing bars
B)their support columns are not sheathed in steel
C)many are built on soft mud and clays
D)the supports are anchored to bedrock
E)the weight of vehicles increases the load on the structure

Question 25

In the last two hundred years, seismic activity in the San Francisco area has produced ____.

A)major earthquakes at intervals of about 60 years, with few smaller earthquakes
B)moderate (magnitude 6+)earthquakes every 10 to 15 years
C)moderate earthquakes every 10 to 15 years, and one major earthquake about 100 years ago
D)a cluster of moderate and major earthquakes in the early 1900s with a gap until recent moderate earthquakes
E)only major earthquakes

Question 26

In an earthquake, reinforced concrete ____.

A)can crumble and fail if it is not sheathed in steel ​
B)prevents lateral motion of building foundations
C)is affected by lateral, but not vertical motion
D)is affected by vertical, but not lateral motion
E)is responsible for most collapses involving a single floor in a building

Question 27

Seismologists use what they have learned about where and when earthquakes occur to construct _______________ maps.

Question 28

The greatest hazard to someone in a wood-frame house during an earthquake is ____.

A)movement of the house off its foundation
B)wall spreading leading to roof collapse
C)crumbling of internal plaster and drywall
D)vertical shaking separating walls from floor joists
E)collapse of walls that are not diagonally braced

Question 29

Which of these states is at the LEAST risk for earthquake hazards?

A)California
B)Washington
C)Missouri
D)South Carolina
E)Minnesota

Question 30

In a city, the best strategy for avoiding injury in an earthquake that arrives suddenly is to ____.

A)make your way to open ground as fast as possible
B)remain where you are during the shaking from P-waves, but attempt to leave the city before S-waves arrive
C)seek cover in the basement of the building or home you are in
D)remain where you are and lie next to a heavy and sturdy object
E)seek cover in the attic or top floor of the building you are in

Question 31

Which construction material would make a house safest in a moderate earthquake?

A)Wood-frame construction sheathed with plywood.
B)Brick and mortar.
C)Adobe.
D)Cinderblock and mortar.
E)Poured concrete.

Question 32

The faults around Los Angeles County at the present time ____.

A)are likely to rupture, since they have more energy stored in slippage than has been released in earthquakes
B)are unlikely to rupture, since they have less energy stored in slippage than has been released in earthquakes
C)regularly release stored energy in moderate earthquakes
D)are in danger of catastrophe, since moderate earthquakes have not occurred for decades
E)are not showing signs of slip and may be inactive in the near future

Question 33

The frequency-magnitude relationship predicts that any 100 km segment of the San Andreas Fault should experience an earthquake magnitude of 6 on average (enough to cause property damage) every ____ years.

A)​8
B)​80
C)​800
D)8,000
E)80,000

Question 34

An important tool in identifying ancient earthquakes is the offset of _______________ layers.

Question 35

Los Angeles County is at risk of an earthquake along the ____ Fault.

A)Hayward
B)Calaveras
C)Rodgers Creek
D)San Jacinto
E)Anaheim

Question 36

Which countries are at the highest risk for major earthquakes?

A)those along the east coast of South America ​
B)those near the Arctic Circle
C)t hose in southern Europe
D)those along the east coast of North America
E)those in the sub-African interior

Question 37

When the location of earthquakes on a fault moves consistently in one direction, they are called _______________ earthquakes.

Question 38

In an earthquake, you are most likely to be injured from ____.

A)ground motion
B)fissures opening in the ground
C)aftereffects like fire, power outages, and lack of clean water
D)objects falling on you
E)epidemics

Question 39

The recurrence interval ____.

A)specifies the time that earthquakes of unknown magnitude will occur in a single area
B)predicts the time and magnitude of major earthquakes
C)predicts the average occurrence of major earthquakes in a single area
D)predicts the time and magnitude of minor earthquakes
E)specifies the average occurrence of major and minor earthquakes along a complete fault

Question 40

In a metropolitan area, buildings of different heights are a danger to each other because ____.

A)tall buildings sway slower than lower buildings, allowing them to collide
B)tall buildings sway faster than lower buildings, allowing them to collide
C)short buildings are more likely to rupture during vertical motion, making them crumble during lateral motion
D)tall buildings are more likely to rupture during vertical motion, making them crumble during lateral motion
E)different building heights resonate with vertical motion at different frequencies and can amplify vibrations

Question 41

Weak floors in a building can be strengthened using _______________ bracing.

Question 42

List several steps that can be taken to "retrofit" an older structure to withstand earthquakes.

Question 43

What major city was affected by the 1989 Loma Prieta earthquake, how strong was it, and how much damage did it do to life and property?

Question 44

Modifying existing structures, or _______________, can reduce earthquake damage.

Question 45

The _______________ of a building's sway tells how many times per second it will sway back and forth.

Question 46

In 1999, a major earthquake on the North Anatolia fault in Turkey struck the city of Izmit. What is significant about this earthquake in terms of past and future events?

Question 47

Thick rubber pads or shock absorbers are mounted under a building to provide _______________. (two words)

Question 48

Where is the Hayward Fault, and why is it dangerous?

Question 49

​Describe the factors that would lead a geologist to conclude that a major earthquake is likely in a certain part of a fault.

Question 50

The Pacific Northwest is at high risk for earthquakes from the _______________ subduction zone.