Geology 110: Earth and Space Science
Chapter 5 (Earthquakes)
Homework
SELF-REFLECTION AND COMPREHENSION SURVEYS
Checkpoint 5.1, p. 115
#1: The map shows the locations of 15 of the world’s largest urban areas. Compare it
with a map of plate boundaries from Chapter 4. On the basis of their locations relative to
plate boundaries, which six cities are most likely to experience an earthquake?
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Checkpoint 5.2, p. 115
#2: Using the map in Checkpoint 5.1, which of the groups of cities below are most likely to
experience subduction zone earthquakes?
a) Istanbul, Los Angeles, Sydney
c) Beijing, Tokyo, Calcutta
b) New York, Rio de Janeiro, Buenos Aires
d) Jakarta, Mexico City, Lima
Checkpoint 5.3, p. 115 (NOT REQUIRED, NOT EXTRA CREDIT…all classes)
#3: The discovery of the potential for mega-earthquakes on the Cascadia subduction zone is an
example of how scientific explanations are developed. Briefly explain how the development of
this hypothesis illustrated the following characteristics of scientific explanations.
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1. It was tentative.
2. It was based on observations.
3. It was predictable and testable.
4. It offered natural causes for natural events.
Checkpoint 5.4, p. 116
#4: Are earthquake insurance rates based on inductive or deductive reasoning? Explain
your choice. (Review information on inductive and deductive reasoning from Chapter 1 if
necessary.)
Checkpoint 5.5, p. 117
#5: An earthquake occurred on the Erie fault 5 kilometers beneath San Gabriel. Damage
from the earthquake was greatest in nearby Fremont. The farthest report of shaking was
recorded in Stockton. Where was the earthquake’s epicenter?
a. The Erie Fault b. San Gabriel c. Fremont d. Stockton
Checkpoint 5.6, p. 118
#6: Examine the following images.
Photo (a) was taken following the Izmit earthquake in Turkey in 1999. On the basis of
your observation of the picture, locate the approximate position of the fault (already done
with red-dashed line) and classify the fault type. Cite the reasons, data, and inferences
supporting your answer.
Photo (b) was taken in the Grand Teton mountain range of northwestern Wyoming.
Which location represents a fault scarp in the picture?
a) 1 b) 2 c) 3 d) 4 Answer:
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Question 5.7, p. 123: Faults and Earthquakes Concept
#7: Map Exercise (ALREADY DONE….STUDY AND UNDERSTAND)
Complete the concept map that links key terms and/or concepts associated with faults and
earthquakes. Select from the list of key terms and concepts provided to fill in the empty
rectangles. There are more terms than spaces available.
Checkpoint 5.8, p. 123 (NOT REQUIRED, NOT EXTRA CREDIT…all classes)
#8: Use the Venn diagram provided to compare and contrast the characteristics of
Convergent PB
Divergent PB
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earthquakes that occur along convergent and divergent plate boundaries. Use at least 7
terms or concepts.
Checkpoint 5.9, p. 126
#9:
Examine the following cutaway view of a section of Earth’s crust containing a fault.
Answer the questions that follow, assuming that an earthquake originated at the focus
shown on the fault surface.
Which locations would experience both body waves and surface waves?
a) A and B only
b) C & D only
c) E only
d) A, B, C, D, & E
Checkpoint 5.10, p. 126
#10: Examine the following seismogram, which shows a 26-minute-long record of the
seismic waves from the 1906 San Francisco earthquake as received by a seismograph
station in Germany, over 14,000 kilometers (8,700 miles) away. Then answer the
questions that follow.
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Which letter represents the arrival of the first S waves?
a) a
b) b
c) c
d) d
e) e
f) f
Approximately how much time elapsed between the arrival of the first P and S waves?
a) 60 seconds
b) 4 minutes
c) 10 minutes
d) 60 minutes
Checkpoint 5.11, p. 127: Ashtabula Earthquake Exercise (EXTRA CREDIT…ALL
CLASSES)
#11: Ashtabula, Ohio, and surrounding communities were shaken by a 4.5-magnitude
earthquake at 10:03 p.m. eastern time on Thursday, January 25, 2001. The event was felt
throughout northern Ohio, western Pennsylvania, Michigan, and Ontario, Canada.
Preliminary damage reports from Ashtabula indicated cracked plaster and masonry, walls
bowed or moved, items knocked off shelves, and a ruptured natural gas line that resulted
in the evacuation of some residents. Graphs a to c represent three seismograms from the
events as recorded at Ashtabula, Lakeland, and Cleveland. Cleveland was farthest from
the earthquake epicenter and Ashtabula was closest.
Describe how the seismograms differ, and identify and label each seismogram as
Ashtabula, Lakeland, and Cleveland. Explain your answer.
Correct station location answers are: a)
b)
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c)
Checkpoint 5.12, p. 128 (FOR NOTEBOOK ONLY…message for online classes)
#12:Place the numbers corresponding to the following phrases in the appropriate
locations in seismic wave Venn diagram below.
1. Most damaging
4. Body wave
7. Second arrival
10. In Earth’s interior
2. First arrival
5. Raleigh wave
8. Love wave
11. On Earth’s surface
3. Last arrival
6. 4-6 km/s in crust 9. 2-3 km/s in crust 12. Determines
magnitude
Surface Waves
P Waves
S Waves
Checkpoint 5.13, p. 129
#13:How much would ground motion increase between magnitude 4.5 and 5.5
earthquakes?
a) No increase
c) 10 times as much
b) 5 times as much
d) 30 times as much
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Checkpoint 5.14, p. 130 (NOT REQUIRED, NOT EXTRA CREDIT…all classes)
#14: Three sites (L1, L2, L3) record earthquake magnitude and earthquake intensity for
the same earthquake. L1 is located closest to the focus and L3 is farthest away. Where is
the intensity greatest and what happens to the earthquake magnitude calculated at the
different sites?
a) Intensity is greatest at L1; calculated magnitude is the same at each site.
b) Intensity is greatest at L3; calculated magnitude is the same for each site.
c) Intensity is greatest at L1; calculated magnitude decreases with distance from the
focus.
d) Intensity is greatest at L3; calculated magnitude decreases with distance from the
focus.
Checkpoint 5.15, p. 130
#15: From the distribution of historical earthquakes shown on the map in Figure 5.19,
recommend 3 states in different parts of the country where would you advise a
seismophobe (a person who is afraid of earthquakes) to take up residence, and three more
where you would recommend that the person stay away from. How would you explain
the distribution of historical earthquakes as shown on the map?
Checkpoint 5.16, p. 132
#16:Examine the following community internet intensity map (CIIM) below for the
Whittier Narrows earthquake in southern California. This earthquake occurred 7 years
before the Northridge earthquake (Fig. 5.20). Compare and contrast the CIIMs for both
events, and suggest possible explanations for the similarities and differences between two
maps.
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Checkpoint 5.17, p. 134(EXTRA CREDIT…ALL CLASSES)
#17:Analyze the Community Internet Intensity Maps for the Northridge and Whittier
Narrows earthquakes in Figure 5.20 and Checkpoint 5.16 and the Modified Mercalli scale
in Table 5.2. Determine approximately how far from the epicenter ground shaking would
have been strong enough to make it difficult for people to stand through both
earthquakes.
Checkpoint 5.18, p. 135(EXTRA CREDIT…ALL CLASSES)
#18:Imagine that 2 inland cities of the same population that experience 2 identical
earthquakes (same magnitude, same focal depth, same location relative to city). One city
is devastated; the other suffers only light damages. Using only information from this
section of the chapter, suggest 2 contrasting scenarios to explain why one city might be
heavily damaged while the other escapes relatively unharmed.
Checkpoint 5.19, p. 139 (NOT REQUIRED…all classes)
#19:Warning times associated with some natural hazards can be measured in months
(volcanoes), days (hurricanes), or minutes (tornadoes). However, so far no system exists
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for warning people of an imminent earthquake. Recently some scientists have suggested
that it would be possible to create an earthquake warning system in regions such as
southern California that have an extensive network of seismograph stations. They suggest
that the arrival of P waves could trigger an alarm that would give people time to react
before the arrival of the more damaging S waves and later surface waves. How would
such a system impact citizens in a densely populated city such as Los Angeles that is
situated near numerous active faults?
Checkpoint 5.20, pp. 140-141: Earthquake Risk Rubric Exercise (ONLINE
CLASSES…PLEASE USE THE DISCUSSION TOOL TO WORK ON THE
FOLLOWING QUESTION WITH YOUR CLASSMATES)
#20:This exercise requires that you consider what combinations of factors is most likely
to contribute to the greatest risk of damage from a future earthquake.
After graduation, you get a job working for a county planning task force in California.
The task force must examine the setting of several different cities and identify which is at
greatest risk for future earthquake damage caused by movement on known faults.
Your assignment is to fill out the evaluation rubric provided here by identifying factors
that would influence the risk of damage from a future earthquake. The location that
scores the highest on your scoring rubric will receive additional county funds to protect
key structures from earthquake damage. The factors you identify may be either physical
(such as nature of the local geology) or cultural (such as size of population centers).
Audience: You will create a scoring scheme that can be applied by most educated
citizens. Specifically, you may consider that you are writing for city council members or
a concerned citizens group.
Main point and purpose: To demonstrate your understanding of the principal factors
that result in damage or loss of life from an earthquake.
Pattern and procedures: You must identify 4 factors and differentiate among
characteristics that make them high-, moderate-, or low-risk phenomena. One factor, the
proximity of the site to a fault, is included as an example (see accompanying table). If the
fault were to move in the future, sites closest to the fault would suffer the most damage
(high risk), whereas those farther away may experience little or no damage (low risk).
Each site with a high-risk factor is scored as 3 points; moderate-risk factors rate 2 points;
and low-risk factors rate 1 point. The site with the highest cumulative score for all factors
is at greatest risk from a future earthquake.
Standards and criteria: You will be assessed on your choice of:
i. Relevant factors that would contribute to the potential for earthquake-related
damages;
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ii. Identification of what constitutes high-, moderate-, or low-risk situations for each
factor;
iii. One factor as most significant;
iv. The applicability of your rubric to 4 sites in an idealized county in California.
Factors
Proximity to fault
Low risk
(1 point)
Moderate risk
(2 points)
moderate
(25-50 km)
far
(>50 km)
High risk
(3 points)
close (<25 km)
(<25 km)
What is the most important factor in your rubric? Distinguish which factor is
the most significant under the circumstances of the exercise. The score for
this factor will be doubled. Discuss your justification for choosing the
particular factor.
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Use your rubric in a hypothetical situation. Examine the information on the geology and
characteristics of 4 cities shown on the following map and rank them in order of greatest
to least risk of damage from a future earthquake.
Rank:
1.
2.
3.
4.
Earthquakes Concept Map (NOT REQUIRED, NOT EXTRA CREDIT…ALL
CLASSES)
#21: Draw a concept map that illustrates the significant characteristics of earthquakes.
Use the scoring rubric provided here to draw a concept map that can be scored as a “4.”
Scoring Rubric
0
The concept map does not contain any information about earthquakes.
1
The concept map contains some terms that are significant to explain the main
features of earthquakes but several key terms are omitted and many linking
phrases are either absent or inaccurate.
2
The concept map contains most terms that are significant to explain the main
features of earthquakes, but they are poorly organized and some linking phrases
are absent or incorrect.
3
The concept map contains most terms that are significant to explain the main
features of earthquakes but one or two key term(s) may be absent. The diagram is
reasonably well organized, and almost all linking phrases are appropriate.
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4
The concept map contains all terms that are significant to explain the main
features of earthquakes in a well-organized display that has appropriate linking
phrases for each pair of terms.
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