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Salt Lake Community College - Geography 1700
Quiz #1 - Summer, 2014
A. J. Allred, Adjunct
Student Name: ____________________
ANSWERS
1. Buildings that survive earthquake damage tend to be made of solid, heavy masonry rather than light-weight, flexible
materials that move easily when shaken.
True ___
False _X__
Heavy buildings made of rigid material tend to fracture and collapse under their own weight. Lightweight, flexible
materials may shake a lot, but they tend to not fall.
For heavy, rigid buildings, base isolation blocks made of rubber can help prevent cracking and collapse.
For lightweight frame buildings made of wood or metal it is usually better to tie buildings tightly to foundations, by
using “seismic” straps (wind straps, hurricane straps, etc.) so that wind or shaking does not push them off their
foundations.
2. The 2011 ‘Fukushima’ catastrophe was started by an earthquake that led to a tsunami. About 26,000 people died.
The event also resulted in the destruction of a nuclear power plant. In your opinion, was the Fukushima event a
natural disaster?
a.
b.
c.
d.
e.
Yes, Fukushima was a natural event. We can’t predict these things, so get over it.
No, Fukushima was man-made. There is no excuse for it.
I follow the old saying: “To every complex problem there is a simple cause, and it’s probably wrong.”
I hate questions like this. Just tell me the answer so I don’t have to worry about it anymore.
All of the above all typical human responses to what happens when disaster strikes.
You can assert any answer you like, but answer ‘e’ is all-inclusive and accurate.
3. All hazards and disasters on Earth are caused by some form of radioactive energy. In fact, human life exists
because of radioactivity.
True _X___
False ____
Solar energy is created by radioactive fusion that turns hydrogen into helium.
Tectonic energy from inside the earth is produced by decay of uranium into lead.
4. The crust of the Earth is soft and flexible, while the underlying asthenosphere is rigid and inflexible. The result is
earthquakes that occur on the surface, causing hazards for everyone nearby.
True ____
False _X___
The asthenosphere is molten material that is not rigid, because it is near the surface of the earth (just underneath the
dry crust). So, it is hot enough to be melted, but not under relatively little pressure so it can move.
Meanwhile, the dry crust is relative hard, dry and rigid, so it can fracture and crumble easily when the
asthenosphere moves underneath.
5. Which of the following types of rocks is mostly likely to be found on the exposed surfaces of the Earth?
a. Igneous
b. Sedimentary
c. Metamorphic
d. Magma
e. All of the above are equally likely to be found at the surface of the Earth’s crust
Igneous crystal that reach the surface of the earth eventually erode and crumble into dust, or other fragments that
eventually settle and compress into layers of sediment. Because of solar and water processes, igneous rocks
eventually turn into dust and sediment. Most of the earth’s surface is sediment and sedimentary rock.
6. Human populations are growing in many of the world’s most quake-prone regions. To compensate for that trend,
buildings are now safer because communities have adopted uniform building codes, and by the universal use of
standardized alert systems and emergency response procedures.
True ___
False _X__
Relatively few buildings are up to modern standards. Codes are always being updated, and few older buildings
have been updated.
In poor countries, very few buildings are designed to modern standards. In many places, buildings are still made of
mud and straw. Many people still live in caves.
In Utah, thousands of buildings are old and lack enough steel rebar or other reinforcing.
Most people have “smart phones” but don’t pay much attention to emergency “apps”. Alert systems are often outof-date or do not work properly.
Often, people ignore building alarms, such as “fire drills”.
7. An earthquake of M = 6.6 releases about how much more energy than a quake of M = 5.6?
a.
b.
c.
d.
e.
1.0 times more
3.2 times more
32.0 times more
320.0 times more
33,000.0 percent more
8. The highest mountains on Earth (Himalaya) were created by heavy, under-sea crust slowly sliding underneath
lighter continental crust.
True ___
False _X__
The Himalayan mountains were created by collision (convergence) of two lightweight crustal blocks. Neither one
subducted, so they both lifted.
9. Which of the following phenomena may suggest that the Earth has entered a new geologic epoch known as the
‘anthropocene’?
a.
b.
c.
d.
e.
Ocean crust is now starting to sub-duct underneath dry continental crust
The existence of a billion automobiles, a billion belching cows, and 150,000 power plants
The rise of the ‘Ring of Fire’ that includes volcanoes and earthquakes around the ‘Pacific Rim’
All of the above are equally important evidence that the Earth is now in a new epoch or era
None of the above means anything in terms of Earth geologic history
“Anthro” means ‘human’. In the human era we see the appearance of billions of domestic animals, power plants
and automobiles.
Our “Anthropocene” epoch is the only known human era in the history of earth.
10. Inland urban centers like Salt Lake County are far enough away from the sea coast to be safe from water waves
caused by earthquakes.
True ___
False _X__
Salt Lake County is safe from ocean tsunami waves, but we do have the Great Salt Lake and many mountain lakes
and reservoirs. Any of these water bodies can produce large seiche waves when quakes and landslides occur.
11. Which of the following statements is not true?
a.
b.
c.
d.
The geometry of triangles can be used to determine the location of an earthquake.
Triangulation can pinpoint the epicenter of an earthquake but not how far away it is
The time delay between the arrival of “P” waves and “S” waves helps determine distance to a quake.
The amount of energy attenuation across distance can be measured by comparing instrument intensity
between several seismograph stations.
e. Most ‘super-shear’ earthquakes are associated with transform or slip-strike faults that may run hundreds of
miles in length.
The highlighted wording in answer ‘b’ is not correct. If we know where something is, then we automatically also
know how far away it is.
12. If the intensity of an earthquake is 7.0 and its largest aftershock is 6.0, then about how much more shaking
occurred in the main shock than in the aftershock?
a.
b.
c.
d.
e.
Five times more shaking
10 times more shaking
32 times more shaking
1,000 times more shaking
There is no way to estimate the difference in shaking between the main shock and the aftershock
The intensity or shaking scale is ranked by an exponent of 10. We multiply or divide everything by 10, not 32.
13. Earthquake energy is released in various shock waves, the fastest of which are:
a.
b.
c.
d.
e.
Primary
Secondary
Surface
Tsunami
Sound (supersonic, or speed of sound)
Primary waves are straight-ahead, not side-to-side energy pulses. P waves travel at about 13,400 miles per hour.
14. What type of earthquake fault is most clearly exhibited by the Wasatch Mountains rising east of Salt Lake valley?
a.
b.
c.
d.
e.
Transform
Slip-Strike
Block
Subduction
None of the above is correct
Block faulting is mostly vertical movement, with one block rising more than the block next to it. Transform, or
slip-strike (strike-slip) quakes tend to be horizontal movement and seldom produce hills or mountains.
15. Aside from death and destruction, earthquakes and other tectonic forces sometimes provide natural service
functions that may benefit people: new land forms, scenic views and new minerals for developing farm soil.
True _X__
False ___
Sometimes natural hazards don’t seem helpful, but everyone appreciates volcanic rock that can turn into good farm
soil. Mountains provide scenic views, ski resorts and places that hold water for farming.
16. The availability of private insurance plans and government emergency response services:
a.
b.
c.
d.
e.
may tend to make people feel complacent, providing a false sense of security
may result in dangerously unrealistic expectations for government help when disaster strikes
can encourage science and engineering to help determine what it really costs to live in hazardous places
protects you from the effects of natural hazards
All of the above are true except answer ‘d’
Many people believe that government programs will provide rescue or recovery from any condition. That may be
true sometimes, but not always. Insurance can be very helpful in recovering from disasters, but no insurance
policy can protect you from a rock falling on your head.
Insurance can replace you more than protect you.
17. Which of the following applies to the term “mitigation”?
a.
b.
c.
d.
e.
Mitigation helps reduce the effects of an event or process
Mitigation can also help prevent losses by advance planning
An ounce of prevention is worth a pound of cure
Insurance can replace you, but it can’t really protect you
All of the above apply
18. An earthquake of M = 6.6 releases about how much more energy than a quake of M = 5.2?
a.
b.
c.
d.
e.
1.4 times more
5.6 times more
64.0 times more
128.0 times more
256.0 percent more
5.2  6.2 = 32x
6.2  6.4 = 2x
6.4  6.6 = 2x
32 x 2 = 64x
64 x 2 = 128 times more energy released
19. Water is a vital component of most natural hazards, natural disasters and catastrophes on Earth.
True _X__
False ___
By itself, solar energy is very limited. But when solar energy converts to heat and goes into water, great power
becomes available. Almost everything that happens on earth depends in some way on the energy in water.
20. Among the following options, the relatively best earthquake warning system would rely on:
a.
b.
c.
d.
e.
The magnitude of “S” waves
Electronic messaging based on the arrival of “P” waves
The time difference between the hypocenter and the epicenter
Surface waves
An alarm that is based on sound waves (supersonic speed) traveling through the air.
A ‘P’ wave is faster than other seismic waves, except during some kinds of ‘super shear’ conditions. So, an
automatic, electronic alert can be sent as soon as a computer runs some calculations based on a ‘P’ wave. More
details about distance and magnitude can be added as more waves arrive at different stations.
A ‘super shear’ earthquake may be too fast for any warning system. Consider how a transform or strike-slip quake
could rupture all the way from one end to another. The rupture could occur all the way along a transform fault, so that
the rupture reaches all the way from one end to another before a warning system could go out.
A ‘super shear’ condition is unusual, and for people located away from the rupture zone might still benefit from an
electronic warning system.
It is also true that a ‘speed of electricity’ warning system could even outrun a ‘P’ wave. If the right equipment is in
place, a warning might be able to give up to a one-minute warning.