CORS 220: NATURAL HAZARDS AND DISASTER PREPAREDNESS (FALL 2006)
MIDTERM EXAM
NAME: ___________________________________
GRADE: ______ / 140
TIME AVAILABLE: 75 MINUTES
Instructions: There are TEN pages of questions. Take a minute or so now to
page through the entire exam and to get a feeling for the length. READ THE
QUESTIONS CAREFULLY. Think carefully about your wording, trying to avoid
ambiguity and unclear answers.
PART 1:
True or False
(24 points)
For each of the following statements, circle whether the statement is true or
false.
IF THE STATEMENT IS FALSE, provide a corrected statement.
Hint: FIVE of the statements are false.
1.
The terms “hazard” and “risk” essentially mean the same thing.
TRUE / FALSE
2.
The worst natural disaster of all time in terms of number of fatalities was
due to an earthquake in 1201 in Egypt.
TRUE / FALSE
3.
The largest tsunami ever recorded occurred at Lituya Bay in Alaska.
4.
A Rayleigh wave is an example of a body wave.
5.
6.
TRUE /
TRUE / FALSE
The point in the earth where an earthquake begins is called the focus. The
point on the surface directly above the focus is the hypocenter.
The largest earthquake in the history of California was the M7.9 Fort
Tejon event in 1857.
TRUE / FALSE
7. Tall buildings have low vibrational frequencies so they are particularly
vulnerable to low frequency surface waves.
TRUE / FALSE
TRUE /
2
8.
Strike-slip faults have produced historically large earthquakes and are
therefore a clear tsunami hazard.
TRUE / FALSE
3
PART 2:
Multiple Choice
(30 points)
Circle the correct answer from those provided for each question.
1.
(
Which of the following would NOT be considered an example of a “risk”?:
20,000 potential fatalities
/
a M7.8 earthquake
damages )
/
(2)
$2 billion in likely
2. The largest death toll for any earthquake in the United States occurred
here:
(2)
(
3.
San Francisco in 1906
/
Northridge in 1994
/
Alaska in 1964
)
An example of a transform plate boundary is provided by the:
(2)
(
4.
Basin and Range
/
Himalayas
/
San Andreas fault
)
Which of the following features would be expected to be found at a
convergent plate boundary?
(2)
(
5.
subduction zone
/
normal fault
/
transform fault
)
Which of the following U.S. states is not considered to be prone to
earthquakes?
(2)
(
6.
South Carolina
/
Texas
/
Missouri
)
A magnitude 7 earthquake releases ______ times as much ENERGY as a
magnitude 6 earthquake.
(2)
(
7.
2
/
10
/
33
)
The 1994 Northridge earthquake and the 1971 Sylmar earthquake in Los
Angeles both had this magnitude:
(2)
(
8.
6.7
/
7.8
/
9.0
)
Which of the following earthquake-prone U.S. cities is NOT within an
intracontinental rift zone?
(2)
(
9.
(
Salt Lake City, UT
/
Memphis, TN
/
Seattle, WA
)
In an earthquake-prone region, just say no to:
reinforced concrete
/
unreinforced masonry
/
wood-frame structures
(2)
)
4
10.
The eastern seaboard of the United States has a tsunami risk posed by
volcanic flank collapse in this location:
(2)
(
11.
12.
(
Canary Islands
/
Big Island of Hawaii
/
Krakatoa
)
The two most voluminous lava flow eruptions in historic times (Laki and
Eldgja) occurred here:
(2)
( Hawaii / Iceland / Indonesia )
Which of the following terms does not belong with the others?
ash fall
/
pyroclastic flow
/
nuée ardentes
/
glowing avalanche
(2)
)
13.
The triggering event that started the chain reaction that resulted in the
eruption of Mount St. Helens was a/an:
(2)
( lateral blast / earthquake / landslide )
14.
The tallest and biggest volcanoes are typically made of basalt and are
called:
(2)
(
15.
shield volcanoes
/
stratovolcanoes
/
cinder cones
)
Which of the following eruptive styles essentially means a steamdominated eruption?
(2)
(
Strombolian
/
Vulcanian
/
Peléan
/
Phreatic
)
5
PART 3:
1.
Fill in the blanks
(46 points)
The largest earthquake on record was a M9.5 event in 1960 in this country:
____________________.
2.
(2)
The term used to describe the average amount of time between hazard events
(i.e., the repeat time), such as between earthquakes or volcanic eruptions,
is called the _______________________________.
3.
(2)
The most tsunami-prone city in the United States is
_______________________________.
(2)
4.
The fastest of all the seismic waves is the __________________________.
5.
The record of an earthquake is provided by a graph of zig-zag lines called
a
6.
_____________________.
(2)
(2)
The distance to an earthquake is related to the time lag between the
arrival of the _____ and _____ waves.
7.
(2)
Sometimes, a large earthquake in a region can start a domino effect of
numerous subsequent earthquakes (not aftershocks) over a period of several
decades due to the disturbance created by the initial quake. This
phenomenon is called
8.
_______________________________.
(2)
In a region undergoing compression, what do we call the type of fault that
does not reach all the way up to the surface, thus making its presence
difficult to identify? ________________________________
9.
The most common mechanism by which tsunamis are produced on earth:
______________________
10.
(2)
The property of a lava flow that measures its resistance to downhill
motion is called __________________.
(2)
(2)
6
11.
The highest death toll from a pyroclastic flow (29,000) occurred from Mt.
Pelée in 1902 on the island of
____________________________
(2)
12.
A volcanic mudflow is better known as a
______________________.
13.
The vertical plume of material from an explosively erupting volcano is
called a ______________________.
14.
(2)
(2)
One of the potential warning signs that indicates that a volcano is
getting ready to erupt in the not-to-distant future is:
____________________________________
15.
(2)
Prior to the eruption of Mount St. Helens in 1980, the last Cascades
volcano to erupt (from 1914-1917) was:
____________________________________
16.
(2)
After a volcano erupts, it may start to build up material inside the
crater again by oozing out viscous rhyolite lava. The feature thus created
inside the crater is called a
17.
_____________________.
(2)
An example of a giant continental caldera style of volcano:
_____________________________
19.
(2)
Loose sediment typically comes to rest at a slope angle where it is at
the critical point of failure for further downslope movement.
is referred to as the
20.
(2)
A large flood of water caused by the eruption of a subglacial volcano is
called a
18.
___________________________.
_____________________________. (2)
Landslides come in three varieties:
falls,
example of each:
Fall:
Slide:
Flow:
This angle
slides, and flows. Give an
(6)
_____________________
_____________________
_____________________
7
21.
Debris flows commonly occur across an existing slope of boulders and
debris previously deposited near the base of a mountain range. This type of
sediment deposit is called an
_____________________________.
(2)
8
PART 4:
Short-answer questions
(40 points)
From the questions shown below, choose FIVE to answer in the form of a short
paragraph. Make sure you address ALL components of the questions you select.
Use the back side of the page if you need more space.
1. Explain what is meant by seafloor spreading, how we know it exists, and
what the consequences are for hazards in this type of environment.
(8)
2.
Explain what concept is being represented by this figure.
(8)
9
3.
What is meant by earthquake intensity, how is it related to earthquake
magnitude, and how does intensity vary relative to the epicenter of an
earthquake?
(8)
4.
The 1906 earthquake along the San Andreas fault had both short-term and
long-term effects in the San Francisco region. Describe some of the details
of the earthquake event itself and some of its lasting repercussions.
(8)
10
5.
The map to the right shows the Pacific Northwest region of the U.S.A. Also
shown is the approximate equivalent size of the rupture zone of the M9.1
Sumatra-Andaman earthquake on December 26th, 2004. Explain why the size of
the 2004 earthquake rupture zone is relevant to the Pacific Northwest. Your
answer should include details of any similarities in the tectonic setting
of the two regions.
(8)
6.
What is being represented in this figure? Indicate the nature of the
hazard involved and why it exists in this region. Also, indicate how we
know where to plot the gray stars and what the meaning is of the red stars.(8)
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
11
7.
What phenomenon is being demonstrated in the laboratory experiment below?
Describe specifically what the experiment is attempting to explain, and
mention an enigmatic case example that was ultimately solved using this
experiment.
(8)
8.
Write a short paragraph about ocean tsunamis, including their cause, their
size on the open ocean relative to the shoreline, their wavelength, telltale signs of their approach at a coastline, and the number of waves
typically produced.
(8)
12
9.
The photo below shows a region where a trench was dug into coastal
sediments. Describe what the scientists were looking for, what they could
see in this particular trench, and how it can be interpreted specifically.
Finally, indicate a possible geographic locality where this trench may have
been dug.
(8)
10. What type of volcanic feature is shown in the photograph below? Explain
how it forms, the type of eruption style it produces, the type of volcano
with which it is usually associated, and the type of rock it produces
around the vent.
(8)
11. BONUS QUESTION:
(8)
Answer one more of the above questions for up to 8 bonus points. Hooray!
[148 possible points]