# Axia College Material

```Axia College Material
Appendix F
Week Three Lab Report: Earthquakes
Answer the lab questions for this week and summarize the lab experience using this form.
Full Name
Date
Carefully read pages 156-170 of Geoscience Laboratory.
Complete this week’s lab by filling in your responses to the questions from Geoscience
Laboratory. Select answers are provided for you in red font to assist you with your lab work.
Although you are only required to respond to the questions in this worksheet, you are encouraged
Lab Questions
9.1.
Judging from the seismogram in Figure 9.4 of the lab book, which wave appears to be
the most damaging?
Surface Wave
9.3.
Determine the distance to an earthquake at a station that receives P and S waves 5.0
minutes apart. Hint: (a) Place tick marks on a scrap of paper equal to 5.0 on the minutes
axis. (b) Fit that to the horizontal separation between P and S curves. (c) Read distance
directly across on the distance axis.
3,000 km
9.4.
At this point, from the information in Figure 9.6A, how specific can you be as concerns
the location of that earthquake?
Answer: The earthquake is somewhere on the circle around Seattle
9.5.
At this point, from the information in Figure 9.6B, how specific can you now be as
concerns the location of that earthquake?
The earthquake is located at one of the two points where the two circles intersect.
9.6.
At this point, from the information in Figure 9.6C, how specific can you now be as
concerns the location of that earthquake?
The earthquake is located at the point in Montana where the three circle intersect
9.10.
Using the nomogram, determine the Richter magnitude for the three earthquakes listed
(see, p. 169 in the lab book).
S arrival minus p arrival
Amplitude
(A) 8 seconds
(B) 8 seconds
(C) 6 seconds
20 millimeters
0.2 millimeters
10 millimeters
9.14.
Magnitude
4
2
3.5
The 2002 Afghanistan earthquake measured 5.9 on the Richter scale and killed 1,800
people. The 2001 western Washington earthquake measured 6.8 on the Richter scale
and killed only one person. Can you imagine why the huge difference in the numbers of
deaths? Hint: It has to do with construction materials.
The mud walls used in construction of Afghan homes could not withstand the shaking from the
earthquakes whereas construction in the United States tends to be better reinforced.
9.17.
Where is the location of that June 19 quake (to the nearest tenth of a degree latitude and
longitude)? Follow the steps 1 through 4 to complete the table below (see lab book pp.
164-165).
P arrival time
S arrival time
hours: minutes: seconds tenths of seconds
LTN
GOIL
POW
3:46:45.7
3:46:0.9
3:47:3:0
3:46:50.0
3:47:17.2
3:47:20.8
Difference in P &amp; S
Distance
seconds
kilometers
4.3
16.3
17.8
35.6
137
149
9.20.
One of the curious things about the loss of life in regions surrounding the Bay of Bengal
is that some 38,195 lives were lost in Sri Lanka, whereas only 2 lives were lost in
Bangladesh. How could this be? It certainly couldn’t be the difference in distance. Hint:
To answer this question, you should first contour the map in Figure 9.20 (see p. 170 in
the Lab book) and then follow ‘the rule.’ Note: You do not need to submit the contour map
with this report.
The path that the tsunami would travel to Bangladesh goes through much shallower
water than the path to Sri Lanka. According to the rule, less energy is expended when the
tsunami travels through deeper water, causing the run-up to be higher with more destruction.
Lab Summary
Address the following questions in a 100- to 200-word summary:
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Summarize the general principles and purpose of the lab.
Explain how this lab helped you better understand the topics and concepts addressed this
week.