Global GIS Lesson:
Exploring North
American Earthquakes
By Joseph J.
Kerski
Loma Prieta, California, Earthquake October
17, 1989, Moss Landing. Damaged approach and abutment of the bridge linking the
Moss Landing spit to the mainland near the Moss Landing Marine Laboratory.
Liquefaction of the beach and Salinas River deposits caused ground cracking and
differential settlement. Slide XV-2, U.S. Geological Survey Open-File Report
90-547. Open File Report-90-547 (http://130.11.57.28/of90547.htm), Digital
File:tjc00009, ID. Tinsley, J.C. 9ct
Global GIS
Lesson: Exploring North American Earthquakes
Description
In this lesson, students use Geographic Information
Systems (GIS) together with the tools and data from the North America Global
GIS CD to investigate earthquakes, volcanoes, and population from a local to
global scale. The lessons can be
used with other data in the Global GIS project to investigate earthquakes in
other continents. Furthermore, the
methods used here can be applied to other map themes contained within the North
America Global GIS CD.
The lesson is organized into 7 parts:
Part 1—What’s Shakin’?
Part 2—Digging Deeper
Part 3—The Loma Prieta Earthquake
Part 4—Investigating Your Community
Part 5—Earthquakes Everyday
Part 6—Analyzing Recent Earthquakes
Part 7—Earthquakes Respect No Boundaries
What is GIS?
Maps have always
been powerful ways to represent information.
A GIS combines the power of maps, satellite images, and aerial
photographs with databases that store information behind the maps and images. One way to think about GIS is to break it up
into its three initials. The “G” part
of GIS could be a map, a three-dimensional representation of the Earth’s
surface, or an image. The “I” part of
GIS is the Information, or the database, containing attributes behind each map
feature. This could be the magnitude of
an earthquake, for example, or the population of a country. The “S” part of GIS is invisible to the
user, but this Systems part makes it possible to analyze the maps and
attributes together.
Another way to think about GIS is to think of it in
terms of computer hardware, software, methods, and a human explorer. GIS requires computer hardware and software
to use. In the case of this lesson,
ArcReader and ArcView software from ESRI, Inc. will be used. GIS involves specific methods, or procedures. In this lesson, students will have the
opportunity to use many of these procedures, such as querying, sorting,
changing legends, creating buffers, and others. GIS also requires certain kinds of spatial data. These are produced by national governmental
organizations such as the USGS, the US Census Bureau, NASA, and others, as well
as tribal, state, and local government, nonprofit organizations, and private
industry. However, the most important
component of a GIS is the user. It is
the person that must make sense of what the GIS tools and methods are saying,
and it is the person who must decide what action to take.
Why Use GIS in Education?
As the world becomes ever more monitored, mapped, and
surveyed, students have the opportunity as never before to take advantage of
the same tools that scientists are using.
One tool essential for analyzing the Earth is a Geographic Information
System (GIS). A GIS allows the user not
just to create computerized maps, but also to analyze patterns,
linkages, and trends that exist above, on, or below the Earth’s surface. Oceanographers, geologists, geographers,
seismologists, climatologists, biologists, chemists, zoologists, and other
scientists regularly use GIS to help them make wise decisions about the
planet. Why not tap into this powerful
tool for teaching and learning?
A GIS user is not confined to the static content,
locked scale, and symbols of a paper map.
Rather, a GIS allows the user to create his or her own map—one
that is customized to address the issues and problem at hand.
Analyzing the Earth with a GIS in the classroom
provides for inquiry-based, problem-solving learning. Students ask a question, acquire the necessary tools and data to
address the question, analyze the data using the GIS and other tools, and
assess the results of their investigation.
This may lead to further investigation and additional questions. In addition, learning with GIS allows for
the integration of field data collection with Global Positioning Systems (GPS)
to obtain the precise coordinates of where the data were collected. It also allows for interdisciplinary
learning that is exciting and relevant to address the major issues of the 21st
Century, such as biodiversity, population growth, climate change, natural
hazards, and energy. In this lesson,
students are given the opportunity to analyze a specific natural
hazard—earthquakes—using GIS software and methods of analysis.
Problem
Setting
Earthquakes in North America are costly in both lives
and property. For the past 25 years, the average cost of North American
earthquakes has been approximately $2.5 billion dollars per year in property
and critical infrastructure damage. On average, 1,000 people have
died in North American earthquakes each year for the past 25 years. As
the population grows and development expands to cover more and more of the land
area of North America, this average will grow as well.
In this earthquakes lesson, students are given a
scenario where they must report on the distribution and frequency of
earthquakes in North America related to cities, political boundaries,
volcanoes, and fault lines. They analyze current earthquakes from
the Internet, and assess the hazards from a continental to a local scale, to
their community.
Linkages to Science Standards
Teaching Standards
This lesson supports national teaching science
standards because the lesson was developed as an inquiry-based approach to
teaching. Specifically, it supports
Teaching Standard A because it is interdisciplinary and nurtures a community of
science learners. Teaching Standard B
focuses on modeling the skills of scientific inquiry, which students do while
analyzing earthquakes within a GIS environment. Teaching Standard C is supported because the questions use multiple
methods of assessment, and many sections of the lesson do not have one “right
answer;” rather, the questions encourage students to reflect upon their
learning. It supports Teaching Standard
D because through the Global GIS project, it makes the available science tools,
materials, media, and technological resources accessible to students. Teaching Standard E is supported because
students are encouraged to collaborate with each other, and because the lesson
models emphasize the skills, attitudes, and values of scientific inquiry. In short, with GIS, constructivist teaching
is supported because students are not memorizing facts, and the teachers’ role
changes to one of guiding the students in their inquiry.
Professional Development Standards
Teaching with GIS support the vision of professional
development standards for the teaching of science. Specifically, in the learning of science content through inquiry
standard, GIS was created as an inquiry-based, problem-solving tool. It was not something “made up” for the
classroom. Rather, teachers using GIS
are themselves learning science content in the same way as a scientist in
government, business, or a nonprofit organization does everyday on the job. Furthermore, the development of the
understanding and ability for lifelong learning is supported because GIS is not
a “plug and play” CD. It is a system,
and indeed, geographic information science is a science in its own
right. Therefore, teaching with GIS
cannot be dismissed as easy. It is hard
work, but in so doing, teachers learn continual reflection, new strategies,
best practice, and learning alongside the students. Despite the hard work, most teachers using GIS in the classroom
indicate that it is a worthwhile endeavor.
Science Content Standards
Investigating the Earth with a GIS supports science
content standards. For example, the
“unifying concepts and processes” standard is integrated into the lesson in
that students are provided with a system, a way of organizing their data within
a GIS. They are also provided evidence
for earthquake and volcano hazards as real scientific data. Students examine
evidence and explain the distribution of phenomena across Earth's
surface. They measure phenomena and they analyze changes over
time and space.
Investigating Earth with a GIS also addresses the
science as inquiry standard, because students learn scientific concepts (plate
tectonics) by developing the skills scientists use on the job. GIS is a
real-world tool used by thousands of scientists daily. The process of
inquiry within a GIS is more important than the "final answer" that
the students provide. GIS-driven inquiry gives students an appreciation
of scientific investigation, because it is the same tool that scientists use.
Using GIS, students ask questions, acquire or generate necessary data, analyze
the data, draw conclusions, and ask new questions. They conduct their own
investigations in a hands-on way.
In so doing, they are developing skills necessary to become independent
inquirers about the natural world.
Students using GIS through this lesson begin to see that their analysis hinges largely on the quality of the data provided. They learn to be critical of the data. Too often, when data are viewed on the computer, they are considered to be perfect; without error. However, computer-based data are no more accurate or precise than the paper maps and original sources they were derived from. This is especially important with map data because maps are representations of the Earth. They all contain inaccuracies because they are based on specific map projections, which distort the three-dimensional earth to depict it on a two-dimensional paper map or computer screen. Being critical of data and recognizing the limitations of data and analysis are essential science learning skills.
Using this CD and lesson, emphasis is on
investigation and analysis, rather than on demonstration. The GIS skills
the students are learning are in context with the lesson on seismicity, and
they are using multiple skills—process, computer, analysis. Instead of
simply providing answers to questions, students are communicating science
explanations about science content through their maps, tables, and charts
from GIS. Their conclusions must be backed by real-world data.
The lesson supports the physical science standards
because students learn about tectonic forces, motions, and patterns, and the
structure of the earth system. The science and technology standards are
addressed because students learn science through GIS technology.
Natural hazards are a component in the science in personal and social
perspectives standards, and with this lesson, students assess risks and
benefits of living with earthquakes, and the relationship of earthquakes to
cities and critical infrastructure such as roads, utility lines, and railroads.
GIS
Skills Involved
1) Navigating
through and effectively using a GIS interface and software.
2)
Changing map symbology to create different thematic maps.
3)
Manipulating tabular information, including selecting attributes, querying
tables, and sorting tables.
4)
Querying map data, including proximity analysis.
5)
Downloading and formatting data from the Internet for use in GIS.
6)
Changing map projections.
7)
Creating new information from existing data.
Options
for Running the Software:
1. For users who have installed ArcView Data Publisher,
start the “North America Global GIS” icon from the Windows start bar under the
‘Global GIS’ folder. ArcView Data
Publisher users will not be able to complete parts 6 and 7 of this lesson.
2. Users who own a version ArcView 3.x can open the
ArcView GIS project named “Namerica_global_gis5_v3.apr” directly off the Global
GIS CD. This will give the user the opportunity to save his/her project.
·
Notes: Before starting,
please see http://www.agiweb.org/pubs/globalgis/
under “support and downloads” for any data updates or project updates. The
ArcView project delivered on this disk is not compatible with ArcView version
3.0 because of the use of the MrSid image format. ArcView version 3.1 and
higher will work. Thus, for Macintosh ArcView version 3.0, users will need to
download a compatible Macintosh project, which removes the MrSid image
references from the AGI site mentioned above.
Investigation
The U.S. Geological Survey was created in 1879 to
help understand the geologic, biologic, hydrologic, and geographic
characteristics and phenomena of the planet.
Included in this mission is a thorough understanding of
earthquakes. To help assess where and
why earthquakes occur in North America, the U.S. Geological Survey has hired
you as an earth systems scientist to provide them a report that will include
the distribution, frequency, and causes of earthquakes in North America,
specific regions of the continent, and the state where you attend school. Included in the report must be an analysis
of the depth and magnitude of the earthquakes, and the locations and
characteristics of cities, volcanoes, and faults in relationship to
earthquakes.
As noted above, earthquakes cause millions of dollars
of property and critical infrastructure damage each year. "Critical infrastructure" refers
to large-scale systems that local, regional, and national governments build
across the landscape. These include roads, airport runways, powerlines,
gas pipelines, water pipelines, sewer lines, railroads, fiber optic cable,
broadband Internet lines, telephone lines, shipping docks, power stations,
radio and television transmission towers, and canals.
0) List three kinds of critical
infrastructure that could be destroyed or damaged during an earthquake.
For each, describe why the destruction of these infrastructure resources is so
disruptive to local, regional, and national government and commerce.
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Part 1: What’s Shakin’?
In this part, you
will examine earthquakes across North America, noting their distribution,
magnitude, and depth, and also examining certain regions on the continent.
After accessing
the Global GIS interface, you will be viewing the "G" part of GIS
with the map on the right side and a set of tools across the left and the top.
Turn off (uncheck) all themes except for the
following:
·
shaded relief base (at
the bottom of the table of contents)
·
earthquakes 1973-1994
(about 1/3 down on the table of contents)
Access the
Movies, 3D menu at the top 
and run nam_eq_anima.avi. Use the slider bar to position the movie at
specific years you wish to investigate further.
1) What years do the earthquakes cover?
2) The USGS seismologists want you to make
three observations about the spatial pattern of earthquakes that you
notice as they occur across the North American continent. Consider the extent of the earthquakes, and
specific areas of North America where earthquakes occur more often.
3) Make three observations about the magnitude
of earthquakes and where earthquakes of certain magnitudes occur across
North America. Do large earthquakes
only occur in specific regions? If so,
where are they?
4) Do any specific years seem to have more
earthquakes than others, or would you say that about the same number of
earthquakes occur each year?
Close the movie
and return to your GIS. Now you can
further analyze the earthquake theme and draw some conclusions.
5) Do more earthquakes occur near oceans or in
the interior of the North American continent? Why?
6) Do more earthquakes occur near the Pacific
Ocean to the west of North America or near the Atlantic Ocean to the east of
North America? Why?
7) Compare the number of earthquakes that occur
in the oceans versus land.
8) Compare the Atlantic versus Pacific Ocean
earthquakes.
9) What feature runs down the middle of the
Atlantic, and why is it so prone to earthquakes?
10) What particular hazard exists to people when
an earthquake occurs in the ocean?
11) In what part(s) of North America would
people need to be concerned about earthquakes occurring in the ocean?
Make volcanoes
visible by checking the box to the left of the theme name.
12) Make three observations about the pattern of
volcanoes in North America.
13) The USGS wants you to determine the
relationship of earthquakes and volcanoes.
Examine at least three different places around North America and
investigate the spatial relationship between earthquakes and volcanoes.
Do volcanoes and earthquakes occur in the same places? Include the three
places you examined, your conclusions about the relationship, and why you
believe the relationship either exists or does not exist.
Single click on
the earthquakes theme so that it becomes raised up, or “active.”
Each row in the
table represents one earthquake in the dataset.
14) Look in the upper left part of your screen
under ArcView GIS. How many earthquakes are recorded in this dataset?
15) Approximately how many earthquakes are
recorded during an average year? Show
how you determined this answer.
Click on the
"magnitude" field and sort it in descending order
Navigate to the top of the table and click on the row containing the earthquake
with the highest magnitude to select it. You may have to select the black
selection arrow to select a row. 
.
The row will appear in yellow.
16) What is the magnitude of this earthquake?
Close the table. In the Global GIS Tools box, on the right side of Viewing Tools,
go to “More Tools.” Select the
"Zoom to Selected" tool 
in the Global GIS Tools box:
.
Use the "zoom into center" button
a number of times to zoom into your selected earthquake 
.
Turn on the themes political boundaries, and
political boundary labels.
17)
In which country did the largest earthquake occur?
Access the earthquakes table again and clear
your selection 
.
Select the field "km" in the
table. This represents the depth of the earthquakes in kilometers
underneath the surface.
Click on the
"km" field and sort it in descending order .
Navigate to the top of the table and click on the row containing the earthquake
with the greatest depth to select it. The row will appear in yellow.
18)
What is the depth of this earthquake?
Close the table
and select the "Zoom to Selected" tool in the Global GIS Tools box .
Use the "zoom into center" button a number of times to zoom to your selected
earthquake.
19)
In which country has the deepest earthquake occurred?
20)
In what continent is this country?
Pan 
to the United States.
21) You are asked to list in your USGS report
that states you consider to be most vulnerable to earthquakes. List the top three states, and your reasons
for including them.
Pan to the western side of the United States to
the area of California. You could turn on the US Counties theme to see
California counties all in the same color.
22) You receive an email from the USGS
seismologists that ask you to determine four major areas of California where
most earthquakes occur. What four areas will you list in your report?
Turn on major
cities and turn off earthquakes. You
might have to zoom in to see the labels.
Zoom to the
center of the Pacific Coast of the United States, central California and
Nevada.
Use the
"Create Profile" tool 
and draw a line from Carson City, Nevada,
southwest to San Francisco, California.
Choose to profile the data set “elevation.”
23) Describe how the land elevation changes from
Carson City to San Francisco.
Turn earthquakes
back on.
24) Examine the earthquakes across your
profile. What kind of terrain is more
prone to earthquakes—valleys or mountains? Why?
Zoom out to
California, turn off earthquakes, and note the location and names of the 6
major cities. Turn earthquakes back
on.
25) Of the 6 major cities in California,
indicate in your report to the USGS the 2 cities that you consider to be the
most vulnerable to an earthquake.
Indicate why you consider them to be the most vulnerable.
26) Congratulations! You have completed the first part of the assignment and have
contributed much to the understanding of earthquakes in North America. Indicate what you consider to be the most
surprising thing you have learned in this part, the most interesting thing, and
the most significant thing.
Most surprising:
Most interesting:
Most significant:
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▬▬▬▬ Part 2: Digging Deeper
In this part, you
will examine the relationship between earthquakes and cities, and investigate
earthquakes in a specific area in California.
Click on the
Advanced Interface button at the bottom of the Global GIS Tools window. You will notice the additional tools now at
the top of your computer screen.
Make major cities
the active theme by clicking once on it. Clear any previous city selections .
Make earthquakes
the active theme by clicking once on it. Clear any previous earthquake selections .
Under the Theme
pull-down menu, press "Select By Theme" to discover how many
earthquakes are within 50 kilometers of major cities.
Examine the
resulting earthquake table 
.
Look in the upper left of your computer screen.
27) How many earthquakes resulted from your
query of the data?
28) What percentage of North American
earthquakes are within 50 kilometers of major cities? Show how you determined this answer.
29) Make 3 observations about the pattern of
earthquakes near California cities.
30) Compare the amount of earthquakes in Alaska
versus California. Which state would
you say receives the most earthquakes?
31) Which state would you say receives the most
publicity about earthquakes in newspapers, television, radio, and on the
Internet?
32) Compare your answers to the two previous
questions. Did you write a different
answer for the two questions? If so,
why do you suppose this is the case?
As you move
around the map, notice the latitude and longitude values to the upper right of
the view (map) window.
Zoom to the
earthquakes at 36.91 north latitude and 121.65 west longitude. Set
the scale to 1:10,000. There will be two earthquakes at this exact spot.
33) Identify 
these earthquakes and indicate their
magnitudes:
Click on "Global GIS Help" 
in Global GIS Tools. Go to
"Datasets" and select the earthquakes theme.
34) What field name contains the time
when the earthquakes occurred?
Based on this
information, go back to your map and examine the time when the three
earthquakes occurred. List the earthquakes below in the order of their
occurrence.
35) Were these earthquakes associated with the
same seismic event? Explain your answer.
36) What is an aftershock?
37) Do you think the earthquakes you are examining
include an aftershock? If so, which
earthquake was an aftershock of the first?
38) Notice the “feature search radius settings”
near the bottom of the Global GIS Tools window.
Drag a new search
radius – a circle -- from these two earthquakes until the circle just touches
the Pacific coastline. This should be a
13 kilometer search radius, and the number 13 should appear in the kilometers
field.
Generate a map
report 
and click on the earthquake on the map
again. Print the map report of this area.
39) Summarize what this report tells you in your
own words.
You need to
assess possible damage from future earthquakes in this region in your report,
in terms of roads, airports, and population.
40) What is the 1998 population within 13km of
these earthquakes?
41) Who, in your opinion, are the most
vulnerable segments of the population to earthquakes?
42)
How far is the nearest road from the earthquakes?
43) Do you think roads could be damaged by
earthquakes? Name three ways roads
could be damaged.
44) How could the disruption of transportation
affect evacuation from an earthquake and rescue operations?
45) What is the name of the nearest airfield to
these earthquakes? How far is it from
the earthquakes?
46) Do you think an airfield could be damaged by
an earthquake? Describe three ways air
services could be disrupted.
47) Congratulations! You have completed the second part of your mission and have
contributed much to the understanding of earthquakes in North America. Indicate what you consider to be the most
surprising thing you have learned in this part, the most interesting thing, and
the most significant thing.
Most surprising:
Most interesting:
Most significant:
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▬▬▬▬ Part 3: Investigating the Loma Prieta Earthquake
In this part, you
will investigate one of the worst earthquakes ever to strike the United States,
assess critical infrastructure, and assess the relationship of fault lines to
earthquakes.
The USGS has
indicated that your report needs to include an analysis of the following
earthquake: In October 1989, as over
62,000 fans filled Candlestick Park for the third game of the World Series
baseball game and millions of San Francisco Bay Area workers were commuting
home, a major earthquake struck. This was the Loma Prieta Earthquake, damaging
many neighborhoods in San Francisco and Oakland, and collapsing a major portion
of an interstate highway in Oakland, killing many of the drivers.
Make themes you
have been working with the active theme by clicking once on it. Use
shift-click to select multiple themes.
Clear any previous selections .
Open the earthquake table .
Query 
the table to find the Loma Prieta earthquake
by its date and magnitude, as follows. Be sure to enter the information
by clicking on the field names and equals sign.
Zoom to the Loma
Prieta epicenter at a scale of 1:1,000,000. The scale is in the upper
right of the map. You can type in the exact scale as 1000000 if you wish
in the scale box.
48) In what part of California did this
earthquake occur?
49) Use the identify button with the US Counties theme active to answer
the following: In what county did the
earthquake occur?
50) What direction from San Francisco was this
earthquake’s epicenter?
51) Use the measure tool 
,
answer the following. How far was the
epicenter from San Francisco?
52) Based on what you just measured, discuss how
an earthquake occurring many miles from San Francisco and Oakland could have
caused damage in those cities.
Earlier, you
considered the disruption that earthquakes pose to critical
infrastructure. Turn on the airfields theme and name the nearest airfield
to the earthquake.
53) Use the measure tool to measure the distance to this airfield.
54) Find the airfield at latitude 37.36 north
and 121.93 west, the nearest international airport to the epicenter. What
city is the airport associated with?
55) Have you ever flown into this airport? Ask to find out if any of your classmates
have flown into this airport.
56) Make roads, railroads, and utility lines
visible. Make at least four observations about the proximity of these
features to the earthquake.
57) Have other earthquakes occurred in this area
of California, or was the Loma Prieta earthquake an isolated case?
58) Turn on the US Faults theme and discuss the
relationship between earthquakes in this part of California and fault lines.
59) Based on your investigations, indicate in
your report to the USGS what you consider to be the two main reasons why this
earthquake in October 1989 caused more damage and death than others in this
area.
60) Do some research on the Loma Prieta
earthquake and indicate your findings below.
61) How does your research enhance what you
learned about Loma Prieta through GIS?
Next, you will examine
faults in relationship to earthquakes throughout North America.
Turn off all
themes except faults, Alaska faults, US faults, earthquakes, and the shaded
relief base.
Zoom out to all
of North America using the globe symbol on the Global GIS Tools menu.
It is difficult
to detect the relationship of earthquakes and faults, because of the large
number of earthquakes. Reduce this
number by clicking on “earthquake tools” in your Global GIS window. Show magnitudes between 6 and 9, as follows:
62) Describe the relationship between fault
lines and earthquakes. Consider these
questions in your narrative: Do
earthquakes usually, or always occur near fault lines? Do earthquakes ever occur away from fault
lines? If so, where? Do you think this map shows ALL of the
faults in North America, or just a few?
How does this affect your answer?
63) Turn on earthquakes between 4 and 9, instead
of 6 and 9. Does this affect your
answer, above? Why or why not?
64) Turn on cities. Discuss the relationship between cities and fault lines for your
report to the USGS.
65) Congratulations! You have completed the third part of the assignment and have
contributed much to the understanding of earthquakes in North America. Indicate what you consider to be the most
surprising thing you have learned in this part, the most interesting thing, and
the most significant thing.
Most surprising:
Most interesting:
Most significant:
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Part 4: Investigating Your Community
In this part, the
USGS needs you to report on your own community’s vulnerability to earthquakes.
Make the themes
you have been working with the active theme by clicking once on it. Use
shift-click to select multiple themes.
Clear any previous selections using the clear selection tool .
Zoom to the state where you go to school (or your
country if you live in Canada, Mexico, or Central America).
Make earthquakes
the active theme by single clicking on it.
Label 
the magnitudes of the earthquakes.
66) In what country do you live?
67) In what state or region do you live?
68) Describe what you consider to be the major
natural hazards faced by your community, and where you consider earthquakes to
be in this list of hazards.
69) Describe the pattern and the number of
earthquakes in your country, state, region, and community.
70) Use the select feature button 
to draw a box around the earthquakes that are
in your region or state. After
selecting the earthquakes, access the table . Look in the box in the upper left that
indicates how many earthquakes are selected.
How many earthquakes occurred in your selected region? Include a description of how much land you
included in your selection box in your answer.
71) How do the pattern and number of earthquakes
in your area compare to what you learned earlier about the pattern and number
of earthquakes in Alaska and California?
Examine the
earthquake map theme legend.
72) What is the range (minimum and maximum) of
earthquakes that you are examining?
In the Global GIS
Tools box, select the Earthquake Tool.
Click the
"Show Magnitudes Between Min and Max" button and set the minimum
magnitude to 6 and the maximum to 9. Press "Reset Mag Range" to
reset the map, as follows:
73) Where do most of the large (at least magnitude
6) earthquakes occur?
74) Do the large earthquakes have the same
pattern of occurrence in North America as those that you examined earlier that
included magnitude 4 and 5 earthquakes? Why or why not?
Zoom closer to
your own community at a scale of approximately 1:700,000.
75) Now that you know how to move to specific
earthquakes, generate a search radius, as follows:
Next, generate a
report ,
generate a report for the earthquake nearest your community. Print the report and make at least five
observations for your report for the USGS about the vulnerability of your own
area—its population, roads, airfields, dams, and other critical infrastructure.
76) Describe the earthquake nearest your
community: Indicate the location of
your school and community area, the direction from your school, the date it
occurred, the magnitude, the depth, and the time of day it occurred.
77) Does anything surprise you about the
earthquake event? Do you remember the
earthquake? Did it cause any damage? Ask someone in your community to determine
if they remember it; if you can find someone, indicate their response. If not, do some research on the earthquake
and report the findings.
78) Congratulations! You have completed the fourth part of the assignment and are
contributing much to the understanding of earthquakes in North America. Indicate what you consider to be the most
surprising thing you have learned in this part, the most interesting thing, and
the most significant thing.
Most surprising:
Most interesting:
Most significant:
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Part 5: Earthquakes Everyday
In this part, you
will examine earthquakes by country in North America, and compare recent
earthquakes to your existing data.
Make the themes
you have been working with the active theme by clicking once on it. Use
shift-click to select multiple themes.
Clear any previous selections using the clear selection tool .
Make political
boundaries and political boundary labels visible by checking the small boxes to
the left of the theme names.
79) What country will you list in your report to
the USGS that appears to suffer the most earthquakes?
80) Name two reasons, based on your observations
of the map, why more earthquakes occur in this country than any other.
Make US Counties
visible. With this map theme, notice that each state's counties are one
color.
81) What state will you indicate to the USGS has
the most earthquakes?
82) Name two reasons why you believe more
earthquakes occur in this state than any other.
83) Did any US states experience no earthquakes? Give two reasons for your answer.
84) Change the legend from magnitude that you
have been analyzing to examine the depth (“km” field) of earthquakes. Do this by double-clicking on the theme name to pull up the
legend editor. Change the field name to
depth, as follows:
Use this new
legend by clicking on Apply.
Your new map
represents the depth under Earth’s surface at which the movement occurred, in
kilometers underneath the surface.
85) Describe the pattern of the depth of the
earthquakes and their distribution across North America.
86) Is there a relationship between magnitude
and depth? Why or why not?
87) What is the relationship between magnitude
to the plate boundaries? Why? You may need a reference for plate
boundaries on a map, in a textbook, or on the Internet.
88) What is the relationship between depth and
the plate boundaries? Why?
89) Are certain
types of plate boundaries associated with certain earthquake magnitudes and
depth? Summarize what you know and can
find out about this topic.
Minimize your GIS
session.
Access the USGS
National Earthquake Information Center by using an Internet browser. This is the site in Golden, Colorado, that
collects seismic information from all over the world.
Select
"Current Worldwide Earthquake List."
90) Examine this list. How many days does
this information cover?
91) Does the number of earthquakes surprise
you? Why or why not?
92) Are you familiar with any of these
earthquakes? Did you hear about any of
them on the radio, the newspaper, or on the Internet?
93) How many earthquakes appear in the
list? [a]
94) How many earthquakes occur each day? Show your work.
95) Examine the information about the list on
the NEIC web site. Does the list
indicate ALL recorded earthquakes, or just the major ones? What is the cutoff criterion?
96) What percentage of earthquakes in the list
occurred in North America? Show how you
determined your answer.
97) Does the pattern of new earthquakes in North
America fit the pattern you have been analyzing using your GIS tools and
methods? Why or why not?
98) Indicate at least three things that you have
learned about earthquakes in North America from this lesson to this point.
99) Indicate at least three things that you have
learned about GIS in this lesson to this point.
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▬▬▬▬ Part 6: Analyzing Recent Earthquakes
Only users who
have a full version of ArcView can continue with this section.
In this part, you
will incorporate the recent earthquakes as recorded on the USGS National
Earthquake Information Center into your GIS so that you can further analyze
them.
On the site:
There are choices
at the end of the current earthquakes list.
Select "comma-delimited earthquake list" to see it in the web
browser window.
Using File, Save
As, save the resulting file that appears in the list as a plain text file
(not HTML, MS Word, or anything else) in an appropriate folder on your
computer named "current.txt" as follows:
Back in your GIS
session, access the project window by going to the Window pull down menu and
selecting the APR file:
