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|
| Step 1 | Start ArcView.
Open your Africa Add a new view to the project: 
Set the Working Directory to the same directory you selected in Activity 1 to save your work. |
| Step 2 | Rename and Define Your New
View.
Choose Properties from the View pull down menu, and rename the view to "Tsunami Effects in Africa". Select "decimal degrees" from the Map Units pull down list. Select "kilometers" from the Distance Units pull down list. Click on Projection and check to make sure the Category is "Projections of the World" and the Type is "Geographic". Click OK. |
| Step 3 | Add Data to the View.
Add the following themes to the view from your
computer's Africa directory:
Add the following themes to the view from
the same directory as before:
|
| Step 4 | Rename the Themes
Under "View" --> "Properties": Rename the t_source.shp theme to Tsunami
Sources
Save your project! |
| Step 5 | Display the Cities Theme as a Graduated
Symbol
Double-click on the Cities theme to bring
up the Legend Editor.
|
| Step 6 | Display the Tsunami Effects as Bright
Blue Stars
Double-click on the Tsunami Effects theme
to bring up the Legend Editor.
Symbolize the earthquakes with a star. There are two stars--select the star that is filled with green. Change the size to 14. Click on the paintbrush icon to bring up
the Color Palette |
| Step 7 | Change the Colors, Sizes, and Symbols
of the Themes
Change the colors, sizes, and symbols of the themes below:
Select the paint bucket icon. 
and select the upper left (white) box. Click Apply.
In the same manner, Enter the Legend Editor
for the Tsunami Sources theme.
Access the marker symbol |
| Step 8 | Arrange the Themes in the View Window
Arrange the themes in your view window
in the following order:
|
| Step 9 | Display the Themes in the View
Click on the raised box to the left of
the Theme names to make a check mark and see the coverages displayed in
the View window.
You may want to turn off one or more themes in order
to view the distribution of a particular theme. You may need to maximize
or resize the ArcView window and the View window to see the entire
view. |
| Step 10 | Determine the Distance between two Points
One of the tools provided by a GIS is the ability to determine distance on a map by clicking on two different points. To measure the distance between the Tsunami
Effect locations on the northwest coast of Africa, click on the Measure
Distance button
When you move the arrow over the view it should turn into a symbol with
crosshairs. Click once on a point and move the symbol to another point
and click twice.
A display in the lower left corner should appear
giving you the distance between the points. The distance between the two
points should be approximately 534 km. |
| Step 11 |
Create and Print a Layout
Prepare of Layout of Tsunami Effects, Tsunami Sources, Cities and Countries. Arrange the themes in your view window in the following order: Tsunami
Sources
Save your project! |
| Question 1 | Use the Information button 
to name the two cities and the two countries with a population greater
than 2 million that you believe to be most at risk from a tsunami in
Africa. |
| Question 2 | Why do you believe these two cities and two
countries are most at risk? Defend your answer.
|
| Question 3 | What other cities over 2 million in population
have a risk of tsunamis in Africa?
|
| Question 4 | Make the Tsunami Sources theme the active
theme and zoom to the extent of that theme. Examine the source in the Atlantic
Ocean northwest of the coast of Morocco. During what year did it
occur? How far was the earthquake from where the tsunami struck the
shore? |
| Question 5 | If the same earthquake struck today, name all
of the coastal cities in Algeria and Morocco that could be affected. |
| Question 6 | What is the combined population of the coastal
cities in Algeria and Morocco that could be affected? Show your work. |
| Question 7 | Use the Open Theme Table Button
to open both the Tsunami Effects table and the Tsunami Sources table. Arrange
the two tables next to each other so that you can compare the dates in
the two tables.
By comparing the two tables, determine
which Tsunami Sources caused Tsunami Effects in more than one location.
Leave the tables open for the next
question. |
| Question 8 | Which tsunamis actually caused some type
of damage? |
| Question 9 | When an earthquake causes a disturbance
in a lake rather than in the ocean it is called a "seiche". Determine the date and name of the city and country where the Tsunami Effect was a seiche rather than a tsunami.
|
| Question 10 | How do you know that this was a seiche rather than a tsunami?
|
Back
to Africa Lesson Index
U.S. Department of
the Interior
U.S. Geological Survey
Rocky Mountain Mapping Center
URL: http://rockyweb.cr.usgs.gov/outreach/africa/act6.html
Last modified: 1 September 2004
Activity
6:
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in the lower tool bar.