Global GIS Lesson:
Exploring North American Earthquakes
By Joseph J. Kerski
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 .
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.
the magnitudes of the earthquakes.
- In what country do you live?
- In what state or region do you live?
- 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.
- Describe the pattern and the number of earthquakes in your country,
state, region, and community.
- 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.
- 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.
- What is the range (minimum and maximum) of earthquakes that you
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:
- Where do most of the large (at least magnitude 6) earthquakes occur?
- 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.
- 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.
- 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
- 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
- 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.