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Practice Problems
Problem W9.1. Plotting Recent Earthquakes. (Note: This is a long-term project,
spanning several weeks.) Earthquakes occur daily. Most are minor or occur in remote
areas, and thus don’t make the news. But some are either large in scale or strike
populated areas, or both. In this problem, you’ll visit Web sites to learn about recent
quakes—and volcanoes, while we are at it—and plot their locations on a world map.
Then you will study the patterns on the map and draw conclusions.
Procedure
1. Obtain a world map on which you can write. It may be available from your bookstore,
photocopied, or printed from the Internet—for example:
www.lib.utexas.edu/Libs/PCL/Map_collection/world_maps/World_pol98.jpg
2. Find Web sites that display recent earthquake and volcano data. Here are some
possibilities availability at the time this site was last updated (your instructor
may recommend others, and you may discover others):
• The Discovery Channel:
www.discovery.com/news/earthalert/earthalert.html
• Recent natural hazards news:
www.eqe.com/
• NGDC natural hazards data:
www.ngdc.noaa.gov/seg/hazard/
• Natural Hazards Mitigation Group, University of Geneva:
www.unige.ch/hazards/
• NASA Natural Disasters Reference Database:
ltpwww.gsfc.nasa.gov/ndrd
Also, here are some sites you might try searching for recent earthquakes:
• www.google.com
• www.nlsearch.com
• www.altavista.com
3. Transfer the earthquake information from the articles you find onto your world map.
Use a dot to represent each earthquake location.
4. Do the same for any volcanic eruptions that occurred during the week, using a triangle
symbol.
(Note: Your data will be very biased, largely ignoring the 71% of the planet that is
covered by water, where many quakes occur. However, you will learn much from this
exercise!)
4. You will be working on this project over several weeks, so keep your materials handy.
5. Continue transferring information to the figure week by week. Your instructor
will indicate when you have gathered enough data.
6. Using a red pencil, mark on your map locations where one or more volcanoes erupted
during the time you have been working on this project. Using a blue pencil, shade in any
bands or zones that have experienced multiple earthquakes.
7. Referring to your textbook, study maps that show the distribution of tectonic plates
worldwide.
WQ9.1. What kind of plate boundaries are associated with the earthquakes your have
recorded?
WQ9.2. What kind of plate boundaries are associated with the volcanic eruptions you
have recorded?
WQ9.3. What place on Earth has experienced the most earthquakes during your project?
WQ9.4. What place on Earth has experienced the most volcanic eruptions during your
project?
WQ9.5. What are the names of the tectonic plates at (or very near) the two places in the
preceding two questions?
WQ9.6. During your study, did any volcanic eruptions occur that appear unrelated to
plate boundaries?
WQ9.7. In general, do the locations of your earthquake and volcanic eruption records fit
well with plate tectonic theory?
Problem W9.2. The Hawaiian Islands. Study Figure WS9.1. Note the names of each
island. Study the ages of the points shown (millions of years), looking for a trend.
Figure WS9.1 The Hawaiian Islands. Rock ages are shown in millions of years.
WQ9.8. When tourists from North America visit Hawaii, they fly into the airport at
Honolulu. Most never leave the island of their arrival (Oahu). Geologists, however, need
to visit the Big Island because it has the active volcanoes. Its name is _______.
WQ9.9. Referring to Figure WS9.1, complete Table 9.1.
Table 9.1 Ages and distances for Hawaiian Islands.
Island
Ages of rocks (million
years). List ALL shown
on map. Use 0 for age of
active volcanoes.
Average age of rock
samples shown on
each island (million
years)
Distance from
center of island to
center of Hawaii
(“Big Island”) km)
Niihau
Kauai
Oahu
Molokai
Lanai
Maui
Kahoolawe
Hawaii
0
WQ9.10. On Figure WS9.2, graph the values for the last two columns of Table 9.1.
Make the vertical axis “average age of rock samples” and the horizontal axis “distance
between island centers.”
Figure WS9.2 Graph of average rock ages and distance between island
centers.