The Theory of Plate Tectonics Interactive Software
To access the software open the Plate Tectonics folder on the desktop, and then
double click on the icon. After a short introductory sequence, you will see the "home
page" that contains 19 clickable topics. Click on Introduction to begin. The program will
take you through the topics successively unless you click on the square button to return to
the home page. Review questions are provided after each topic. These are a good way to
test your comprehension of the topic. If a topic is not clear, you may click on the
backward arrows to reverse direction in the program. Otherwise, click the forward button
when you are ready to move to the next "page". Take turns clicking the buttons and be
sure that each person in the group is ready before you move forward.
Questions
1. Continental Drift
(a.) What is Pangaea and when did it exist?
(b.) List and briefly describe the four lines of evidence that support the idea of
continental drift.
(1)
(2)
(3)
(4)
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When you see the topic Continental Drift and Paleomagnetism, return to the home page
and click on topic 8: Sea-floor spreading.
2. Sea-floor Spreading
(a.) When had technology advanced to the point that detailed maps of the sea floor
could be produced and the global oceanic ridge system was discovered?
(b.) The large continuous mountain ranges called oceanic ridges are prominent seafloor features. Describe the processes that occur at these ridges. Why are the ridges so
important?
3. Plate Tectonics
(a.) Complete the plate identifying exercise to familiarize yourself with the names and
locations of the tectonic plates. What are the names of the plates that make up the
Pacific Ocean?
(b.) What is the difference between the lithosphere and the asthenosphere? How do
they
contribute to plate tectonic processes?
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4. Plate Boundaries
(a.) List below the 3 types of plate boundaries. Briefly describe what kind of motion
occurs at each plate boundary type and provide an example of each.
I.)
ii.)
iii.)
(b.) Volcanoes form at which types of plate boundaries? Why?
5. Testing the Plate Model
What evidence is given here to support the plate tectonic model?
6. Geomagnetic Reversals and Plate Tectonics
(a.) Another piece of evidence that supports the plate tectonic model is described in
this
section. What kind of pattern do scientists observe when they pull instruments
called magnetometers across the sea floor? Draw a picture to explain the pattern.
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(b.) If sea-floor spreading at the East Pacific Ridge is occurring at a rate of 5 cm/yr,
how long does it take to create 100 km (60 miles) of new crust on either side of the
ridge?
7. Plate Tectonics and Earthquakes
(a.) Deep trenches are another prominent sea-floor feature. What plate tectonic process
is occurring at the trenches?
(b.) Earthquakes occur at all types of plate boundaries. However, deep-focus
earthquakes only occur near the trenches. Why?
(c.) How deep are the earthquakes that occur at oceanic ridges?
(d.) Answer the review questions. One of the largest historical earthquakes in the U.S.
was the great 1906 San Francisco earthquake. This earthquake was the result of
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movement along which type of plate boundary (you listed the types in question
4)?
What two plates are interacting at this plate boundary? What is the name of the
boundary?
How deep are the earthquakes that occur along this plate boundary near SFSU?
When you see the topic Hot Spots and Plate Tectonics, return to the home page and click
on topic 19: Plate Tectonics into the Future.
8. Plate Tectonics into the Future
At the rate of 5 cm/yr, how long will it take for Los Angeles to become a suburb of San
Francisco? (Hint: the cities are now about 700 km-425 miles-apart.)
9. Hot Spots and Plate Tectonics
Like earthquakes, most volcanoes form at the edges of plates. To find out how the
Hawaiian Islands formed in the center of a plate, explore topic 17.
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