Where Are We Going?
By Jennifer Rogstad
Note to Teacher: I have compiled questions for
students to think about and answer as they explore fantastic animations,
pictures and information on a CD-ROM. The Multimedia
CD-ROM is The Theory of Plate Tectonics by Ed Tarbuck and Fred Lutgens Version 2.1 produced by Tasa
Graphic Arts, Inc. (See ordering info below) By utilizing the CD-ROM,
students have the opportunity to see what is happening with the Earth’s plates
and take-in the information at their own pace (within reason of course!). The Theory of Plate Tectonics has excellent questions at the end of each section
that the student can even print out. However, I really wanted a set of
questions that students could answer as they progress through the CD. My hope
is that this will motivate students to look at, read and analyze each
slide/frame rather than just flip through the CD until they find the answers to
the questions at the end. I recommend that beyond the scope of this lesson you
talk about each piece of evidence for the Theory of Plate Tectonics, look at
several animations (the animations by Dr. Tanya Atwater are wonderful! Check
them out at http://emvc.geol.ucsb.edu/),
and explore the continents on maps. Then, at some point during your unit on
Plate Tectonics, go to the computer lab where students can answer the questions
I have provided below. Oh, and make sure students choose the “Advanced” version on the Table of Contents when
they begin the session. I am not sure how long this set of questions will take
students to complete since I am not teaching Earth Science this year and have
no students to test it out on. I compiled the questions in sections, so you
don’t have to assign them all at once. You can print out the questions for
students or…however you want to use them!
I
created a quick PowerPoint with the same info (but without the questions) and
with a few pictures that I took near the
site
with many more amazing pictures! To check out the pictures I used and others,
visit the web site. Click on the “geology” link. Click on the “Search the USGS”
heading. Then, in the search box, type in “plate tectonics pictures”. Go to the
“Educators page for volcanoes”. Click on “This Dynamic Earth- The Story of
Plate Tectonics”. Choose from the “Contents” selections.
This lesson addresses the
following Grades 9-12 Earth Science Standards:
3a. Students know features
of the ocean floor (magnetic patterns, age, and sea-floor topography) provide
evidence of plate tectonics.
Ordering Information: Obviously, I highly
recommend this CD. Again, it is the Version 2.1 Multimedia CD-ROM The Theory of Plate Tectonics by Ed
Tarbuck and Fred Lutgens and produced by Tasa Graphic Arts, Inc. The CD also
includes animations, pictures and information on Divergent, Convergent &
Transform Fault Boundaries, Testing the Plate Tectonics Model, What Drives
Plate Motions, and Pangaea: Before And After. The Single User cost of the CD is
$59.00 and the Multi User cost is $155.00. (The last time I checked anyway!
Double-check on prices.) You can order by phone:
1-800-293-2725 or by internet: www.TasaGraphicArts.com.
You can also email for more information on purchasing CDs at
info@tasagraphicarts.com.
Where
are we going?
A Look at Plate
Tectonics and the Evidence Behind the Theory
As any good scientist
would do, we'll begin by asking a few questions:
How did the mountains
get there?
What caused the huge
tsunami?
What causes some
volcanoes to erupt while others lay dormant?
These questions arise
when we look around us and question what's going on.
For example: Look at
the picture. This picture was taken near the
This is caused by
movement of the Earth's tectonic plates. The idea that the Earth has plates of
material that are actively moving around and changing the shape of our planet
was not articulated until 1912 by Alfred Wegener in what is now known as the Theory
of Continental Drift. Wegener believed that these plates were once part of one
giant supercontinent, Pangaea, which broke apart and allowed the continents to
“drift.” Since then it has been determined that the continents are not just
“drifting” but rather moving apart due to plate tectonics. Wegener’s theory
was, however, instrumental in paving the way for the Theory of Plate Tectonics.
The Theory of Plate Tectonics, as proposed by William Ewing and Harry Hess,
states that the Earth’s outermost layer is fragmented into a dozen or more
large and small plates that are moving relative to one another as they ride
above the hotter, more mobile material below. (USGS) In this lesson, we will
look at the existing evidence for this theory.
This evidence includes:
Fit of the Continents
Fossils
Rocks
Paleoclimatic
Patterns
Paleomagnetic
Patterns
Sea Floor Topography
This lesson addresses
the following Grades 9-12 Earth Science Standards:
3a. Students know
features of the ocean floor (magnetic patterns, age, and sea-floor topography)
provide evidence of plate tectonics.
Questions
correspond with the Multimedia CD-ROM version 2.1 (Advanced) written by Ed
Tarbuck and Fred Lutgens and published by Tasa Graphic Arts, Inc.
1.
True or
False: The Earth is a static, unchanging planet.
2.
Was the
3.
Was
4.
Earth
Scientists have shown that the ____________ are ____________ fixed.
5.
What
generates earthquakes, volcanoes, mountains and new ocean basins?
6.
What
helps explain the distribution of fossils?
7.
Plate
Tectonics is the name given to the scientific theory that describes what?
8.
On slide
14, what color is what is now known as
9.
The
hypothesis that preceded the theory of Plate Tectonics is known as
____________ ____________.
1.
Who is
credited with the development of the Continental Drift hypothesis? ____________
____________
2.
Wegener
hypothesized that over 200 million years ago there was a ____________ called
____________ meaning “all land.”
3.
Using the
down arrow on the keyboard (slide 19), see how the positions of the continents
have changed over time (at 0° longitude). Was
4.
What 4
pieces of evidence did Wegener and his colleagues collect to support the
Continental Drift hypothesis?
5.
Wegener
thought that ____________ ____________
and ____________ fit together like pieces of a jigsaw puzzle. Why would they
probably not fit together perfectly today?
6.
In what
year did Alfred Wegener publish a picture of the supercontinent in the 4th
edition of The Origins of Continents and Oceans?
7.
Can you
fit together the continental shelves of
8.
When did
Wegener first take the idea of continental drift seriously?
9.
Fossils
of the same ancient ____________ and ____________ were found on widely
separated continents.
10.
Describe
a Cynognathus.
11.
Where
were Cynognathus fossils found?
12.
Describe
a Lystrosaurus.
13.
Where
were Lystrosaurus fossils found?
14.
On which
continents has evidence of the plant Glossopteris been found?
15.
Does
fossil evidence indicate that the Mesosaurus was able to swim to
16.
What 3
ideas were proposed to explain how identical fossils could be found on
continents separated by thousands of kilometers of open ocean?
17.
What was
Wegener’s explanation for this mysterious distribution of fossils?
18.
When
working with a jigsaw puzzle, what are two requirements?
19.
In the
“Continental Drift Puzzle,” rocks must be of similar ____________ and
____________.
20.
Similar 2
billion year old rocks have been found in ____________ and in the
____________ ____________.
21.
The
22.
Between
______ and ______ million years ago, vast ____________ ____________ covered extensive portions of
Earth’s landmasses.
23.
Click on
the shovel in slide 52. Where did evidence of this glaciation come from?
24.
What lies
below these layers?
25.
Where on
the globe is much of the glaciated area found?
26.
Why have
scientists rejected the explanation that the equatorial region was once as cold
as
27.
Click on
the shovel in slide 55 and keep clicking on “forward.” Stop when you come to
the remains of a plant. What are two characteristics of plants that grow in the
tropics?
28.
Click on
“return” and then go forward to slide 56. Today, how do scientists explain the
location of ancient glaciated landscapes as far North as
29.
Was
present-day
30.
One
critic of Wegener’s hypothesis said that the idea “takes considerable ____________
____________ ____________ ____________.”
31.
Go
forward to slide 60. What is the Coast Guard Cutter POLAR STAR?
32.
Explain
why Wegener was incorrect in his proposition that the continents broke through
the ocean floor like an ice breaker cuts through ice?
33.
How much
time passed before most of the scientific community accepted the idea that the
continents had indeed moved?
1.
Why did
people become interested in continental drift in the early 1050’s?
2.
Do the
Earth’s magnetic and rotational poles line up exactly?
3.
Explain
how a compass works.
4.
What is a
“fossil compass”? Give one example.
5.
Give an
example of a mineral with a lot of iron in it.
6.
Where is
the iron-rich basalt flow of the
7.
When lava
with basalt in it cools, what happens to the iron-rich mineral grains?
8.
What is
paleomagnetism?
9.
How does
the present-day North Pole compare with the magnetic pole of 400 mya?
10. Explain
“polar wandering”.
11. What is another possibility for the change in
location of magnetic poles?
12. What explanation best accounts for polar
wandering?
13. So, do some scientists think that the poles
have moved? Or is it the continents that have moved?
14. Are the migration paths of the poles more
similar today or when the continents were together as one supercontinent?
15. What new technology enabled scientists to gain
a better understanding on the ocean floor?
16. How can an echo sounder find out a particular
water depth?
17. What is your answer to the question on slide
118?
18. Look at the data table on slide 121. What is
the depth in meters at point 10?
19. How is a profile of the ocean floor
constructed?
20. Once you plot points 12-22 on slide 123, does
the profile rise at around 2900 km or does it remain flat?
21. What do you notice about the middle of the
profile of the ocean floor from
22. What do we call this rise in seafloor?
23. What was discovered at the middle of this rise
in seafloor?
24. What are 2 characteristics of the oceanic
ridge system?
25. Click inside the box to view the movie on
slide 130. What is happening to the blue oceanic floor?
26. What else was discovered by mapping the ocean
floor?
27. Is the ocean floor relatively young or old?
28. This information was used to create which
hypothesis?
29. What effect do the convection cells in the
mantle have on the seafloor?
30. How is new oceanic crust created?
31. What happens to older parts of the seafloor?
32. So why is the ocean floor so “young”?
IV. Plate Tectonics: The New Paradigm
1.
Plate
tectonics is a theory that includes ideas from which two concepts?
2.
The stiff
lithosphere is made up of the ____________
____________ and the ____________.
3.
The
asthenosphere is located in what layer of the earth?
4.
What
allows the Earth’s rigid outer shell to move?
5.
The
Earth’s plates are part of the ____________.
6.
How many
major lithospheric plates are there? Name one of them.
7.
How is
our knowledge of the plates today different from that of Wegener’s when he
proposed the continental drift hypothesis?
8.
Are there
smaller, intermediate-sized plates?
9.
On which
plate is the West Coast of the
10. Does one plate affect another plate when it
moves?
11. Why does most of the earthquake activity,
volcanism and mountain building take place at plate boundaries?
12. List the 3 types of plate boundaries.
13. What is the symbol for a divergent boundary?
14. Which plate is growing larger?
15. Which plate is shrinking?
16. Which plate may eventually split into 2 plates
as a result of a divergent boundary?