Animations
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Photograph of the San Andreas fault
by Robert E. Wallace, USGS.
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There's nothing stationary about plate tectonics; motion is its motto. That
said, lithospheric plates do not move at velocities that would wow a crowd of
moviegoers—or middle schoolers. It's true that plate motion can cause rapid
events (think of the major California earthquakes), but none of us live long
enough to see the creeping plate movement leading up to such events. We also
have a viewpoint challenge when it comes to observing lithospheric plates that
are many kilometers thick and located beneath our feet. Animations like those
described below can be just what you need to hook students and to help build
their understanding of plate tectonics. These animations make visible what
students normally can't see. They are short depictions (less than a minute in
duration) of plate motions and the geologic events that they cause. Key
features are labeled in each animation, and most of them include an
introductory paragraph.
A few notes:
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If you are using any of the activities that guide
students in discovering that there are lithospheric plates, save these
animations until after that fact has been learned.
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Because the animations are short and some include two views of the same
tectonic event, their movie control buttons are helpful tools. Encourage
students to use the buttons to play, pause, scroll, and step through the
animations to really digest what they are viewing. Students can hone their
observation skills with these mini-movies, especially if the animations are the
basis for classroom activities like discussions or writing assignments.
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Remind students to consider the amount of real time that's been compressed into
each animation.
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The animations featured here all come from the same source and were developed
to complement a specific textbook; you may use them without the text.
Students see what occurs at each of the three main types of plate boundaries:
transform, convergent, and divergent boundaries. Each of these three animations
has its own set of control buttons. Because there is no introductory paragraph
(only labeled features and arrows in the animations), these animations can
support student engagement in an array of tasks that require students to
observe, analyze, and communicate about what they have viewed. For example, you
might want students to write a short piece in which they compare and contrast
the three types of boundaries. Or students could pair up after viewing the
animations to discuss a set of questions that you provide. MSP full record
What does it take for a continent to grow? Before students interact with this
animation, you might want to ask them if they think that continents can
increase in size, and if so, where do they think that growth happens. Then let
them view this animation to see a terrane attach to a continent at a subduction
zone. Students can research what Earth scientists know about how terranes
originate. MSP full record
Each of the next three animations depicts one of the distinct ways that
volcanoes form. The three together provide a nice body of evidence for plate
tectonics and reinforce the theory's explanations about where and why
geological events occur. If you plan to follow up your students’ study of plate
tectonics with a unit on volcanoes, these animations could serve as a bridge
between the two topics.
This animation shows the volcanic activity that occurs when an oceanic plate
subducts under a continental plate. Students who are already familiar with the
three main categories of plate boundaries should recognize this as a specific
kind of convergent boundary. Consider asking students why the oceanic plate
subducts under the continental plate and not the other way around. MSP full record
If you ask students to imagine a picture of a volcano, how many of them envision
an underwater scene? There's plenty of volcanism under the ocean waters. In
terms of volume, more volcanic rock is produced in the oceans than on land.
This animation reveals what occurs at divergent plate boundaries, most of which
are on the seafloor. To help students place the animation in a real setting,
ask them to locate mid-ocean ridges on a map. You can connect this animation to
a number of important ideas concerning plate tectonics. For example, it can
reinforce the fact that plate edges--where so much geologic activity occurs—are
not always the edges of continents. In the 1960s in particular, data from areas
of seafloor spreading lent significant support to the theory of plate
tectonics. This animation can link with explorations of those data, including
the age of rocks in the ocean and the magnetic reversals captured in them.
MSP full record
The movie control buttons really come in handy here. They let students take in
the visuals and embedded descriptions in two coordinated video clips that
provide different views of the formation of the Hawaiian Islands. Unlike the
animations listed above, this one does not focus on plate interactions. With
that in mind, ask students to consider how the depicted events provide evidence
of plate tectonics. Students can also investigate how scientists determine the
age of islands. The island chain illustrates the continuous nature of plate
movement throughout Earth's history. MSP full record
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Copyright
November 2004 — The Ohio State University. This material is based upon work
supported by the National Science Foundation under Grant No. 0424671. Any
opinions, findings, and conclusions or recommendations expressed in this
material are those of the author(s) and do not necessarily reflect the views of
the National Science Foundation.
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This work is licensed under a
Creative Commons License.
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