Transcript Edible Tectonics

Edible Tectonics
With the vocabulary words, try to match the words to the correct
definition.
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Layer that is thinner than the others and nearly all solid
rock.
This layer is about 750 mi thick and is the hottest layer. It
is solid made up of very hot iron and nickel. High pressure
here keeps these metals from melting.
This layer has both solid and melted parts. The melted, yet
still solid part flows very slowly.
The solid upper layer of the mantle and the crust join to
form this.
This layer is the only liquid layer on Earth. It is about 1400
mi thick. This liquid is extremely hot.
Edible Tectonics
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As you know the Earth’s crust and upper
mantle combine to make the lithosphere.
These plates “float” on the asthenosphere
or middle mantle. As the convection
currents rise and fall, the plates move in a
variety of ways. These ways are known as
boundaries.
Boundary Type
Divergent
Convergent
Subduction
Transform
Guess what it looks like
Edible Milky Way Tectonics
Each of you have 1 fun size milky ways.
We are going to use these to demonstrate
the types of boundaries present that cause
geologic features such as volcanoes,
earthquakes, mountains. trenches, etc.
 1-Take a moment with your team and
come up with an operational definition for
plate tectonics
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Look at one of the fun size candy bars.
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Observe the cross-section of the candy bar.
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Carefully pull the candy-bar apart in half.
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Illustrate this and label it candy-bar cross-section in your
journal.
Illustrate your observations. Label it “pulled apart.”Talk
with your partners; what do you notice?
The candy-bar will be used as a model of Earth.
Identify Characteristics of the candy-bar which
make it suitable to model the layers of the Earth.
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Draw the inside cross-section of the candy-bar and label
what each part could represent.
Divergent Boundaries
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Also called spreading centers
because they are fractures in
the lithosphere where the
plates are moving apart, as in
the Mid-Ocean Ridge system
or rift valleys like the one
running through eastern
Africa. As the plates separate,
pressure on the mantle
directly below decreases. The
decrease in pressure causes
the temperature in that
portion of the mantle to rise
above its melting point. The
small amount of melting
mantle produced rises to the
surface and erupts creating
new crust, as well as
earthquakes and volcanoes.
Diverging Boundaries
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What types of geologic features could be
created by this?
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Now take the candy-bar and gently push it
back together. What happens to the
chocolate?
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Illustrate what the candy-bar looks like now.
Label it “pushed together.”
What type of geologic features could this
make?
Convergent Boundaries
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When two plates with
continental crust at the
leading edge collide,
they buckle and are
pushed upward, creating
towering mountain
ranges like the
Himalayas, the Alps and
the Appalachians. (The
Rockies were not created
by convergent plates.
They were formed by
glaciers.)
Another type 
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Now take the candy bar and force it even
harder together.
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What happens? Illustrate this cross-section
now.
You should notice that the parts pushed hard together
are forced so tightly that one half goes below the
other.
What types of features do you think this makes?
Subduction Boundaries
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Continental crust is thicker than
oceanic crust and considerably
less dense. When dense ocean
crust collides with a continental
crust, the ocean crust bends and
slides under the continental crust.
As it plunges deep into the
mantle the plate going under
dehydrates. The super hot water
coming out of it, causes the
overlying mantle to melt and
create volcanoes. When oceanic
crust on one plate collides with
oceanic crust on another plate,
one plate will slide under the
other. A deep oceanic trench
forms at the boundary. The
molten rock of the plate that went
under rises through the
overriding plate, erupting on the
surface to create volcanic
mountains or chains of volcanic
islands.
How are subduction boundaries similar
to converging boundaries?
These are similar because they are both
being pushed together! 
 However, in subducting boundaries, the
denser crust will bend and slide under the
continental crust. One side goes under
like a submarine! 
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Place both candy-bars at your table and
put them side by side- one in each hand.
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Now gently slide the two bars across each
other.
What happens?
Transform Boundaries
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A place where two plates
slide past each other is
another type of boundary.
These plates catch and
grind causing powerful
earthquakes. The San
Andreas Fault,
responsible for the
devastating earthquakes
in San Francisco and Los
Angeles, is this type of
boundary between the
Pacific Plate and the
North American Plate.
Let’s look at a couple videos!
Basic Boundaries
http://www.wwnorton.com/college/geo/animations/basic_pl
ate_boundaries.htm
 http://www.classzone.com/books/earth_science/terc/conte
nt/visualizations/es0804/es0804page01.cfm?chapter_no=vi
sualization
 Divergent
http://www.wwnorton.com/college/geo/animations/the_pro
cess_of_rifting.htm
 Subducting:
http://www.wwnorton.com/college/geo/animations/the_pro
cess_of_subduction.htm
 Let’s look at all the types. Can you identify them?
http://www.wwnorton.com/college/geo/animations/earth3e
Brainpop-Plate
Tectonics
/04.htm
http://www.brainpop.com/science/earthsystem/platetectonics/
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