A Lesson about

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A Lesson about
Volcanoes
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WHAT ARE
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(No Transcript)
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A volcano is an opening exposed on the earths
surface where volcanic material (or magmamolten
rock) is emitted. The volcanoes cone-shaped
structure is build by the accumulation of lava
around its summit. There are many types of
volcanoes. Here are some examples below that
demonstrate the various shapes and sizes.
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Volcanoes are all shapes and sizes, as weve
seen earlier. Did you know they can be flat as
well? Yes, volcanoes that are newly formed are
flat. The build-up of lava over a long period of
time is what creates the cone-like shape.
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Question Are volcanoes only on land? Can
volcanoes exist under water like in the ocean?
Take a few minutes and write your thoughts in
your science journal. Then discuss with a partner.
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So, can volcanoes exist in the ocean? YES! As you
can see, volcanoes exist on land AND in the
ocean. Now, how do you think volcanoes are
formed?
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Volcanoes occur because the Earths crust is
broken into plates that resemble a jigsaw puzzle.
There are 16 major plates. These rigid plates
float on a softer layer of rock in the Earths
mantle. As the plates move about they push
together or pull apart. Most volcanoes occur near
the edges of these plates. When plates push
together, one plate slides beneath the other.
This is called a subduction zone. When the
plunging plate gets deep enough inside the
mantle, some of the rock on the overlying plate
melts and forms magma that can move upward and
erupt at the Earths surface. Some volcanoes can
occur in the middle of plates at areas called
hotspotsplaces where magma melts through the
plate and erupts.
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Why do volcanoes erupt? Deep within the Earth it
is so hot that some rocks slowly melt and become
a thick flowing substance called magma. Because
it is lighter than the solid rock around it,
magma rises and collects in magma chambers.
Eventually some of the magma pushes through vents
and fissures in the Earth's surface. A volcanic
eruption occurs! Magma that has erupted is called
lava.
The volcano erupts!
Hot magma rises to the surface
Deep in the Earths core is where magma is formed
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LAVA
What is lava? Lava is the magma that has risen to
the surface and is expelled by the volcano. Below
are some different types of lava.
Aa lava
Block lava
Pahoehoe
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Lets Review!

• What are volcanoes?
• 2. Why do volcanoes erupt?
• 3. What is magma?
• 4. What makes a volcano?
• 5. Where do volcanoes exist?
• 6. What is lava?
• 7. What are some types of lava?
• 8. Now

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Lets draw our own volcano!!
Arts and crafts activity. Draw your own picture
of a volcano and write a story about it!
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Volcano activity!
Now it's time to make a volcano right here in
class! WOW!
Science lesson! Create a volcano right in your
own classroom!
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I sure hope you have enjoyed this wonderful and
exciting lesson about volcanoes! Please ask your
teacher to press PLAY on the VCR to watch a great
movie about volcanoes and see some beautiful
pictures of real live volcanoes!