Download volcanoes

A POWERPOINT BY
CHANTEL MONCUR
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A volcano is a mountain that opens downward
to a pool of molten rock below the surface of
the earth.
Volcanic eruptions have been known to knock
down entire forests.
An erupting volcano can trigger tsunamis,
flash floods, earthquakes, mudflows and
rockfalls.
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Most volcanoes are 10,000 to 100,000 years old
Gasses that are emitted from volcanoes are
sometimes really dangerous and can cause
pollution problems.
Magma is called lava after it comes out of a
volcano.
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The biggest known volcano in our solar system
is on Mars. Its name is Olympus Mons and it
measures 600km wide and 21km high.
The word volcano actually comes from the
roman god of fire, Vulcan.
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Mount Vesuvius destroyed the ancient city of
Pompeii in AD79.
Has erupted many times but the most recent
was in 1944.
Mount Vesuvius is considered one of the most
dangerous volcanoes in the world!
There are more than 1500 active volcanoes on the
Earth. We currently know of 80 or more which
are under the oceans. Active volcanoes in the
U.S. are found mainly in Hawaii, Alaska,
California, Oregon and Washington.
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A lahar is a type of mudflow or debris flow
composed of pyroclastic material, rocky debris,
and water.
The material flows down from a volcano,
typically along a river valley. It is very
dangerous because it's consistency and the way
it acts is very much like cement.
It is liquid when it's moving, but when it stops,
it solidifies. This can cause just as much
devastation as lava itself.
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How are volcanoes formed?
Volcanoes are formed when magma from within
the Earth's upper mantle works its way to the
surface. Over time as the volcano continues to
erupt, it will get bigger and bigger.
Why do volcanoes erupt?
The Earth's crust is made up of huge slabs called
plates, which fit together like a jigsaw puzzle.
These plates sometimes move. The friction causes
earthquakes and volcanic eruptions near the edges
of the plates.
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What is the difference between lava and magma?
Magma is liquid rock inside a volcano. Lava is
liquid rock (magma) that flows out of a volcano.
Fresh lava glows red hot to white hot as it flows.
Why does lava take a long time to cool down?
Lava cools slowly because lava is a poor conductor
of heat. Lava flows slow down and thicken as they
harden.
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Volcano Experiment: Here is an experiment on
how to make a soda bottle volcano with
Mentos.
Volcano Experiment: Here is another
experiment on how to make a baking soda
volcano.
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