2. Volcanoes
• A volcano is an opening
or rupture, in the surface
or crust of the Earth or a
planetary mass object,
which allows hot lava,
volcanic ash and gases to
escape from the magma
chamber below the
surface.
Highlights of Arenal: one of the 10
most active volcanoes in the world
3. How volcanoes are formed
• Deep inside Earth,
between the molten
iron core and the thin
crust at the surface,
there is a solid body of
rock called mantle.
When rock from the
mantle melts, moves
to the surface through
the crust, and releases
pent-up gasses,
volcanoes erupt.
4. Continuation…
• Extremely high
temperature and
pressure cause the rock
to melt and become
liquid rock or magma.
When a large body of
magma has formed, it
rises through and the
denser rock layers
toward Earth’s surface.
Magma that has reached
the surface is called lava.
5. Where volcanoes are located
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.
7. Effects of volcanoes
• The effect an eruption will
have on a nearby city could
vary from none at all to
catastrophic. For
example, atmospheric
conditions might carry ash
away from the city or
topography might direct
lahars and pyroclastic flows to
unpopulated areas. In
contrast, under certain
atmospheric, eruption and/or
topographic
conditions, lahars, pyroclastic
flows, and/or ash fall could
enter the city causing death
and destruction
8. Benefits
• many of the volcanic
materials have important
industrial and chemical
uses.
• A natural glass that comes
from lava is pumice, it is
widely used for grinding
and polishing metals,
stones, and other
materials. When lava dries
and makes a rock form it is
commonly used in building
roads.
• Volcanic ash that has been
weathered greatly
improves soil fertility
• Volcanic material has a
source of precious gems,
Opal. It also has a source
for metals, gold, silver,
molybdenum, copper, zinc,
lead, and mercury. When
volcanoes erupt, the lava
releases some healthy
gases, including carbon
dioxide and
hydrogen. When oxygen
mixes with hydrogen, it
creates water vapor and
that begins the water cycle.
9. Volcanic Issues
• What happens to the
towns around a volcano
when it erupts depends
on many things. It
depends of the size and
type of eruption and the
size and location of the
town. A few examples
might help. The 1984
eruption of Mauna Loa
in Hawaii sent lava
towards Hilo but the
eruption stopped before
the flows reached the
town.
• The 1973 eruption
of Heimaey in Iceland
buried much of the
nearby town of Heimaey
under lava and cinder.
The 1960 eruption of
Kilauea in Hawaii buried
all of the nearby town of
Kapoho under lava and
cinder
10.
11.
12. Solution
• There is not a way to
stop volcanoes from
erupting, making their
no solution for
volcanoes. However you
can do many things to
protect yourself and your
family from the dangers
a volcanic eruption can
cause.
• The best way to protect
yourself is to follow the
advice of local officials.
They can help and
provide you with
information in ways to
prepare for a volcanic
eruption, and if
necessary, on how to
evacuate or take shelter
where you are, according
to the CDC (Centers for
Disease Control and
Prevention).
13. Sources
•
• Learner, Annenberg. “Volcanoes. Interactivities. Annenberg Learner Acitivies,
2013. Web. 14 Oct. 2013 <http://www.learner.org/interactives/volcanoes/>
•
• Volcano World | Your World Is Erupting." Volcano World | Your World Is Erupting.
Oregon Space Grant Consortium, n.d. Web. 14 Oct. 2013.
•
• Volcano Hazards Program." Volcano Hazards Program. U.S. Department of the
Interior, Oct.-Nov. 2013. Web. 14 Oct. 2013.
• <http://Volcanoes.com>
•
• "Volcano Hazards Program." Volcano Hazards Program. U.S. Department of the
Interior, Oct.-Nov. 2013. Web. 14 Oct. 2013.
• <http://en.wikipedia.org/wiki/Volcano>
•
• Weston, Meg. "Volcano Photos, Information and Stories." Volcano Photos,
Information and Stories. SiteGround, 17 Apr. 2013. Web. 14 Oct. 2013.
