Transcript Volcano: Creator or Destroyer?

Lesson Plan/EDSE 401
Emily Marshall
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Review theories and terms:
 Plate Tectonic Theory
 Relevant Plate Boundaries
 Divergent vs. Convergent
 Subduction Zone
 Show movie clips
 Show videos of explosive and extrusive flows
 Does a volcano create or destroy?
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What does a volcanic eruption look like?
What do we do when/if we were to experience
one?
Is it dramatic? Does it explode and destroy
homes and hillsides or take lives? Can a
person survive a volcanic eruption?
Where do they happen? Only in far away exotic
locations like Hawaii and the Philippines? Can
they be anywhere?
 Ring of Fire handout
 Plate tectonics
 Pacific Plate
 Subduction Zones
 Viscosity
 Types of Volcanoes
 Shield
 Hawaii, India
 Effusive
 Cone shaped
 Philippines, Japan, El Salvador
 Explosive/pyroclastic flow
 Hot Spot
 Hawaii
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Most volcanic activity takes place
along the boundaries of the Pacific
Plate
Most of these volcanoes are created
in a subduction zone. This is an area
where one plate is dragged
underneath the other and a chain of
volcanoes forms along the coastline.
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There are two kinds of volcanoes:
 Shield volcanoes
 Cone shaped volcanoes
 Draw me a picture!
They are named for the way they are
shaped.
The way they are shaped is dependent
upon the way the lava that makes them
flows.
The way lava flows depends upon it’s
VISCOSITY.
Viscous = sticky/resistant to flow
Tell me some fluids that are more and less
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How VISCOUS the lava is also
determines how the volcano behaves
when the lava comes out.
There are two ways lava can flow:
 Explosive (explosions!) – highly viscous
 Effusive (blurbling pancake batter type
flow) – less viscous
This gets us back to shape…let’s take a
look at some examples:
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A’a
– Rough, jagged surface
– Higher viscosity
• Pahoehoe
– Smooth, ropy surface
– Lower viscosity
 Pyroclasts
(hot fragments) and tephra (ash)
Ave. Particle Size
Pyroclast/Tephra
>64 mm
Bomb/Blocks
24-64 mm (walnut)
Lapilli
2-24 mm (pea)
Cinder
<2 mm
ash
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Make your own diagram for one of the
two kinds of volcanoes (shield or cone)
that also tells where this type of
volcano might be found in the world
and whether or not it would more likely
be found near a subduction zone or a
hot spot.
Then we’re going to share them!