Volcanoes

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Volcanoes
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What is a volcano?

• An opening in the Earth that erupts gases, ash,
  and lava. http//www.youtube.com/watch?vxExdEXOaA
  9A

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Mountains form when layers of lava, ash, and
other materials build up around these openings.
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How are volcanoes formed?
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Convergent volcanoes
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• At convergent boundaries, one plate subducts
  (sinks) under the other, the plate melts and
  magma is forced to the surface.
• These volcanoes have the most violent eruptions
• http//www.classzone.com/books/earth_science/terc/
  content/visualizations/es0902/es0902page01.cfm?cha
  pter_novisualization

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Divergent volcanoes
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• At divergent boundaries, plates move apart and
  magma rises to the surface.
• Also known as seafloor spreading.
• These eruptions are not as violent
• http//www.classzone.com/books/earth_science/terc/
  content/visualizations/es0903/es0903page01.cfm?cha
  pter_novisualization

http//www.youtube.com/watch?vy3YNpzZWbmU Lava
in the water
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Hot Spot
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Hot Spots

• Form in the middle of plates.
• As the plate moves, new volcanoes are created.

http//www.youtube.com/watch?vAhSaE0omw9o
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• When the plate moves, the older volcanoes lose
  their magma source and are now dormant (inactive)

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• http//www.classzone.com/books/earth_science/terc/
  content/visualizations/es0904/es0904page01.cfm?cha
  pter_novisualization

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Iceland

• Divergent

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Geothermal Activity on Iceland
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Surtsey
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Natural geothermal pools
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Geysers and mud pots
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Hawaii

• Hot Spot

http//www.youtube.com/watch?vbYv6V5EJAKc
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(No Transcript)
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Hot Spot Locations
http//mms.nps.gov/yell/ofvec/exhibits/eruption/vo
lcanoes/hotspot3.htm
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Soufriere Hills in Montserrat

• Convergent

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If the Pacific Plate stops moving, what will
happed to the Big Island of Hawaii?
X
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It will just keep getting bigger!
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What destruction can volcanoes cause?
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Block roadways
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Collapse buildings
www.maps.google.com
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Lahars

• Mudslides created by volcanic eruption
• Heat from volcano melts glaciers on mountain
• Will usually take out everything in its path

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Can cause lung disease in animals and humans
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Ring of Fire
-a chain of convergent volcanoes found circling
the Pacific Ocean
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http//www.classzone.com/books/earth_science/terc/
content/investigations/es0810/es0810page01.cfm?cha
pter_noinvestigation How fast do plates move
computer investigation
http//www.youtube.com/watch?vbgRnVhbfIKQfeature
related Mount st helens
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Volcano Review
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Where do we find most volcanoes?

• Near plate boundaries

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What are the three types of volcanoes?

• Convergent, divergent, and hot spot

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What and where is the Ring of Fire

• A chain of volcanoes circling the Pacific Ocean