Volcanoes

What is a volcano?

• An opening in the Earth that erupts gases, ash, and lava. http://www.youtube.com/watch?v=xExdEXOaA9A

Mountains form when layers of lava, ash, and other materials build up

around these openings.

How are volcanoes formed?

Convergent/Destructive volcanoes

• At convergent/destructive 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?chapter_no=visualization

Divergent/Constructive volcanoes

• At divergent/constructive 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?chapter_no=visualization

Hot Spot

Hot Spots• Form in the middle of plates.

• As the plate moves, new volcanoes are created.

• When the plate moves, the older volcanoes lose their magma source and are now dormant (inactive)

•http://www.classzone.com/books/earth_science/terc/content/visualizations/es0904/es0904page01.cfm?chapter_no=visualization

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Iceland• Divergent

Geothermal Activity on Iceland

Surtsey

Natural geothermal pools

Geysers and mud pots

Hawaii• Hot Spot http://www.youtube.com/watch?

v=bYv6V5EJAKc

Hot Spot Locations

http://mms.nps.gov/yell/ofvec/exhibits/eruption/volcanoes/hotspot3.htm

Soufriere Hills in Montserrat

• Convergent

If the Pacific Plate stops moving, what will happed to the Big Island of

Hawaii?

X

It will just keep getting bigger!

What destruction can volcanoes cause?

Block roadways

www.maps.google.com

Collapse buildings

LaharsLahars• Mudslides created by

volcanic eruption

• Heat from volcano melts glaciers on mountain

• Will usually take out everything in its path

Can cause lung disease in animals and humans

Ring of Fire -a chain of convergent volcanoes found circling the Pacific Ocean

http://www.classzone.com/books/earth_science/terc/content/investigations/es0810/es0810page01.cfm?chapter_no=investigationHow fast do plates move computer investigation

http://www.youtube.com/watch?v=-H_HZVY1tT4

Volcano Review

Where do we find most volcanoes?

• Near plate boundaries

What are the three types of volcanoes?

• Convergent, divergent, and hot spot

What and where is the Ring of Fire

• A chain of volcanoes circling the Pacific Ocean