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VOLCANOESLauren Dennis, Rebecca Layman, Kyle McGinley,
Stephanie Spears
EARTH’S INTERIOR
Core (inner layer)-temperatures are extremely
high: 3000 degrees Celsius.
Mantle (middle layer)-mainly solid rock, but
there is also a layer of molten rock called magma.
Temperature: 2000 degrees Celsius.
Crust (outer layer)-this is where we live. Includes
ocean, and land.
DIFFERENT PLATES
Eurasian plates, African plate, North American
plate, South American plate, Arctic plate,
Indoaustralian plate, Pacific plate, Nazca plate
Most volcanic eruptions occur along or around
the plate edges
SEA FLOOR SPREADING
This is when the two plates move apart, the rocks
break and form a crack in between the plates.
The magma rises through the cracks and spreads
out along the ocean floor.
As the magma cools, it forms small mountains
called oceanic ridges.
This is a slow and regular process.
STRUCTURE OF A VOLCANO
Vent-opening at the earths surface
Pipe-the passageway of the magma
Crater-the opening at the top of the volcano
Cone-made up of lava, ashes, and cinder (a
fragment of lava) ; sides of the volcano.
TYPES OF VOLCANOES
Composite
Shield
Cinder
Spatter
Complex
DIFFERENT VOLCANOES
http://www.youtube.com/watch?v=DnBggrCdkN0
VOLCANIC ERUPTIONS
They begin when pressure on the magma
chamber forces magma up.
When the magma chamber is completely filled, it
causes different types of eruptions.
One type is described as low water, low silica, and
low flow
Another is low water, high silica, and pasty lava
Another is high water, low silica, and runny lava
Another is high water, high silica, and explosion
VOLCANOES IN THE UNITED STATES
Most volcanoes are found in the western United
States, Hawaii, and Alaska.
RING OF FIRE
The Ring of Fire is a zone of frequent
earthquakes and volcanic eruptions that outlines
the Pacific Ocean
NEGATIVE EFFECTS OF VOLCANOES
They are extremely destructive.
Lava can flow for miles and ash can travel very
far distances as well.
POSITIVE EFFECTS OF VOLCANOES
Volcanoes help enrich soil for farming and in some cases provide reservoirs for the storage of ground water.
The earth's valuable resources are formed in volcanoes. These elements include fluorine, sulfur, zinc, copper, lead, arsenic, tin, molybdenum, uranium, tungsten, silver, mercury, and gold.
Geothermal power is an alternate energy source that is better for the environment and volcanoes provide this to society also.
Volcanoes even help us understand past civilizations and cultures. The lava preserves fossils and artifacts that scientists can learn from.
OUR PHOTOS!
ACKNOWLEDGEMENTS
Mr. Mike Willard, Science Dept. Laboratory
Coordinator – helped us to problem solve the
chemical reaction and necessary ingredients
C. Dianne Phillips, Physical Science Instructor
Content and technical support
NWACC Art Department – gave us clay and
other materials to build the volcano
REFERENCES
http://library.thinkquest.org/17457/english.html
http://pubs.usgs.gov/gip/volcus/page03.html
http://www.umich.edu/~gs265/society/volcanoes.h
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http://www.crystalinks.com/rof.html