Transcript volcano - Madison County Schools

Bellringer
Create an explanation that correlates plate
tectonics, earthquakes, AND volcanoes.
Volcanoes and Plate
Tectonics
Notes
Volcanoes and Plate
Boundaries
• A volcano is a weak spot in the crust
where melted material comes to the
surface. The melted material is called
magma. Magma rises to the surface
because it is less dense than solid rock.
Volcanoes and Plate
Boundaries
• Most volcanoes happen at either a convergent
plate boundary or a divergent plate boundary.
• Where plates pull apart, magma eventually
rises and pours out of cracks in the crust.
• Where plates push together, the denser plate
subducts into the mantle. Some of the sinking
plate melts and forms magma. The magma
rises and pours out of cracks that forms along
the surface.
Divergent Volcanism
Click to play animation
Convergent Volcanism
Click to play animation
Volcanoes and Plate
Boundaries
• Once magma reaches the surface, it is
called lava. As lava cools, it forms solid
rock.
• Lava can build up to form mountains.
When the mountains are on the ocean
floor, islands form if the mountains
breach the water’s surface.
Hot Spot Volcanoes
• A hot spot is a place where material
rises from deep in the mantle. The
material forms magma.
• If the magma breaks through the crust, a
volcano forms. How spot volcanoes on
the ocean floor can become islands. This
is how the Hawai’ian Islands formed. As
the Pacific Plate continues to move, the
hot spot remains stationary, continuing to
punch up through the crust.
http://www.wiley.com/college/strahler/0471480533/ani
mations/ch14_animations/hot_spot.html
Oldest Islands
now Seamounts
Plate Mov’t over
millions of years
Newest Islands
Hot Spot Location
Hot Spot Volcanoes
• Some hot spots are under the middle of
plates, far from plate boundaries. For
example, there is a hot spot under the
North American Plate at Yellowstone
National Park in Wyoming.