Volcanoes are mountains that erupt due to pressure from magma below the Earth's crust. Magma is less dense than the surrounding rock, so it rises toward the surface. When the pressure in the magma chamber becomes too great, the magma explodes through the vent, causing an eruption. During an eruption, lava, rock fragments, gases, and vapor are released from the volcano.

1. Volcano PowerPoint
By: Brody Snook

2. What is a volcano?
a mountain or hill, typically conical, having
a crater or vent through which lava, rock
fragments, hot vapor, and gas are being or
have been erupted from the earth's crust.

3. Why do volcanoes erupt
Volcanoes erupt because of density and
pressure. The lower density of the magma
relative to the surrounding rocks causes it
to rise (like air bubbles in syrup). It will rise
to the surface or to a depth that is
determined by the density of the magma
and the weight of the rocks above it.

4. What happens when a volcano erupts
An eruption begins when pressure on
magma chamber forces magma up through
the conduit and out the volcanos vents,
when the magma chamber has been
completely filled it blows out of the
volcanos vent.

5. What causes a volcano