A volcano is a mountain that erupts, ejecting lava, rock fragments, gases, and vapor from the earth's crust. Volcanoes erupt due to differences in density that cause magma to rise toward the surface. An eruption occurs when pressure in the magma chamber forces magma up through the conduit and out of the vent. Volcanoes are caused by magma rising to the earth's surface, where gas bubbles form and build pressure until the volcano explodes.

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
Volcanoes happen when magma rises to the
surface of the earth, which causes bubbles
of gas to appear in it. The gas can cause
pressure to build up in the mountain, that’s
when it explodes.

6. Pictures of exploding volcanoes