Download Why do Volcanoes erupt? A volcano is a mountain that opens

Why do Volcanoes erupt?
A volcano is a mountain that opens downward to a pool of molten rock below the surface of the earth. The large masses build up
over time through eruptions in the earth’s upper mantle. They look like large mountains but are far more dangerous.
.How are volcanoes formed?
Volcanoes are formed when magma from
within the Earth's upper mantle works its
way to the surface. At the surface, it
erupts to form lava flow and ash
deposits.
Over time as the volcano continues to
erupt
it gets bigger and bigger.
What happens below the surface?
The Earth's crust is made up of huge slabs called plates, which fit
together like a jigsaw puzzle. These plates sometimes move, whenever
they do magma from the earth’s upper mantle seeps through the gaps into
the magma chamber building pressure below.
Why does this cause an eruption?
Eventually this high pressure causes friction
which in turn creates volcanic eruptions near
the edges of the plates. The theory that
explains this process is called plate tectonics.
What damage can an eruption cause?
What happens to the magma?
Eruptions can cause lateral blasts, lava flows,
hot ash flows, mudslides, avalanches, falling
ash and floods. Volcano eruptions have been
known to knock down entire forests.
The magma is forced up the conduit. As it reaches the
surface it shoots up through the opening spilling over
or filling the air with fragments. Did you know that
when the magma reaches the surface it is called lava?
There are more than 1500 active volcanoes on the Earth. Most are above land although we currently know of 80 or more which are
under the oceans. Active volcanoes in America are found mainly in Hawaii, Alaska, California, Oregon and Washington.