When
rocks deep inside the mantle melt they form magma. When the magma
rises through the crust it forms a volcano. The magma spews out and
the magma turns into lava. When lava cools it forms new rock over
there area. Lots of the lava cools when it hits the ocean.
Volcanoes erupt in different ways.
When plates collide they form mountains this is because they are on plate
boundaries. Plate boundaries are always moving. This is also
how earthquakes occur.
Volcanoes
can be very dangerous. Lava will melt anything when it touches it.
All of the debris that flies all over is dangerous as well. Volcanoes
that have erupted have destroyed whole civilizations. Those are just
some of the reasons that you should stay away from active volcanoes that
are ready to erupt.