Why do volcanoes erupt?
● A volcano is a mountain that opens downward to a pool of molten rock below the
The surface of the earth. When pressure builds up, eruptions occur. Gases and rock
shoot up through the opening and spill over or fill the air with lava fragments.
● An erupting volcano can trigger tsunamis, flash floods, earthquakes, mudflows
● The Earth’s crust is made up of huge slabs called plates, which fit together like a
jigsaw puzzle. These plates sometimes move. The friction causes earthquakes
and volcanic eruptions near the edges of the plates. The theory that explains this
The process is called plate tectonics.
● There are more than 1500 active volcanoes on the Earth. We currently know of
80 or more which are under the oceans.