Page 270 - DK Children's Encyclopedia

Volcanoes SEE ALSO

▸ ▸ Earth’s surface
p.84

A volcano is a mountain or crater that forms when melted ▸ ▸ Earthquakes p.85
rock, called magma, breaks through the Earth’s surface. ▸ ▸ Inside Earth
As soon as the magma breaks through, or erupts, from, p.135

a volcano, it is known as lava. Every year around the ▸ ▸ Rock cycle p.213
world, between 50 and 70 volcanoes erupt. ▸ ▸ Rocks and
minerals p.214

Volcanic eruption Gas in the magma can Types of volcano
Volcanoes erupt in different make it blast high into Volcanoes come in all shapes
ways. In some eruptions, lava the sky, forming a lava and sizes. Some are small,
gently flows out or spurts fountain. cone-shaped hills formed in
like a fountain. In other a single eruption. Others are
eruptions, gas, giant mountains built up by
ash, and rocks About many eruptions.
explode out of 80 percent
the volcano. of volcanic
eruptions take
place under
the sea.
Small pieces of
lava fall around
the crater, forming
a cone-shaped Caldera
mountain. Lava flows are slow- The biggest volcanic eruptions
moving rivers of melted leave behind an enormous crater
rock that can bury or known as a caldera. Some craters
destroy everything fill with water and become lakes.
in their path.

Cinder cone
Built of fragments of cooled lava
called cinders, cinder cones are
the smallest and most common
type of volcano.

Stratovolcano
This type of volcano is made up of
layers of ash and lava from many
eruptions. Stratovolcanoes are
steep-sided and cone-shaped.

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