What is it a volcano?
A volcano is like a chimney in the Earth’s crust
(surface) where magma flows out.
In 1883, in Indonesia, a volcano called
Krakatoa erupted at first.
The inside of the Earth is very hot, and
some of the solid rock melts to form hot,
liquid rock called magma.
The hole of the volcano is called vent.
When magma leaves the vent it becomes
The life of a volcano
Inside a volcano
The theory called plate tectonics explains
how volcanoes form.
Some volcanoes form above a hot spot, which is
a very hot place in the mantle.
A volcanic eruption
Contents: gas, dust, water vapour, lava and ash
Gas, dust and
Layers of lava and
Types of volcano
Scientists put volcanoes into three groups:
1. An Active volcano is one that is erupting or
will soon erupt.
2. A Dormant volcano is one that has not
erupted for a long time.
3. An Extinct volcano is one that has not
erupted for more than 10.000 years.
Are in many places in the world, in many
different shapes and sizes.
TYPES OF VOLCANOES:
Fissure volcano, Shield volcano, Dome
volcano, Ash-cinder volcano, Composite
volcano and Caldera volcano.
Rocks and lava
Volcanoes produce lava and rocks we find
on the Earth’s Surface. Magma forms igneous
rocks. These fragments are called tephra.
Liquid lava flows fast and form smooth folds that
look like rope this is called pahoehoe.
When slow, sticky lava gets hard, it forms rocks
with sharp edges; it’s called aa.
Sometimes lava forms long, thing strings like human
are called Pele’s hair.
The floor of the ocean is similar to dry land.
There are flat plains, mountain ridges,
canyons and trenches in the ocean floor.
There are more volcanoes under the ocean
than on the land.
Living with volcanoes
The minerals and chemicals in the lava and ash make
soil fertile so it’s good for farming.
Volcanoes also produce electricity.
This electricity is called geothermal energy
and the people use it.
Special scientists are called volcanologists.
They study volcanoes in different ways. This
helps to learn about the volcano’s history and
to know what it is going to do.
Laura GARRIGA SAGALÉS
Laia GONZÀLEZ TORNER