Burst of Fire

The ground rumbles. Hot liquid, ash
ash
PAUL SOUDERS—GETTY IMAGES
the soft powder that remains after something has burned
(noun)
The volcano pushed clouds of ash into the air.
, and rocks shoot out of a mountaintop. The air is filled with smoke. These are the sights and sounds of an erupting
erupt
PETER CADE—GETTY IMAGES
to burst out; to explode
(verb)
The audience erupts with laughter.
volcano.

Hot lava pours out of a volcano in Iceland on March 21.
AANADOLU AGENCY/GETTY IMAGESA volcano is a kind of mountain. The mountain has an opening at the top. The opening allows hot liquid to escape from the Earth’s crust. (See “A Closer Look.”)
There are different types of volcanoes. Some are active
active
JOHANN K JOHANNSSON—GETTY IMAGES
capable of producing action or movement; likely to erupt
(adjective)
Most of the island's volcanoes are active.
. They can erupt at any time. Others are dormant. They have not erupted in a while. Extinct volcanoes no longer erupt and are not a threat.

Mount Taranaki is in New Zealand. It is dormant. It last erupted in 1775.
ISTOCKPHOTO/GETTY IMAGESVolcanologists are scientists. They study volcanoes. They predict when an eruption will happen. Volcanologists use measuring instruments to check on a volcano’s rumblings. They can warn people of eruptions. Volcanologists can save lives.

A volcanologist works near the Bardabunga volcano. It is in Iceland.
THE IMAGE BANK UNRELEASED/GETTY IMAGESHeating Up
Volcanoes can be dangerous. When one is ready to erupt, people must evacuate for safety. But there are benefits to these flaming mountains. They create new land. The Hawaiian Islands were formed by eruptions.
Volcanoes can also benefit the planet. When a volcano explodes, it releases dust. This can block sunlight and help cool the planet. And a volcano’s ash can be healthy for plants. It adds minerals to soil.
Did you know that people use volcanic heat as a source of energy? The energy powers things in a natural way.
A Closer Look

Magma is hot liquid rock. It bubbles deep underground. This leads to a buildup of pressure. Burning liquid is then forced to the surface of the Earth. Boom! Magma blasts through a vent inside the mountain. The volcano erupts.
Lava
lava
WESTEND61—GETTY IMAGES
hot semiliquid rock that flows from a volcano
(noun)
Lava burst out of the mountain.
is the hot liquid rock that erupts out of a volcano. Volcanoes can also spew ash and rock.