The ground rumbles. Hot liquid, ash , and rocks shoot out of a mountaintop. The air is filled with smoke. These are the sights and sounds of an erupting volcano.
A 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 . 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.
Volcanologists 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.
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 is the hot liquid rock that erupts out of a volcano. Volcanoes can also spew ash and rock.