Read About Volcanoes
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A volcano is a mountain that has an opening at the top called a crater.
Molten rock inside a volcano is called magma.
A volcano is a mountain that has an opening at the top called a crater. This opening travels deep into Earth, where there is molten, or melted, rock.
When a volcano erupts, molten rock and ash are pushed out of the crater. Molten rock inside a volcano is called magma. When molten rock flows outside of a volcano, it is called lava. When the lava cools, it becomes solid rock.
Lava is much, much hotter than boiling water and it cools slowly. Sometimes it can take more than a year for lava to cool completely.
There are three different types of volcanoes:
An active volcano is one that erupted recently and might erupt again soon.
A dormant volcano is one that has not erupted for a long time, but it might erupt again soon.
An extinct volcano is one that erupted thousands of years ago and will not erupt again.
Volcanoes are found all over Earth. There are even volcanoes under the oceans. Today, there are more than 500 active volcanoes in the world. Most of these volcanoes are on land next to the Pacific Ocean.
Did You Know?
The tallest volcano we know about is not on Earth. You will have to travel to Mars to see the volcano. This giant volcano is 25 km tall!
To learn more about volcanoes, watch the video by National Geographic on Youtube.
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