Power of Eruptions
Understand that volcanic eruptions can send out lava and ash and can change the land by removing material or adding new rock
What a learner can do afterwards
- Describe what can happen during a large, explosive eruption
- Give examples of how an eruption changes the area around a volcano
- Compare the landscape before and after an eruption using pictures
1 · Read
Some volcanic eruptions are big and loud. They can throw lava and ash into the air. Lava is hot melted rock. Ash is made of tiny pieces of rock. Other eruptions send lava flowing over the ground without a big explosion. Both kinds can change the land.
Mount St. Helens once had a high peak and wooded slopes. During its big eruption, a huge landslide removed part of its north side. Afterward, the mountain had a lower peak and a large crater. Ash covered nearby land and reached towns far away.
An eruption can add land too. Lava cools and becomes hard rock. More lava can flow over that rock and cool. Over time, the new rock can build hills or islands.
Compare pictures of the same place before and after an eruption. Look for fresh ash, new rock, or a change in the mountain's shape. Pictures of two different volcanoes cannot show how one place changed.
An eruption is powerful and can change the land in big ways.
Readings and flashcards written for this dataset, using volcano references for facts and design ideas rather than their wording.
More to read
Follow a lava flow
Follow these changes in a volcano video: lava comes out, spreads over ground and cools. The cooled flow becomes solid rock.
The lava need not shoot high into the air. Some eruptions have flowing lava without a big explosion. A slow-moving flow is still hot melted rock. Its speed does not make it safe to approach.
Afterward, the new rock can cover ground that had grass or trees before.
More flows, more rock
One cooled lava flow leaves rock behind. Another flow may later cover part of it and leave more rock. The land can grow as this happens again and again.
A hill or island can gain new rock this way. Compare views of the same place at different times. Look at where the land ends and how high it rises. The change may come from many flows rather than one big blast.
2 · Watch
Take it off screen
Where it sits
Learn first
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Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.