Why do some volcanoes explode?

The Birth of Rocks Unit

Lesson 2 of 5

Volcanoes & Rock Cycle

Lesson narration:
English
Spanish

Discuss:

Here are some examples of each kind of volcano. What do you notice about the shape?

Discuss:

Here are a couple of rocks collected from each type of volcano. What do you notice?

Vocabulary

rock

1 of 10

a solid natural material that is found on and under the surface of the Earth

volcano

2 of 10

a high area of land with an opening where lava flows or explodes out from

erupt

3 of 10

when lava quickly comes out of a volcano

lava

4 of 10

liquid rock that flows or explodes from a volcano

cone volcano

5 of 10

a volcano with slow-flowing, thick lava that usually erupts with an explosion

shield volcano

6 of 10

a volcano with fast-flowing, thin lava that does not usually erupt with an explosion

basalt

7 of 10

a type of rock formed when thin, fast-moving lava cools and is usually very dark in color

felsite

8 of 10

a type of rock formed when thick, slow-moving lava cools and is usually light in color

experiment

9 of 10

a test used to discover new information about a question

model

10 of 10

a pretend version of something that scientists use when the real thing is too big, small, or complicated to work with

🎉 That’s it for this lesson! How did it go?

Activity Prep

In this lesson, students will investigate how differences in lava types explain differences in the shape and eruption patterns among volcanoes. In the activity, Bubble Trouble, students compare two different types of "lava" -- thin and thick. They use this information to figure out why volcanoes have different shapes and how the type of lava explains why some volcanoes explode.

Prepare the "Lava"

To prepare the “lava,” you will need water, flour, a 1-gallon Ziploc bag (or large mixing bowl), measuring cups, scissors, and (optional) red food coloring.

For thin lava, use plain water. You can optionally add a drop or two of red food coloring to make it look more like lava. A few cups of water will be enough for about 30 students (15 pairs).

To make thick lava, mix up the flour with water and (optional) red food coloring. You can also mix your lava in a mixing bowl. This should make enough thick lava for about 30 students (15 pairs).

Fill Cups with “Lava”

Fill half of the cups about halfway with the “thin lava.” Fill the other half of the cups about halfway with the “thick lava.”

4-ESS1-1 Identify evidence from patterns in rock formations and fossils in rock layers to support an explanation for changes in a landscape over time.