Last updated: November 21, 2023
Lesson Plan
Types of Volcanoes
- Grade Level:
- Upper Elementary: Third Grade through Fifth Grade
- Subject:
- Science
- Lesson Duration:
- 30 Minutes
- State Standards:
- Colorado Academic Standards for Science: 4th grade;
3.3.b - Plate Tectonics and Large-Scale System Interactions: The locations of mountain ranges, deep ocean trenches, ocean floor structures, earthquakes and volcanoes occur in patterns. - Thinking Skills:
- Understanding: Understand the main idea of material heard, viewed, or read. Interpret or summarize the ideas in own words. Analyzing: Break down a concept or idea into parts and show the relationships among the parts.
Essential Question
Why do certain types of volcanoes have different types of eruptions?
Objective
Students will learn about four types of volcanoes: lava dome, shield volcano, conical composite (stratovolcano), and cinder cone volcanoes. Each of these volcanoes has different types of eruptions based on magmatic composition and gas content. A simple lava lamp activity is used to illustrate how gases move through liquids, by discussing concepts such as density and viscosity.
Background
Volcanoes are openings called vents that allow for lava, rock fragments or debris, and steam to escape onto the earth's surface. Magma is molten rock beneath the earth's surface that is lighter than the surrounding rock and is able to rise to the surface by its buoyancy and gas pressure within magma.
The volcano vent can be visible as a crater or bowl-shaped depression at the top of the volcano. This vent connects to the magma chamber through various cracks or side vents, which allows for a continuous supply of magma to get erupted until there's no longer any magma left. Erupted lava slowly accumulates and builds up the volcano and surrounding volcanic terrain. As more material is erupted, the volcano builds up until it's unstable and collapses on itself either through rock falls or landslides.
Main Types of Volcanoes
Cinder Cone
- These are the simplest type of volocano that is made up of cinders, which are smaller broken-up pieces of hardened lava. Rising magma shakes the ground. Pressure sends gases, molten rock, and ash into the air which allow the molten material to cool quickly in the air, which then fall and break to form bubbly cinders around the vent.
- The vent is characterized by a crater-shaped depression at the top of the cinder cone volcano. Eruptions of lava flows outward from the vent, and repeated flows that build-up along an eruptive vent can even form stratovolcanoes.
Conical Composite or Stratovolcano
- Composite volcanoes are often referred to as stratovolcanoes. These types of volcanoes are usually what make up the tallest mountains we see, rising to heights of over 8,000 feet (2,400 meters). They are tall and steep because of repeated lava flows, volcanic ash, cinders, blocks and bombs, which are larger debris erupted from these volcanoes.
- These types of volcanoes are highly eruptive because of thick, silica-rich and gas content in its magma.
Lava Dome
- These volcanoes have very thick lava that doesn’t flow far from the central vent. Lava can barely squeeze out of the vent and continues to build over it. Lava domes are often found on the sides or craters in a composite volcano. Lava domes mostly grow from within and can be dangerous because as fresh magma fills the inside of it, the outer surface shatters causing hot rocks and gases to spill down from the mountainside.
Shield Volcano
- These types of volcanoes are almost entirely built out of fluid lava flows, which pur out in all directions from the vent. As these lava flows build-up on top of each other, they create a gentle slope. These volcanoes build-up slowly over time and over thousands of lava flows.
Lava Lamp Experiment
Water is denser or heavier than oil, so the oil can easily sit on top of the water. When salt is added, it’s denser than both the water and oil. As the salt is poured, it brings down oil to the bottom of the container. Since salt dissolves in water, as it dissolves, the oil that was brought down floats back up to the surface.When an antacid tab is added, it immediately reacts with the water to create various gas bubbles that move the oil throughout the container.
Preparation
Educational Materials
- Diagram illustrating four types of volcanoes along with their silica and gas content to better understand the types of eruptions for each.
Supplies Needed
For two separate lava lamps (1 with salt and 1 with an antacid tablet).
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2 clean plastic containers
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Water
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4 tbsp vegetable oil
- Food coloring
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1 antacid tablet (sodium bicarbonate)
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1 tbsp salt
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Glitter (optional)
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Neon or glow in the dark paint
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Flashlight (optional)
Materials
Diagram illustrating the main volcano types and their viscosity and explosivity.
Download Four types of volcanoes
A fun moving image that shows the difference between lava and magma.
Download Lava lamp versus magma lamp
Lesson Hook/Preview
Have you ever wondered what the inside of a volcano looks like, how they form, and what are the main types of volcanoes? Why do some volcanoes have more explosive eruptions than others?
This activity will answer these questions, and you'll make your very own lava lamp! Through your lava lamp, you'll be making observations on how thick a liquid can be and how gases move through it.
Procedure
Step 1:
- Take an empty container and fill it halfway with water. This will be the lava lamp that contains the salt.
- Take a second container and fill it halfway with water. This will be the lava lamp that contains the antacid tablet.
Step 2:
- Place 2 tbsp of vegetable oil into each container with water.
Step 3:
- Put several drops of food coloring, glitter, or neon/glow in the dark paint into both of the containers with the water and oil.
Step 4:
- Put salt in one container then put the antacid tablet into the other container. You’ll notice that the container with the antacid tablet will have more of an immediate bubbly reaction than the container with salt.
Step 6:
- To see your lava lamp glow in the dark, use your flashlight to shine beneath the container that has the neon or glow in the dark paint.
- Write down your observations for each lava lamp.
Vocabulary
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Lava dome: noun; a type of volcano that has very thick lava.
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Shield volcano: noun; a large, gently sloping volcano with fluid lava flows.
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Cinder cone: noun; the simplest type of volcano that is built of cinders that get erupted.
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Stratovolcano: noun; or conical composite volcano is large, tall, steep and has explosive and violent eruptions.
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Magma: noun; molten rock and material beneath earth’s surface
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Lava: noun; molten rock and material that gets erupted from a volcano.
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Viscosity: noun; when a fluid is thick or “sticky”.
- Buoyancy: noun; the ability to float.
Assessment Materials
ReflectionNow that you've made your own lava lamp and have more of an understanding of the four main types of volcanoes and why certain types have different eruptions, answer the following questions below:
- Which types of volcanoes are most explosive and least explosive? Why?
- What is the difference between lava and magma?
- Which lava lamp (salt versus antacid tablet) had more movement and why?
- Which liquid is denser, water or oil? How do you know?
- Describe how the liquids in your lava lamps moved.
Rubric/Answer Key
- Stratovolcanoes because their magma contains more silica making it more viscous and more gas content which causes it to have more explosive eruptions.
- Lava is erupted onto earth's surface and magma is molten material beneath earth's surface.
- The lava lamp had more movement because it had more gases produced in the container.
- Water is denser than oil because the oil can easily sit on top of the water.
- The oil was brought down and moved back up.
Additional Resources
See each step to making your own lava lamp.
United States Geological Survey Volcano Hazards Program.