Make your own Lava Lamp

Learn about volcanoes!

NPS / Astrid Garcia

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.

 

Magma is molten material beneath earth's surface. Whereas, lava is molten material erupted above earth's surface.

NPS / Astrid Garcia

What are Volcanoes?

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. Magma is lighter than the surrounding rock and is able to rise to the surface because of its buoyancy (ability to float) and gas pressure within the 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 builds up the volcano and surrounding landscape. 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. As 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. As the molten material cools, it falls and breaks 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 come out 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 pour 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.

 

Shield volcanoes are the least explosive with stratovolcanoes or conical composite volcanoes being the most explosive.

NPS / Astrid Garcia

 

Supplies Needed

• Safety glasses
• 2 clean plastic containers for two separate lava lamps (1 with salt and 1 with the antacid tablet)

• Water

• 4 tbsp vegetable oil

• Food coloring

• Glitter

• Neon or glow in the dark paint

• 1 antacid tablet (sodium bicarbonate)

• 1 tbsp salt

• Flashlight (optional)

 

Make two types of lava lamps: one with salt and another with an antacid tablet then describe the different reactions!

NPS / Astrid Garcia

 

Directions

Step 1:

• Take your 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 of water.

Step 3:

• Put a couple drops of food coloring, glitter, or neon/glow in the dark paint into both of the containers of water and oil.

Step 4:

• Put salt in one container then put the antacid tablet into the other container. Note the reaction of each as soon as you add the salt and antacid tablet.

Step 6:

• To see your lava lamp glow in the dark, use your flashlight to shine beneath the container that has the neon/glow in the dark paint.

 

Reflection

Now that you've made your own lava lamp and have more of an understanding 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?

From your lava lamp experiment:

• 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.

 

Answers

• 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 with the antacid tablet 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 by the salt in the first lava lamp, and the carbon dioxide gases created by the antacid tablet in the second lava lamp.

 

Lesson Plan

Lesson Plan for Types of Volcanoes Activity