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Weather experiment learning about volcanoes

Posted at 7:04 AM, May 07, 2020
and last updated 2020-05-07 08:15:51-04

GRAND RAPIDS — Many different types of extreme weather can happen in West Michigan but one type we never see are volcanoes. Today we will be learning all about how they form and why they erupt by making a salt volcano that actually looks somewhat like a lava lamp. Lets get started!

What you need:
- A bottle or jar
- One cup of room temperature water
- ¼ cup of vegetable oil
- Salt

Step 1: Pour the water into the jar

Step 2: Pour the oil into the jar but don’t mix it together with the water

Step 3: Sprinkle salt into the jar

Step 4: Watch what happens!

We made a salt volcano or it even looks like a lava lamp! Water and oil are immiscible liquids which means they don’t mix together. For this experiment when you sprinkle in the salt it sinks to the bottom. When the salt is sinking the oil clings on to it, but when the salt reaches the bottom of the jar it dissolves the oil does not. The oil then starts to rise to the top giving us this salt volcano or lava lamp look.

Oil is less dense than water which is why it floats on top at the surface and why the oil fights to get back to the surface after the salt pulls it down to the bottom of the jar. The salt is denser than the water which is why that sinks to the bottom and then dissolves.

This whole process can be related back to volcanoes. A volcano forms when magma from the earths upper mantle pushes its way to the surface and then at the surface it erupts to form lava and ash. When a volcano is at rest the magma material contains a lot of dissolved gas, but when the pressure between the outside rock and within the volcano changes that dissolved gas within the magma starts to expand and form tiny gas bubbles. Some of the magma is then filled with those little tiny gas bubbles. The magma with gas bubbles now has a much lower density than the surrounding magma so it pushes out to escape at the surface and we see an erupting volcano.

There you have it, we just made a salt volcano! Send our meteorologist Candace Monacelli your pictures doing this experiments at home! She will feature future meteorologists on my Facebook page daily!