Making Waves: Explaining how an ocean wave works

Sharing is caring!

Disclosure: this post contains affiliate links, which means I may receive a commission if you click a link and purchase something at no extra cost to you. Please check out our policies pageOpens in a new tab. for more details.

If your child loves making waves in the bathtub or going to the beach to see the waves crash on the shore, then this experiment is for them.

This experiment teaches some basic principles of oceanography while creating an interesting wave visual for play. In the Making Waves experiment, we cover how a wave moves (spoiler: the water itself barely moves horizontally!), the type of energy a wave makes, and how a wave “crashes” at the beach.

We have lots to cover here, so let’s dive on in!

How to make the Making Waves oceanography science experiment

Supplies you will need

For the Making Waves experiment, you’ll need the following:

Supplies needed for the Making Waves experiment

Before you start

I recommend placing a towel on the table to do this science experiment since we are filling a container with liquids and it could get messy.

Instructions

Here is how to do the Making Waves experiment with your toddler:

Step 1: Fill your container about half full of water and add food coloring

Add water into container first

The water in the container will be your ocean, so I ended up choosing blue food coloring.

Once you have added the food coloring, give it a good swirl to mix the color in before moving on to the next step.

Get your preschooler involved: Have your toddler choose the color you use and/or add the color to the container. This is a good fine motor skill activity plus gives them a little control over the experiment.

Step 2: Fill up the container the rest of the way with oil

Fill the rest of the container with cooking oil

Do not skimp on the oil! Fill the rest of the container up with oil so there is little to no room for air at the top.

The more air you leave in the container, the more likely you will have bubbles forming in your liquid when you do the experiment. Even if you fill it entirely, you may still have bubbles, but it will be less than if air was left in the container.

Get your preschooler involved: Your toddler can add the oil to the container too. Talk about how the oil sits on top of the water (great opportunity to talk about density!)

Step 3: Screw on the lid and ensure you have no leaks

Ensure that the lid is secured and there are no leaks

Since you will be shaking the container quite a bit to make waves, you certainly want to avoid any leaks to get in the way of your fun.

I did a quick test by tilting the container to ensure there were no leaks before starting.

Step 4: Gently move the container to initiate waves

Gently tilt each side of the container to initiate the wave

A simple, gentle movement should do the trick. Tilt the lid side of the container down toward the ground, then back up again to initiate the wave.

The more aggressive you are with the movement, the more bubbles will form. But don’t worry: let your container sit for about 5-10 minutes and the bubbles should subside.

Get your preschooler involved: Guide your child’s hand at first so they don’t get too aggressive, but allow them to see how tall they can make the waves!

The science behind the Making Waves oceanography experiment

The Making Waves experiment teaches:

  • How a wave moves
  • The type of energy a wave makes
  • Why waves “crash” on the beach

How it works

This experiment is great for the child who enjoys making waves in the bathtub! Our container shows how a wave moves and gives you an opportunity to talk about waves with your child.

How a wave moves

Did you know that the water that a wave is comprised of has very little horizontal movement?

A wave is the transfer of energy through water. So when you see a wave moving, you are seeing energy traveling. I think this quote from Roger Williams UniversityOpens in a new tab. does a great job of explaining this:

Although waves can travel over great distances, the water itself shows little horizontal movement; it is the energy of the wave that is being transmitted, not the water. Instead, the water particles move in circular orbits, with the size of the orbit equal to the wave height. This orbital motion occurs because water waves contain components of both longitudinal (side to side) and transverse (up and down) waves, leading to circular motion. As a wave passes, water moves forwards and up over the wave crests, then down and backwards into the troughs, so there is little horizontal movement. This is evident if you have ever watched an object such as a seabird floating at the surface. The bird bobs up and down as the wave pass underneath it; it does not get carried horizontally by a single wave crest.

https://rwu.pressbooks.pub/webboceanography/chapter/10-1-wave-basics/

We see this clearly in our Making Waves experiment: the energy is contained in our container, and you can see that the waves generated move up and down instead of horizontally.

The type of energy a wave makes

We’ve talked about potential and kinetic energy in the Catapults experiment. In short, when we pulled back on the catapult (before releasing), we were generating potential energy. When we let go of the catapult to launch our object, that object had kinetic energy.

This is another great way to demonstrate kinetic energy to your child!

The energy in a wave is all about movement and can harness a great deal of kinetic energy.

When a wave is large and travels far, you know that it has more kinetic energy than a short, shallow wave!

Why waves “crash” on the beach

When a wave approaches the shore, the friction due to the bottom of the wave hitting the ocean floor causes it to slow down, making the wave tilt forward.

As the wave gets closer and closer to the shoreline with more shallow water, the top eventually runs over the wave, causing the wave crash that we are familiar with on the shoreline.

More earth science experiments to try out with your child

FAQ about the Making Waves oceanography science experiment

What is the reason why the water in the container creates a wave-like motion?

Wind generates most of the waves in the ocean, and in this experiment, we are acting as the wind by moving the container to generate the wave. As the crest (top of the wave) forms and pushes water down, water is then pushed out from the trough (bottom of the wave). This movement forms a circular pattern and forms the wave we see in the container.

Recent Posts