Science becomes truly magical when children can see, touch, and explore real-world concepts with their own hands. At The Kids Point, we believe that the best way to spark curiosity and inspire young minds is through interactive, meaningful learning experiences. One of the most fascinating and seasonally appropriate science activities you can do with children is the Iceberg Experiment. It’s simple, safe, and wonderfully educational, allowing kids to explore the mysteries of icebergs, density, buoyancy, and even climate science.
This in-depth guide provides everything you need to know about setting up a fun and educational iceberg experiment at home or in the classroom, while diving deep into the science behind it.
What Is an Iceberg?
Before diving into the experiment, it’s helpful to understand what an iceberg really is.
An iceberg is a huge chunk of freshwater ice that breaks off from glaciers or ice shelves and floats in the ocean. Even though they’re massive, only about 10% of an iceberg is visible above the surface of the water—the rest remains hidden below. That’s why they can be so dangerous to ships, like the infamous iceberg that caused the sinking of the RMS Titanic in 1912.
But why do icebergs float? And why do they float higher in salt water than in fresh water? Let’s find out!
Learning Objectives
Through this experiment, kids will:
- Understand the concept of density and buoyancy
- Observe how salt affects water density
- Discover why ice floats and how much of it remains underwater
- Learn about the real-world importance of icebergs
- Enhance skills in observation, measurement, and prediction
Materials You’ll Need
Here’s what you’ll need for your iceberg science setup:
For the Iceberg:
- Balloons or small containers
- Water (add blue food coloring for fun!)
- Freezer
For the Experiment:
- Large clear container (plastic tub or aquarium)
- Ruler or measuring tape
- Salt
- Spoon for stirring
- Warm water (optional for melt tests)
- Small toy boat or paper boat (optional for added fun)
Step-by-Step Instructions
Step 1: Create Your Icebergs
- Fill a balloon or small container with water and tie it off or cover it.
- Add a few drops of blue food coloring for visibility (optional).
- Freeze overnight or until solid.
Step 2: Prepare the Ocean
- Fill a large clear container with room-temperature fresh water.
- For variation, prepare additional containers with different salt concentrations:
- No salt (freshwater)
- 1 tablespoon salt per cup of water (low salinity)
- 3 tablespoons salt per cup of water (medium salinity)
- 6 tablespoons salt per cup of water (high salinity – like the Dead Sea!)
- No salt (freshwater)
Step 3: Observe the Iceberg in Action
- Remove the ice from the balloon or container.
- Gently place the iceberg in your freshwater “ocean.”
- Observe how much of the iceberg is above and below the surface.
- Repeat the process with your saltwater containers and compare!
Measuring Results
Have kids measure:
- The total height of the iceberg
- How much is above the water
- How much is submerged
Record the data and compare results across different salt concentrations. Ask children to make predictions and write down observations like:
- Does the iceberg float higher in saltier water?
- Does salt water melt the ice faster or slower?
- How does hot water affect the iceberg’s melting rate?
The Science Behind the Experiment
Why Does Ice Float?
Water is unique because its solid form (ice) is less dense than its liquid form. When water freezes, the molecules arrange in a crystalline structure that takes up more space, reducing its density. This arrangement creates gaps between the water molecules, which further reduces the overall density of the ice. As a result, the ice is able to float on top of water because it is lighter than the liquid. If ice were denser than liquid water, it would sink instead.
What Is Buoyancy?
Buoyancy is the upward force a fluid exerts on an object placed in it. If the object is less dense than the fluid, it floats. If it’s denser, it sinks. This principle is what allows ships to float on water despite their large size. The buoyant force must be equal to or greater than the weight of the object for it to stay afloat.
How Does Salt Change Density?
Adding salt to water increases its density. The salt ions fill the gaps between water molecules, making the solution heavier per volume. This higher density allows objects, like icebergs, to float higher in saltwater than in freshwater. Saltwater’s increased density also makes it more difficult for objects to sink, which is why marine creatures have an easier time floating. Additionally, the more salt added, the denser the solution becomes, making the buoyancy effect even more pronounced.
How This Relates to Real Icebergs
Real icebergs are made from freshwater snow that compacts into glacial ice over thousands of years. When chunks break off (a process called calving), they float in the salty ocean. Since the ocean is denser than freshwater, these icebergs float a little higher than they would in a lake.
But because 90% of the iceberg is still submerged, ships can easily underestimate their size or misjudge the danger.
This concept played a critical role in the Titanic disaster, where the ship struck an iceberg that was mostly hidden beneath the surface, damaging multiple watertight compartments and leading to its sinking.
Extension Activities
Want to take the learning further? Try these ideas:
Measure Water Displacement
- Fill a container to the brim.
- Gently place your iceberg in and catch the water that spills over.
- Measure how much water was displaced. This equals the volume of the submerged part of the iceberg!
Make a Saltwater Iceberg
- Freeze a saltwater solution and repeat the experiment. Does a salty iceberg float differently than a freshwater one?
Paper Boat Challenge
- Float a paper boat next to the iceberg.
- Simulate the Titanic’s collision by bumping the boat gently against the underwater part.
- Discuss how a ship could be damaged below the waterline.
Curriculum Connections
This iceberg experiment aligns with topics in:
- Physical Science – states of matter, properties of water, density
- Earth Science – glaciers, oceans, climate change
- Engineering & Design – buoyancy in ships, iceberg tracking
- History – Titanic, maritime disasters, evolution of safety systems
Real-World Relevance
Icebergs & Climate Change
As Earth’s climate warms, glaciers and polar ice are melting at an accelerated rate. This causes more freshwater to enter the ocean, which affects salinity, ocean currents, and sea levels.
Understanding how density and salinity work helps explain these changes and why they matter to our planet’s future.
Modern Iceberg Tracking
After the Titanic tragedy, the International Ice Patrol was formed to track icebergs and prevent future collisions. Today, satellites and GPS systems help ships avoid these massive frozen obstacles.
Fun Facts to Share
- Water is one of the only substances that expands when it freezes.
- The average iceberg can weigh over 100,000 tons!
- Icebergs can “roll over” as they melt, revealing stunning shapes and colors.
- Penguins live near icebergs—but only in the Southern Hemisphere!
Key Takeaways
- Ice floats because it is less dense than liquid water.
- About 90% of an iceberg is hidden below the water’s surface.
- Salt water is denser than fresh water, so icebergs float slightly higher in oceans.
- This fun experiment teaches density, displacement, and buoyancy in a hands-on way!
A Cool Way to Learn
The Iceberg Experiment is more than just a science activity—it’s a gateway into earth science, physics, history, and climate awareness. By exploring concepts like density and buoyancy in a playful and memorable way, kids build a solid foundation for scientific thinking and observation.
At The Kids Point, we’re passionate about making learning exciting, accessible, and meaningful. Activities like these help children connect scientific principles to the real world while having a blast doing it.
So, gather your supplies, freeze some “icebergs,” and let the learning (and splashing) begin!