Icebergs float because ice is less dense than liquid water.
Density and Buoyancy: The Key to Floating Ice
The secret lies in the density difference between ice and water. As the reference states, ice is approximately 9% less dense than liquid water. This means that for a given volume, ice weighs less than the same volume of water. This lower density is a unique property of water, and is crucial to life on Earth.
When an iceberg (which is essentially a large piece of frozen water) is placed in water, it displaces a volume of water equal to its own weight. Because the iceberg is less dense, it displaces a larger volume of water than its own volume. This displaced water weighs more than the iceberg itself, providing the buoyant force that keeps the iceberg afloat.
Think of it like this:
- Imagine a bathtub full of water.
- Now, add a block of wood. The wood floats because it's less dense than water. It displaces a volume of water equal to its weight, and that displaced water exerts an upward force (buoyancy) that supports the wood.
- Icebergs behave in the same way. They are less dense than the surrounding water, causing them to float.
This phenomenon has significant implications for aquatic life and global climate. The fact that ice floats insulates bodies of water, preventing them from freezing solid from the bottom up, allowing aquatic life to survive even in freezing temperatures.
