Iceberg Floating in the Ocean: What Percentage is Submerged?

How much of an iceberg's volume is under water?

Approximately 90% of the volume of the iceberg is submerged underwater. But why is that?

Why is 90% of the iceberg submerged under water?

When an object floats in a fluid, such as an iceberg in the ocean, it displaces a volume of fluid equal to its own volume. In this case, the specific gravity of the iceberg (γice = 0.917) is less than that of seawater (γseawater = 1.025), causing it to float.

The principle at play here is Archimedes' principle, stating that an object will float if the buoyant force acting on it is greater than or equal to the gravitational force pulling it downward. The buoyant force depends on the volume of the object submerged in the fluid.

Calculating the Percentage of Iceberg's Volume Submerged

To determine the percentage of the iceberg's volume submerged underwater, we compare the specific gravity of the iceberg and seawater. By using the ratio of specific gravities, we can calculate the density of the iceberg relative to seawater.

Since the iceberg is floating, its density is equal to the density of seawater. Therefore, the percentage of the iceberg's volume submerged can be calculated as:

Percentage submerged = (1 - ρice/ρseawater) × 100

Substituting the values of specific gravities, we find that approximately 90% of the iceberg's volume is submerged underwater.

Therefore, the reason why a vast majority of the iceberg is under water is due to the differences in specific gravity between the iceberg and seawater, allowing it to float in equilibrium.