A substantial portion of an iceberg remains hidden beneath the water's surface. Based on scientific observations and principles, the vast majority of an iceberg's volume and mass is submerged.
Key Insights on Iceberg Submergence
Scientific understanding provides a clear picture of the distribution of an iceberg's mass and volume above and below the waterline. The key factor determining this is the difference in density between ice and the surrounding water.
According to the provided reference:
- "Over 87% of an iceberg's volume (and mass) is underwater."
This means that less than 13% of an iceberg is typically visible above the surface. The principle behind this is directly related to density.
The Role of Density
The fraction of a floating object that is submerged in a fluid is determined by the ratio of the object's density to the fluid's density. The reference explains this relationship:
- "...the convenient definition of the gram gives us a quick way to see how much of a floating substance lies below the surface of fresh water: the fraction is equal to that substance's mass density in g/cm³."
Since ice has a density that is close to but less than that of water, it floats, but most of its bulk remains below the surface. The density of ice is typically around 0.92 g/cm³, while fresh water is about 1.00 g/cm³ and saltwater is slightly higher (around 1.03 g/cm³). Floating in saltwater (denser), slightly less of the iceberg would be submerged compared to fresh water, but the difference is not dramatic enough to contradict the "Over 87%" figure often cited, which suggests the average density of iceberg ice is such that this large fraction remains below the surface.
Summary of Submersion
The primary takeaway is that the visible part of an iceberg is merely the "tip." The immense majority of its structure is hidden underwater.
Here is a quick summary:
- Submerged Portion: Over 87% of volume and mass.
- Governing Principle: Density of ice relative to water.
Understanding this helps explain why icebergs are such significant hazards to navigation, as their true size is largely concealed.
