Why icebergs do not sink?

[RomanRodinskiy]

Can you please help me to explain from the most scientific point of view (it would be great if there were formulas) why icebergs do not sink? I would be very grateful. 

[StringJunky]

Liquid water has a density of 1g/cm³. Ice has a density of 0..91g/cm³. Anything less dense than the medium will float, so ice floats on water. It's the same with atmospheric air: any gas or vapour less dense will rise through the air.

 

[exchemist]

17 minutes ago, RomanRodinskiy said:

Can you please help me to explain from the most scientific point of view (it would be great if there were formulas) why icebergs do not sink? I would be very grateful. 

The density of ice is lower than that of liquid water at the same temperature. Unlike most materials, ice expands upon freezing. Objects that are lower in density than the liquid in which they are immersed will tend to float in it.

The reason it expands on freezing is because the molecules in the solid take up orientations that maximise the strength of hydrogen bonds between the molecules. This leads to a more "open" structure than in the liquid.  

The physics that governs whether and how an object floats is to do with the relative magnitude of the object's weight and the buoyancy force it experiences from the liquid. This is set out in what is known as Archimedes' Principle. There are details here: https://en.wikipedia.org/wiki/Archimedes'_principle

 

Edited October 5, 2023 by exchemist

[swansont]

2 minutes ago, StringJunky said:

Liquid water has a density of 1g/cm³. 

And ocean (salt water) density is 1.02 - 1.03

[StringJunky]

1 minute ago, swansont said:

And ocean (salt water) density is 1.02 - 1.03

Right.

[exchemist]

5 minutes ago, swansont said:

And ocean (salt water) density is 1.02 - 1.03

And even that varies from ocean to ocean, hence all the markings on the Plimsoll Line on a ship's hull, showing the different limits to which it can be safely loaded:

 

[RomanRodinskiy]

Thank you very much. If anybody have something to add, you're welcome

[John Cuthber]

14 hours ago, exchemist said:

And even that varies from ocean to ocean, hence all the markings on the Plimsoll Line on a ship's hull, showing the different limits to which it can be safely loaded:

 

That ship doesn't travel as far as some.