Re: [Phys-L] Iceberg melting and sea level rise

["John Clement" <clement@hal-pc.org>]

I was not aware of that analysis, but this is a very much smaller effect
than iceberg calving effect.  It is a secondary effect.  So if you put a
block of freshwater ice into a pan of equal volume of salt water, how much
effect would you see when the ice has melted compared to the rise when you
put in the block of ice.  The demo would be interesting.

I still think the commentator was using the wrong model by saying the ocean
rise is due to icebergs melting, and that this was actually due to the
common misconception that melting ice causes water level to rise
appreacably.  So when the ice melts in your drink, the level may rise, but
you will not notice it, while you do notice the effect when you dump in an
ice cube.

Actually this also has to do with the elementary chemistry principle that
when a salt is dissolved in water, the volume change is nonexistant to very
small.  Of course secondary effects are ignored in the elementary texts.  So
using the elementary model, the fact that the freshwater becomes salty does
not change its volume.
  
For an experiment showing the volume decreases slightly as the salt
dissolves:
http://www.nuffieldfoundation.org/practical-physics/volume-change-dissolving
-salt-water


Incidentally what happens to the volume is heavily debated and many web
sites have very different answers.

John M. Clement
Houston, TX


> Hi,
>
> John C. stated a that "But iceberg melting does not 
> contribute to sea level rise.". Here is a link to a paper 
> which challenges this idea:
> <http://scitation.aip.org/content/aapt/journal/tpt/48/5/10.111
> 9/1.3393068>
>
> A short excerpt from the abstract: 
>
> ":..the sea level will rise. The analysis shows the wrong 
> conventional answer [such as the statement above] is due to 
> the wrong assumption that water from a melted iceberg has the 
> same density as seawater."
>
> The argument seems convincing and the demonstration does 
> work. Any counter-arguments?
>
> Cheers,
>
> Antti Savinainen, PhD
> Finland
> --
> **************************************************************
> ***********
> Viesti on tarkastettu roskapostinsuodatus- ja 
> virustorjuntaohjelmistolla.
> **************************************************************
> ***********
>
>
>
>
> _______________________________________________
> Forum for Physics Educators
> Phys-l@phys-l.org
> http://www.phys-l.org/mailman/listinfo/phys-l