Expert: Expert - 11/3/2009

Question
If you take 1 kg of fresh water and add 35 g of salt (average for the oceans)will the volume increase and if - how much? The reason I ask: Could you channel seawater to geographical depressions, let the water evaporate, leave the salt on land and thus fight sea level rise.

Thanks, Jonas

Answer
Either you or I will have to do the following:

1) do an Internet search for

density "sea water"

2) compare that to the defined density of pure water, 1 gram per cubic centimeter.

You'll find you answer more quickly if you do the two steps above.

Then you'll have to answer the following questions:

1) what will happen to the evaporated water?

2) as it flows on land toward the ocean, over salty minerals, what will happen to those minerals?

3) where will those salty minerals ultimately end up?

Then, finally, answer this question:

Over the last three billion years or so, salt water has been constantly evaporating on geographical depressions (visit any dry lake bed if you doubt that). How much has the salt level in the oceans changed over the last three billion years of this?