Question

[Louis the fly]

Here is a question I am sure many will know the answer to, but I do not.

Yesterday I was talking with my grandson about the rain cycle, moisture is drawn from the sea by the heat of the sun, stored in the clouds then falls as rain to begin the cycle again. The sea is salt water but rain is fresh water. How does it change from salt to fresh ??

[Captain Kong]

Only water is evaporated, salt does not evaporate. Ice bergs are made of fresh water. I have drunk from the melted ice of an Ice Berg, when I was in the Antarctic. lovely fresh water.
There is the same amount of water on the planet as there was Billions of years ago when first started.
You cannot destroy water, only its State, Liquid, steam, vapour, ice, snow and so on but the same amount is always here.
Cheers
Brian

[Stan Carter]

now that it's been explained regarding fresh and rain water, my question is what makes the sea salty. my thinking is with all the fresh water rain falling fresh water rivers emptying into the sea, how come the saltiness is not diluted.
baffled,
regards, stan

[Doc Vernon]

Why is the sea salty?

Why Isn't Rain Salty? - Science Questions, from the Naked Scientists

Why is the ocean salty, but rivers flowing into it are not?

https://www.quora.com/If-rain-is-for...hat-filters-it

This may help to explain Louis!
Cheers

[happy daze john in oz]

The amazing thing about water is that when it freezes it expands. So all those 'greenies' who tell us we will be flooded when the ice bergs melt i think have no substance. In my opinion the water will take up less room not more.

[j.sabourn]

A common question when up for 2nd Mate was, why use mercury in a marine barometer and not water..The quick answer was the differential equations of expansion between Mercury and glass. As regards salt in the sea all different parts of the ocean have different salinity amounts. How did it get there, Cappy sitting on the taffrail putting salt and vinegar on his fish and chips. Cheers JS.

[Peter F Chard]

Surely it is all to do with the density -- mercury is about 13.6 times heavier than water which means you can make barometers small enough to be of practical use. Regards Peter in NZ.

[j.sabourn]

Try freezing mercury or boiling and expanding. Never tried myself. Just what am told. Used to learn these questions parrot fashion and answers. Same as the principle of the barometer, air has weight and can support weight or words to that effect, extending from the outermost limits of the earths atmosphere to sea level. Actual wording should have been Due to the differences in coefficients of expansion. Also less friction between glass and mercury as regards previous. Principle of the Aneroid (no mercury) Air has weight and exerts pressure. Every instrument on board a ship used to have to know the principle of and how it worked. What I can remember were the patent sounding machine, Sextant, Barometers, Hygrometers, Hydrometers, Thermometers, Barograph, and numerous more which no doubt will dream of tonight. Still racking what is left of brain for a feasible answer to where the salt comes from in the oceans. Don't think it is Table salt somehow. We used to carry a lot of Brine out to the rigs and cant remember what they used that for, maybe those on site who worked offshore can remember. Cheers JS

[Louis the fly]

Hi John brine was used to pump into the well head to cool the drilling operation. Had to careful on deck not to connect up to potable ( drinking water ) we also carried.

[j.sabourn]

Thanks Louis. The barytes was used for making mud wasn't it, what was the Bentonite used for was that mud as well. Remember the supt. one time came down to the ship in Aberdeen for some cement, opened the wrong tank and gave him Barytes which looks similar to cement. He built his wall which fell down, came back to ship and accused me I did it on purpose, I know I didn't like him, but would I do such a thing. The bigger boats carried about 700 tons of potable water, which was also kept separate from the drill water, well over a thousand tons of water at times, as well as a full deck load. Plus all the chemicals etc. If weather really bad have seen the tuggers slackened off shortly after sailing and run back to Aberdeen to secure and wait for the weather to moderate, in the pub of course. Nothing like that these days everyone sits on board in case they are reported going ashore and coming back inebriated. Such is jolly jack to day, forced to be breathalized before sailing for the Spanish main. A shore person talking about these chemicals might think you are talking about Superman, he used Vulcanite or something similar sounding. Cheers JS PS Told the Supt. his powers of observation were very poor and he should have seen what he used wasn't cement so was giving him a C on his report card. It would of had the same adhesion as mixing sand with sand. JS