Salt Water vs. Fresh Water Dilemma

[The Storyteller]

So I have an idea for a story which I don't plan on writing any time soon, but I do want to juggle around some ideas and do some idea developing so that the story can simmer in the back of my mind before I attempt writing it. I have quite a few different questions already (which I think I'll post a separate thread for at least one other question).


My problem is concerning water. I have drawn up a map for this world, and it is very unusual. Instead of having fairly solid continents of land and oceans of water, it is all kind of jumbled together. The land is basically just a huge jumble of squiggly, odd shaped islands. Some are joined together by thin bits of land, some are completely separate. And there are no huge bodies of water, as these islands are mostly placed fairly close together. The idea is that all of the water is joined together in one way or another; mostly, because not many of the islands have large sections of land, there are not much for lakes or rivers. All runoff, springs, rivers, etc. flow into the 'sea', so all water in this world is connected. It is considered the lifeblood of land, in that it weaves through everything and is all connected.


So I am wondering if it is remotely feasible for this water to all be fresh water? I looked up about how oceans become salty, but I don't know how to apply that to my world. No section of water would be nearly as immense as any of our oceans. For the most part, land and water are in equal parts, with no section of land or water being huge and unbroken by the other. Is it possible that because of that evaporation and rain would all be equal enough that the water didn't become salty over time? Or would everything except for rain and runoff be salty?

Another factor is that magic is one of the greatest forces of nature. It isn't magic that you access and use to cast spells, it is more like a force such as our laws of nature, except that it can override any other law. Because of this, climate and geography can be completely different in two areas, even though these areas might actually be very close to each other. One island could be completely covered in ice while a nearby island might have jungle habitat. (I am not entirely certain about this, I could change it so that magic isn't a force at all. Still deciding on that!) Could this same force be used somehow to explain why no body of water becomes excessively salty?

I like the idea that there is no such thing as salt water and that even the sections they would go sailing on would be fresh water (I have never heard of that, so to me it seems like a unique idea) but I don't want to run with it if it is so implausible that no one would believe it and/or it would seem like an immature idea for a story I'm hoping will end up being a more mature read.


Also, if it is necessary that at least some portions of water are 'salt water', how can I separate what is salt and what is fresh in a world where basically all water is one big sea that runs through and between everything?


Anyway, sorry that was long! I appreciate any and all feedback.

 

[Brian G Turner]

magic ... implausible

If your world contains magic, let alone as part of the natural order, I don't think anyone would begrudge you for applying some imaginative licence in how you shape your world.

The one big issue is to simply remain internally consistent. Aside from that, anything goes in what you write.

 

[psychotick]

Hi,

Um yes it could all be fresh water but I would think it unlikely. The salt in our oceans comes from rocks which have over billions of years eroded. Now in your world I would expect the same scenario to occur. However, our oceans are basically one big mass of water so the salt gets spread around a bit. In yours I see no oceans just a lot of varying sized lakes and small seas, and many of them are not well connected to others. Therefore I would expect to see some of thos lakes / seas being very salty, some being fresh, depending largely on what sort of rock strata surrounds them. Think a mix of fresh water lakes and hugely saline inland seas like the Dead Sea.

Cheers, Greg.

 

[Pyan]

Your planned geography is going to have a major effect on the weather on the planet, as well - without the influence of very large bodies of water, it'll be nothing like anywhere on Earth (unless the magic system adjusts that as well, of course)...

 

[tinkerdan]

I would suggest research on what puts salt in the water in our oceans and such and just how much land to water you want to have. The water has to flow somewhere so there has to be an explanation why the land contains little or no salt.

There are some salt lakes that do not connect to the ocean that actually have more salt so the idea that all water is somehow connected might reduce the amount of salt but if there is potential for salt in the areas that flow that salt will wash into the main water which doesn't flow -except perhaps with tides- and evaporates unless your world doesn't evaporate and rain. Fresh water has salt in it just a very small amount like 500 parts per million(some allow for 1000 to 3000.) Which is helpful because we need some salt to live.

I suppose there could be some weird chemistry that causes salt to evaporate on that world and a rain contains saline wash.

But basically if there is evaporation and any salt in the land below the seas and that flowing into the main seas then the evaporation will cause the main sea where everything flows, to become more salty than the rest. And the stagnant water might just dissolve more salt from the rocks and earth beneath.

You would have to either eliminate most sources of salt or give some reason there is no salt water. Or you could have high content in the fresh water and it all flows-slowly to small areas that are very salty.

Or there is just no salt and life doesn't need salt.

But there is a lot that I don't know about where we get all our salt so research, research, research.

 

[Marvin]

How about this; the water because it is all joined, is uniformly mildly saline and the denizens of your world have evolved to be able to use this in the same way we use fresh water. Some kind of desalination organ? That would give you the same result i.e the sailing on stuff you can drink type thing, which by the way does sound pretty cool.

Slightly off topic, only slightly. I have swam in the sea many times (as I'm sure many of you have) nasty and salty; I have swam in many swimming pools, nasty and full of chlorine. Once I swam in lake Garda, fresh water, it was a very weird experience, swimming about in stuff that tasted good enough to drink I didn't obviously, but you get my gist.

 

[Cosmic Geoff]

You need to think hydrology. If you look into why some bodies of water are salt and some are fresh, you will probably find that the salty ones (the ocean and salt lakes) are where the runoff, with its traces of leached salt, ends up and from where water can only leave by evaporation, and the freshwater lakes are the ones that are continually rinsed fresh by rainwater runoff flowing through them.
If you apply this logic to your imaginary world, I think you will find that the bodies of water will be predominately salty.

 

[chrispenycate]

Let's have a go at this. If I want salt in the environment, yet regions of the ocean that are fresh, or at worst brackish, I'm going to need a powerful freshwater current, continuously refreshing the upper layers.

So, since I can select conditions on an island, I wan't a big one (or group of islands) very cold. About -10°C should do it, and I'd like something about the size of Australia (it's all right, it's not critical, but it needs to be big; a Japan sized won't cut it).

There is a cold wind blowing out from this island at sea level, as dense, freezing air squeezes out, and warmer air at altitude is drawn in. This, having arrived over warm oceans, is rich in humidity, all of which is frozen out as the airmass cools, so it is pretty well permanently cloud-shrouded, and snowing day and night. The snow is compressed by its own weight into glaciers, continuously flowing outward from the kilometres-thick ice sheet, forming first ice floes floating on the ocean then, as they penetrate warmer water, an immense quantity of fresh water, flowing over the denser brines in the depths. If this were a static situation, there'd be a steady flow of fresh water outward from the island; in a dynamic situation we'll get a cold current flowing between other islands of fresh water twenty or thirty metres deep.

Secluded bays, lagoons, fjords will all be salty, and any bit of the sea off the line of the current will be salty, while obviously lakes with rivers flowing through them (and the rivers themselves) will be fresh – well, apart from whatever the inhabitants of the river bank had chucked into it.

 

[The Storyteller]

Hmmm, looks like I've got a lot to think about! I'm not quite sure what to think at this point.

To Pyan, I'm not sure. If I decide to have magic be a major 'force' in this world, then yes, the weather will have very little to do with oceans etc. (Thanks for the clip by the way!) If I decide against that, then I really don't know what to do! I was kind of hoping to do something different, where it isn't just big chunks of land in even bigger oceans, and instead be more like 50% water, 50% land, and all of it very interwoven. But I don't know where I would even begin to figure out how this would affect the world/weather etc.!

As for the salt water problem, one thought is that there was going to be a thicker ring of water around a large grouping of islands, and that this 'sea ring' is one of the main reasons people haven't branched out to farther islands, instead just living on the islands within the ring. Because all the water is connected, I don't know how exactly it would work, but maybe I could work it that currents brought all the water to the ring, and then leaves it there, so that the ring would be saltier water and the further into the group of islands you went the less salty it became.


I also could work with the idea that all of it is varying amounts of salt, (depending on rivers, currents, etc.) but that none of it is worse than mildly salty, and that people are accustomed to drinking varying amounts of saltiness and thus can drink anywhere (but they would likely note which places have better water, and the freshest kinds of water might even be a commodity of some sort).

Depending on what I do with the 'force of magic' thing, it could just be some phenomena which limits the amount of salt in the water. Or maybe I could do a thing where the salt remains solid in certain kinds of water, and thus can't dissolve into the water and make it salty? Maybe salt blocks form on the bottom of the sea, or get pushed out to the salty sea ring where some thing or another allows them to dissolve!

Anyway, lots to think about! Thanks for all the input. Any other thoughts on a workable or somewhat feasible solution are welcome!