[Airthumbs (OP)]

I had several people staying here who told me that in the Koran it is written that there is an area of fresh water located somewhere in the Mediterranean Sea? I have read the Koran and when I pointed out that I did not recall reading this I was told it was written in another book that is not really accessible to non believers. Having spoke at some length with him I asked him if he had ever seen any evidence to support this and did some pretty extensive research on the net to find out if this was true or not.  He was very convincing and seemed absolutely convinced that as the Koran states this area exists it must do.

I doubt very much if this area exists as it seems highly improbable.  Of course with out meaning any disrespect to my previous guests here I have to wonder about how misplaced their beliefs are at times especially when they say to me that Darwinism is just a theory and don't believe me when I tell them it is a science with huge amounts of supporting evidence.
Still having said all that I would like to know if anyone else if familiar with this concept of a large area of drinkable fresh water that apparently can be found in the ocean?

[damocles]

I believe that the surface "ocean" water near the mouths of the Amazon or Orinoco has almost no salt for a few hundred kilometres out from land. What is needed is a large river with a huge flow rate. But I know of no such river discharging into the Mediterranean. The Black Sea has a much lower salt content than (most of) the Mediterranean.

[Geezer]

At one point, wasn't the Med isolated from the Atlantic? It might have had a lower (or higher) salt content during that period.

[damocles]

Of course there IS an area of fresh water right in the middle of the Mediterranean: The Lago del Coghinas on Sardegna is a freshwater lake about 5 km x 2 km in the interior of a Mediterranean Island.

 []

[CliffordK]

I thought I had responded earlier,but seem to have lost the response.

Anyway, one would have to carefully review the declaration.  I find it doubtful.

The only way for the Mediterranean to be freshwater in the absence of a connection to the Atlantic would be if it filled up and had an overflow into the Atlantic, which I don't believe is the case.  Otherwise it would be salty like Great Salt Lake, or some of the small seas that lack an outlet.  And, in fact, I think I read that in the past it had increased salinity in the absence of a connection to the Atlantic. 

Islands, of course, can have fresh water springs.  

And, there could potentially be a subsurface freshwater spring, although I would assume most that are away from the shore would be brackish water.

One could imagine a river with warm, low density water that could potentially create a layer of low salinity near the outlet, but even so, the water in most rivers mixes with the sea water very quickly.  

It is possible for an iceberg to enter through Gibraltar, carrying with it some freshwater, but I would assume such an event would be very rare.  And, even so, it would quickly mix with sea water when it melts.

Some regions have Atols which are subsurface volcanoes.  Perhaps one could have a volcanic crater that would extend a few feet above the surface, just enough to capture rainwater.

[Geezer]

I'm not sure what this means exactly, but the Med and the Atlantic were not always connected.

"Sediment samples from below the deep seafloor of the Mediterranean Sea, which include evaporite minerals, soils, and fossil plants, show that about 5.96 million years ago in the late Miocene period the precursor of the Strait of Gibraltar closed tight, and the Mediterranean Sea, for the first time and then repeatedly, partially desiccated. 5.6 Ma ago the strait closed one last, final time, and because of the generally dry climate conditions, within a millennium the Mediterranean basin nearly completely desiccated, evaporating into a deep dry basin bottoming at some places 3 to 5 km below the world ocean level, with a few hypersaline Dead-Sea-like pockets."

http://en.wikipedia.org/wiki/Messinian_salinity_crisis

[Bored chemist]

If you are determined to believe then you will find a definition that makes it true. For example, any raindrop, as it hits the sea, will be a tiny area of freshwater until it mixes.
Also, on a small enough scale it would be possible to find a cluster of water molecules that don't have any salt in them. The probability drops as the size of the cluster rises but that's just a matter of scale and if your God is infinite then, to him, all things are tiny.

However from a scientific point of view the idea simply isn't plausible

[damocles]

From Bored Chemist:

However from a scientific point of view the idea simply isn't plausible

I am sorry, but it is quite plausible and likely even. In my earlier post I forgot about the Nile

From my earlier post:

What is needed is a large river with a huge flow rate. But I know of no such river discharging into the Mediterranean.

At a time when there was no Aswan High Dam, and during the regular Nile flood season, the surface water in the Mediterranean off Alexandria for maybe 20 km or so would have been (relatively) fresh Nile water rather than very salty Mediterranean water.

[Airthumbs (OP)]

So maybe one time long ago a chappy in a boat was particularly thirsty out in the Med. and had no water.  Maybe this chappy decided he would have to gulp some water down.  The cup full of water he took happened to be much less saline then the normal ocean conditions due all sorts of possible factors.  Then as with most stories, he exagerated it and over time it was writen into the Koran.  Who knows?   []

[Bored chemist]

As the Nile enters the sea the waters will mix. The delta will be less saline, but there will still be salt in it.

[Geezer]

I thought quantities water with different salinities were not very miscible. Doesn't that have something to do with thermoclines?

[damocles]

As the Nile entered the sea (things are different since the Aswan High Dam, hence the past tense) in the flood, Nile water which was less dense both because of lower salinity and higher temperature would have spread across the top of the Mediterranean near its entry point, with only a little mixing at the boundaries in the short term.