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Dead Sea

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Jenny
36116.  Tue Nov 29, 2005 8:39 pm Reply with quote

The Dead Sea is so salty that only bacteria and fungi can live there. Non-swimmers are safe there, as the water is too salty for them to sink.

It is 1,370 feet (418 metres) below sea level, and also contains large quantities of other minerals, such as calcium, magnesium, bromine and potassium. The supposed healing properties of these attract many tourists. Theoretically, tourists don't need to wear sunscreen, as the extra atmosphere above the sea filters out harmful UV rays, but I wouldn't place too much confidence in that assertion - I haven't seen any research to back it up.

However, the Dead Sea is - erm - dying, or at any rate drying up. In the last 75 years it has lost about a third of its surface area, and Israeli researchers think it may be gone by 2050. It used to be fed by the River Jordan, but that water is now used for hydroelectric power as well as to supply cities and farms.

As the sea recedes, it exposes huge pillars of salt - the origin of the legend of Lot's wife, who was supposedly turned to a pillar of salt nearby.

 
djgordy
36128.  Wed Nov 30, 2005 5:37 am Reply with quote

The Dead Sea is part of the same fault that forms the East African Rift Valley as the Nubian African Plate and the Arabian Plate move away from each other.

 
Quaint Idiot
36148.  Wed Nov 30, 2005 6:32 am Reply with quote

And just in case you need proof of the old factoid that it is so salty that one can read a newspaper while floating in the Dead Sea ...

 
samivel
36161.  Wed Nov 30, 2005 7:46 am Reply with quote

Jenny wrote:
The Dead Sea is 1,370 feet (418 metres) below sea level.



I know what you mean, but doesn't that strike you as a bit strange?

 
dr.bob
36177.  Wed Nov 30, 2005 9:07 am Reply with quote

Indeed. If it's a sea it must, by definition, be at sea level :)

 
wibble the lobster
40655.  Mon Dec 19, 2005 3:37 pm Reply with quote

I "swam" in the dead see earlier this year, although the bouyancy means it isn't possible to actually swim, and one moves about by effectively treading water.

There still needs to be a lifeguard as the water is so salty that it is dangerous to splash in case it gets into someone's eyes or to swallow.

Not recommended for cuts or sores. Herpes sufferers may findthemselves embarrassed.

 
Gray
40797.  Tue Dec 20, 2005 7:13 am Reply with quote

I managed to read a book floating on my front in the Dead Sea. It's very weird. You can float right up to the water's edge, and then stand up and it only goes up to your shins. And it really does hurt when you get it in your eyes, too.

When the Straits of Gibraltar were cut off a few million years ago, a similar thing happened to the Mediterranean Sea - it dropped right to the bottom of its basin, and got very salty indeed.

http://mac01.eps.pitt.edu/harbbook/c_vi/chap06.html (about 3/4 of the way down)

 
Mostly Harmless
42994.  Wed Jan 04, 2006 8:24 am Reply with quote

..


Last edited by Mostly Harmless on Sun Jan 08, 2006 2:30 pm; edited 1 time in total

 
samivel
43048.  Wed Jan 04, 2006 12:30 pm Reply with quote

I'd be worried about bombs as well ;)

 
grizzly
43061.  Wed Jan 04, 2006 1:04 pm Reply with quote

The Aral Sea is a lake that shares the fate of the Dead Sea. From 1960 to today the height of the Aral Sea has fallen from 53m to 34.8m above sea level. Its salinity has risen from 10g/l to 45g/l (1998) and is estimated to be as high as 70g/l by 2010. It has shrunk in area by more than 60%. The process is called desiccation. It has reduced from the World's 4th largest to the 8th largest lake (shame it couldn't go in the A series, you could sneek it in under Desiccation though :-)

http://www.dfd.dlr.de/app/land/aralsee/

http://www.dfd.dlr.de/app/land/aralsee/monitor.html

Wikipedia:

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

 
Anachronism
43288.  Thu Jan 05, 2006 1:19 pm Reply with quote

Rather silly questions, but I've always wondered...

What can sink in the dead sea? Sand, I suppose, or it would be a rather odd sea. But could someone sink? A particually... physically dense person?

Also, just how saltly is it? For example, how much salt would you have to add to a pint of water to get the same amount of saltyness?

 
grizzly
43301.  Thu Jan 05, 2006 2:26 pm Reply with quote

Anachronism wrote:
Rather silly questions, but I've always wondered...

What can sink in the dead sea? Sand, I suppose, or it would be a rather odd sea. But could someone sink? A particually... physically dense person?

Also, just how saltly is it? For example, how much salt would you have to add to a pint of water to get the same amount of saltyness?


Effectively anything denser than the salt water will sink.

As for how salty it is. Well it varies both by depth and time of year. During the cold season less water evapourates so it is less salty. During the hottest season a lot more evapourates so it is more salty. The case used to be that the lowest layer was the more salty (100% saturated with dissolved salts and salt precipitated onto the lake bed) whilst higher layers were less so. When the supply of water to the lake was cut the top layer became more salty than the bottom layer. It maintained this because the top layer was warmer. Then as the top layer cooled over several winters the top layer descended and the sea is now a homogeneous body in terms of salt content. The layers have begun to re-establish in recent years though.

It's all under the chemistry part on Wikipedia (provided it is accurate):

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

 
magic sophie
43308.  Thu Jan 05, 2006 2:40 pm Reply with quote

so we are not denser than salt water.... wait just thought about it... ahhh yes...forgive the stupidity that was that last question...

I wonder what's at the bottom...because I don't think we (as in humans) would be able to get down there... maybe there is some sort of creature that lives at the bottom...hmmm the possibilities are endless...

 
Jenny
43423.  Fri Jan 06, 2006 12:06 am Reply with quote

I saw a DVD of David Attenborough's 'Blue Planet' series recently, and on one of the programmes it said that there were 'underwater lakes' in the sea, where areas were so very salty that they formed a separate pool at the bottom of the ocean. I thought that was fascinating.

 
Rory Gilmore
43971.  Sat Jan 07, 2006 5:11 pm Reply with quote

And do fish float on the top of it?

 

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