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The Dead Sea.






There is such a sea in a country with a very ancient history. This, of course, is the famous Dead Sea in Palestine. Its water is so salty that nothing can live in it. Due to the local scorching rainless climate the surface water evaporates. Note, though, that it is only water as such which evaporates. The salt dissolved in it remains making the water still saltier. This explains why the Dead Sea has a salt content not of two or three per cent (by weight) as most seas and oceans but of 27 per cent and even more - the salt content increases with depth.

Thus a quarter of the Dead Sea is made up of the salt dissolved in its water. This sea has been estimated to have a total of 40 million tons of salt. The water of the Dead Sea exhibits a very curious property precisely because of its saltiness. Since it is much heavier than ordinary sea water, you will never sink in it because your body is much lighter.

We weigh noticeably less than an equal volume of very salty water. Hence, according to the law of buoyancy we would never drown in the Dead Sea; we would pop up to the surface just like an ordinary egg in salt water - which, incidentally, sinks in fresh water.

Mark Twain, the famous American humorist, visited the Dead Sea, and in one of his books he wittily describes the unusual sensations that he and his companions experienced when they bathed in it.

" It was a funny bath. We could not sink, one could stretch himself at full length on his back, with his arms on his breast, and all of his body above a line drawn from the corner of his jaw past the middle of his side, the middle of his leg and through his ankle-bone, would remain out of water. He could lift his head clear out if he chose... You can lie comfort­ably on your back, with your head out, and your legs out from your knees down... you can sit, with your knees drawn up to your chin and your arms clasped around them, but you are bound to turn over present­ly, because you are top-heavy in that position. You can stand up straight in water that is over your head, and from the middle of your breast up­ward you will not be wet. But you cannot remain so. The water will soon float your feet to the surface. You cannot swim on your back and make the progress of any consequences, because your feet stick away above the surface, and there is nothing to propel yourself with but your heels. If you swim on your face, you kick up the water like a sternwheel boat. You make no headway. A horse is so top-heavy that he can neither swim nor stand up in the Dead Sea. He turns over on his side at once."

The water of the Kara Bogaz Gol, a gulf in the Caspian, and of Lake Elton - with its 27-per-cent salt content - exhibits the same unusual prop­erties.

 

Ответьте на вопросы по тексту:

1. How does rotation influence climate?

2. How does climate influence rotation?

3. What is the modern understanding of long-term dynamics?

4. What sea is spoken about?

5. What helps people not to sink?

6. Why is Dead Sea the unique sea?

7. What sensations do people experience bathing in the Dead Sea?

 






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