Deep in the Great Rift that runs from Turkey to southern
Africa, at the lowest habitable place on the face of the
earth,
lies a lake that seems
to belong to another world. It is 42 miles long by 11 wide.
On its east and west rise the formidable walls of the
rift.
The salt
concentration varies between 25 and 35%. (The ocean's is 3.5%.) No person has
yet been found who can sink here. Aristotle heard about this buoyancy, perhaps
from his distinguished pupil, Alexander. In the Meteorology
(2, 359a) he
mentions a sea in this land which is so constituted that when you tie a
man up and throw him in, he doesn't sink. Josephus
reports that the
Roman general Vespasian, with plenty of captives on hand, put the statement to a
test (War IV
8.4):
Accordingly,
when Vespasian went to see it, he commanded that some who
could not swim should have their hands tied behind them, and
be thrown into the deep, when it so happened that they all
swam as if a wind had forced them upwards.
The various names of
the lake through the ages reflect the
fascination it has aroused: the Sea of the Desert and the Salt
Sea (both in Deuteronomy
3:17);
the Asphalt Sea; the Sea of Sodom; the Stink Sea,
from a time when the smell of sulfur was more pervasive.
The sulfur led the Crusaders to call it the Devil's Sea.
Where
do the salts come from? There are brackish springs, for one thing. Flash
floods bring in salts. And before the sea had its present form or content,
the region was connected via the
Jordan and Jezreel valleys to the Mediterranean: sea water filled
the deepening rift. To these three factors we must add a
fourth: evaporation. Other things being equal, the lower we go on the face of
the earth, the hotter it is. The evaporation from the Dead
Sea is enormous, reaching 25 mm. per day in the summer months. (In
four summer days it loses the equivalent of its yearly supply
of rain.) When evaporation occurs, the salts are left behind. The
same occurs to the human body here, so you must drink plenty or join
Lot's wife.
On the sea bottom
are large amounts of asphalt (bitumen, referred to in the Bible as pitch
or tar). When the earth trembles (as it often does in this
deep rift) pieces break away and float to the surface. The sea has
been known to spew up chunks as big as houses. In the third
millennium BC, people from the city of Arad (in the
desert west of Masada) exported the asphalt to Egypt, which used it
to seal ships and mummies. (The word "mummy" comes from the Semitic
word for bitumen, "mumiya.")
Sodium chloride was also valuable (as reflected in the root of the English
"salary," and a worker, we hope, is "worth her salt"). Salt appears above the water
in the southern basin, whose western shore includes a mountain of
it eight miles long. In the 2nd century BC, the camel
caravans of the Nabataeans bore it, together with asphalt, to
harbors on the Mediterranean.
Today the Dead Sea is 418 meters below the
level of
the oceans and falling. Its level has varied
greatly throughout the ages, however. In the early 20th century-before the
states of Israel, Jordan and Syria harnessed the sources of the
Jordan River for drinking and irrigation-the sea received 1.2 billion cubic
meters of fresh water yearly. It lost that much through evaporation
(the sky is its only outlet), so a balance was maintained. Today it gets
a billion cubic meters less; its surface is sinking at the rate of a
meter per year. The northern basin is 1100 feet deep, so it will be
around, though shrinking, for a while. The shallow southern basin, however,
would be utterly dry if Israel and Jordan didn't channel
water to it from the northern one.
These two nations have an economic interest
in keeping the southern basin wet. The salts are valuable. Among
them are chlorides of
potash,
magnesium and bromide. The shallow
southern basin is divided into a series of evaporation pools. The
salts reach saturation points at different stages and are then
hauled in.
Afloat in the Dead Sea
Floating in the Dead Sea is a unique experience, but there
are several cautions: |
