How did the Dead Sea form?
In this part of the world there is a rift forming where two crustal plates
are spreading apart. The East Rift Valley runs through most of Africa, but
it starts north of the Dead Sea and runs south along the eastern side of
the continent. The Sea is located right along the Rift Valley where the
Earth's crust is being stretched thin.
To get an idea of how this "crustal
spreading" occurs, take a bar of taffy and try to pull it apart. You'll
see where the candy starts to stretch it gets really thin just before it
breaks. That's what is happening to the Earth's crust in the Rift Valley.
Where the Earth's crust gets thin that part of the surface sinks lower.
The Dead Sea is still sinking lower even today. Scientists estimate the Dead
Sea sinks an average of 13 inches each year. On a geologic time scale
that's incredibly fast!
Why is the Dead Sea so salty?
Approximately three million years ago the Mediterranean Sea penetrated the
East Rift Valley, emptying seawater into the region. This deposited
enormous amounts of salt in the region. Over time, the early lagoon that
had formed became separated from the nearby lakes as the Mediterranean Sea
withdrew. Since then, the Dead Sea has been continually fed water from the
Jordan River and other small streams that surround it.
The most unique aspect of all this is the
evaporation that occurs. This is the only way water gets out of the Dead
Sea. And boy does it evaporate! This part of the world gets plenty hot!
When the water evaporates, it leaves behind
all the dissolved minerals in the Sea, just making it saltier. In fact,
it's a combination of the action of (1) huge deposits of salts from the
ancient Mediterranean ocean (2) continued evaporation and (3) mineral
salts carried in the sea from the local rivers, the Dead Sea continues to
Since the water does not escape and just
traps the salts within its shores, evolution has not had a chance to
produce any creatures that could adapt to such brutal conditions.
The Dead Sea Minerals & Their Benefits