John Hall, age 12, of Allentown, Penna., for his question:
What makes the Dead Sea so salty?
The Dead Sea is actually a lake, for it has no outlet to the ocean. The surface of its salty water is about 1300 feet below the level of the sea, which makes it the lowest body of water in the world. Every day, the river Jordan empties some six million tons of water into this ancient lake. The lake water is warm, warmer than the air above it. Hazy patches of vapor hang over the water and lazily form clouds that drift and fade in the brilliant desert sky.
This vapor gives us the clue to what makes the Dead Sea so salty . and why it gets saltier with every day. Those six million tons of water poured in daily from the Jordan and its streams do not cause the level of the lake to rise, Instead, every day an equal amount of water evaporates into the air.
In warm dry air, molecules of water get enough energy to free themselves and take to the air as gaseous molecules of vapor. This does not happen to the salts and other chemicals which happen to be dissolved in the water. Streams, springs and rivers dissolve those chemicals as they run over the ground and seep into the rocks. These tumbling waters eventually collect in lakes and seas. Here the surface water.. is forever evaporating into the air as vapor. As it does so, the salts and dissolved chemicals are left behind.
The waters of the river Jordan rise far to the north of the Dead Sea. They flow first through the beautiful little Lake of Gallilee. A number of hot springs empty their waters into the floor of this lake. These deep springs have run through rocks containing bromine salts. These chemicals are dissolved and carried up into the lake.
The Jordan, flowing through the Lake of Gallilee, sweeps along with these dissolved bromine salts and finally empties them into the Dead Sea. It is estimated that there are about 180 million tons of bromine salts dissolved in the waters of the Dead Sea. Altogether, the concentration of salts in the lake is about five and a half times greater` than that in ocean water.
These salts make it impossible for fish or any other creatures to live in the salty little lake which is why this lifeless little body of water is called the Dead Sea. Fish are able to live in the river Jordan, but when they aye swept into the lake, they soon perish. Plants cannot even live around the salt crusted shores. The only creatures around are sea birds. They sweep in to feed on the unlucky fish that perish in the lake.
Geologists believe that at one time the waters of the Dead Sea filled most of the Jordan Valley. The lake was then about 190 miles long. Through the ages, the little lake shrank and is perhaps still shrinking. It is now one forth of its original length arid one forth of its original volume,