Dead Sea research could unearth geological secrets of the earth's past
Researchers have long pondered how the less dense salty warm water on the top of the lake "snows" downward to the bottom where there is the more dense, cold water.
By JERUSALEM POST STAFFThe Dead Sea as photographed by Leonid Padrul (photo credit: LEONID PADRUL)
The American Geophysical Union released a new that explains why salt crystals pile up on the Dead Sea's floor. The results of these findings could help scientists understand how large salt deposits have formed in the past.The Dead Sea is known for being the lowest point of land in the world as well as one the world's saltiest bodies of water. The lake is nearly 10 times saltier than average ocean water.Researchers have long pondered how the less dense salty warm water on the top of the lake "snows" downward to the bottom of the lake where there is the more dense, cold water. This scenario ostensibly defies the law of physics, where something less dense falls downward into a more dense area.“Initially you form these tiny fingers that are too small to observe... but quickly they interact with each other as they move down, and form larger and larger structures,” said Raphael Ouillon, a mechanical engineer at the University of California Santa Barbara and lead author of the new study.The scientists proposed that as waves and motion disturb the lake, some of the warm water enters and mixes with the cool water. While the warm water quickly dissipates and becomes cool, some of the salt precipitates. This salt then forms crystals and sinks to the bottom.The study used a computer simulation to confirm their suspicions: that movement in the water causes the salt to slowly accumulate and create "salt fingers" at the bottom of the lake.“We know that many places around the world have thick salt deposits in the Earth's crust, and these deposits can be up to a kilometer thick,” another lead researcher, Eckart Meiburg, said. “But we're uncertain how these salt deposits were generated throughout geological history.”One example is the Strait of Gibraltar, which was once closed off and later dried out, leaving thick deposits of salt. Based on this study of the Dead Sea, researchers believe the salt reached the bottom of the lake via the same method.
