12 December 2011
A dry Dead Sea before biblical times
The Dead Sea nearly disappeared about 120,000 years ago, say researchers who drilled below one of the deepest parts.
The new research started as an attempt to understand the history of the Dead Sea, which has been drying up at dramatic rates in recent decades. As a result of both evaporation and intensive human demands for water from inflowing rivers, the surface of the lake dropped 23 metres from 1930 to 2000, said Emi Ito, a geochemist at the University of Minnesota (USA). What is more, the rate of shrinking seems to be accelerating. From 2000 to 2008, levels dropped 8 metres, with another 1.5 metre lost in 2010 alone.
An international team of researchers drilled down about 460 metres into sediments of the Dead Sea, at a spot just slightly shallower than the lake's deepest point. The cores they pulled up stretched back 200,000 years. At a level corresponding with 120,000 years ago, during a warm period between ice ages, the researchers found a layer of small round pebbles sitting on top of 45 meters of thick salt deposits. Those pebbles look just like the rocks that normally appear on the lake's beaches, suggesting that one of the deepest parts of the lake was once dry.
If the Dead Sea could become mostly dry once, the concern is that it could happen again, raising the likelihood for wars over water and the loss of still mostly unstudied life forms that manage to thrive in such saline waters.
Edited from Discovery News (8 December 2011)
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