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Isabel Kershner -
Five miles out, nearly to the center of the Dead Sea, an international team of scientists has been drilling beneath the seabed to extract a record of climate change and earthquake history stretching back half a million years.
The preliminary evidence and clues found halfway through the 40-day project are more than the team could have hoped for. The scientists did not expect to pull up a wood fragment that was roughly 400,000 years old. Nor did they expect to come across a layer of gravel from a mere 50,000 to 100,000 years ago. That finding would seem to indicate that what is now the middle of the Dead Sea — which is really a big salt lake — was once a shore, and that the water level had managed to recover naturally.
“We knew the lake went through high levels and lower levels,” said Prof. Zvi Ben-Avraham, a leading Dead Sea expert and the driving force behind the project, “but we did not know it got so low.” Professor Ben-Avraham, a member of the Israel Academy of Sciences and Humanities and chief of the Minerva Dead Sea Research Center at Tel Aviv University, had been pushing for such a drilling operation for 10 years. The idea was to bore under the sea and extract a continuous geological core that, once analyzed, could supply information of global importance on natural processes and environmental changes. The Dead Sea sits in the largest and deepest basin in the world. The scientists chose to drill at its center because they assumed that the sediment that had accumulated there had always been under water, the better preserved for having never been exposed to the atmosphere. The special composition of the Dead Sea waters also affords unique opportunities for research. A special mineral found in the lake can be used for dating much further back in time than the more common radiocarbon method allows, giving the scientists an unprecedented insight into the history of natural forces in the region.
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