The Dead Sea and Climate Change Over 220,000 Years
April 4, 2017
The Jerusalem Post — There is a direct relationship between hydrological and chemical changes in the Dead Sea and global climate change over the past 220,000 years, according to new research conducted at Ben-Gurion University of the Negev.
The research was published recently in the leading geoscience journal Geology as part of the doctoral study of Elan Levy, a Ph.D. student at BGU’s Department of Geological and Environmental Sciences.
Previously, records of sea water levels have served as a barometer for how dry or wet a particular period of time was. But, this marks the first time a direct relationship has been established between Dead Sea water composition and regional climate change.
Levy’s research focused on reconstructing climate conditions of the past by using “pore water” — the pressure of groundwater held within soil or rock in gaps between particles, or pores — trapped within sediments in the Dead Sea. Levy and his team extracted pore fluids trapped in a 1,470-foot sediment core that was drilled from the sea floor in 2011, and measured its geochemical and isotopic parameters.
By studying the sediment core, the researchers were able to look at sea water from multiple time periods. They found that during glacial periods, when there was a drop in global temperatures, there was a dilution of the lake accompanied by greater dissolving of Halite, or rock salt, in the sea.
Conversely, during warmer interglacial periods when there was a rise in oceanic sea levels, the deep waters became more concentrated and Halite was precipitated, or crystalized, in greater quantities.
“The similarity between global climate records and the pore water records from the Dead Sea emphasize a strong relationship between rainfall and humidity in the region and global climate changes, findings that are important for understanding and predicting climate change in Israel and the region,” the researchers note.