Drilling Project in the Dead Sea Warns of Climate Change
An international team of scientists drilling deep under the bed of the Dead Sea has found evidence that the sea may have dried up during a past warm period similar to predicted scenarios for climate change in coming decades. University of Minnesota College of Science and Engineering professor of earth sciences Emi Ito is one of the researchers on the team.With nations in the volatile region already running short on water, the finding could be a warning of worse shortages to come, the researchers say. The lakebed cores, which contain about 200,000 years of environmental history – the Mideast’s longest archive – also record earthquakes and other natural phenomena, and may shed light on human development and current seismic risks.
The Dead Sea is the world’s lowest-lying place on land, with shores some 1,400 feet below sea level, and salty waters going down another 1,200 feet. Fed by the Jordan River, it has shrunk rapidly over past decades, as water is pulled for farming and other uses.
Near the sea’s center, under 900 feet of water, the team penetrated some 750 feet of muddy sediment, then hit a layer of nearly pure pebbles, underlain by some 120 feet of salt. The salt suggests to them that the lake dried quickly, precipitating out solids. The pebbles appear to be a beach – given their position near the middle, a signal that the sea more or less disappeared. Research by others already has shown that the sea has fluctuated, but this is the first time anyone has found that it actually disappeared.
The cores have not yet been precisely dated, but the researchers have correlated some layers with isotopes found in Mideast cave deposits, and believe the total drying took place around 125,000 years ago – the height of a warm period between the two most recent ice ages, when the Mideast already is known to have been not only warmer, but drier, than today. Climate projections say that if the world keeps warming as it is now, the Mideast could return to this more arid state within decades.
Reports by the United Nations and other bodies have cited water as a potential spark for future Mideast conflicts. In the past, the governments of Egypt and Jordan have said that they would never go to war again against Israel – except over water.
“The Dead Sea has witnessed so much of human history from the migration of early humans out of Africa, habitation by early Stone Age people all the way to the Near East politics of today,” says Ito. “To think that we, the humans, are helping it perhaps dry up, is very sobering.”
Ito says the Dead Sea water level has been going down by three feet to five feet each year, due to a combination of dry climate of the region and human activity. Jordan River’s water is heavily used for irrigation and little is left to flow into the Dead Sea. If the previous warm period before the last ice age is any guide, the Near East is going to become drier and drier under warming climate.
The Dead Sea’s basin is a plate boundary like the San Andreas Fault in California, and the cores also contain a detailed log of past earthquakes there. When quakes occur, typically flat layers of sediment are twisted into convoluted shapes. With precise dating, these should form a history from ancient times to the present, and perhaps give a better picture of future risks faced in the region. It could help answer longstanding questions. For instance, some say the Biblical overthrow of the walls of Jericho was performed by an earthquake – but whether such a quake took place, and when, has remained controversial. The research team now is in the process of doing more precise dating.
The drilling, some 10 years in the making, was done under the auspices of the International Continental Scientific Drilling Program (ICDP), which sponsored the project and covered much of the cost.
The Latest from EPA on Hydrofracturing: Blame for Pollution
The U.S. Environmental Protection Agency (EPA) recently announced for the first time that hydrofracturing may be to blame for causing ground water pollution.The agency released a draft analysis of data from its Pavillion, Wyo., ground water investigation. At the request of Pavillion residents, EPA began investigating water-quality concerns in private drinking water wells three years ago. Since that time, in conjunction with the state of Wyoming, the local community, and the owner of the gas field, Encana, EPA has been working to assess ground water quality and identify potential sources of contamination.
EPA constructed two deep monitoring wells to sample water in the aquifer. The draft report indicates that ground water in the aquifer contains compounds likely associated with gas production practices, including hydraulic fracturing. EPA also re-tested private and public drinking water wells in the community. The samples were consistent with chemicals identified in earlier EPA results released in 2010, and generally are below established health and safety standards. To ensure a transparent and rigorous analysis, EPA is releasing these findings for public comment and will submit them to an independent scientific review panel. The draft findings announced are specific to Pavillion, where the fracturing is taking place in and below the drinking water aquifer and in close proximity to drinking water wells – production conditions different from those in many other areas of the country.
Natural gas plays a key role in our nation’s clean energy future and the Obama administration is committed to ensuring that the development of this vital resource occurs safely and responsibly. At the direction of Congress, and separate from this ground water investigation, EPA has begun a national study on the potential impacts of hydraulic fracturing on drinking water resources.
EPA’s analysis of samples taken from the agency’s deep monitoring wells in the aquifer indicates detection of synthetic chemicals, like glycols and alcohols consistent with gas production and hydraulic fracturing fluids, benzene concentrations well above Safe Drinking Water Act standards and high methane levels. Given the area’s complex geology and the proximity of drinking water wells to ground water contamination, EPA is concerned about the movement of contaminants within the aquifer and the safety of drinking water wells over time.
EPA also updated its sampling of Pavillion area drinking water wells. Chemicals detected in the most recent samples are consistent with those identified in earlier EPA samples and include methane, other petroleum hydrocarbons and other chemical compounds. The presence of these compounds is consistent with migration from areas of gas production. Detections in drinking water wells are generally below established health and safety standards.
The draft finding could have significant implications while states try to determine how to regulate the process.
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