Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Two water testing methods could prove useful in predicting effects of global climate change

12.05.2004


Ohio State University geologists and their colleagues have used two water-testing methods together for the first time to help a Gulf Coast tourist community manage its water supply.

The two methods could prove useful for gauging how rising sea levels -- one of the possible effects of global climate change -- might cause salt water to infiltrate drinking water along coastal areas in the future.

Anne Carey, assistant professor of geological sciences at Ohio State, likened Baldwin County in southwestern Alabama -- where the study was conducted -- to the Chesapeake Bay area, where rising seawater has already covered some islands and ruined agriculture on others.



“Sea level is rising in places where coastal development is rapid,” Carey said. “Some wells have been abandoned in Baldwin County due to salt water intrusion. Increased water usage and sea-level rise are likely to exacerbate the problem.”

To map water usage, geologists often measure the age of water taken from different sites around a region. The age suggests how quickly rainwater renews the water supply, and how quickly seawater could potentially enter the system.

The Alabama site was ideal for Carolyn Dowling, a post-doctoral investigator with Ohio State’s Byrd Polar Research Center, to compare two different methods of water dating for her doctoral dissertation. One was the well-known radiocarbon dating, which measures the presence of the isotope carbon-14, while the other was a lesser-known method that measured the isotope helium-4.

Though scientists long thought the two methods were incompatible, Carey and Dowling successfully used both together to determine that ages in different wells ranged from 50 years to 7,500 years. The results appear in a recent issue of the Geological Society of America journal Geology.

Carbon dating placed the ages of water from different wells in a range of approximately 375 to 7,000 years old, and the helium method suggested a similar range -- 50 to 7,500 years old.

To Carey, the ages themselves are not particularly surprising.

“This isn’t really, really old water -- it’s all from the Holocene, the period since the last ice age,” she said. “In northern Ohio, there are places where people are pumping Pleistocene water [more than 10,000 years old].”

“It was startling to the well operators that their waters were that old, but it isn’t a startling story geologically,” she continued. “The important part of the research is that we could show the nice correspondence between the two methods, which has never been done before.”

Any prediction of how quickly global climate change could cause salt water to infiltrate Baldwin County would require further study, Carey said. But this early work shows that scientists can use both dating methods simultaneously to get a more reliable view of water usage.

“Any time you can measure something with two different methods, you can be more confident in the results,” she said.

Water usage in Baldwin County surges during the spring and summer tourist seasons, when turf grass farms also draw on freshwater supplies for irrigation. More than 20 percent of the county is water, and its extensive lowlands would make it particularly susceptible to flooding, should water levels rise in the Gulf of Mexico.

That’s why the Department of Energy’s National Institute for Global Environmental Change was interested in the region, and commissioned the study.

Carey, Dowling, and colleague Robert Poreda at the University of Rochester tested the water from 12 wells around Baldwin County using both methods.

Carbon dating measures how much carbon-14 is left in the water since the last time the water contacted carbon dioxide in the air. Helium dating measures how much helium has dissolved into the water from surrounding rock as it lay underground. Both give scientists a measure of how long water has been in a particular well or aquifer.

The results also suggested that the Baldwin County well operators are doing a good job of drawing fresh water from the right places at the right time to keep salt water from entering the system for now.

Saltwater infiltration could become a bigger issue in the future with global climate change.

Over the last 100 years, sea level worldwide has risen an average of 2 millimeters per year. The melting of tropical glaciers and polar ice caps, which scientists have documented in recent years, could increase that rate. A warmer climate would also heat the oceans, causing them to expand -- and sea level to rise further.


Contact: Anne Carey, (614) 292-2375; Carey.145@osu.edu
Carolyn Dowling, (614) 292-3229; Dowling.37@osu.edu

Pam Frost Gorder | OSU
Further information:
http://researchnews.osu.edu/archive/waterage.htm

More articles from Earth Sciences:

nachricht The seismicity of Mars
25.02.2020 | ETH Zurich

nachricht Major wind-driven ocean currents are shifting toward the poles
25.02.2020 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: High-pressure scientists in Bayreuth discover promising material for information technology

Researchers at the University of Bayreuth have discovered an unusual material: When cooled down to two degrees Celsius, its crystal structure and electronic properties change abruptly and significantly. In this new state, the distances between iron atoms can be tailored with the help of light beams. This opens up intriguing possibilities for application in the field of information technology. The scientists have presented their discovery in the journal "Angewandte Chemie - International Edition". The new findings are the result of close cooperation with partnering facilities in Augsburg, Dresden, Hamburg, and Moscow.

The material is an unusual form of iron oxide with the formula Fe₅O₆. The researchers produced it at a pressure of 15 gigapascals in a high-pressure laboratory...

Im Focus: From China to the South Pole: Joining forces to solve the neutrino mass puzzle

Study by Mainz physicists indicates that the next generation of neutrino experiments may well find the answer to one of the most pressing issues in neutrino physics

Among the most exciting challenges in modern physics is the identification of the neutrino mass ordering. Physicists from the Cluster of Excellence PRISMA+ at...

Im Focus: Therapies without drugs

Fraunhofer researchers are investigating the potential of microimplants to stimulate nerve cells and treat chronic conditions like asthma, diabetes, or Parkinson’s disease. Find out what makes this form of treatment so appealing and which challenges the researchers still have to master.

A study by the Robert Koch Institute has found that one in four women will suffer from weak bladders at some point in their lives. Treatments of this condition...

Im Focus: A step towards controlling spin-dependent petahertz electronics by material defects

The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.

Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...

Im Focus: Freiburg researcher investigate the origins of surface texture

Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.

Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

Scientists develop algorithm for researching evolution of species with WGD

26.02.2020 | Information Technology

MOF co-catalyst allows selectivity of branched aldehydes of up to 90%

26.02.2020 | Life Sciences

Structural framework for tumors also provides immune protection

26.02.2020 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>