(Press-News.org) A portion of the groundwater in the upper Patapsco aquifer underlying Maryland is over a million years old. A new study suggests that this ancient groundwater, a vital source of freshwater supplies for the region east of Washington, D.C. and Baltimore, was recharged over periods of time much greater than human timescales.
"Understanding the average age of groundwater allows scientists to estimate at what rate water is re-entering the aquifer to replace the water we are currently extracting for human use," explained USGS Director Marcia McNutt. "This is the first step in designing sustainable practices of aquifer management that take into account the added challenges of sea level rise and increased human demand for quality water supplies."
This new study from the USGS, the Maryland Geological Survey (MGS) and the Maryland Department of the Environment (MDE) documents for the first time the occurrence of groundwater that is more than one million years old in a major water-supply aquifer along the Atlantic Coast. The oldest groundwater was found in the deepest parts of the aquifer, but groundwater even in shallower parts of the aquifer is tens to hundreds of thousands years old.
Groundwater age indicates the length of time that a sample of water has been in the ground since infiltrating from the land surface. This study reveals that modern pumping in southern Maryland west of the Chesapeake Bay and on the Eastern Shore is tapping groundwater resources that have accumulated in the aquifer over multiple cycles of climate change and are not quickly recharging.
The analysis shows that water flowed from the land surface into the deep aquifer during cooler periods in earth's history, when glaciers covered much of the northeastern U.S. and sea level was about 125 meters lower than it is today. During warmer periods in earth's history, such as in modern times, higher sea levels slow recharge of fresh water to the aquifer, due to a lower gradient between the recharge and discharge areas.
Modern-day pumping rates have lowered water pressures and changed water chemistry, affecting the aquifer's ability to provide freshwater for drinking and other uses. Concerns over saltwater intrusion in some areas have led water managers to increasingly move groundwater production from shallower aquifers to the deeper upper Patapsco aquifer, which has caused groundwater levels to decline.
The findings are being used to help understand the patterns and rates of groundwater movement in the aquifers of the Coastal Plain. Such information will be used by the Maryland Department of the Environment to ensure that the management and use of the State's groundwater resources are being carried out to protect its long-term sustainability. The findings bring into focus that current users are withdrawing groundwater that was recharged eons ago and accentuate the need to review current water-supply management strategies and develop new tools and models to protect this valuable resource for the future.
There are relatively few aquifers in the world in which million-year-old groundwater has been documented, including the Nubian aquifer in the Sahara Desert, Canada's Alberta Basin, and the Great Artesian Basin in Australia
Aquifer sustainability is one of several priority topics currently being addressed by the USGS Groundwater Resources Program (http://water.usgs.gov/ogw/gwrp/), the USGS National Research Program (http://water.usgs.gov/nrp/), and the USGS Cooperative Water Program (http://water.usgs.gov/coop/).
###More information about the study is available online (http://www.springerlink.com/content/j08u34jh46r632v4/) and in Hydrogeology Journal in an article titled, "Old groundwater in parts of the upper Patapsco aquifer, Atlantic Coastal Plain, Maryland, USA: evidence from radiocarbon, chlorine-36 and helium-4," by L. N. Plummer, J. R. Eggleston, D. C. Andreasen, J. P. Raffensperger, A. G. Hunt, and G. C. Casile. If you would like a copy of the report, contact Kara Capelli at kcapelli@usgs.gov.
USGS provides science for a changing world. Visit USGS.gov, and follow us on Twitter @USGS and our other social media channels.
Subscribe to our news releases via e-mail, RSS or Twitter.
Links and contacts within this release are valid at the time of publication.
Million year old groundwater in Maryland water supply
2012-06-19
ELSE PRESS RELEASES FROM THIS DATE:
Anti-cocaine vaccine described in Human Gene Therapy Journal
2012-06-19
New Rochelle, NY, June 18, 2012—A single-dose vaccine capable of providing immunity against the effects of cocaine offers a novel and groundbreaking strategy for treating cocaine addiction is described in an article published Instant Online in Human Gene Therapy, a peer-reviewed journal from Mary Ann Liebert, Inc. (http://www.liebertpub.com) The article is available free online at the Human Gene Therapy website (http://www.liebertpub.com/hum).
"This is a very novel approach for addressing the huge medical problem of cocaine addiction," says James M. Wilson, MD, PhD, Editor-in-Chief, ...
Doctors cite concern for patients, colleagues top motives for working sick
2012-06-19
An unwavering work ethic is a hallmark of many health professionals. But a new survey finds that when a doctor is sick, staunch dedication can have unintended consequences.
A poll of 150 attendees of an American College of Physicians meeting in 2010 revealed that more than half of resident physicians had worked with flu-like symptoms at least once in the last year. One in six reported working sick on three or more occasions during the year, according to the survey conducted by researchers at the University of Chicago Medicine and Massachusetts General Hospital. Notably, ...
Canadian teen moms run higher risk of abuse, depression than older mothers
2012-06-19
(Edmonton) Teen mothers are far more likely to suffer abuse and postpartum depression than older moms, according to a study of Canadian women's maternity experiences by a University of Alberta researcher.
Dawn Kingston, an assistant professor in the Faculty of Nursing, analyzed data from the Maternity Experiences Survey, which asked more than 6,400 new mothers about their experiences with stress, violence, pre- and postnatal care, breastfeeding and risky behaviour like smoking and drug use before, during and after pregnancy.
Kingston said the survey offers the first ...
Understanding faults and volcanics, plus life inside a rock
2012-06-19
Boulder, Colo., USA – This posting: Orange-like rocks in Utah with iron-oxide rinds and fossilized bacteria inside that are believed to have eaten the interior rock material, plus noted similarities to "bacterial meal" ingredients and rock types on Mars; fine-tuning the prediction of volcanic hazards and warning systems for both high population zones and at Tristan da Cunha, home to the most remote population on Earth; news from SAFOD; and discovery in Germany of the world's oldest known mosses.
Biosignatures link microorganisms to iron mineralization in a paleoaquifer
Karrie ...
Psoriasis increases risk of diabetes, Penn study shows
2012-06-19
PHILADELPHIA - Psoriasis is an independent risk for Type 2 Diabetes, according to a new study by researchers with the Perelman School of Medicine at the University of Pennsylvania, with the greatest risk seen in patients with severe psoriasis. Researchers estimate that an additional 115,500 people will develop diabetes each year due to the risk posed by psoriasis above and beyond conventional risk factors. The research is published in the latest issue of the Archives of Dermatology, a JAMA Network publication.
"These data suggest that patients with psoriasis are at increased ...
Cheaper drug could lead to serious eye issues
2012-06-19
A Queen's University study of two eye drugs used to treat wet Age-related Macular Degeneration (AMD) has determined the cheaper of the two could lead to eye inflammation, a potentially blinding adverse effect.
"This is a very important finding," says Sanjay Sharma (Ophthalmology and Epidemiology), a noted AMD and health policy researcher who also practices at Hotel Dieu Hospital. "It is particularly important because many seniors need numerous injections so the risk is cumulative."
AMD is the leading cause of severe visual loss and blindness in Canada. It is linked to ...
Brothers in arms: Commensal bacteria help fight viruses
2012-06-19
PHILADELPHIA – Healthy humans harbor an enormous and diverse group of bacteria and other bugs that live within their intestines. These microbial partners provide beneficial aid in multiple ways – from helping digest food to the development of a healthy immune system. In a new study published online in the journal Immunity, David Artis, PhD, associate professor of Microbiology, and Michael Abt, PhD, a postdoctoral researcher in the Artis lab, Perelman School of Medicine, University of Pennsylvania, show that commensal bacteria are also essential to fight off viral infections. ...
Discovery helps mice beat urinary tract infections
2012-06-19
Scientists at Washington University School of Medicine in St. Louis have found new clues to why some urinary tract infections recur persistently after multiple rounds of treatment.
Their research, conducted in mice, suggests that the bacteria that cause urinary tract infections take advantage of a cellular waste disposal system that normally helps fight invaders. In a counterintuitive finding, they learned that when the disposal system was disabled, the mice cleared urinary tract infections much more quickly and thoroughly.
"This could be the beginning of a paradigm ...
Social-class discrimination contributes to poorer health
2012-06-19
Discrimination felt by teenagers based on their social class background can contribute to physiologic changes associated with poorer health, according to a new study published online in Psychological Science, a journal of the Association for Psychological Science.
Lead author Dr. Thomas Fuller-Rowell, a researcher at the University of Wisconsin-Madison and a Robert Wood Johnson Foundation Health & Society Scholar, says that while the link between poverty and poor health has long been known, this is one of the first studies to consider the impact of class discrimination.
"The ...
Clues to nervous system evolution found in nerve-less sponge
2012-06-19
(Santa Barbara, Calif.) –– UC Santa Barbara scientists turned to the simple sponge to find clues about the evolution of the complex nervous system and found that, but for a mechanism that coordinates the expression of genes that lead to the formation of neural synapses, sponges and the rest of the animal world may not be so distant after all. Their findings, titled "Functionalization of a protosynaptic gene expression network," are published in the Proceedings of the National Academy of Sciences.
"If you're interested in finding the truly ancient origins of the nervous ...