Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Natural radioactivity used to determine seasonal changes in groundwater supply

22.11.2002


The discharge of groundwater to coastal waters represents an important source of dissolved nutrients and contaminants that may affect chemical and biological processes in coastal ecosystems. In a journal article published in a recent issue of Limnology and Oceanography, URI Graduate School of Oceanography chemical oceanographers Roger P. Kelly and S. Bradley Moran describe how they used radium isotopes as tracers to determine seasonal changes in groundwater input to the Pettasquamscutt estuary from June 1999 to June 2000.

Radioactive isotopes of the naturally occurring element radium have recently been used as tracers of groundwater input to coastal zones. None of these studies, however, have evaluated seasonal changes in groundwater input. Measuring seasonal changes, as opposed to total input over the course of a year, provides scientists and managers with a more accurate understanding of coastal ecosystems as well as information about the periods of greatest impact over the annual cycle.

The Pettasquamscutt estuary, locally known as the Narrow River, is located adjacent to Narragansett Bay in southern Rhode Island and discharges into Rhode Island Sound. The estuary is approximately 6.5 miles long and has an average depth of 6 feet. Previous studies of the Pettasquamscutt estuary have determined that up to 50% of the freshwater input may be from groundwater.



Radium isotopes in the groundwater of the Pettasquamscutt are derived naturally from the weathering of the underlying metasediment and granite bedrock within the watershed. Using a mathematical model that considers the exchange of water between the river and Rhode Island Sound, the amount of radium desorbed from particles suspended in the water, and groundwater supply, Kelly and Moran observed seasonal changes in groundwater input to the estuary by measuring the excess radium derived from groundwater.

They determined that groundwater input was highest in the summer, lowest in the winter, and intermediate in the spring and fall. Kelly and Moran also estimated the quantity of inorganic nitrogen and phosphorous supplied by groundwater. They speculate that seasonal changes in groundwater supply of these nutrients may influence the occurrence of phytoplankton bloom events in such coastal systems through the annual cycle.

"There is a real need for reliable data on groundwater supply as demands on fresh water reservoirs continue to increase," said Moran.



The URI Graduate School of Oceanography is one of the country’s largest marine science education programs, and one of the world’s foremost marine research institutions. Founded in 1961 in Narragansett, RI, GSO serves a community of scientists who are researching the causes of and solutions to such problems as acid rain, harmful algal blooms, global warming, air and water pollution, oil spills, overfishing, and coastal erosion. GSO is home to the Coastal Institute, the Coastal Resources Center, Rhode Island Sea Grant, the Institute for Archaeological Oceanography, and the National Sea Grant Library.


Lisa Cugini | EurekAlert!
Further information:
http://aslo.org/lo/toc/vol_47/issue_6/1976.pdf

More articles from Earth Sciences:

nachricht Heidelberg Researchers Study Unique Underwater Stalactites
24.11.2017 | Universität Heidelberg

nachricht Lightning, with a chance of antimatter
24.11.2017 | Kyoto University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>