Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Oceanographers in noble pursuit

21.01.2002


The warm gulf stream (red) as it travels across the Atlantic.
© RSMAS


Vast warm and cold currents loop around the globe.


Argon traces keep tabs on climate change.

A new method for detecting tiny quantities of a rare form of the element argon may help oceanographers to trace the vast undersea currents that regulate our planet’s climate.

The technique can pick out one atom of the rare isotope argon-39 (39Ar) amid 10 million billion other atoms. That’s equivalent to detecting less than a litre of water in America’s 300-mile Lake Michigan.



Philippe Collon, a nuclear physicist at the Lamont-Doherty Earth Observatory in Palisades, New York, and his colleagues modified a particle accelerator at Argonne National Laboratory near Chicago to find and count 39Ar atoms. Counting 39Ar "is decidedly tricky", says Collon. His team are still perfecting their technique.

Previous efforts to count 39Ar atoms in seawater required thousands of litres of water and months of processing. Collon’s technique should be able to measure the isotope’s concentration in about 10 litres of water in a few hours.

Ideal gas

Rare 39Ar is produced in the atmosphere by cosmic rays hitting ordinary 40Ar - it then dissolves into the sea. Because the isotope decays at a fixed rate, the amount that remains at different depths tells researchers how long it has been since the water was last at the surface.

If the team can provide a reliable way to measure 39Ar, samples from the deep ocean could begin to yield new clues about the huge currents of the Great Ocean Conveyor Belt, and whether they are changing over time.

The conveyor belt is a giant loop that spans most of the world’s oceans - cold water moves from north to south along the sea floor, whereas warm water travels the other way at the surface. A complete cycle takes about 1,000 years.

The water in the conveyor belt carries much of the Earth’s heat, making it crucial to climate. Melting ice after the most recent Ice Age is thought to have halted the conveyor, causing sudden and massive shifts in climate. Some climatologists worry that melting of ice caps as a result of global warming could have the same effect.

The half-life of 39Ar - 269 years - "falls into a timescale that’s very useful for measuring climate change", says Bill Jenkins, who studies ocean circulation at the University of Southampton, UK.

Even better, Jenkins adds, argon is biologically inert. The movement of radioactive carbon in the bodies of plants and animals have confused previous ocean studies using that element.

But argon "doesn’t solve all of oceanography’s problems", warns Jenkins. There is still some question as to whether 39Ar is produced at a constant rate in the atmosphere. If it isn’t, fluctuations measured in the ocean may not have a direct bearing on ocean circulation.




TOM CLARKE | © Nature News Service
Further information:
http://www.nature.com/nsu/020114/020114-14.html

More articles from Earth Sciences:

nachricht World’s oldest known oxygen oasis discovered
18.01.2018 | Eberhard Karls Universität Tübingen

nachricht A close-up look at an uncommon underwater eruption
11.01.2018 | Woods Hole Oceanographic Institution

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>