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 New Technique for Finding Weakness in Earth’s Crust
30.09.2016 | University of Adelaide

nachricht Researcher creates a controlled rogue wave in realistic oceanic conditions
30.09.2016 | Aalto 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: First-Ever 3D Printed Excavator Project Advances Large-Scale Additive Manufacturing R&D

Heavy construction machinery is the focus of Oak Ridge National Laboratory’s latest advance in additive manufacturing research. With industry partners and university students, ORNL researchers are designing and producing the world’s first 3D printed excavator, a prototype that will leverage large-scale AM technologies and explore the feasibility of printing with metal alloys.

Increasing the size and speed of metal-based 3D printing techniques, using low-cost alloys like steel and aluminum, could create new industrial applications...

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Paper – Panacea Green Infrastructure?

30.09.2016 | Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

 
Latest News

First-Ever 3D Printed Excavator Project Advances Large-Scale Additive Manufacturing R&D

30.09.2016 | Materials Sciences

New Technique for Finding Weakness in Earth’s Crust

30.09.2016 | Earth Sciences

Cells migrate collectively by intermittent bursts of activity

30.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>