Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Research in Antarctica reveals non-organic mechanism for production of important greenhouse gas

26.04.2010
In so many ways, Don Juan Pond in the Dry Valleys of Antarctica is one of the most unearthly places on the planet. An ankle-deep mirror between mountain peaks and rubbled moraine, the pond is an astonishing 18 times saltier than the Earth's oceans and virtually never freezes, even in temperatures of more than 40 degrees below zero Fahrenheit.

Now, a research team led by biogeochemists from the University of Georgia has discovered at the site a previously unreported chemical mechanism for the production of nitrous oxide, an important greenhouse gas. Possibly even more important, the discovery could help space scientists understand the meaning of similar brine pools in a place whose ecosystem most closely resembles that of Don Juan Pond: Mars.

The research, published April 25 in the journal Nature Geoscience, adds an intriguing new variable to growing evidence that there has been—and may still be—liquid water on Mars, a usual prerequisite for the formation of life. In fact, the new findings could help space scientists develop sensors for detecting such brines on Mars—thus narrowing the search for places where life may exist.

"The pond's soils and brines and the surrounding rock types are similar to those found on Mars," said Samantha Joye, a faculty member in the department of marine sciences in the Franklin College of Arts and Sciences and lead author on the paper. "So it provides an ideal location to assess microbial activity in extreme environments. While we did not detect any 'bio-gases' such as hydrogen sulfide and methane, we did, surprisingly, measure high concentrations of nitrous oxide, which is normally an indicator of microbial activity. We needed to find out whether a non-organic process could account for this nitrous oxide production."

Other authors on the paper include Vladimir Samarkin, a research scientist, and Marshall Bowles, a graduate student, also of the department of marine sciences at UGA; Michael Madigan of Southern Illinois University; Karen Casciotti of the Woods Hole Oceanographic Institution; John Priscu of Montana State University; and Christopher McKay of the Ames Research Center of NASA.

The research was supported by grants from the National Science Foundation's Antarctic Organisms and Ecosystems Program and the McMurdo Microbial Observatory Program.

Scientists have been fascinated with Don Juan Pond since its discovery in 1961. (While the site is lovely, there's nothing romantic about the name, which comes from the helicopter pilots who first found it, Don Roe and John Hickey.) From the time of its discovery, researchers realized they had found a place like nowhere else on Earth.

The pond, which is a roughly 1,000- by 400-meter basin, is the saltiest body of water on Earth by far, some eight times saltier than the Dead Sea. While researchers more than 30 years ago reported finding abundant and varied microflora of fungi, bacteria, blue-green algae and yeasts, since then and during the Joye team's work, such life has been non-existent. Since the depth level and area covered by the pond (which is fed by hypersaline groundwater) have demonstrably varied over the years, this wasn't unexpected. What did surprise the team was that even with no life-forms present, they were able to measure nitrous oxide, perhaps best known to most people as the "laughing gas" used in dental procedures. (The amounts measured in the air were beneath a level that could make a person light-headed or giddy, as "laughing gas" can.)

"What we found was a suite of brine-rock reactions that generates a variety of products, including nitrous oxide and hydrogen," said Joye. "In addition to Don Juan Pond, this novel mechanism may occur in other environments on Earth as well and could serve as both an important component of the Martian nitrogen cycle and a source of fuel [hydrogen] to support microbial chemosynthesis."

Even more interesting, perhaps, is that the results suggest that an additional mechanism—the reaction of brine-derived nitrates with basaltic rock—could be a "previously unrecognized means for mobilizing nitrate from the surface soils . . . and returning it to the Martian atmosphere as nitrous oxide," Joye said.

The discovery of water has been the holy grail of numerous Mars missions over the years, and in 2009 the Mars Phoenix mission's cameras photographed on the legs of the lander what appeared to be liquid water. If ultimately confirmed—and growing evidence appears to be solidifying in favor of such an analysis—it would be the first time liquid water was detected and photographed outside the Earth.

Working in such a beautiful but unearthly area presents stern challenges to researchers, Joye said.

"It's a 40-minute helicopter ride over the McMurdo Sound just to get there," she said. "Once in the Wright Valley, we enter a tight enclosure with steep, rocky cliffs on both sides, and between them is Don Juan Pond. I believe it must be one of the most beautiful places in Antarctica."

Samarkin agreed.

"It has the kind of beauty that rock parks in Japan have," he said, "except this is made by nature."

Beauty aside, though, the team had to dress in sterile suits and masks and use sterile instruments for sampling to avoid possible contamination. They also collected the minimal amount of material necessary to achieve their research goals.

The discovery of the new mechanism opens numerous questions that must be studied, including the possibility that the process is taking place in other extreme Antarctic habitats or that it might contribute to nitrous oxide in temperate soils—a possible new clue to understanding greenhouse gases involved in global warming.

The most crucial result, however, may be in understanding how similar brine pools on Mars might work and whether they could support life.

Sam Fahmy | EurekAlert!
Further information:
http://www.uga.edu

More articles from Earth Sciences:

nachricht New plate adds plot twist to ancient tectonic tale
15.08.2017 | Rice University

nachricht Global warming will leave different fingerprints on global subtropical anticyclones
14.08.2017 | Institute of Atmospheric Physics, Chinese Academy of Sciences

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

Im Focus: Scientists improve forecast of increasing hazard on Ecuadorian volcano

Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).

The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

New thruster design increases efficiency for future spaceflight

16.08.2017 | Physics and Astronomy

Transporting spin: A graphene and boron nitride heterostructure creates large spin signals

16.08.2017 | Materials Sciences

A new method for the 3-D printing of living tissues

16.08.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>