Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers uncover extreme lake - and 3000-year-old microbes - in Mars-like antarctic environment

17.12.2002


Researchers sawing an observation hole in the permanent lake ice of a dry valley lake.
Image courtesy of the Priscu Research Group, Montana State University at Bozeman


Small segment of ice core from Lake Vida showing a layer of sediment. Researchers have discovered that the microbes are found with the sediment.
Image courtesy of the Priscu Research Group, Montana State University at Bozeman


NSF-supported researchers drilling into Lake Vida, an Antarctic "ice-block" lake, have found the lake isn’t really an ice block at all. In the December 16 issue of the Proceedings of the National Academy of Sciences, the team reveals that Antarctic Lake Vida may represent a previously unknown ecosystem, a frigid, "ice-sealed," lake that contains the thickest non-glacial lake ice cover on Earth and water seven times saltier than seawater.

Because of the arid, chilled environment in which it resides, scientists believe the lake may be an important template for the search for evidence of ancient microbial life on Mars and other icy worlds.

Researchers previously thought Vida was one of several Antarctic lakes that are frozen to their beds year-round. However, using ground-penetrating radar, ice core analyses, and long-term temperature data, the researchers now show that Vida has a thick light-blocking ice cover, a vast amount of ancient organic material and sediment, and a cold, super-salty, liquid zone underlying the ice - an environment that remains liquid at temperatures under -10°C, well below the freezing point of pure water.



Peter Doran of the University of Illinois at Chicago conducted the research along with colleagues at the Desert Research Institute in Reno, Nevada; NASA’s Ames Research Center in Moffett Field, California; and Montana State University in Bozeman.

The researchers extracted two ice cores from Lake Vida in early Antarctic spring (October) 1996. With an electromechanical drill, team members spent two weeks at temperatures below -35°C drilling a 10-cm-diameter core through 16-m of ice cover.

The researchers filled both of the holes with deionized water (to seal the columns with an ice plug), emplacing temperature measuring instruments in one of the shafts.

"The sediment within the ice made coring extremely difficult and required frequent bit changes and a complete motor replacement at one stage," said John Priscu of Montana State University.

"It was some very cold drilling," added Doran. "We were there for two weeks at temperatures approaching -40°C . . . camping. The drillers had a hard time getting through the sediment layers. They were used to drilling clean ice up on the polar plateau; the dirt in the ice tended to dull the cutting bits."

Despite these difficulties, said Priscu, the core segments collected provided new insights to a previously undescribed Antarctic ecosystem.

From the cores, the scientists found a layered chemical and biological history preserved in the ice, and revived viable microbes that are at least 2,800 years old.

"The ice covers of these lakes represent an oasis for life in an environment previously thought to be inhospitable," said Priscu. "These life forms may possess novel ice-active substances such as antifreezes and ice nucleation inhibitors that allow the organisms to survive the freeze-thaw cycles and come back to life when exposed to liquid water," he said.

"Importantly, the cold temperatures preserve DNA extremely well making them perfect ’ice museums’ for the study of ancient DNA," Priscu added. Research on the ancient DNA will provide an evolutionary and functional history of the microorganisms, he said, and he believes the findings might help scientists draw implications for the type of life that may exist in Lake Vostok, a huge lake which lies more than 4 km beneath the East Antarctic Ice Sheet.

Lake Vida, more than 5 km long, is one of the largest in the cold Antarctic desert region known as the McMurdo Dry Valleys. The area receives less than 10 cm of snow per year and the average annual temperature hovers around -30°C.

Using data from the ice sensors and from an automatic meteorological station on the shore of the lake, the researchers created a thermodynamic model to understand the complex melting and freezing processes within Vida.

The model provided a better understanding of the evolution of the ice cover and the underlying salt water. The freezing, growing ice cover concentrates the salt, thereby depressing the freezing point of the water, and extending the viability of a lake ecosystem.

"Lake Vida provides insight into a novel terrestrial ecosystem," said Doran. "What happened at Lake Vida may have been the fate of other Antarctic lakes, during even colder times, and more tropical aquatic ecosystems during extreme global glaciations of the past, such as the ’snowball Earth’ 550 Million years ago."

The researchers believe that Lake Vida may also offer clues to likely environments for finding signs of ancient, Martian, microbial life. Said Doran, "Mars is believed to have a water rich past, and if life developed, a Lake Vida-type ecosystem may have been the final niche for life on Mars before the water bodies froze solid."

The research was carried out as part of NSF’s McMurdo Long Term Ecological Research (LTER) project, and was also funded in part by NASA’s Exobiology program.

Josh Chamot, | NSF
Further information:
http://huey.colorado.edu/LTER/
http://www.nsf.gov/od/lpa/news/02/pr02100.htm

More articles from Earth Sciences:

nachricht Filling the gap: High-latitude volcanic eruptions also have global impact
20.11.2017 | Institute of Atmospheric Physics, Chinese Academy of Sciences

nachricht Antarctic landscape insights keep ice loss forecasts on the radar
20.11.2017 | University of Edinburgh

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

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

Previous evidence of water on mars now identified as grainflows

21.11.2017 | Physics and Astronomy

NASA's James Webb Space Telescope completes final cryogenic testing

21.11.2017 | Physics and Astronomy

New catalyst controls activation of a carbon-hydrogen bond

21.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>