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 Early organic carbon got deep burial in mantle
25.04.2017 | Rice University

nachricht New atlas provides highest-resolution imagery of the Polar Regions seafloor
25.04.2017 | British Antarctic Survey

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>