Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Frozen ’lake’ beneath Antarctica ideal to test sterile drilling techniques

02.07.2002


UC Berkeley scientist urges drilling into frozen lake under ice near South Pole as prelude to drilling into subglacial lakes in Antarctica and into Mars polar caps



Measurements of the ice temperature far below the South Pole suggest that a so-called "lake" discovered at the base of the ice is most likely permafrost - a frozen mixture of dirt and ice - because the temperature is too low for liquid water.
Far from being a disappointment, says a University of California, Berkeley physicist, the permafrost subglacial lake may be ideal for developing and testing sterile drilling techniques needed before scientists attempt to punch through the ice into pristine liquid lakes elsewhere in Antarctica in search of exotic microbes.

Techniques that avoid contaminating a drill site with microbes also would prove useful for future drilling into Mars’ polar caps in search of life.



"This would be an excellent place to develop a sterile drill," said P. Buford Price, professor of physics at UC Berkeley. "Then, if we find that we’ve inadvertently contaminated the permafrost lake, we can be confident that the contamination is confined to only a small area."

Drilling into a frozen lake 2.8 kilometers below South Pole Station would have scientific interest in its own right, he said.

"We are likely to find interesting microbial life in the permafrost, in addition to learning how to drill in a sterile way," he said.

Price and colleagues in the United States and Russia made the recommendation in a paper that appeared in the June 11 issue of the Proceedings of the National Academy of Sciences. In their paper, the team reported data on temperature versus depth down to 2.3 kilometers beneath South Pole Station, based on temperature sensors implanted as part of the Antarctic Muon and Neutrino Detector Array (AMANDA) observatory.

Price, a cosmic ray physicist, is one of more than 100 collaborators in the AMANDA project, a National Science Foundation-funded array of detectors imbedded in deep ice at the South Pole and primed to look for high-energy neutrinos originating in exotic objects outside our solar system, such as black holes or the active centers of distant galaxies. AMANDA will become part of a larger, kilometer-scale neutrino observatory named IceCube, for which funding by NSF began earlier this year.

Based on measurements down to 2.3 kilometers, the team estimated the temperature at the bottom of the ice, 2.8 kilometers below the surface. This temperature - 9 degrees below zero Celsius (about 15 degrees Fahrenheit) - is 7 degrees colder than the temperature at which ice melts under the pressure of nearly 3 kilometers of ice.

Several years ago, radar images of the ice around the South Pole showed evidence of a subglacial lake about 10 kilometers from the pole. Price said that the temperature there should be about the same as the temperature at the AMANDA site, meaning that the under-ice lake would likely be a frozen mixture of ice and sediment in order to explain the flat terrain indicated by radar images. The permafrost, similar to that found in Arctic regions of North America and Europe, may be 10 or 20 million years old, dating from before the Antarctic continent was covered by a sheet of ice.

Since any contamination introduced by drilling into the permafrost would not travel far, the site would make a good place to test such techniques in preparation for drilling into Lake Vostok, a huge, Lake Ontario-sized subglacial sea that has intrigued scientists since it was detected four kilometers below the ice in 1996.

Proposals to drill into Lake Vostok have met with opposition because of the danger of contamination. In addition, many of the nearly 100 under-ice seas discovered to date may be interconnected, so contaminating one could contaminate them all. An international committee is discussing the issue, which may delay drilling for a decade.

Drilling first at the site near the South Pole also would be more convenient, because there currently are no permanent facilities near Antarctica’s subglacial lakes comparable to South Pole Station.

As part of the AMANDA and IceCube projects, temperature gauges were installed in bore holes that had been drilled with hot water down to 2,345 meters, nearly to the base of the ice at 2,810 meters at the South Pole. The gauges provided a detailed profile of temperature under the surface and also allowed Price and his colleagues to predict the temperature at the base of the ice: -9ºC

Price is primarily interested in the kinds of exotic microbes that might live inside solid ice, either as dormant spores or at a low level of activity. He said that life has been found wherever people have looked, from deep in the Earth’s crust to high-altitude clouds, and he thinks they also reside deep inside glacial ice. In fact, he will present a poster on life in solid ice at the Bioastronomy 2002 meeting in Australia during the week of July 8.

Such creatures would not live in ice crystals, but in interconnected liquid veins at the boundaries where ice crystals meet.

"Even at temperatures far below the freezing point, there is always some liquid," he said. "As water freezes, soluble salts and acids are excluded from the interiors of the freezing crystals, creating a network of thin liquid veins rich in nutrients for energy and elements such as carbon necessary for building more microbes. Bacteria are small enough to fit and move inside the veins. Why wouldn’t bacteria take advantage of that? Well, they probably do."

He and UC Berkeley colleagues have developed instruments that they have lowered into boreholes in Greenland and Antarctic ice to search for microbial life. The devices flash ultraviolet light, and detectors record any telltale fluorescence from bacteria. Such fluorescence is faint, however, and the team is still perfecting the instrument.

In a second approach, Price and his colleagues have built at UC Berkeley a refrigerated box in which they can investigate sections of ice cores from Antarctica and Greenland in search of exotic, deep-ice bacteria new to science. With a fluorescence microscope mounted inside the cold box, they can search for the faint light emitted by fluorescing bacteria.

"With the refrigerated microscope, we can catch any microbes trapped in liquid veins in their icy habitats," Price said. "This greatly reduces the possibility of contamination. If we just looked in melted ice, we wouldn’t know where the bacteria had come from."

Drilling in Antarctic ice, including to within about 100 meters of Lake Vostok, has turned up some bacteria, according to Russian scientists, but all were known before. Bacteria also have been found in ocean ice. Price and other scientists hope to discover new species in solid ice, analogous to the novel thermophiles found in hot seafloor vents living at temperatures above the sea-level boiling point of water (100ºC or 212ºF).

"If microbes can exist in glacial ice on Earth, they can also exist in Martian permafrost and in certain regions of Jupiter’s ice-covered moons," he said.

Price’s colleagues on the recent PNAS paper are Oleg V. Nagornov of the Moscow Engineering Physics Institute; Ryan Bay, Dmitry Chirkin, Predrag Miocinovic and Kurt Woschnagg of UC Berkeley; Yudong He of Rosetta Inpharmatics in Kirkland, Wash.; Austin Richards of Indigo Systems Corporation in Santa Barbara, Calif.; Bruce Koci of the Space Sciences and Engineering Laboratory at the University of Wisconsin, Madison; and Victor Zagorodnov of the Byrd Polar Research Center at Ohio State University in Columbus.

Robert Sanders | EurekAlert!
Further information:
http://www.berkeley.edu/

More articles from Earth Sciences:

nachricht Sediment from Himalayas may have made 2004 Indian Ocean earthquake more severe
26.05.2017 | Oregon State University

nachricht Devils Hole: Ancient Traces of Climate History
24.05.2017 | Universität Innsbruck

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>