Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Landscapes on buried glaciers in Antarctica’s dry valleys help decipher recent ice ages on Mars

19.12.2003


Studies of the unique landscape in the Dry Valleys of Antarctica provide new insights into the origin of similar features on Mars and provide one line of evidence that suggests the Red Planet has recently experienced an ice age, according to a paper in this week’s issue of the journal Nature.

The distribution of hexagonal mounds and other features on the Martian surface at mid-latitudes similar to those in the Dry Valleys also supports previous scientific assertions that a significant amount of ice lies trapped beneath the Red Planet’s surface.

David Marchant, a Boston University researcher who has studied the Dry Valleys for 17 years, co-authored the paper with James W. Head (lead author), John Mustard and Ralph Milliken, at Brown University, and Mikhail Kreslavsky of Kharkov National University in Ukraine.



The National Science Foundation (NSF) supported Marchant’s work in the Dry Valleys, which helped underlie the assertions in the Nature paper. NSF is an independent federal agency that supports fundamental research and education across all fields of science and engineering. NSF manages the U.S. Antarctic Program, which supports and coordinates virtually all U.S. scientific research on the southernmost continent.

Head, Mustard and Milliken were supported by NASA.

The floor of Antarctica’s Beacon Valley, in particular, is covered with hexagonal mounds that, from the air, resemble the patterns of cracked mud on a dry lakebed. The Dry Valleys mounds, however, often measure meters in diameter.

Although these polygon-shaped features occur throughout the Arctic and Antarctic, an unusual variety found in the western Dry Valleys region has received particular attention because it forms only in perennially frozen soils with significant ice content. These polygons form as sub-freezing temperatures fluctuate, causing the underlying ice to contract in a hexagonal pattern. As the ice contracts, fine sediments sift down into the cracks, leaving a coarse-grained deposit covering the ice.

The research reported in Nature shows that similar mounds and other formations that appear in the mid-to-high latitudes on Mars could indicate ice buried near the planet’s surface as well. Using new information on the global distribution of surface landforms on Mars, together with data gathered from NASA’s Mars Global Surveyor and Mars Odyssey missions, Head and other researchers were able to piece together a history of recent ice ages on Mars.

"The last ice age on Mars began about 2.1 million years ago and ended as recently as 400,000 years ago," according to Head.

Like ice ages on Earth, Martian ice ages are driven by variations in the planet’s orbit, particularly the tilt of the planet’s axis. But Martian ice ages, unlike ice ages on Earth, appear to begin as the polar regions warm, rather than cool.

Warming of the Martian Poles causes the planet’s ice caps to partially vaporize and release water vapor into the Martian atmosphere. Winds transport the water vapor, along with ubiquitous Martian dust, toward the equator and deposit it in a meters-thick layer as far as 30 degrees north and south latitude. There, it drapes over existing terrain, smoothing the Martian surface.

Head and his co-authors report that emplacement of this meters- thick layer of snow and dust at 30 degree latitudes represents an "ice age" on Mars. The small number of impact craters seen in these features, along with the known patterns of changes in Mars’ orbit and tilt, are used to estimate the age of these Martian ice ages.

The Nature findings complement a paper recently published in the journal Geology, in which Head and Marchant argue that features on the surface of the Red Planet are remarkably like glacial features found only in the Dry Valleys.

The findings not only have implications for the search for microbial life on Mars, but also may help scientists better understand the unique Polar desert environment of the Dry Valleys, and in particular the ancient climate record that may be stored in the landscape.

"These extreme changes on Mars provide perspective for interpreting what we see on Earth. Landforms on Mars that appear to be related to climate changes help us calibrate and understand similar landforms on Earth. Furthermore, the range of microenvironments in the Antarctic Dry Valleys helps us read the Mars record," said Marchant.

If the analogy between the geologic processes on Mars and those in the Dry Valleys holds true, then scientists may conclude that Mars may be more hospitable to microbial life than previously suspected.

Biologists continue to make discoveries that push back the boundaries at which conditions are too extreme to support life. NSF-funded researchers, for example, have offered evidence that microbes can survive in extremes of cold and darkness between ice crystals at the South Pole.

Although the Dry Valleys were thought to be a virtual dead zone when first explored a century ago, new evidence suggests that the lakes and other landscape features support microscopic life.

Images/B-Roll: For Betacam SP B-roll of the Antarctic Dry Valleys, please contact Dena Headlee, dheadlee@nsf.gov, 703-292-7739

NSF Program Officer: Scott Borg, 703-292-8030, sborg@nsf.gov

Principal Investigator: David Marchant, 617-353-3236, marchant@bu.edu

Peter West | NSF
Further information:
http://www.nsf.gov

More articles from Earth Sciences:

nachricht Multi-year submarine-canyon study challenges textbook theories about turbidity currents
12.12.2017 | Monterey Bay Aquarium Research Institute

nachricht How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas
11.12.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Long-lived storage of a photonic qubit for worldwide teleportation

12.12.2017 | Physics and Astronomy

Multi-year submarine-canyon study challenges textbook theories about turbidity currents

12.12.2017 | Earth Sciences

Electromagnetic water cloak eliminates drag and wake

12.12.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>