Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mars’ climate in flux: Mid-latitude glaciers

18.10.2005


New high-resolution images of mid-latitude Mars are revealing glacier-formed landscapes far from the Martian poles, says a leading Mars researcher.



Conspicuous trains of debris in valleys, arcs of debris on steep slopes and other features far from the polar ice caps bear striking similarities to glacial landscapes of Earth, says Brown University’s James Head III. When combined with the latest climate models and orbital calculation for Mars, the geological features make a compelling case for Mars having ongoing climate shifts that allow ice to leave the poles and accumulate at lower latitudes.

"The exciting thing is a real convergence of these things," said Head, who presented the latest Mars climate discoveries on Sunday, 16 October, at the Annual Meeting of the Geological Society of America in Salt Lake City.


"For decades people have been saying that deposits at mid and equatorial latitudes look like they are ice-created," said Head. But without better images, elevation data and some way of explaining it, ice outside of Mars’ polar regions was a hard sell.

Now high-resolution images from the Mars Odyssey spacecraft’s Thermal Emission Imaging System combined with images from the Mars Global Surveyor spacecraft’s Mars Orbiter Camera and Mars Orbiter Laser Altimeter can be compared directly with glacier features in mountain and polar regions of Earth. The likenesses are hard to ignore.

For instance, consider what Head calls "lineated valley fill." These are lines of debris on valley floors that run downhill and parallel to the valley walls, as if they mark some sort of past flow. The same sorts of lines of debris are seen in aerial images of Earth glaciers. The difference is that on Mars the water ice sublimes away (goes directly from solid ice to gas, without any liquid phase between) and leaves the debris lines intact. On Earth the lines of debris are usually washed away as a glacier melts.

The lines of debris on Mars continue down valleys and converges with other lines of debris - again, just like what’s seen on Earth where glaciers converge.

"There’s so much topography and the debris is so thick (on Mars) that it’s possible some of the ice might still be there," said Head. The evidence for present day ice includes unusually degraded recent impact craters in these areas - just what you’d expect to see if a lot of the material ejected from the impact was ice that quickly sublimed away.

Another peculiarly glacier-like feature seen in Martian mid-latitudes are concentric arcs of debris breaking away from steep mountain alcoves - just as they do at the heads of glaciers on Earth.

As for how ice could reach Mars lower latitudes, orbital calculations indicate that Mars may slowly wobble on its spin axis far more than Earth does (the Moon minimizes Earth’s wobble). This means that as Mars’ axis tilted to the extremes - up to 60 degrees from the plane of Mars’ orbit - the Martian poles get a whole lot more sunshine in the summertime than they do now. That extra sun would likely sublime water from the polar ice caps, explains Head.

"When you do that you are mobilizing a lot of ice and redistributing it to the equator," Head said. "The climate models are saying it’s possible."

It’s pure chance that we happen to be exploring Mars when its axis is at a lesser, more Earth-like tilt. This has led to the false impression of Mars being a place that’s geologically and climatically dead. In fact, says Head, Mars is turning out to be a place that is constantly changing.

Ann Cairns | EurekAlert!
Further information:
http://www.geosociety.org
http://www.geosociety.org/news/pr/05-37.htm

More articles from Earth Sciences:

nachricht NASA flights gauge summer sea ice melt in the Arctic
25.07.2017 | NASA/Goddard Space Flight Center

nachricht NASA looks to solar eclipse to help understand Earth's energy system
21.07.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA flights gauge summer sea ice melt in the Arctic

25.07.2017 | Earth Sciences

Fungi that evolved to eat wood offer new biomass conversion tool

25.07.2017 | Life Sciences

New map may lead to drug development for complex brain disorders, USC researcher says

25.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>