Evidence of Cold-based Glaciers in the Dry Valleys of Antartica Could Help Scientists

Evidence of Cold-based Glaciers in the Dry Valleys of Antarctica Could Help Scientists Study the Terrain of the Martian Landscape

Research by Dr. James Head of Brown University-- Funded by the MDAP Program

Taylor Valley, Antarctica: small, ice-free region at edge of Antarctic continent - one of the coldest, driest areas on Earth- and probably the remnant of an enormous cold-based glacier that overrode the area some 15 million years ago.

Cold Based Glaciers Leave Key Signatures

Map of Antarctica showing bottom corner inhabited by rocky, Dry Valley region. Red box indicates location of Taylor Valley. Image courtesy USGS.

• Dr. James Head has looked at the terrain, and rock distribution in the Dry Valleys of Antarctica, and compared features to Mars surface.
• Strong evidence that cold-based glaciers present on Mars, similar to Dry Valleys area
• Cold-based glaciers leave three key signatures: drop moraines, sublimation till and rock glacier deposits. These types of glaciers are too cold to advance, melt and cause erosion. Instead they evaporate, leaving tiny traces in rocks, sediment and terrain.
• Gradient "SA" on the map, (left below) shows region on southeastern flank of the giant Martian volcano, Arsia Mons, having large lobes of material extending down its slopes and grooved near the edges like a phonograph record. Moreover, the grooves and ridges lie over a large impact crater, indicating potential clues to Mar's geological record and climate.
• Rock distribution patterns in both areas were similar -- Head concluded that cold-based glaciers could have existed on Mars surface

Landsat Map of the Dry Valleys of Antarctica- Large blue square in map shows evidence of ridges, large lobes of material extending downward, indicating presence of cold-based glacier.

Significance to Solar System Exploration

This research may help uncover clues about the nature of the Martian landscape. The Mars Exploration Rover Mission is currently examining samples of the rocks they find on the Red Planet, and are studying the terrain of Mars as we do here on Earth, to test the theories and see if the analogies make sense.

Implications

If cold-based glaciers did exist on Mars, this discovery means that ice was probably deposited there at a time when Mars tilted differently toward the sun, which supports the important theory that the planet's orientation has varied significantly over time, distributing ice not only at the poles, but several other areas as well.. It also means that there may be buried ice at several latitudes on the planet.

Terrains on Arsia Mons, one of Mars' largest known volcanoes. A topographic gradient map is superimposed to reveal different facies -- from ridged to knobby to smooth.

Taylor Valley image courtesy The Encyclopedia of Astrobiology, Astronomy and Spaceflight

Map of Antartica image courtesy USGS

Landsat Map of the Dry Valleys of Antartica image courtesy Landsat, 1975

Terrains on Arsia Mons image courtesy of MOLA Science Team

For further information about science highlights and having your research highlighted, please contact Samantha Harvey at NASA's Jet Propulsion Laboratory, Samantha.K.Harvey@jpl.nasa.gov.

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