Researchers: Mars' features not eroded by running water
AMERICAN GEOPHYSICAL UNION NEWS RELEASE
Posted: March 13, 2002

Scientists have provided new evidence that liquid carbon dioxide, not running water, may have been the primary cause of erosional features such as gullies, valley networks, and channels that cover the surface of Mars. Research suggesting that condensed carbon dioxide found in Martian crust carved these features is reported by Kenneth L. Tanaka and colleagues at the U.S. Geological Survey in Flagstaff, Arizona, and the University of Melbourne, Australia, will appear this month in Geophysical Research Letters, published by the American Geophysical Union.

Using Mars Orbiter Laser Altimeter (MOLA) data, Tanaka and his colleagues constructed elevation profiles of the Hellas basin, which, at 2000 kilometers [1,240 miles] wide and nine kilometers [six miles] deep, is the largest well-preserved impact basin on Mars. By examination of digitally created elevation profiles with 500-meter [2,000 foot] resolution, they found that the volcanic regions of Malea and Hesperia Plana, along the rim of the Hellas basin, are several hundred meters [yards] lower than adjacent rim sectors. Additionally, these areas lack the prominent triangular peaks, called massifs, that are common in nearby areas.

Along the inner slopes of these regions, the researchers found, however, evidence of old massifs covered by volcanic rocks. They are too low to be covered, if there were volcanic activity today. The researchers suggest as an explanation that prior to volcanic activity, these regions along the rim of the basin resembled nearby areas, but were eroded to their present-day elevations following the emplacement of the volcanic rocks.

Tanaka and his colleagues propose a "magmatic erosion model" to explain the features of the volcanic areas of Malea and Hesperia Plana, suggesting that they underwent catastrophic erosion associated with explosive eruptions of molten rock. They suggest that liquid in the Martian crust was heated when molten rock, or magma, rose to the surface. As the liquid was heated, it expanded, until the pressure of overlying material was too great, and an explosive eruption occurred, shattering overlying rock, and causing it to move with the magma in an erosive debris flow.

The authors believe that the fluid in the crust along this area of the rim of the Hellas basin was mainly liquid carbon dioxide. A debris flow dominated by carbon dioxide would flow faster and farther than a water-based flow, they say. Also, carbon dioxide is more volatile than water at lower temperatures, and the cold temperatures found on Mars would mean that less carbon dioxide- based magma would be required to produce the observed erosion than magma containing mainly water.

The researchers suggest that this mechanism of erosion can also explain collapse features and channels elsewhere on Mars. They also note, however, that their model is based on a variety of assumptions that must be further tested.

The paper by Kenneth L. Tanaka, Jeffrey S. Kargel, David J. MacKinnon, Trent M. Hare [Astrogeology Team, U.S. Geological Survey], and Nick Hoffman [University of Melbourne], "Catastrophic Erosion of Hellas Basin Rim on Mars Induced by Magmatic Instrusion in Volatile-Rich Rocks," will be published online within the next two weeks and later in the print edition of Geophysical Research Letters. Its citation, which is to the online version, is 10.1029/2001GL13885, 2002.

Creating Space
Creating Space groups together the history, the vehicles and the models into logical and meaningful categories. This book is equally valuable to space enthusiasts, modellers, and space historians.
 U.S. STORE
 WORLDWIDE STORE

Columbia Report
A reproduction of the official accident investigation report into the loss of the space shuttle Columbia and its crew of seven.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Mars Panorama

DISCOUNTED! This 360 degree image was taken by the Mars Pathfinder, which landed on the Red Planet in July 1997. The Sojourner Rover is visible in the image.
 Choose your store:
U.S.

Apollo 11 Mission Report
Apollo 11 - The NASA Mission Reports Vol. 3 is the first comprehensive study of man's first mission to another world is revealed in all of its startling complexity. Includes DVD!
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Rocket DVD
If you've ever watched a launch from Kennedy Space Center, Cape Canaveral, Vandenberg Air Force Base or even Kodiak Island Alaska, there's no better way to describe what you witnessed than with this DVD.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Apollo 12 tribute DVD set

New! Featuring the jovial crew of Pete Conrad, Dick Gordon and Alan Bean, the Apollo 12 mission was struck by lightning shortly after liftoff but proceeded on the second successful exploration voyage to the lunar surface. This three-disc DVD brings the mission to life with extraordinary detail.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Fallen Heroes special patch
This special 12-inch embroidered patch commemorates the U.S. astronauts who made the ultimate sacrifice, honoring the crews of Apollo 1, Challenger and Columbia.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Women in Space
Women of Space: Cool Careers on the Final Frontier is for girls, young women, and anyone else interested in learning about exciting careers in space exploration. Includes CD-ROM.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Mars rover poster
This new poster features some of the best pictures from NASA's amazing Mars Exploration Rovers Spirit and Opportunity.
 Choose your store:
U.S.

Columbia Report
The official accident investigation report into the loss of the space shuttle Columbia and its crew of seven. Includes CD-ROM.
 Choose your store:
U.S.

STS-134 Patch

Free shipping to U.S. addresses!

The final planned flight of space shuttle Endeavour is symbolized in the official embroidered crew patch for STS-134. Available in our store!
 U.S. STORE
 WORLDWIDE STORE

Final Shuttle Mission Patch

Free shipping to U.S. addresses!

The crew emblem for the final space shuttle mission is now available in our store. Get this piece of history!
 U.S. STORE
 WORLDWIDE STORE

Apollo Collage
This beautiful one piece set features the Apollo program emblem surrounded by the individual mission logos.
 U.S. STORE

STS-133 Patch

Free shipping to U.S. addresses!

The final planned flight of space shuttle Discovery is symbolized in the official embroidered crew patch for STS-133. Available in our store!
 U.S. STORE
 WORLDWIDE STORE

Anniversary Shuttle Patch

Free shipping to U.S. addresses!

This embroidered patch commemorates the 30th anniversary of the Space Shuttle Program. The design features the space shuttle Columbia's historic maiden flight of April 12, 1981.
 U.S. STORE
 WORLDWIDE STORE

Mercury anniversary

Free shipping to U.S. addresses!


Celebrate the 50th anniversary of Alan Shephard's historic Mercury mission with this collectors' item, the official commemorative embroidered patch.
 U.S. STORE
 WORLDWIDE STORE

INDEX | PLUS | NEWS ARCHIVE | LAUNCH SCHEDULE
ASTRONOMY NOW | STORE

ADVERTISE

© 2014 Spaceflight Now Inc.