Ice sculpture in the Martian outflow channels

Journal of Geophysical Research B: Solid Earth
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Abstract

Many landforms in Martian outflow channels have characteristics that suggest sculpture by glaciers, ice streams, or ice sheets. Viking Orbiter and terrestrial satellite images were examined at similar resolution to compare features of the Martian outflow channels to features produced by the movement of ice on earth. Many resemblances were found. They include the anastomoses, sinuosities, and U‐shaped cross profiles of valleys; hanging valleys; and linear scour marks on valley walls, grooves and ridges on valley floors, and streamlining of bedrock highs. The question of whether ice could have moved in the Martian environment is investigated. Since gradients on Martian channel floors are extremely low or even reversed, a certain thickness of ice is required to initiate glacial motion. If ice filled the Martian channels to the level of interior plateaus, flow could have occurred, even under present climatic conditions, although warmer climates in the past would have been more favorable. Additionally, if the channel fluids were brines, ice might have been wet based and would have moved readily by slipping over the ground. It is envisioned that springs or small catastrophic outbursts discharged fluids from structural outlets or chaotic terrains. The fluids built icings that may have grown into substantial masses and eventually flowed like glaciers down preexisting valleys. Alternatively, the fluids may have formed rivers or floods that formed ice jams and consolidated into icy masses in places where obstacles blocked their flow. These masses of ice or slush were probably episodic and temporary, but where they occurred within the channels, they may have produced landforms that are characteristic of glacial sculpture on earth.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Ice sculpture in the Martian outflow channels
Series title Journal of Geophysical Research B: Solid Earth
DOI 10.1029/JB087iB12p09951
Volume 87
Issue B12
Year Published 1982
Language English
Publisher American Geophysical Union
Contributing office(s) Astrogeology Science Center
Description 23 p.
First page 9951
Last page 9973