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Possible ancient oceans on Mars: evidence from Mars Orbiter Laser Altimeter data
J W Head1, H Hiesinger, M A Ivanov
1Department of Geological Sciences, Brown University, Providence, RI 02912, USA.
Science (New York, N.Y.)
|December 11, 1999
Summary
High-resolution data suggest a Martian shoreline exists in the northern lowlands. This ancient shoreline, consistent with a large body of water, features terraces and smoother topography below it.
Area of Science:
- Planetary Science
- Geology
- Hydrology
Background:
- Mars' northern lowlands possess complex topography.
- Previous hypotheses suggest a large body of water existed in Mars' middle history.
Purpose of the Study:
- To analyze high-resolution altimetric data of Mars' northern lowlands.
- To evaluate the hypothesis of an ancient shoreline in this region.
Main Methods:
- Utilized high-resolution altimetric data to map Martian topography.
- Analyzed geological features and topographic variations relative to a proposed contact line.
Main Results:
- A distinct geologic contact encircling the northern lowlands was identified.
- The contact's altitude aligns with an equipotential line.
- Topography below the contact is significantly smoother than above it.
- Extensive terraces parallel the contact in numerous locations.
- The estimated water volume aligns with prior estimates for Mars.
Conclusions:
- The identified geologic contact strongly supports the hypothesis of an ancient Martian shoreline.
- This shoreline likely demarcates a large, stable body of water during Mars' middle history.
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