| Abstract: | The new Mars Global Surveyor altimetry shows that the heavily cratered southern hemisphere of Mars is 5 km higher that the sparely cratered plains of the northern hemisphere. Previous suggestions that oceans formerly occupied that northern plains as evidenced by shorelines are partly supported by the new data. A previously identified outer boundary has a wide range of elevations and is unlikely to be a shoreline but an inner contact with a narrow range of elevations is a more likely candidate. No shorelines are visible in the newly acquired, 2.5 metre/pixel imaging. Newly imaged valleys provide strong support for sustained or episodic flow of water across the Martian surface. A major surprise, however, is the near absence of valleys less than 100 m across. Martian valleys seemingly do not divide into ever smaller valleys as terrestrial valleys commonly do. This could be due to lack of precipitation or lack of surface runoff because of high infiltration rates. High erosion rates and supports warm climates and presence of large bodies of water during heavy bombardment. The climate history and fate of the water after heavy bombardment remain cotroversial. |
| Genre: | Article |
| ProdID: | 70022656 |
| Citation Author: | Carr, M. H. |
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| Citation End Page: | 326 |
| Citation Issue: | 3 |
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| Citation Language: | English |
| Citation Larger Work Title: | Astronomy and Geophysics |
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| Citation Number Of Pages: | 7 |
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| Citation Search Results Text: | Martian oceans, valleys and climate; 2000; Article; Journal; Astronomy and Geophysics; Carr, M. H. |
| Citation Start Page: | 320 |
| Citation Volume: | 41 |
| Citation Year: | 2000 |
| Type: | citation/reference |
| Text: | Martian oceans, valleys and climate; 2000; Article; Journal; Astronomy and Geophysics; Carr, M. H. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sat, 1 Jan 2000 00:00 -0600 |
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