The influence of obliquity change on flow rates of ice-rich deposits on Mars
| Autor: | Ishii, Tetsuyuki, Miyamoto, Hirdy, Sasaki, Sho, Tajika, Eiichi |
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| Jazyk: | angličtina |
| Rok vydání: | 2006 |
| Předmět: | |
| Zdroj: | 第38回月・惑星シンポジウム = Proceedings of the 38th ISAS Lunar and Planetary Symposium. :216-219 |
| Popis: | The morphology of viscous flow features suggest that ice-rich deposits may still exist in middle latitudes on Mars today. According to the study of flow rates of these ice-dust mixtures based on a flow law for polycrystalline ice, crystal size of ice should be less than 100 m. However, crystal size of ice in polar glaciers on Earth is generally larger than 1 mm in diameter. This may suggest that flow rates of ice-rich deposits on Mars could have been considerably enhanced by increased solar insolation in summertime during periods of high obliquity. Here, we investigate flow rates of water ice for different insolation caused by obliquity change. We found that there is no significant difference in surface flow rates of an ice slab with thickness of 20 m between high and low obliquity conditions when the crystal size of ice is assumed to be 1 mm. This indicates that the Martian atmosphere might have been thicker during periods of high obliquity and that the stronger greenhouse effect might have caused global warming, which could have drastically quickened the flow rates of ice-dust mixtures. 資料番号: AA0063350058 |
| Databáze: | OpenAIRE |
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