کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8136722 | 1523539 | 2015 | 20 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Long-term monitoring of martian gully formation and evolution with MRO/HiRISE
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علوم فضا و نجوم
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![عکس صفحه اول مقاله: Long-term monitoring of martian gully formation and evolution with MRO/HiRISE Long-term monitoring of martian gully formation and evolution with MRO/HiRISE](/preview/png/8136722.png)
چکیده انگلیسی
Gully landforms are commonly taken as evidence for surface liquid water in the recent geological history of Mars. Repeat observations with the High Resolution Imaging Science Experiment (HiRISE) instrument on the Mars Reconnaissance Orbiter demonstrate widespread activity in gullies in the southern hemisphere, particularly in those with the freshest morphologies. This activity includes substantial channel incision and large-scale mass movements, and constitutes ongoing gully formation rather than degradation of older landforms. New apron deposits that are bright, dark and neutrally toned have all been observed. The timing of gully activity is seasonally controlled and occurs during the period when seasonal frost is present and defrosting. These observations support a model in which currently active gully formation is driven mainly by seasonal CO2 frost. Gullies in the northern hemisphere are far less active than those in the south. This may be due to the current timing of perihelion near the northern winter solstice. Integrated over time, activity like that observed within the past few years appears capable of forming all of the martian gully landforms on timescales of millions of years. Additionally, the current style and rate of activity is able to erase meter- to decameter-scale surface features that might have been uniquely produced by other processes during the last obliquity high â¼0.4Â Ma. Although it is impossible to rule out a past role for water in the formation of martian gullies, a model in which gullies form only through currently active processes with little or no liquid water is consistent with our observations.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Icarus - Volume 251, 1 May 2015, Pages 244-263
Journal: Icarus - Volume 251, 1 May 2015, Pages 244-263
نویسندگان
Colin M. Dundas, Serina Diniega, Alfred S. McEwen,