DOI: 10.1038/ngeo2619
论文题名: Formation of gullies on Mars by debris flows triggered by CO2 sublimation
作者: Pilorget C. ; Forget F.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2016
卷: 9, 期: 1 起始页码: 65
结束页码: 69
语种: 英语
英文摘要: Martian gully landforms resemble terrestrial debris flows formed by the action of liquid water and have thus been interpreted as evidence for potential habitable environments on Mars within the past few millennia. However, ongoing gully formation has been detected under surface conditions much too cold for liquid water, but at times in the martian year when a thin layer of seasonal CO2 frost is present and defrosting above the regolith. These observations suggest that the CO2 condensation-sublimation cycle could play a role in gully formation. Here we use a thermo-physical numerical model of the martian regolith underlying a CO2 ice layer and atmosphere to show that the pores beneath the ice layer can be filled with CO2 ice and subjected to extreme pressure variations during the defrosting season. The subsequent gas fluxes can destabilize the regolith material and induce gas-lubricated debris flows with geomorphic characteristics similar to martian gullies. Moreover, we find that subsurface CO2 ice condensation, sublimation and pressurization occurs at conditions found at latitudes and slope orientations where gullies are observed. We conclude that martian gullies can result from geologic dry ice processes that have no terrestrial analogues and do not require liquid water. Such dry ice processes may have helped shape the evolution of landforms elsewhere on the martian surface. © 2015 Macmillan Publishers Limited. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106114
Appears in Collections: 气候减缓与适应 科学计划与规划
There are no files associated with this item.
作者单位: Institut d'Astrophysique Spatiale (IAS), CNRS, Université Paris-Sud, Orsay, France; Division of Geological and Planetary Sciences, Caltech, Pasadena, CA, United States; Laboratoire de Méteórologie Dynamique (LMD), CNRS, Sorbonne Universités, Paris, France
Recommended Citation:
Pilorget C.,Forget F.. Formation of gullies on Mars by debris flows triggered by CO2 sublimation[J]. Nature Geoscience,2016-01-01,9(1)