气候变化领域集成服务门户(CCPortal): Overspilling small craters on a dry Mars: Insights from breach erosion modeling

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DOI	10.1016/j.epsl.2020.116671
	Overspilling small craters on a dry Mars: Insights from breach erosion modeling
	Warren A.O.; Holo S.; Kite E.S.; Wilson S.A.
发表日期	2021
ISSN	0012821X
卷号	554
英文摘要	Understanding when, where, and how frequently liquid water was stable on Mars since the Late Noachian/Early Hesperian (3.2-3.9 Ga) is important for understanding the evolution of Mars' climate and hydrology. Some relatively young features on Mars require multiple wetting events to form, whereas others are consistent with single wetting events. Small and rare exit breach craters or “pollywogs” are craters between 0.5 and 15 km in diameter with valleys leading away from the lowest point on their rims but no visible inlet valleys. These craters must have been filled with water to the point of overspill to form the observed valleys. The two possible water sources are precipitation and groundwater. In this paper we use measurements from Digital Elevation Models (DEMs) of 18 pollywog craters (21 outlet valleys) and a fixed channel width 0-D breach erosion model to determine whether pollywog exit breach valleys are consistent with a single crater overspill event, or if their formation requires multiple overspill events. Our model, which we compare to a selection of dam breaching events on Earth, predicts runaway erosion for two pollywog exit breaches. No runaway erosion is observed. We discuss potential explanations for this mismatch between the data and our model. We show that the majority of pollywog craters on Mars are consistent with formation during a single crater overspill event, incorporating a work around for the long-standing problem of unknown grainsize into our approach. Three pollywog craters require either multiple events or sustained water supply to drive erosion. We discuss potential source mechanisms for crater-filling water and conclude that pollywogs either formed in a single erosion event, driven by groundwater discharge, or through many small erosion events, driven by draining of small meltwater lakes formed on crater-filling bodies of ice. © 2020 Elsevier B.V.
关键词	Mars planetary science sediment transport
英文关键词	Digital storage; Groundwater; Landforms; Water supply; Wetting; Breach erosion models; Channel widths; Dam breaching; Digital elevation model; Ground water discharge; Multiple events; Potential sources; Standing problems; Erosion; crater; digital elevation model; erosion; grain size; Mars; modeling; sediment transport; valley
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203333
作者单位	University of Chicago, Chicago, IL 6063, United States; Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, 6th at Independence SW, Washington, DC, 20560, United States
推荐引用方式 GB/T 7714	Warren A.O.,Holo S.,Kite E.S.,et al. Overspilling small craters on a dry Mars: Insights from breach erosion modeling[J],2021,554.
APA	Warren A.O.,Holo S.,Kite E.S.,&Wilson S.A..(2021).Overspilling small craters on a dry Mars: Insights from breach erosion modeling.Earth and Planetary Science Letters,554.
MLA	Warren A.O.,et al."Overspilling small craters on a dry Mars: Insights from breach erosion modeling".Earth and Planetary Science Letters 554(2021).