DOI: 10.1016/j.epsl.2020.116671
论文题名: Overspilling small craters on a dry Mars: Insights from breach erosion modeling
作者: Warren A.O. ; Holo S. ; Kite E.S. ; Wilson S.A.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 554 语种: 英语
中文关键词: 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
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165711
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
Warren A.O.,Holo S.,Kite E.S.,et al. Overspilling small craters on a dry Mars: Insights from breach erosion modeling[J]. Earth and Planetary Science Letters,2021-01-01,554