DOI: 10.1016/j.epsl.2020.116325
论文题名: Morphometry of a glacier-linked esker in NW Tempe Terra, Mars, and implications for sediment-discharge dynamics of subglacial drainage
作者: Butcher F.E.G. ; Balme M.R. ; Conway S.J. ; Gallagher C. ; Arnold N.S. ; Storrar R.D. ; Lewis S.R. ; Hagermann A.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 542 语种: 英语
中文关键词: esker
; glacial hydrology
; glaciers on Mars
; Mars geomorphology
; wet-based glaciation
英文关键词: Morphology
; Debris covered glaciers
; Digital elevation model
; Environmental control
; High-resolution imaging
; Melt-water discharges
; Reference relationships
; Science experiments
; Spatial and temporal variation
; Sediments
; esker
; glacier
; Mars
; meltwater
; morphometry
; sediment
; spatial variation
; subglacial environment
; temporal variation
英文摘要: We present a systematic, metre-scale characterisation of the 3D morphometry of an esker on Mars, and the first attempt to reconstruct the multi-stage dynamics of esker formation on Mars. Eskers are sinuous ridges comprising sediment deposited by meltwater draining through ice-confined tunnels within or beneath glaciers. Detailed morphometric insights into eskers on Mars are important for (i) informing morphometric tests of whether sinuous ridges elsewhere on Mars are eskers, and (ii) informing modelling experiments which aim to reconstruct the glaciological and environmental controls on esker formation on Mars. We use a digital elevation model generated from High Resolution Imaging Science Experiment (HiRISE) images to characterise the height and width of an extremely rare esker associated with a late-Amazonian-aged viscous flow feature (debris-covered glacier) in NW Tempe Terra, Mars. Our measurements suggest that the NW Tempe Terra esker is a ‘stacked’ formation comprising an underlying ‘lower member’ ridge that is superposed by a narrower ‘upper member’ ridge. We used a novel morphometric approach to test whether the apparent stacking records two distinct esker deposition regimes (either within the same drainage episode, or within temporally-separated drainage episodes). This approach posits that esker crest morphology is controlled by primary esker formation processes and, by extension, that portions of eskers with similar crest morphologies should have similar morphometric relationships. We predicted the morphometric relationships described by the constituent upper and lower member ridges based on ‘reference relationships’ observed for morphologically-similar portions of the esker where no evidence of stacking was observed. Our observations corresponded well with the predicted relationships, supporting our stacked esker hypothesis. We propose conceptual models, which invoke spatial and temporal variations in sediment supply and meltwater discharge, to explain the stacked morphology. These models are informed by morpho-sedimentary relationships observed along eskers on Earth. © 2020 The Author(s) Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164897
Appears in Collections: 气候变化与战略
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作者单位: School of Physical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom; Department of Geography, The University of Sheffield, Sheffield, S10 2TN, United Kingdom; CNRS, UMR 6112, Laboratoire de Planétologie et Géodynamique, Université de Nantes, France; UCD School of Geography, University College Dublin, Dublin 4, Ireland; UCD Earth Institute, University College Dublin, Dublin 4, Ireland; Scott Polar Research Institute, University of Cambridge, Cambridge, CB2 1ER, United Kingdom; Department of the Natural and Built Environment, Faculty of Social Sciences and Humanities, Sheffield Hallam University, Sheffield, S1 1WB, United Kingdom; Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA, United Kingdom
Recommended Citation:
Butcher F.E.G.,Balme M.R.,Conway S.J.,et al. Morphometry of a glacier-linked esker in NW Tempe Terra, Mars, and implications for sediment-discharge dynamics of subglacial drainage[J]. Earth and Planetary Science Letters,2020-01-01,542