DOI: 10.1016/j.epsl.2020.116482
论文题名: Did Martian valley networks substantially modify the landscape?
作者: Grau Galofre A. ; Bahia R.S. ; Jellinek A.M. ; Whipple K.X. ; Gallo R.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 547 语种: 英语
中文关键词: fluvial erosion
; Mars
; maturity
; precipitation
; profile analysis
; valley networks
英文关键词: Topography
; Compare and analyze
; Different stages
; Drainage systems
; Landscape evolutions
; Longitudinal profile
; Martian valleys
; Southern Hemisphere
; Theoretical framework
; Landforms
; drainage network
; geomorphological response
; landscape evolution
; Mars
; planetary landform
; planetary surface
; valley
英文摘要: Valley networks are ancient drainage systems incised on the southern hemisphere of Mars, and stand as evidence that liquid water once sculpted its surface. The duration of valley network activity and the sources of water are key questions in deciphering the timing of water stability on early Mars, but remain poorly constrained. In this study we address two questions: Did Martian valley networks evolve for sufficiently long to establish their own erosional basins, or do their profiles primarily reflect landscape pre-incision topography? And were these valleys precipitation-fed or spring-fed? Our analysis uses the theoretical framework built to describe the shape of steady-state river profiles on Earth to compare and analyze the concavity of 62 valley network longitudinal profiles on Mars. Using non-linear fits to valley profiles we evaluate the degree to which valley networks are consistent with fluvial steady-state. The fit enables the identification of valley network concavity index and area-discharge exponent, which we then interpret in terms of the theoretical framework to discuss valley network maturity and water source. Our results show that the majority of valley networks do not have concave or even smooth profiles, and did not substantially modify their surrounding landscape. We observe disparity in concavity indexes of valley networks belonging in the same integrated basins, indicating different stages of landscape evolution and lack of synchronous valley development. However, our results identify six valley networks consistent with fluvial steady-state and areally uniform precipitation. © 2020 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164994
Appears in Collections: 气候变化与战略
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作者单位: School of Earth and Space Exploration, Arizona State University, United States; School of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Ireland; Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Canada; School of Earth and Sustainability, Northern Arizona University, United States
Recommended Citation:
Grau Galofre A.,Bahia R.S.,Jellinek A.M.,et al. Did Martian valley networks substantially modify the landscape?[J]. Earth and Planetary Science Letters,2020-01-01,547