DOI: 10.1016/j.epsl.2017.12.025
Scopus记录号: 2-s2.0-85044728870
论文题名: Subterranean karst environments as a global sink for atmospheric methane
作者: Webster K.D. ; Drobniak A. ; Etiope G. ; Mastalerz M. ; Sauer P.E. ; Schimmelmann A.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 485 起始页码: 9
结束页码: 18
语种: 英语
英文关键词: cave
; greenhouse gas
; karst
; methane
; methanogenesis
; methanotrophy
Scopus关键词: Atmospheric chemistry
; Drainage
; Greenhouse gases
; Groundwater flow
; Methane
; Sewage
; Atmospheric exchange
; Atmospheric greenhouse
; Atmospheric methanes
; Carbonate reduction
; karst
; Methanogenesis
; Methanotrophy
; Subsurface drainages
; Caves
; atmospheric chemistry
; cave
; concentration (composition)
; data interpretation
; fermentation
; greenhouse gas
; isotopic analysis
; karst
; methane
; methanogenesis
; subterranean environment
; Australia
; Gibraltar
; Indiana
; New Zealand
; Spain
; United States
; Viet Nam
英文摘要: The air in subterranean karst cavities is often depleted in methane (CH4) relative to the atmosphere. Karst is considered a potential sink for the atmospheric greenhouse gas CH4 because its subsurface drainage networks and solution-enlarged fractures facilitate atmospheric exchange. Karst landscapes cover about 14% of earth's continental surface, but observations of CH4 concentrations in cave air are limited to localized studies in Gibraltar, Spain, Indiana (USA), Vietnam, Australia, and by incomplete isotopic data. To test if karst is acting as a global CH4 sink, we measured the CH4 concentrations, δ13CCH4, and δ2HCH4 values of cave air from 33 caves in the USA and three caves in New Zealand. We also measured CO2 concentrations, δ13CCO2, and radon (Rn) concentrations to support CH4 data interpretation by assessing cave air residence times and mixing processes. Among these caves, 35 exhibited subatmospheric CH4 concentrations in at least one location compared to their local atmospheric backgrounds. CH4 concentrations, δ13CCH4, and δ2HCH4 values suggest that microbial methanotrophy within caves is the primary CH4 consumption mechanism. Only 5 locations from 3 caves showed elevated CH4 concentrations compared to the atmospheric background and could be ascribed to local CH4 sources from sewage and outgassing swamp water. Several associated δ13CCH4 and δ2HCH4 values point to carbonate reduction and acetate fermentation as biochemical pathways of limited methanogenesis in karst environments and suggest that these pathways occur in the environment over large spatial scales. Our data show that karst environments function as a global CH4 sink. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110043
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: School of Natural Resources and the Environment, University of Arizona, 1064 E Lowell St, Tucson, Arizona 85721, United States; Department of Ecology and Evolutionary Biology, University of Arizona, 1041 E Lowell St, Tucson, Arizona 85721, United States; Indiana Geological Survey, Indiana University, 611 North Walnut Grove Ave., Bloomington, Indiana 47405, United States; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma 2, Italy; Faculty of Environmental Science and Engineering, Babes-Bolyai University, Cluj-Napoca, Romania; Department of Earth and Atmospheric Sciences, Indiana University, 1001 E 10th St., Bloomington, Indiana 47405, United States
Recommended Citation:
Webster K.D.,Drobniak A.,Etiope G.,et al. Subterranean karst environments as a global sink for atmospheric methane[J]. Earth and Planetary Science Letters,2018-01-01,485